GORILLA ETHOGRAMS--COMPILED BY THE GORILLA ADVISORY GROUP
Collection of Gorilla Ethograms
Compiled by:
The Gorilla Behavior Advisory Group
[affiliated with the Gorilla SSP]
Jackie Ogden, Zoo Atlanta and Georgia Institute of Technology
Deborah Schildkraut, Ph.D., Boston MetroParks Zoos
Co-chairs
Anne Baker, Ph.D., Brookfield Zoo
Benjamin B. Beck, Ph.D., National Zoo
Cynthia Bennett, Ph.D., Dallas Zoo
Thaya duBois, Los Angeles Zoo
Cathleen Cox, Ph.D., Los Angeles Zoo
Ken Gold, Zoo Atlanta and Georgia Institute of Technology
Donna Fernandes, Ph.D., MetroParks Zoos, Boston
Carol Glick, Arizona State University
Ingrid Porton, St. Louis Zoo
Jill Mellen, Ph.D., Washington Park Zoo, Consultant
The Gorilla Behavior Advisory Group (GBAG) would like to gratefully
acknowledge all those researchers who gave permission to include their
ethograms in this compilation, as well as those who had previously
published their ethograms. Additionally, GBAG would like to thank the
Gorilla SSP Group for their sanction. Each ethogram is listed under the
name of the respective author(s), with either the author's affiliation or
the reference from which it was taken. The majority of these ethograms
were, of course, built upon previous work of other researchers. Any
typographical errors or errors of interpretation are of course the
responsibility of the compilers, not the respective authors. This work
represents a compilation, not a recommendation of any particular
ethogram. Although an attempt was made, this compilation is by no means
exhaustive. Copies of this compilation are available for $5.00 from
Jackie Ogden, Zoo Atlanta, 800 Cherokee Avenue SE, Atlanta, GA 30315.
[Checks should be made payable to the Atlanta/Fulton County Zoo.] You may
also obtain a copy of this document in electronic form in either
WordPerfect 4.2 or in ASCII text-files [please indicate which version you
can use]. Send one formatted 5 1/4 inch diskette to Donna Hardy, Dept. of
Psychology, Calif. State Univ. Northridge, Northridge, CA 91330. [Since
this is a service of the Consortium of Aquariums, Universities and Zoos,
no charge is made for the ethograms in electronic form.]
updated January, 1991
TABLE OF CONTENTS
Beck, B. Phase 1...............................................page 3
Beck, B. Phase 2...............................................page 5
Bennett, C. and Fried, J. (1990)...............................page 7
Bowen, R.A. (1980).............................................page 25
Brown, S.G. (1988).............................................page 26
duBois, T., Mead, J. & Cox, C..................................page 27
Elliott, R.C. (1976)...........................................page 37
Fischer, R.B. (1984)...........................................page 38
Fossey, D. (1972)..............................................page 39
Fossey, D. (1979)..............................................page 41
Fossey, D. (1982)..............................................page 45
Frisch, D. J...................................................page 46
Goerke, B., Fleming, L., & Creel, M. (1987)....................page 48
Gold, K. (a)...................................................page 50
Gold, K. (b)...................................................page 52
Gould, J. E....................................................page 54
Harcourt, A. H. (1979a)........................................page 67
Harcourt, A. H. (1979b)........................................page 68
Harcourt, A. H. & Stewart, K. J. (1981)........................page 69
Hoff, M. P., Nadler, R. D., & Maple, T. L. (1981a).............page 70
Hoff, M. P., Nadler, R. D., & Maple, T. L. (1981b).............page 72
Lockard, J. S..................................................page 73
Mannchen, K. (1980)...........................................page 79
Maple, T.L. & Hoff, M..........................................page 81
Meder, A. (1985)...............................................page 86
Meder, A. (1986)...............................................page 87
Meder, A. (1990)...............................................page 88
Mitchell, R.W. (1989)..........................................page 89
Nadler, R.D., Collins, D.C., Miller, C., & Graham, C.E. (1983).page 90
Nadler, R.D. (1985)............................................page 91
Ogden, J.J., Hoff, M., & Maple, T.L............................page 92
Quiatt, D., Miller, L., & Cambre, R. (1986)....................page 96
Riess, B.F., Ross, S., Lyerly, S.B., & Birch, H.G. (1949)......page 97
Schaller, G. (1963)............................................page 99
Schildkraut, D. & Akers, J.....................................page 100
Schildkraut, D. (a)............................................page 102
Schildkraut, D. (b)............................................page 103
Schildkraut, D. (c)............................................page 105
Schildkraut, D. (d)............................................page 106
Schildkraut, D. (e)............................................page 107
Smalley, S.L. (1979)...........................................page 108
Watts, D.P. (1988).............................................page 109
Watts, D.P. (1990).............................................page 110
Woods, S.......................................................page 111
Wood, G., Forthman, D.L., & Ogden, J.J.........................page 113
Yamagiwa, J. (1986)............................................page 115
Index..........................................................page 116
Appendix.......................................................page 117
Beck, B. Phase 1: National Zoo, Gorilla Research Project
(study at the Brookfield Zoo)
Purpose: To compile data on the social behavior and social structure of
gorilla groupings to better inform management decisions and to plan
strategies for reproduction.
Sampling methods: Scans of location and activity (5 minute intervals).
Other behaviors, all occurrences.
Ethogram key words: Activity budgets/General behaviors, Social behavior.
Behaviors:
Activity:
Lie: Being recumbent with little or no weight being borne on hands or
feet.
Sit: Bearing most weight on buttocks.
Stand still: Bearing weight on feet quadrupedally or bipedally with
hands holding on to mesh, glass, tree, etc.
Locomote: Walking, running, or climbing.
?: If activity can't be scored.
Other behaviors:
Rest Near: Sitting or lying within arm's reach of another for at
least 10 seconds. Initiator is second animal to rest. The receiver
must be relatively immobile but need not be resting.
Groom: Directed touching, licking, or intense visual inspection of
another's (GO) or own skin (GS) or pelage. Scratching excluded.
Intimidation display: Resting on chest or abdomen, beating on cage
surface, rapid exaggerated running or strutting, pursed lips, and/or
exaggerated throwing or shoving of objects. Score when any two or
more of these behaviors occur simultaneously or sequentially. Score
initiator only.
Rough-up: Slapping, poking, elbowing, punching, hair pulling,
pushing, shoving, or wrestling when not in play or sexual context.
Aggressive bite: Biting when not in play.
Crouch: Initiator lowers ventrum toward or to substrate, or curls
fetally on substrate. Event terminated when normal locomotor or
resting posture resumed.
Inspect genitalia: Sniffing, touching, or intense visual inspection
of another's genitalia or own genitalia.
Sex solicit: Female purses lips and stares at/follows/reaches toward
male. Event terminated when lips relax for at least 10 seconds.
Copulation: Dorso-ventral mounting or ventro-ventral mounting with
pelvic thrusting. Event terminated when either animal breaks bodily
contact. Note if intromission confirmed (very difficult) or if semen
observed afterward on penis or vagina.
Masturbate: Rhythmic rubbing of genitalia with any part of own body
(e.g., fingers, toe), or against inanimate object.
Yawn: Per usual definition. Score each yawn.
Feces: Manipulation or mouthing of own or another's feces. Note
whose feces if possible. Note "eat" if fecal material actually
ingested.
Regurgitate: Vomiting into mouth, hand, or onto substrate; note if
reswallowed.
Termination of behavior: Termination of yawn, crouch, sex solicit and
copulation is specified in definition of those patterns. For all
other patterns, an event is terminated when discontinued for 10 or
more seconds or if the participating animal(s) engage in another
scored pattern within 10 seconds. However, Rest Near is not rescored
until one partner moves out of arm's reach for 10 seconds regardless
of concomitant behavior.
Beck, B. Phase 2: National Zoo, Gorilla Research Project
(study at the Brookfield Zoo)
Purpose: To study social development of captive-born lowland gorilla
infants being mother-raised in a group.
Sampling methods: 1-0 sampling at 60 seconds intervals. Note occurrence
of rough-up, aggressive bite, or crouch by putting initiator-receiver
letter codes.
Ethogram key words: Development.
Behaviors:
Infant location relative to other animals:
Contact: In physical contact with mother, whether carried or simply
touching.
Other contact: Any physical contact between infant and nonmother.
Proximate: Within arm's reach of other animal, but only when not in
contact with mother.
Distant: Beyond arm's reach but less than 15 feet of other animal,
but only when not in contact with mother.
Independence:
Nursing: Infant's mouth on mother's nipple, with or without actual
suckling.
Eating: Infant puts any solid food (including hay) into its own
mouth, with or without actual chewing or swallowing.
Wean: Mother actively terminates or prevents nursing.
Struggle: Infant trying to break contact withmother while being
restrained by her.
Play :Low intensity slapping, wrestling, or mouthing when initiator
has slack lips or "smile."
Aggressive behavior:
Rough-up: Slapping, poking, elbowing, punching, hair pulling,
holding, or wrestling, when not in play.
Aggressive bite: Biting, when not in play.
Crouch: Initiator lowers ventrum toward or to substrate, or curls
fetally on substrate.
Copulation: Dorso-ventral mounting or ventro-ventral mounting with
pelvic thrusting. Event terminated when either animal breaks bodily
contact. Note if intromission confirmed (very difficult) or if semen
observed afterward on penis or vagina.
Masturbate: Rhythmic rubbing of genitalia with any part of own body
(e.g., fingers, toe), or against inanimate object.
Bennett, C. and Fried, J. (1990) Dallas Zoo. Gorilla Ethology Study.
Purpose: To investigate the effects of exhibit modifications on gorilla
activity budgets.
Sampling: 15 minute focal sampling, with scan sampling at 15 minute
intervals of all individuals.
Ethogram key words: Activity budgets/General behaviors, Social behavior,
Sexual behavior, Post-occupancy evaluation, Display/Agonistic behavior,
Abnormal/Stereotypic behavior.
Behaviors:
Locomotion:
Walk: Individual travels from one location to another by using two,
three, or four limbs to propel the body. Two or three limbs are
always on the ground at one time.
Walk quadrupedal :The animal uses all four limbs to travel forwards,
backwards, or to the side. Leg movement is transverse (i.e., left
forefoot and right hindfoot moving together, then right forefoot and
left hindfoot moving together). Gorillas primarily knucklewalk, but
occasionally walk on the sides of closed fists.
Walk bidpedal: In this form of locomotion, the torso is perpendicular
to the ground. Travel is executed by using hind limbs alone. Legs
are extended and support the body. Forward motion of the legs comes
more from a forward and backward rocking of the pelvis rather than
rotational movements in the hip joints. Arms are usually held close
to the side or are wrapped around the torso. Sometimes, individuals
walk bipedally for short distances while holding onto a structure
(i.e., cage bars, bench, door frame edge, ropes, trees, vines) or
while carrying object(s).
Run: Three gaits can be observed: transverse quadrupedal, lateral
quadrupedal (gallop) and bipedal. Regardless of the gait; none, only
one, or two limbs will be on the ground at a time. Bipedal run is
achieved by slightly elevating the torso and lifting the arms during
a transverse run. This usually occurs within aggressive display
sequences or bouts of play behavior.
Slide: Occurs at end of a run. The animal remains quadrupedal but
stops the running motion while keeping the limbs rigid. The body
might be turned at an angle to the direction of travel. A slide may
be terminated by the presence of cage bars, wall, limbs, etc.
Arm over arm swing: An animal grasps an overhead structure with its
hands. The arms are nearly fully or fully extended. The animal
releases one hand and pivots the body forward from the still grasping
hand while extending the other hand to grasp a structure. It then
pivots the body forward. Swinging movements are slow and deliberate.
Reminiscent of brachiation.
Skip: Not observed in Dallas animals.
Swing: Not observed in Dallas animals.
Circle: Not observed in Dallas animals.
Scoot: Two forms of scoot have been observed, and both occur with the
animal in the squat position. One is a wobble like movement, where
the animal leans from side to side while swinging the elevated side
of the body forward. This can be done with the arms crossed on the
chest or resting on the knees, but the arms could be used to pull the
animal along while it moves next to the cage bars or ropes. The
second form is characterized by use of the arms in a crutch like
manner. The arms are placed on the ground in front of the body.
With the arms rigid and braced on the ground by tightly closed
fists, the body is pivoted forward by swinging between the arms.
Both modes of scoot are primarily used for short distance travel, but
individuals have been observed to travel up to twelve feet in this
manner.
Climb: Gorillas are methodical climbers moving carefully and always
having two limbs in contact with a structure at any one time. The
type of structure being climbed appears to influence the specific
climbing movements used. When climbing cage bars, wood ties, or
trees, movement of the limbs is basically transverse quadrupedal
(transverse limbs may move together or in series). When climbing up
ropes or horizontal bars, an animal may grasp them with its forelimbs
and partially swing its body up off of the ground until the hindlimbs
can also grasp or lean on the structure, thereby assisting the
forelimbs in pulling the body up.
Inactive:
Sit: Basically, sitting consists of: torso erect, not in contact
with ground, resting platform, substrate, etc.; buttock on ground,
legs in front or to the side of the body. Several variations of
sitting postures are regularly displayed:
Legs: bent acutely at the knees, rotated outwards from body
(outer thighs are close to the ground), and crossed at the ankles or
shins (aka: Indian style). The legs can also be extended forward and
crossed at ankles, bent with knee(s) up and foot/feet flat on ground,
legs extended and near parallel, or extended and split apart up to a
90 degree angle.
Arms/hands: crossed on chest, crossed or lying in lap, gripping
feet, resting on knee(s), or extended with knuckles resting on ground
for additional support. Animals will frequently hold on to structure
(i.e., ropes, cage bars, cross-ties) or rest limbs on it.
Torso: upright almost perpendicular to the floor, angled acutely
forward over legs at about a 45 degree angle or less to the floor, or
leaning to the side supported by structure, object, or extended arm.
Record as torso upright, torso hunched over, or back, side or arms
supported.
Squat: In this posture, legs are acutely bent at the knees and
thighs, with the feet under the body and heels tucked into the
buttocks. Feet and legs bear the bulk of the weight and can be in
front of the body or to the side. Buttock does not contact surface.
A squat position is assumed when the animals defecate or urinate (see
Elimination category). There are several variations of the squat
position:
Legs - Knees are bent and can be tucked up in front of the
chest or angled outwards until they form an almost straight line with
the body.
Arms - Forearms or elbows are frequently resting on knees,
thighs or holding onto a structure (i.e., cagebars), but may also be
crossed on chest or extended to the ground for additional support.
Torso - Squatting animals will frequently have their backs
upright against a structure (i.e., cage bars, walls, concrete posts).
When supported by arms extended out, the torso may be bent at a 10
to 15 degree angle.
Perch: Animals assume a squat posture when they are off of the
ground. The feet are used for grasping surfaces.
Legs/feet - Grasp structure with feet side by side or one in
front of the other.
Arms/hands - Grasp same structure/object or nearby
structure/object with hand(s) for additional support.
Lie: In this posture, the body is in a recumbent, prostrate
position. The body can be dorsally, ventrally, or laterally
recumbent. Variations within these positions include:
Ventral: Primarily the ventrum is on the resting surface.
Variations of ventrum include:
Arm(s) - May rest chin on forearm or hand.
Legs - May be bent at knees and tucked the body or hips may
be rotated so both legs lay out to the side.
Dorsal: Primarily the back is on the resting surface.
Variations of dorsal include:
Arms/hands - Are frequently folded across the chest or are
elevated with the elbows extended out and hands resting on
the head. Occasionally, the arms are extended outwards and
are grasping a structure.
Legs/feet - May be crossed at ankles or knees, sometimes an
ankle may rest on opposite knee. The feet may be gripping
an object or could be propped up against a structure.
Sometimes, legs may just stick up in the air at a 90
degree angle to the plane of body. Foot-foot and
hand-foot grasping occurs frequently.
Lateral: Primarily the left or right side of the torso is on
resting surface. Variations include:
Arms/hands - May be folded on chest, lying along length of
body or one/both arm(s) may be bent up under head as a
"pillow."
Legs/feet - Are usually bent at knees, pulled up towards
the body, and laid one on top of the other. The legs also
can be crossed at knees or ankles. Foot-foot and hand-foot
grasping occurs frequently.
Torso - The back may be against an object or unsupported.
Stand: Outstretched or extended arms and/or legs are in contact with
a surface and bear body weight. Stand, like sit and lie, can take
several forms.
Stand quadrupedally: All four limbs are extended, are in contact
with a surface, and support the body weight. The torso is
generally parallel to the ground. Animals will stand on
knuckles or on closed fists; on flat feet with thumbs extended
or on the side of the feet. Variations on the basic quadrupedal
stance can be identified as threat behavior (see descriptions on
agonistic behavior).
Stand bipedally: The torso is in an upright or nearly upright
position (perpendicular to the ground). The legs support the
body, are widely spaced, and bowed or slightly bent. The feet
are turned out, and thumbs extended out from foot. There is no
other support.
Stand supported: The animal is in a bipedal or monopedal
position with the torso perpendicular or even parallel to the
ground. The weight is supported by the legs, hands, or arms,
which may be grasping or resting on some structure.
Environmental exploration:
Survey:
Visual: Animal stops an ongoing behavior or is engaged in no
other behavior and orients head and eyes toward a specific
direction or component of the environment. This orientation can
be prolonged (greater than 2 sec).
Visual side glance: The animal repeatedly shifts its eyes to the
side and focuses momentarily on components of the environment.
The head is stationary and may be oriented away from the
object(s) of scrutiny.
Inspect: Includes both tactile and olfactory components. The
animal reaches out and touches an object with its knuckle(s) or
forefingers. The digit(s) are then brought to the nose and
apparently sniffed.
Olfactory: An animal brings the nose close to an object or the
object near the nose and sniffs.
Gustatory: An animal licks an object, places it momentarily in
the mouth or between the lips, or touches something then places
fingers in the mouth.
Object manipulation:
Object-gather: An animal accumulates objects that are dispersed
and brings them to a central location.
Object-dissemble: Involves a wide variety of actions where the
hands, feet, and mouth, are used to rip, shred, twist apart,
remove components, or peel an object (normally inanimate, but
not necessarily).
Object hold: An animal is inactive/idle with an object resting
in the hand, foot, mouth, or pressed against the body. No other
manipulation is occurring.
Object carry: An animal uses its hands, mouth, legs, and/or feet
to transport an object. Objects may also be carried by tucking
them between the thigh and belly.
Object rigid manipulation: An animal uses an object to rattle,
shake, bang, or pound.
Object use: Involves utilizing objects which are not permanent
fixtures for a number of different purposes: use of an object as
an extension of the body in order to attain an immediate goal
(tool), to increase comfort (furniture, nest), as covering, as a
weapon, etc.
Object varied or non-specific manipulation: This is a catch all
category that includes touching, pushing, absently rocking,
bending, lip rolling, etc.
Auto involved: Manipulate, eliminate, play, ingest:
Manipulate:
Autogroom: Animal uses fingers and/or lips and teeth to manipulate
and remove items from its fur.
Autopick: Animal uses fingers and/or lips to pick debris from its
teeth, nails, nose, ears, and eyes.
Probe anus: animal uses fingers to poke at or rub its anal region.
Masturbate: Self-stimulation of genitalia.
Manual: Animal manipulates its genitals with its hands or feet.
Pelvic rub: Female backs up to an object and rubs anogenital area
against it.
Haunch bounce: From a squatting position animal bounces up and down
on haunches. Males may create a false vagina with hands and haunch
bounce while directing the penis into the hands.
Autoinspect: Animal makes a close visual or olfactory examination of
own body parts.
Comfort: Comfort movements consist of brief, transitory movements
such as changes in posture; e.g., rolling over and changing
orientation of limbs and attempts to ease or relieve an uncomfortable
situation; e.g., stretching, scratching, yawning, coughing, clearing
the throat, etc.
Eliminate:
Urinate: Expel urine. Animals assume a squat position with
torso tipped forward and weight on its arms which are extended
in front of the body.
Defecate: Expel feces. Position during defecation is similar to
that described for urinate. Animals may urinate and defecate at
the same time.
Regurgitate: To eject part or all of the stomach contents through the
mouth, usually in a series of involuntary spasms. However, gorillas
seem to have a high degree of control over regurgitation. Record
this only if the animal regurgitates but does not reingest vomitus.
Play: Lone play includes repetitive, exaggerated, disjointed, and
seemingly nonpurposeful behavior. When alone, such behavior usually
involves an inanimate object or consists of repetitive movements
accompanied by a play face.
Object: Shake, bounce, hit, juggle item, hug, rub, swing, toss in
air. Movement is exaggerated. Water can be considered to be an
object.
Peregration or locomotor play: Clap, rock, somersault, shake, twist,
run, slap, pat, circle, lip flap.
Body oriented: Manipulate body part, exaggerated head and/or body
rubbing, pulling of extremities, etc. - chest beat.
Ingest: Includes a wide array of behavior associated with the
location, procurement, processing, and consumption of items.
Forage: Manipulation of substrate or objects in the environment
which results in obtaining food items (substrate is frequently
edible itself). This includes the periodic transfer of food
from hand/foot to mouth and travel of one or two steps between
searches. Several foraging motions can be used. For example,
animals may sweep an arm from side to side and move substrate
with the back of the hand or pick up the substrate and place or
throw it aside, or a substrate might be picked up and held while
an animal forages through it. To pick up food items, animals
will use a finger pinch (forefinger or middle finger and thumb
or tip of forefinger or middle finger for small forage
items). A variety of postures may also be assumed while an
animal forages: tripedal with free arm foraging, sitting,
squatting, or lying ventrally while resting on forearm(s) or
elbow(s).
Food carry: Travel while holding food items. Food can be
carried by mouth, hand, feet, in the crook of the arm, against
the chest, against the stomach, or any combination of these
methods. Animals walk bipedally (rarely), tripedally (most
commonly), or quadrupedally. Animals will knuckle walk with
food in their hands or will walk on the back of the hands/wrists
while holding food. When climbing, animals will frequently
carry food in their mouths. Animals may also scoot along for
short distances while carrying food.
Food gather: See object gather.
Food process: Various manipulations of food items (provisions,
browse, bedding) that give an animal access to an otherwise
inaccessible edible or preferred portion. This might involve
one or more of the following: stripping (usually length wise),
peeling, shredding, breaking apart, husking, shelling, or
shaking apart. Each action can be carried out with the teeth,
hands, lips, or feet, but usually occur in combination. Visual
and olfactory inspection of food frequently occurs during
processing. Individuals usually sit while food processing, but
will also recline ventrally.
Food beg: The animals will extend arms and clap hands together
several times or will clap hands together and then open hands
palms upwards. Hands are held in a relaxed manner with fingers
curled inwards. Knuckles on each hand are actually tapped
gently together. If this does not get a response, the animals
may rap on the bars or doors. Grunt-like vocalizations may
accompany begging. This behavior is usually directed towards a
keeper.
Eat: Placement of food items in the mouth by hands, feet, or
lips followed by chewing and swallowing. "Eat" does not require
that a substrate be manipulated in order to obtain food. Visual
inspection, olfactory inspection, manipulation, and/or food
processing may occur prior to and during eating. Food may be
regular provisions (record separately), browse or forage (record
separately), or body waste (record separately) (excrement,
cerumen, nasal mucus, scabs, sweat, dead skin, etc).
Individuals have also been observed to wipe sweat from their arm
pits with their hands and then lick their hands.
Drink: Animals drink from fountains, pools, streams, or from
areas where fluid has accumulated. Similar drinking postures
are used by the Dallas individuals. From a quadruped stance, an
animal either bends forward and places both hands against a
wall, fountain edge, or on each side of the body; or crouches
down with torso supported by all four bent limbs and ventrum
close to the ground. The head is horizontal when drinking. The
animals will lick up fluids or suck them directly into the
mouth. Fluids may be water or juice (record separately), or
urine (record separately),
Regurgitate and reingest: Expelling stomach contents through the
mouth and then consuming the regurgitate. Specify body position
during regurgitate, location regurgitation is deposited in,
method of reingest, body position during reingest. Specify body
position while regurgitating:
Tilt position - The legs are straight or slightly bent at
the knees. Body is bent at the hips with the torso
straight and angled downwards. Body weight is supported by
one forearm, both forearms (parallel along the orientation
of the body, parallel and running across the chest or
crossed across the chest) or one or both arms can be
resting with the palms flat on the ground and elbows
pointing out to the sides or backwards along the body.
The head is lower than the hips. Dallas gorillas will
regurgitate onto a surface or into their mouths from this
position. The gorillas will assume a tilt posture usually
from a sitting or squatting stance. Several head bobs
frequently occur prior to regurgitation.
Lie ventral - The animal reclines ventrally on the ground,
resting on the forearms (which are held parallel across the
chest). Head bobs usually precede regurgitation.
Quadrupedal stance - The animal assumes a quadrupedal
stance with legs and arms bent to varying degrees, but the
torso remains parallel to the ground. Vomitus is
forcefully expelled from 1/3 to 1/2 m (1.5 ft) above the
receiving surface.
Quick tilt - From a squat or sit position the animal
rapidly tilts forwards on its palms then quickly returns to
the previous position (looks like a pushup from a sitting
position). The gorilla might straighten its back legs a
bit when tilting forward but bends them again when it
returns to the sit/squat position. Regurgitation is
usually into the mouth and reingestion occurs while in the
sit/squat position.
Headshake - From a sitting or squatting position the
gorilla moves its head to one side and slightly upwards in
a somewhat circular motion or quickly up and down. The
mouth might open and then close quickly. The movement can
be so slight that it may seem as if the gorilla is moving
its head in order to relieve a crick in the neck. It may
be mistaken for a comfort movement. The gorilla appears to
regurgitate into the mouth; cheek bulging and chewing
movement can be seen. Vomitus is usually retained in the
mouth.
Methods of reingestion:
Reingest with the hand - An animal will dip or run its
fingers and whole hand into vomitus and then lick the
material off. Usually, the material has a liquid
consistency. An animal sometimes uses its hand to scoop
and maintain vomitus in small puddle. If the vomitus is
thick or chunky, the fingers and thumb, in a pincer motion,
are used to pick up matter and transfer it to the mouth.
Reingest with the mouth - Use mouth, lips and tongue to
suck, lick, or pick up vomitus.
Positions for reingestion:
Squat on elbows - Feet are flat on the ground, the body is
bent forward at the hips so that the ventrum is on the
ground. The gorilla is resting on the forearm(s). Hand or
mouth will be used to reingest from this position.
Sit/squat - Animal assumes a sit or squat posture
(described elsewhere) after the quadrupedal, quick tilt, or
head shake regurgitation.
Lie ventral - Similar to the squat on elbows position but
the feet are not flat on the ground but extend out from the
body. The usually rests on the forearms.
Tilt position - This is the same posture as used during the
regurgitation phase.
Stereotypic, unusual, aberrant behavior:
Stereotypic: Stereotypic behavior is characterized by excessive
repetition of or lack of variation in vocalizations, movements,
postures, or patterns of travel.
Stereotypic posture: Prolonged maintenance of an unusual or
bizarre stance, placement of extremities, or attitude. Specify
act.
Stereotypic movement: Involves body or limb movements but not
travel.
Head circle: A series of 2-12 unidirectional head rotations
which occur most frequently while in a quadrupedal stance with
the head, neck, and shoulders oriented towards a corner of an
enclosure. The head is only 1/3 to 1/2 m from the wall. This
behavior has been observed only in the younger silverbacked
male.
Head swing: This motion is similar to head circles but the head
hangs down and swings back and forth. The head does not make
full rotations. It occurs mainly while sideways walking and
occasionally while facing the wall or into a corner. This
behavior has been observed only in the younger silverbacked
male.
Rock: Legs are bent and the knees are near chest, arms are on
knees or folded across chest. From this position, the animal
sways from side to side (movements are no more than 5-10 cm to
each side). This is usually done while the animal's back or
side is against a vertical structure but has occurred while it
is gripping the cage bars with its hands or while perched
on a horizontal bar. Rocking occurs in association with finger
sucking. This behavior has been observed only in the younger
adult female.
Hand clap: Hands, with fingers curled in, are brought together
rapidly several times. This behavior has been observed only in
the younger adult female.
Stereotypic locomotion: Repetitive, unvarying, and seemingly
meaningless pattern of travel.
Pace: Repetitious, patterned and usually unidirectional movement
around the exhibit/habitat. The animal seldom makes more than
two complete circles about an enclosure. Pacing speed is faster
than the usual walking speed. This behavior is seen in the
younger silverbacked male and in both adult females.
Stereotypic self-oriented: Excessive repetition of an unvarying
form of self manipulation or self grooming.
Finger sucking: Animal will insert forefinger and/or middle
finger of either hand completely into mouth. Seen frequently in
association with rocking. Occurs while the animal is in a
sitting, squatting, or perched position. Legs are bent up near
chest, arms are on knees, or folded across chest. This behavior
has been observed only in the younger adult female.
Belly scratching: Belly scratching consists of a rhythmic
flexion of fingers or up and down movement of wrists so that the
fingers are rubbed gently across the stomach region. Hands may
alternate scratching, scratch in unison, or scratch singly. The
animal will belly scratch while holding straw in the scratching
hand. The scratching posture is sitting with knees acutely bent
and rotated outwards so the soles of feet are flat against each
other or legs may be slightly extended with feet gripping cage
bars. Seen only in the older adult female.
Stereotypic object use: Repetitive, unvarying, and seemingly
useless manipulation of an object.
Stereotypic noises (Auditory): Repetitive, unvarying, and
seemingly useless production of sound. This does not include
the occasional production of unusual sounds or noise.
Motor boat sounds: Forcing air through tight lips makes a sound
similar to a high pitched motor boat. Emissions are of short
duration (< 1 sec), but occur in series (one bout had 35).
Occurs primarily while the animal is in a resting/idle posture.
This behavior has only been observed in the younger silverback
male.
Unusual/idiosyncratic:..........
Lip hang: The lower lip droops loosely down exposing gums
and inner lips. This behavior occurs in a
variety of contexts, such as after aggressive
encounters, during resting periods, during
foraging bouts, while locomoting, while
manipulating objects, and when head circling or
head swinging. This behavior has been
observed only in the younger silverbacked male
who displays it frequently and incorporates it
into many behavior patterns.
Affiliative:
Reproductive/Sexual:
Precopulatory: Sexual behavior which occurs prior to
copulatory mounting.
Penile erection:There is no mounting. This is very difficult
to observe.
Inspect genitalia:Close visual, tactile, or olfactory scrutiny
of the genitalia or genital region of another.
Touch: An animal briefly touches, holds, fondles, or
mouths the genitalia of another.
Olfactory/sniff: An animal leans over and presumably sniffs
the genital region of another. Touching
another's genitalia and then sniffing the
fingers/hand is included in this category.
Solicit: One animal engages in a variety of postures,
gestures, or movements which have a high
probability of eliciting sexual behavior from
another.
Stare: Female stands motionless while intensely
watching the male.
Extended arm
invitation: Female reaches toward male with arm stretched
and palm facing the male.
Head jerk: While staring at a male, a female
intermittently tosses her head to one side.
Her body appears relaxed and the lips are not
compressed.
Present
quadrupedal: Female stands on all four limbs (see stand
quadrupedal) and orients her anogenital region
directly towards another animal. She may
slightly elevate her hindquarters or display a
head jerk.
Back into: Female first presents and then walks backward
into the male.
Open leg display:Female slides down past another while her
legs are spread widely apart. This behavior
occurs in a playful context.
Crouch: While in front of another, female bends low to
the ground with her limbs pulled underneath
her.
Ground object tap:While male is oriented towards a female, he
repeatedly taps the substrate with the
fingertips of both hands.
Haunch scoot: While squatting, a female uses her arms to
propel herself towards the male.
Quad-bounce: While standing on all fours and facing another
animal, a female bounces her hindquarters up
and down. Similar to a haunch bounce, but done
while animal is standing--may be a form of
masturbation as well as solicitation.
Pronk: While standing quadrupedally and facing another
animal, a female hops about in a jerky fashion.
The hindquarters are slightly elevated.
Pronk-mount: A female pronks while grasping another animal
around the waist.
Play present: A female presents in an "apparently playful
context"?. The angle of bend at the hips is
greater than in the other "present" solicit.
The female may rest on her forearms and
occasionally look backwards (over her shoulder
or between her legs) at the male.
Copulatory:
Mount attempt: Male attempts to make genital contact with
female (in any posture), but the attempt fails.
Mount: One animal positions itself on another such
that their genitalia are in contact (can be
same sexed), mount is of short duration with no
pelvic thrust observed. Orientation of mount
can be dorso-ventral, ventro-ventral, or
ventro-lateral.
Copulation: One animal mounts another in any orientation
(D/V, V/V, L/V). Mounting is followed by about
30 to 45 sec of position adjustments before
pelvic thrusting begins. During copulation the
female exhibits compressed lips and the male
exhibits pursed lips. The female will
occasionally look over her shoulder at the
male, and sometimes wave her head side to side
with her eyes closed and may emit copulatory
whimpers. It is very difficult to observe
intromission.
Reach around: During copulation, while in the D/V position,
the female twists shoulders and neck to look at
the male, and reaches back and touches the male
on the head.
Copulatory whimpers:
Pursed/compressed lips:
Postcopulatory:
Touch genitalia:Visual and tactile inspection of an
individual's own genitalia following
copulation.
Vocalization: After copulation.
Play: Repetitive, exaggerated, disjointed, and
seemingly nonpurposeful behavior involving two
or more individuals. This behavior is
accompanied by the "play face" which is
characterized by an open mouth which partially
exposes the teeth, but the lips are relaxed at
the edges. Social play may be accompanied by
soft chuckling or a throaty grumbling. Both
gentle and aggressive components may be
observed, so it is easily confused with
aggression (which is generally much louder).
Contact/direct play:Two or more individuals are engaged in play
involving almost continuous contact. This
includes such interactive acts as:
Stand/climb on, wrestle, slap/beat, tickle,
poke, grab, kick, carry, ambush, tag,
push/nudge, swat, tap on another, object
tug/grab, mouth (specify act).
No contact/
indirect play: Two or more individuals are involved in play
that does not involve direct contact. This
could include such acts as:
Chase, throw at, ground/water slap, object
wave/shake/brush on ground, arm shake, chest
beat, body slap (own), circle (specify act).
Solicit play: One animal engages in a series of postures,
movements, or gestures (runaway, swagger,
chestbeat) which has a high probability of
eliciting play from another.
Parallel play: Two animals engage in lone or object play (see
those categories) within proximate distance of
one another.
Groom:
Allogroom: One animal manipulates the fur, extremity, or
orifice of another. During a grooming episode,
the groomer often looks intently at the portion
of the body which is being manipulated.
Grooming may include both manual and oral
components.
Manual: Individuals use the fingers and whole hand to
manipulate and remove materials.
Oral: Use of mouth and lips to manipulate and/or
remove materials.
Mutual groom: Same as above, except the two animals groom
each other simultaneously.
Allomanipulate: One animal rubs, pats at, or fondles the fur,
orifices, or extremities of another (not
including genitalia).
Social locomotor: Involves travel while in contact with another.
Buddywalk: Animals walking tripedally or bipedally while
holding each other across the shoulder or on
the hips. This form of travel could involve
more than one other individual.
Carry/cling: One animal transports or is transported by
another:
Ventral carry/cling: While standing or moving quadrupedally
the focal animal transports another which is hanging on
to its ventrum (carry). The walk is
quadrupedal or tripedal (if the focal animal is
using one of its arms to support the
passenger). The focal animal is transported in
the manner described above (cling).
Dorsal or lateral c/c:While standing or moving quadrupedally,
the focal animal transports another on its
back, side, neck, shoulders, or head (carry) or
is transported by another in this manner
(cling).
Extended arm carry:An animal carries another (usually an
infant) in the palm of the hand and walks
either tripedally (carrying the infant football
style) or quadrupedally (carrying arm is
inverted and weight is on the backside of the
hand/wrist).
Leg drag: An animal holds onto another's ankle and is
pulled along in the direction in which latter
animal is traveling.
General social contact:
Active maintenance
of contact: Consists of a group of actions which establish,
regulate, or maintain contact with another.
Withdraw: One animal moves from within to beyond contact
distance of another.
Approach: One animal moves from beyond contact distance
to within contact distance of another.
Maintain: Preserve social distance with a withdrawing
animal.
Follow:One animal maintains proximity (1-3 BL)
with another and simultaneously parallels its
route of travel. Delay of follow is minimal.
Restrain:One animal physically prevents another
from moving out of contact distance.
Fetch/retrieve:One animal approaches and makes
contact (grasp, pull, push) with a withdrawing
animal or one who is beyond social distance (4
m), which results in that individual returning
to an original location or group.
Herd:An individual guides the movement of an
individual or troop by a series of approaches
and withdrawals.
Greet: Involves a group of actions which occur when
individuals are seeing each other for the first
time or are entering into the contact distance
of one another. These actions are typically
brief (momentary to 5 sec).
Muzzle-muzzle:One animal places its face within
15 cm of another's muzzle.
Kiss:One animal places its lips against the
head or face of another.
Touch:One animal reaches with any limb and
makes contact with another on any part of the
body except the genital region. The contact is
momentary (1-2 sec).
Embrace: One animal wraps arms and/or legs
around the body of another. Duration is short
(< 10 sec).
Grasp:One animal momentarily seizes another
with the hand(s).
Offer food:An animal holds food in the hand and
then extends that hand towards another.
Inactive social contact:Individuals are inactive, are within
social proximity (0-4 m) of one another, and
have the option to withdraw from social
proximity.
Huddle: Two or more individuals are inactive with
torsos in direct contact, lateral or ventral.
Arms may be wrapped around one another.
Rest in contact:Individuals are inactive with some part of
the body (exclusive of the position described
in huddle) in contact i.e., back to back, toes
touching, arms intertwined.
Rest proximate:Individuals are inactive, not in contact, but
within arms length of one another.
Rest distal: Individuals are inactive, not in contact,
greater than arms length away but within 4 m of
one another.
Agonistic:
Submissive/avoidance:
Turn away: An animal moves its body so that it is oriented
away from another, but does not travel.
Avoid: An animal moves out of the path of an
approaching animal or takes a less direct route
around that animal.
Hide: An animal removes itself from the view of
another. This may occur following an
aggressive attack or threat.
Crouch/crawl: This behavior can take two forms: 1) An animal
bends all four limbs, presses its ventrum to
the ground, and may try to travel while in this
position; or 2) the animal may crouch while in
one of the sitting positions by lowering the
head, hunching the shoulders, and often
covering the head with an arm.
Present: May take two forms. One form is similar to a
sexual present, but is much briefer. It may be
accompanied by a series of brief glances
directed towards the presentee. An animal may
also "offer-up" or present an arm to the
presentee. (specify act)
Run away: An animal moves rapidly (with a running gait)
away from another.
Supplant:
Supplant position:An animal approaches another which then moves
away. The former assumes the position of the
latter.
Supplant take object:An animal takes an object from another or
picks up one which was dropped as the former
approached.
Threat: Posture, facial expression, or movement,
usually accompanied by a vocalization, which
results in keeping rivals at a distance,
obtaining desired objects or space, and
controlling another's behavior without undue
expenditure of energy or risk of injury
(McFarland, 1982, slightly modified).
Threat: May appear to be undirected and for our
purposes, does not involve movement towards
another.
Stare: An animal looks towards and fixates on another
for an extended time. The brow is furrowed and
the face is tense.
Tight lipped face:An animal's lips are compressed tightly so
that the upper and lower lips protruded
somewhat.
Rigid quadrupedal
stance: An animal assumes a quadrupedal stance, with
the legs widely spaced and placed behind the
torso. The arms are rigid with elbows rotated
outwards, and the weight of the upper body on
the knuckles.
Rigid quadrupedal
walk: From the rigid quadrupedal stand, an animal
moves forwards with short stiff steps. The
walking speed may be faster than normal,
creating a trot like gait. This is undirected.
Object slap: An animal slaps ground, rock, wall, tree, door,
etc., with the palm or back of the hand. This
usually results in a loud sound.
Head divert: One animal turns its head away from another in
an exaggerated manner and glances repeatedly
and rapidly back at them.
Yawn: The mouth opens widely, head tips back, lips
are pulled back so that the teeth are exposed.
Looks like exaggerated form of a yawn.
Chest beat: An animal repetitively strikes the chest or
belly area with outstretched or cupped hands.
The animal is usually bipedal; either walking,
running, standing, or standing and rapidly
swaying. An animal may also strike his/her
chest once with a cupped hand. This can occur
in any posture. The chest beat, like all
agonistic behavior, may include a vocal
component such as a roar or pant hoots. Note:
chest beating can be observed in a number of
contexts: i.e., lone and social play,
reproductive, and agonistic.
Ground slap: An animal thumps the ground with one or both
hands. The strike may be with open hands, back
of hands, or side of closed fists.
Directed chest beat:An animal chest beats while oriented
towards another.
Directed object slap:An animal strikes at an object with an
open hand while oriented towards another.
Open mouth threat:An animal looks at another and lunges
forward with a tense, open-mouthed expression.
The lips are raised and pulled back so that the
canines are exposed; muscles in the forehead
are taut.
Threat display:A series of threats, postures, facial
expressions, or movements, that are accompanied
by a roar, bar, or rumble vocalization. Many
of the threat displays include a rapid advance
directed towards specific individuals.
Bluff charge: An animal runs quadrupedally on the diagonal
past another but does not make contact. The
bluff charge usually ends in a slide, and may
be accompanied by an object flail, drag, or
throw.
Rush charge: An animal runs quadrupedally towards, but stops
just short of another.
Object grab: One animal grasps or snatches an object (food,
browse, or otherwise) from another.
Attack: Includes hostile acts involving active pursuit
or physical contact between two individuals.
Hit: While rapidly charging towards another
(bipedally or quadrupedally), one animal
reaches out and strikes the other with an open
hand or fist.
Hit with object:An animal uses an object to strike out and
makes contact with another. This behavior
occurs at the end of a charge.
Hit/slap: An animal strikes another with its hand(s), but
there is not charge component to this behavior.
Push: Animal uses arms or legs to forcefully move
another away.
Pull: An animal grasps another and forcefully moves
them closer.
Chase: An animal runs in pursuit of another which is
rapidly withdrawing.
Bite: An animal closes its mouth on the extremities
or body of another. Damage may or may not
occur.
Author Note:
The authors would like to acknowledge that this ethogram was derived
in part from ethograms provided by the Los Angeles Zoo, Zoo Atlanta,
and Seattle, as well as through observations of the gorillas located
at the Dallas Zoo.
Bowen, R. A. (1980). The behaviour of three hand-reared lowland
gorillas (Gorilla gorilla gorilla) with
emphasis on the response to a change in
accommodation. Dodo, R. Jersey Wildlife
Preservation Trust, 17, 63-79.
Purpose: To measure effects of change in accommodation.
Sampling methods: Scans, one minute intervals for one hour
periods.
Ethogram key words:Activity budgets/General behaviors, Environment
change, Influence of.
Behaviors: (full listing available from author)
Resting: Lying, sitting, standing, clinging and hanging,
except when accompanied by any other behavior;
thus leaving only those occasions on which the
animal was sedentary in both gross and local
terms (apart from visual behavior or gestures).
Gross locomotion: Walking, running, climbing, brachiating,
swinging, rolling, and wrestling.
Local manipulation:Manipulating with hands or feet, mouthing,
scratching, hairplucking, grooming,
nose-picking, coprophagy, drinking water or
urine, foraging, feeding, and mauling (gentle
wrestling).
Social play: Wrestling, mauling, sparring, chasing and
social grooming.
Self-directed: Grooming, scratching, plucking hairs and
nose-picking.
Visual: Watching, looking at, and glancing at one
another.
Gestures: Including facial expressions (play face and
fear grin), playing-walking/running, tapping
and slapping objects/substrate, chest beating
and patting parts of the body.
Public-oriented: Watching or interacting with members of the
public, by throwing items of food or play
objects, for example.
Feeding: Eating, drinking, foraging for food, coprophagy
and drinking urine.
Stereotyped: 'Rocking' and 'shuffling.' These are
behavioural abnormalities peculiar to captivity
in which the animal sits, sometimes holding a
quantity of wood-wool or similar nesting
material, and either rocks back and forth with
it in a sort of scrubbing motion, or shuffles
backwards with it, using the hands placed on
the surface in front as a means of propulsion.
Brown, S. G. (1988). Play behaviour in lowland gorillas: Age
differences, sex differences, and possible
functions. Primates, 29(2):219-228.
Purpose: To document play in a large sample of gorilla
groups, in order to better understand the
possible functions of social play in gorillas.
Sampling: Frequencies recorded.
Ethogram key words:Social behavior.
Behaviors:
Solitary play:
Rotational/locomotor:
Twirl:Spinning around bipedally.
Somersault:Turning the body one full rotation
head over heels.
Roll:Turning the body from side to side while
supine; can be complete or incomplete rotation.
Run:Loose limbed gait, usually bipedal.
Self:Slapping the face, clapping hands, or
rubbing oneself without grooming.
Object play: Play with inanimate objects and other species.
Climb/swing: From a tree, boulder, or ledge.
Manipulate: An external object such as grass, dirt, or a
branch.
Throw: An external object while in a relaxed stance.
Swing: An external object while in a relaxed stance.
Water: Water is used in the play sequence.
Social play:
Moderate play:
Open-mouth-
wrestling:Limbs entwined while sitting or
laying; gorillas roll/twist together placing
open mouths on each other.
Active play:
Rough/tumble:Vigorous bipedal wrestling.
Chasing:One gorilla rapidly following another,
both with relaxed running gaits.
Chest-pounding
duBois, T., Mead, J., & Cox, C. Lowland gorillas: Ethogram. Los
Angeles Zoo.
Ethogram key words:Activity budgets/General behaviors, Social
behavior, Sexual behavior, Display/Agonistic behavior.
Abnormal/Stereotypic behavior, Development, Maternal behavior,
Vocalizations.
Behaviors:
Masturbation:
Manual:An animal rubs its genitals repeatedly
with hands.
Pelvic rub:A female backs up to an object
(tree, rock, etc.) and rubs anogenital area
against it.
Haunch-bounce:While in a squatting position, a
female bounces up and down on her haunches.
(Referred to as Evie's "hiccuping.")
Coo vocalization:Pursed lip vocalization
sometimes given when female's masturbate.
Sexual behavior:
Anogenital touch:An animal examines or fondles
the anogenital region of another.
Anogenital sniff:An animal sniffs the
anogenital region of another, excluding
occasions when the latter animal has just
defecated or has feces on fur.
Stare:A female stands motionless while
intensely observing the male.
Head jerk:While staring, a female
intermittently jerks head to the side. The
body is relaxed and lips are not compressed.
(Referred to as "the come hither look".)
Extended arm invitation:A female extends her
arm with open palm toward the male.
Ground or object tap:While orienting toward the
male, a female repeatedly taps ground, rock or
log with both hands (as if playing a drum).
Haunch-scoot:While squatting, a female uses her
arms to propel herself on her haunches toward
the male.
Quadrupedal-bounce:While standing on all fours
and facing another animal, a female bounces
hindquarters up and down. (Similar to
haunch-bounce but done while animal is standing
- may be form of masturbation as well as sexual
solicitation.)
Pronk:While standing on all fours and facing
another animal, a female hops about in a jerky
fashion. The hindquarters tend to be slightly
elevated. (Behavior "invented" by Cleo.)
Pronk-mount:A female pronks while grasping
another animal around the waist.
Present:A female stands quadrupedally and
orients anogenital region directly toward
another animal; hindquarters are slightly
elevated (but not an exaggerated display as in
some primates).
Back-into:While presenting, a female walks
backwards directly into another animal.
Play-present:A female presents in a playful
context. Form is generally exaggerated, e.g.,
animal bends way over with head close to ground
and rump in the air. (May occur only in young
animals.)
Spread-legs display:A female slides on an
incline past another with legs spread widely
apart. Occurs in a playful context.
Crouch:A female bends low to the ground with
her limbs pulled in. Another animal may then
mount dorso-ventrally.
Lie prone:An animal lies flat on the ground
face downward during a sexual encounter.
Lie supine:An animal lies flat on the ground
face upward during a sexual encounter.
Dorso-ventral mount:An animal mounts another
from behind.
Ventro-ventral mount:An animal mounts another
from the front. (Both animals face each
other.)
Ventro-ventral mount
of infant:An adult animal stands quadrupedally
over a supine infant and thrusts without making
contact.
Awkward mount:An animal mounts another, but
orientation is improper, e.g., mounts from
side, etc.
Mount and thrust:An animal mounts another and
thrusts, but intromission does not occur.
Copulation:An animal mounts another and
intromission occurs (hard to determine whether
ejaculation occurs).
Coo vocalization:Pursed lips vocalization given
by female which may occur before, during or
after copulation.
Reach and touch:During copulation, a female
reaches around with one arm and touches male on
the head.
Social play:
Social play:Repetitive, exaggerated,
disjointed, and seemingly non-purposeful
behavior involving two or more animals. May
have both gentle and aggressive components.
The list is almost infinite but includes the
following:
Climb or stand on another, turn circles around
another, piggy back ride, peek-a-boo, mouth,
tickle, foot dangle (an animal dangles foot in
front of another), tap on another, dangle (an
animal holds an infant by its hands and allows
it to dangle in the air), arm shake, run-away
(one animal runs away from another as an
invitation to chase), chase or play tag,
swagger walk, chest beat, beat or slap other
body part, ground or water slap, object wave,
shake, or brush on ground (usually a branch),
object throw/hit, object tug/grab, swat, push
or nudge, grab/pull, kick, wrestle, bite,
play-face (relaxed, open-mouth expression with
teeth exposed).
Social other/maternal:
Approach:An animal draws closer to another:
because of context and relaxed body posture,
motivation presumed to be friendly.
Follow:An animal walks behind another; because
of context and relaxed body posture, motivation
presumed to be friendly.
Muzzle-muzzle:An animal places its face
directly in front of another (within 6 inches).
Groom/inspect:Using the hands or mouth, an
animal grooms or examines another's body parts,
excluding the anogenital region except when
feces being removed.
Active contact:Friendly contact behaviors which
occur outside of play context. Includes the
following:
Touch (excluding the genitals), grasp, sniff
(an animal sniffs another's body parts,
excluding anogenital region unless feces are
obviously being sniffed), mouth, kiss (an
animal puckers its lips against head or face of
another), pat or caress, hug or embrace, hold,
huddle (animals sit in groups of two or more
with bodies in close contact).
Passive contact:An animal sits, lies, or
sometimes walks with body in contact with
another. Behavior is not as "intimate" as
active contact, e.g., animals may sit with only
feet touching.
Inside with:Two or more animals, excluding
infants being carried, are inside cave or
planter together and are not visible to the
observer; assume association to be affiliative,
although specific behaviors not visible.
Food offer:An animal offers food, browse, or
regurgitate to another.
Special social behaviors observed in mothers or caretakers:
Rock:A mother supports her infant in arms or on
lap and rocks it back and forth.
Jiggle-bounce:A mother supports her infant in
lap or on legs and bounces and jiggles the
infant.
Dangle-groom:A mother dangles her infant by one
ankle and grooms the anal area.
Flex-manipulate:An animal bends and manipulates
the infant's body parts.
Coax:A mother places her infant on the ground
and then walks away and stands or sits at a
distance. The mother observes infant
intensely, seemingly encouraging it to
approach.
Retrieve:An animal picks up an infant when
infant is alone.
Restrain:An animal holds an infant firmly when
the infant attempts to leave.
Shield:An animal uses its arms or body to
shield an infant from another animal or other
potential danger.
Special social behaviors observed in infants:
Climb on or over:An infant climbs on or over
another animal.
Nose/eye poke:An infant pokes its finger in
another's nose or eye.
Manipulate mother's
nipples:An infant pulls at or handles mother's
nipples (not to be confused with rooting
behavior).
Distress vocalization:An infant whines or cries
when alone; appears to be an attempt to get
mother to return.
Agonistic:
Turn away:An animal turns away from another in
order to avoid, but does not vacate its spot.
Avoid:An animal moves away from or gets out of
path of another.
Crouch:An animal crouches when threatened or
attacked by another.
Hide:An animal presses itself against a surface
so that it is hidden or partially hidden from
the view of another.
Supplant:One animal approaches another and the
latter moves away. The approaching animal then
takes that spot.
Stare:A fixed, unwavering stare at another with
brow furrowed and facial muscles tense.
Tight-lip face:A facial expression in which the
lips are tightly compressed and the head
diverges from side to side.
Stiff stance:An animal stands with the legs
held rigidly and the body stiff and erect;
tight lip face often accompanies.
Strut-walk:While in the stiff stance, an animal
walks with stiff, short steps.
Directed chest beat:An animal chest beats while
orienting toward another gorilla in the same
exhibit.
Directed object slap:An animal orients toward
another and slaps ground, rock, wall, inside
door, or makes loud splash in the pond.
Bluff charge:An animal runs on the diagonal
past another but does not make contact.
Rush charge:An animal rushes up to and stops
just short of another.
Charge with chest beat:While charging, an
animal beats its chest.
Charge w/object display:While charging, an
animal waves or throws an object or slaps
ground with an object (usually browse).
Charge and hit:While charging, an animal hits
another with an object (usually browse).
Leg kick:An animal kicks its leg in the air at
the end of a charge, chest beat or object
display.
Object grab:An animal snatches an object or
browse away from another.
Object drop or throw:An animal drops an object
down on another from above, or throws an
object at another.
Hit with object:An animal hits another with an
object.
Hit/slap:With hands.
Push
Grab/pull
Chase
Open-mouth threat:A tense, open-mouth
expression with lips raised and pulled back so
that canines are exposed; muscles and the
forehead are taut and drawn back.
Agonistic -- Vocalizations:
Soft pant-hoot:A quiet vocalization in which an
animal makes rapid exhalations through "o"
shaped lips. The abdomen may be seen heaving
up and down.
Scream
Pig grunts:Short, rough, guttural grunts.
Growl:A deep, guttural noise similar to a dog's
growl.
Bark:A deep, gruff noise similar to a dog's
bark.
Roar:A loud explosive outburst given by a male
silverback.
Herd/herded:
Herd:A silverback male controls the movement of
a group by following at a close distance
(formerly called pursue; may be an attempt to
keep females together and in sight.)
Herded:Refers to a group being herded by a
silverback male. Animals appear to be avoiding
the male as they move away whenever he
approaches.
Visual attention:
Observe:An animal watches another gorilla in
the same exhibit.
To outside gorillas: [The following behaviors are directed to
gorillas in 1)an adjacent exhibit, 2) in night quarters, or to 3)
"missing" gorillas (gorillas which have recently been sent out).]
Observe:An animal watches another gorilla in an
adjacent exhibit.
Display:Includes behaviors such as chest
beating, object throwing, waving, etc., which
are directed toward gorillas in an adjacent
exhibit.
Bang door:An animal bangs on the inside door
when there are group members kept inside night
quarters.
Search:An animal travels about exhibit or goes
in and out of cave seemingly looking for a
missing group member.
Hoot series vocalization:Low pitched "hoo hoo
hoos" which can build up to more plaintive
sounding, higher-pitched "hoos." Vocalization
often terminated by banging on door and has
been heard only when group members are missing.
Stereotyped behavior:
Head toss:An animal repeatedly tosses its head
in circular fashion; sometimes followed by
regurgitation and reingestion.
Arm fling:While sitting, an animal repeatedly
flings its arm out for no obvious reason.
Hair pluck:An animal plucks hair from its own
body, usually the facial region.
Self-flagellation:While sitting, an animal
flogs itself with browse.
Regurgitation and reingestion: [Refers to behaviors in which food
is brought up from the stomach to the mouth and then eaten.
Gorillas tend to use idiosyncratic methods.]
Reg. into cupped hand:An animal regurgitates
into hand and then eats out of hand.
Reg. onto substrate:An animal bends over,
regurgitates onto ground and then ingests
directly from ground.
Bent-arm regurgitate:An animal lifts and bends
arm at elbow while regurgitating in a jerky
fashion into cupped hand.
Suck-regurgitate:An animal brings lips into
extreme sucking position and brings regurgitate
up into mouth.
Backward neckAn animal leans head backward with
neck stretched taut,
stretch regurgitate: then regurgitates with
mouth closed.
Regurgitate into mouth:An animal makes "o"
shape with lips and brings regurgitate up into
mouth.
Head jerk regurgitate:An animal jerks head in
circular fashion while bringing up
regurgitate.
Bend over regurgitate:While sitting, an animal
bends over with mouth close to the ground and
regurgitates into mouth.
Self-play and object explore:
Self-play:Includes all solitary play behaviors
which are not directed to other animals or to
the zoo patrons, including:
Rock body, roll on ground or grass, somersault,
turn circles, thigh slap/pat, chest pat (very
mild chest beating), lip flap (using fingers),
clap hands, manipulate body parts (exaggerated
body or head rubbing, pulling on toes, etc.),
water play (wading, splashing, etc.), object
play (waving branches, tossing leaving in air,
playing with tubs, burlaps sacks, etc.).
Object explore and Refers to all behaviors in
which an animal uses its hands
manipulate:to investigate or handle objects,
excluding those which are preparatory to
feeding, including:
Browse manipulate, browse or object wear (an
animal drapes browse, burlap sack, etc., over
back, shoulders, head), other vegetation
inspect/manipulate (rubbing grass on body,
throwing grass clumps in air, etc.),
manipulate feces or regurgitate (not associated
with ingestion), poke at dirt/dig holes, rub
self with dirt, mouth objects (including
biting, sucking, licking, chewing, or
manipulating with tongue), manipulate
miscellaneous objects (such as drain covers),
items thrown in by patrons, etc.), observe
objects (visual examination of an object which
is being held or which is within reach), sniff
objects, and carry objects (in mouth, hand, or
on small of back).
Food getting and ingestion:
Ingest:Includes the following: eat browse, eat
grass, weeds, leaves, bark, flowers, or other
vegetation, eat miscellaneous food items
(including food thrown in by keepers and
patrons), spit food out, drink, eat food out of
another animal's mouth (seen in infants).
Forage:Behaviors which are preparatory to
feeding. Includes the following: gathering,
carrying, or dragging browse, bark stripping,
gathering and eating seeds, picking and/or
carrying grass, weeds, leaves, bark, flowers,
or other vegetation or food items.
Audience interaction:
Audience interaction:Includes all behaviors in
which an animal interacts with humans (keepers,
patrons, etc.), or vehicles drawn in front of
an exhibit. Includes: approach/observe,
extend arm (animal stretches arm outward toward
audience, probably begging for food), point at,
clap hands, arm shake, blow kisses, self-play
behaviors (which are obviously directed to
audience), chest pats, splash water, object
throw (including feces, dirt clods, rocks,
etc.), threaten audience (animal directs
agonistic behavior toward humans, including
growl, roar, open-mouth threat, bluff charge,
chest beat).
Carry/cling or ride:
Ventral carry/cling:While standing or moving
quadrupedally an animal carries an infant who
clings to the ventrum.
Dorsal or lateral
carry/cling:While standing or moving
quadrupedally an animal carries an infant on
the back, side, neck, shoulders or head.
Leg drag:An infant grasps another's ankle and
clings while the latter animal walks about.
Extended arm carry:An animal carries an infant
in palm of outstretched hand and walks
tripedally (the "football carry").
Tripedal walk:An animal holds infant against
the ventrum and walks tripedally.
Locomotion: [Includes all forms of movement and travel occurring
outside of a friendly/social or agonistic context. Also excludes
self play and occasions when an animal is carrying an infant.]
Walk quadrupedally:An animal walks on four
legs.
Walk tripedally:An animal walks on three legs.
Walk bipedally:An animal walks on two legs.
Stand quadrupedally
Stand bipedally
Climb
Scoot
Slide
Roll
Jump
Hang by arms
Swing by arms
Run: (in non-agonistic context).
Change stance:Go from sitting to standing
position, etc.
Special locomotor behaviors observed in infants:
Arm/leg flail:An infant jerks its arms and/or
legs about in a seemingly random fashion.
Root:An infant gropes and moves head about
mother's ventrum in search of mother's nipple.
Crawl:An infant drags its prone body along the
ground.
Toddle:An infant walks quadrupedally with
short, uncertain steps.
Rest and body maintenance:
Rest:Periods of quiet repose in which any of
the following behaviors may occur:
Sit/lie without performing other behaviors,
sleep, yawn, stretch, cough, comfort movements
(slight position shifts or rolling over while
resting).
Self-exploration and
body maintenance:Includes the following
behaviors:
Groom/self-inspect (an animal picks at or
examines its toes, hands, or any other body
parts), oral explore (an animal mouths or licks
its body parts), scratch, nose-pick, sniff
self, rub eyes, pick teeth, rub self, poke
anus/remove feces.
Urinate/defecate
Vomit:(when not part of R/R).
Look out/look about:An animal sits or lies
quietly but appears to be observing
environment, although specific object of focus
is not apparent (same as "stationary alert").
Special rest behaviors seen in infants:
Nurse:An infant suckles at its mother's breast
(it is often hard for an observer to tell
whether an infant is nursing or sleeping, so we
are including "nurse" under rest behaviors).
Other: [These include behaviors which do not readily fall into any
category or whose functions are unclear.]
Non-directed agonistic:Includes agonistic
behaviors such as chest beat, growl, object
slap, etc., which do not appear directed toward
other gorillas or to audience, and which occur
outside of play context.
Interspecific agonism:An animal directs
agonistic behavior toward animals other than
gorillas or humans (e.g., swiping at insects,
chasing peacocks, etc.).
Visual exploreIncludes the following: visual
attention toward objects in
environment:environment which are not within
reach (such as planes, helicopters, etc.), and
observe animals other than gorillas or humans
(such as peacocks, insects, etc.).
Eat feces
Drink urine
Eat another's regurgitate
Monitor/search:An animal looks about exhibit as
if to locate the whereabouts of other group
members.
Armpit sniff/touch/
manipulate:An animal sniffs or touches own
armpit, or manipulates area under armpit.
Nipple rub:An animal repeatedly rubs its own
nipple.
Self-directed lactating
behaviors:Behaviors shown by lactating mothers
including:
Manipulate nipples, squirt milk from nipples,
and bend over to drink milk from own nipples.
Escape/escape attempt:An animal attempts or
succeeds in climbing out of exhibit. May stand
on back of another gorilla to reach handhold.
Nest-build:An animal manipulates browse around
itself to form a crude, circular nest.
Not visible:An animal is not visible to the
observer excluding cases of inside with.
Elliott, R. C. (1976). Observations on a small group of mountain
gorillas (Gorilla gorilla beringei). Folia
Primatologica, 25, 12-24.
Purpose: To summarize the characteristics of range and
behaviour in a small gorilla group.
Sampling methods: Modified time sampling technique to record
inter-individual distance data. Position
mapped at 10 min intervals. Longhand field
notes apparently taken on behavior, but no info
on how or definitions.
Ethogram key words:Activity budgets/General behaviors, Field study,
Gorilla g. beringei.
Behaviors:
Agonistic behavior
Allogrooming
Social play
Vocalizations
Fischer, R. B. (1984). Observations of group introductions in
lowland gorillas. Behavioural Processes,
9, 293-296.
Purpose: To investigate agonistic responses during and
just after group formation.
Sampling: Two hours of continuous observation followed
each introduction.
Ethogram key words:Display/Agonistic behavior,
Introductions/Socialization.
Behaviors:
Nonagonistic behaviors:
Proximity:When two or more animals were less
than 4 m apart for at least one minute.
Arm-over:Lateral extension of arm towards
another. Arm was typically relaxed.
Aggression has not been observed following
approach preceded by arm-over.
Agonistic behaviors:
Contact aggression:Frequencies of hitting,
biting or grappling observed between
individuals.
Noncontact aggression:Instances of directed
pursuit (subsuming charging and chasing),
demonstration (species typical postural and
facial displays, chest beating, throwing, or
aggressively striking an object as part of a
sequence of activities), and lunging.
Behaviors not clearly directed toward a
specific individual were omitted.
Fossey, D. (1972). Vocalizations of the mountain gorilla (Gorilla
gorilla beringei). Animal Behaviour, 20:36-53.
Purpose: To describe the vocalizations of the mountain
gorilla.
Ethogram key words:Vocalizations, Field study, Gorilla g. beringei.
Behaviors: (See also: Fossey, D. (1983). Gorillas in the
mist. Boston: Houghton Mifflin.)
Roar: Monosyllabic loud outburst of low-pitched harsh
sound, lasting from .20 to .65 seconds,
beginning and ending abruptly. Individual
differences in frequency concentrations. Heard
only from silverbacks in situations of stress
or threat, and primarily directed at human
beings, although occasionally at buffalo herds.
Always followed, on the part of the emitter,
with varying degrees of display, ranging from
bluff charges to small forward lunges.
Alarm calls:
Scream:Shrill and prolonged emission of
extremely loud sound, lasting up to 2.13
seconds and repeated as often as 10 times.
Individual differences not denoted. Screams
heard from all age and sex classes, but most
frequently from silverbacks. Vocalization
heard most often during intragroup disputes,
though could be directed toward human beings or
ravens if alarm rather than threat was
motivation for call.
Wraagh:Explosive monosyllabic loud vocal
outburst not as deep as a roar nor as shrill as
a scream. Began and ended abruptly and lasted
between .2 and .8 second. Individual
differences in sound, which were more
harmonically structured than roars. Heard from
all adults but most frequently from
silverbacks. Usually precipitated by sudden
situations of stress--the unexpected arrival of
an observer, etc. Most effective in scattering
group members and never accompanied by
aggressive display behavior.
Question bark:Characteristic composition of
three notes with the first and third lower than
the middle, as if asking the question "Who are
you?" Sound was short, lasting between .2 and
.3 second, heard more from silverbacks.
Usually in situations of mild alarm or
curiosity and was common response to discovery
of obscured observer, etc.
Cries:Resembling wails of human infants, could
build up into shrieks much like human beings'
temper tantrums. Emitted between .03 and .05
seconds apart, and could last for nearly 19
seconds. Wails had four distinct frequency
concentrations, but shrieks were much less
structured. Cries were heard only from infants
or young juveniles, frequently when left alone.
Cries built up into temper tantrums if
stressful situation was prolonged.
Coordination Vocalizations:
Pig-grunts:Series of short, rough, guttural
noises, pig-grunts are usually delivered
between .15 and .4 seconds apart in sequences
of nine or ten outbursts. Resembling grunting
of pigs feeding, tended to become louder and
more closely spaced if prolonged. Most
frequently heard during traveling, when trail
disputes and altercations over limited food
resources were more apt to occur. Pig-grunts
were effective rebuttal vocalizations and
disciplinary enforcements between adults and
young.
Belch vocalizations:Deep, prolonged rumbles
(naoom, naoom, naoom) rather like
throat-clearing utterances. The belch
vocalization is one of the most complex because
of multiple intergradations and functional
variations. Variations heard from all sex and
age classes. For expressing contentment and
verifying position; a slightly shortened belch
vocalization was often used when mildly
disciplining gorilla young or observers.
Chuckles:Raspy expirations of noise verge in
intensity depending on degree of play involved.
Irregularly spaced spurts of sound varying from
.02 to .1 seconds with low frequency
concentration. No individual differences.
Intergroup vocalizations:
Hootseries preceding
chestbeats:Given with or without a terminating
chestbeat, consists of prolonged distinct
hoo-hoo-hoos. Low-pitched, often undetectable
to human ear at beginning, but usually built up
into plaintive-sounding and longer hoots
toward the end. The lengthier the series, the
more fluctuations in harmony and phasing.
Frequencies ranged between 1.4 and 1.8
kilocycles per second for as many as
eighty-four hoots per second. Silverbacks were
most frequent emitters. Depending on distance
between groups, would or would not terminate
vocalizations with displays.
Fossey, D. (1979). Development of the mountain gorilla (Gorilla g.
beringei): The first thirty-six months. In D.
A. Hamburg and E. R. McCown (Eds.), Great apes
of Africa (pp. 139-186). Menlo Park, CA:
Benjamin-Cummings.
Purpose: To begin describing quantitatively individual
differences of mother-infant relations; also
describes behavior during pregnancy.
Sampling method: Ad lib field notes, later classified under
specific subject headings. Data were then
grouped according to two month units of infant
age (e.g., 1-2 months old). This paper also
describes physical development in detail.
Ethogram key words:Development, Pregnancy, Behavior during, Field
study, Gorilla g. beringei.
Behaviors: (3 main categories: maintenance activities,
maternal interactions, and social awareness,
listed according to time unit.) (See also:
Fossey, D. (1983). Gorillas in the mist.
Boston: Houghton Mifflin.)
Newborn (first 24 hrs):
Whines:Weak, puppy-type.
Grasping reflex
Rooting
Nuzzling of nipple
Sleep
Ventral carry
Grooming by mother
Nurse
1-2 months:
Ventral clinging
Ventral carry
Low abdominal ride
Thigh ride
Dorsal ride
Rooting
Nuzzling of nipple
Mouthing or chewing of
vegetation debris
Sleep
Whines
Wails:Loud, high pitched.
Exploring own body
Rolling over
Creeping
Look around
Grooming by mother
Nurse
2-4 months:
Ventral clinging
Ventral carry
Dorsal ride
Crawl
Sitting attempts
Kick, whack, push
Exploratory play,
surrounding
vegetation:Gross, jerky extensions with
fingers widely spread before object is
contacted, usually only grasp object.
Exploratory play,
mother's body:Unbalanced crawling, sliding,
patting, and hair pulling.
Discipline:Mock-biting, pushing back at infant.
Eating vegetation debris
Grooming by mother
Distress face
Play face
Whines
Wails
Screeches
Panting play chuckles
Nurse
4-6 months:
Ventral carry
Ventral cling
Dorsal ride
Grooming by mother
Nurse
Exploratory play,
surrounding
vegetation:Includes manipulation of
vegetation.
Exploratory play,
mother's body:More strenuous, includes
mock-wrestling with extremities.
Solo play:Patting, clapping and whacking own
body.
Restrain infant
Eating vegetation:No food prep, just plucking
leaves or gnawing.
Quadrupedal walking
Whines
Wails
Panting chuckles
Screeches
Screams
Sits
Stand bipedally
Social contact w/others
Chest beat
6-12 months:
Ventral ride
Dorsal ride
Rump-clinging:Infant follows mother with one or
both hands clasping hair on rump.
Nursing
Solo play:Now includes tree climbing.
Leave mother
Infant restrain
Contact with mother
Within arm's reach
Within 15 feet
Social play
Eating vegetation:No food prep, just plucking
leaves or gnawing.
Genital touching:Mother uses genital touching
as training method by which infant is urged to
crawl, climb, walk, and run (observed only in
captives).
Walk bipedally
Travel quadrupedally
Stand bipedally
Sit
Nurse
Push from nipple
12-24 months:
Dorsal ride
Ventral carry
Travel quadrupedally
Rump-clinging
Nurse
Push from nipple
Social play:More vigorous.
Solo play:Swinging, twirling and
semi-brachiating in trees.
Eating vegetation:Now includes stripping
leaves.
Grooming mother
Chest-patting
Foliage-whacking
Strut-walking
Compressed-lip
Whines
Wails
Panting chuckles
Screeches
Hoot cries
Shrieks
Temper tantrum
screams
Howls
Pig-grunts
Leave mother
Mother restrain
Contact with mother
Within arm's reach
Within 15 feet
24-36 months:
Dorsal ride
Travel quadrupedal:Includes canter gait.
Ventral carry
Nursing
Push from nipple
Solo play:Tree play increases, becomes more
inventive and daring.
Social play:Begins including more tree play.
Eating vegetation:Includes preparation:
wadding, stripping, peeling.
Grooming:Includes siblings, peers, and
silverback.
Whines
Wails
Panting chuckles
Screeches
Hoot cries
Shrieks
Temper tantrum
screams
Howls
Pig-grunts
Belch vocalization:Basic disyllabic variant of.
Mount
Leave mother
Mother restrain
Contact with mother
Within arm's reach
Within 15 feet
Behavior during pregnancy:
Proximity
Groom infants
Staring at infants
Contact with mother/infant
Distant travel
Feeding
Mount
Copulation
Irritability
Fossey, D. (1982). Reproduction among free-living mountain
gorillas.
American Journal of Primatology Supplement,
1:97-104.
Purpose: To summarize status of and reproduction in
free-living gorillas.
Sampling method: Ad lib field notes.
Ethogram key words:Sexual behavior, Field study, Gorilla g.
beringei.
Behaviors:
Copulation: Nearly all solicited by females, most commonly
dorsoventral. Male sat upright or leaned
forward bipedally and held female around waist.
Female squatted on lap or bent forward on
flexed elbows with rump accessible. Brief
adjustment occurred first. Held position from
5 to 20 minutes. Accompanied by
vocalizations, primarily by male. Female often
had compressed lips; male pursed-lips.
Copulation vocalization:Panting and soft hoots.
Solicitation by female:Sometimes included extending hands
fleetingly to touch male's body before
retreating; often included glance over
shoulder.
Glance over shoulder:To male during solicitation: "come hither
look."
Sexual play
Pseudosexual mounting
Interference w/copulation
Genital touching
Frisch, D. J. Columbus Zoo, Gorilla Birth Watch Protocol.
Purpose: To recognize changes in behavior of pregnant
female, to record onset of labor.
Sampling method: Every 15 minutes, note activity of pregnant
female. If unusual behavior occurs between
interval, write in time and explain.
Ethogram key words:Birthwatch.
Behaviors:
Lie: Being recumbent with little or no weight being
borne on hands or feet.
Sit: Bearing most weight on buttocks.
Stand still: Bearing weight on feet quadrupedally, or
bipedally with hands holding on to mesh, glass,
trees, etc.
Locomote: Walking, running, or climbing.
? Activity can't be scored.
Rest near: Sitting or lying within arm's reach of another
for at least 10 seconds. Initiator is second
animal to rest. The receiver must be
relatively immobile but need not be resting.
Grooming: Directed touching, licking, or intense visual
inspection of another's (GO) or own (GS) skin
or pelage. Scratching excluded.
Intimidation display:Beating on chest or abdomen, beating on cage
surface, rapid exaggerated throwing or shoving
of objects. Score when any two or more of
these behaviors occur simultaneously or
sequentially. Score initiator only.
Rough up: Slapping, poking, elbowing, punching, hair
pulling, pushing, shoving, or wrestling when
not in play or sexual context.
Aggressive bite: Biting when not in play.
Crouch: Initiator lowers ventrum toward or to
substrate, or curls fetally on substrate.
Event terminated when normal or resting
posture resumed.
Inspect genitalia: Sniffing, touching, or intense visual
inspection of another's genitalia (IGO) or own
genitalia (IGS).
Sex solicit: Female purses lips and stares
at/follows/reaches toward male. Event
terminated when lips relax for at least 10
seconds.
Copulation: Dorso-ventral mounting (DVC) or ventro-ventro
mounting (VVC) with pelvic thrusting. Event
terminated when either animal breaks body
contact. Note if intromission confirmed (very
difficult) or if semen observed afterward on
penis or vagina.
Masturbate: Rhythmic rubbing of genitalia with any part of
own body (e.g., finger or toe) or against
inanimate object.
Yawn: Per usual definition. Score each yawn.
Feces: Manipulation or mouthing of own or another's
feces. Note "eat" if fecal material actually
ingested.
Regurgitate: Vomiting into mouth, hand, or onto substrate.
Note if reingested.
Play behavior: Poking, tickling, wrestling, chasing in
nonaggressive manner.
Goerke, B., Fleming, L., & Creel, M. (1987). Behavioral changes of
a
juvenile gorilla after
a transfer to a more
naturalistic
environment. Zoo
Biology, 6, 283-295.
Purpose: Investigation of one male juvenile lowland
gorilla before and after transfer to new
environment, particularly play and
stress-related behaviors.
Sampling: 10 minute periods from 10 am to 4 pm daily.
Two indices: play index: number of minutes
during which some play occurred in each 10
minute observation period. Frequency: is the
number of occurrences in each period of 19
selected play activities, divided into social
or solitary play.
Ethogram key words:Post-occupancy evaluation, Environment change,
Influence of, Abnormal/Stereotypic behavior.
Behaviors:
19 play activities:
Gentle wrestling:Hugging and rolling.
Rough wrestling:Standing up, more aggressive
behavior.
Chasing
Running alone
Playing with water
Slapping
Chest pounding
Clapping
Playing with branches
Swinging
Jumping
Tumbling
Spinning
Throwing
Manipulating objects
Moving of the body
Solitary sexual play
Social sexual play
Climbing
Grass play
Dirt play
Tree play
Stress-related behaviors:
Coprophagy
Regurgitation/reingestion
Self-clasping
Gold, K. (a) Noise disturbance study, San Francisco Zoological
Gardens (currently affiliated with Zoo Atlanta).
Purpose:To study effects of construction noise on gorilla behavior.
Ethogram key words:Activity budgets/General behaviors, Noise
disturbance, Effects of.
Locations: Trees, rocks, quadrants 1-7, gorilla world, out
of sight.
Behaviors:
Environmental exploration: Investigation such as touching,
sniffing, close visual inspection of parts of
the exhibit, habitat, or cage other than
gorillas, loose objects, or toys. Does not
include aimless oral or manual activities.
Eat: Chewing/ingestion of food/browse.
Self directed behavior:Self groom, self clasp, self suck,
scratching, rubbing, etc.
Display behavior: Behaviors used by an animal to draw attention
to oneself, oftentimes communicating a specific
behavioral state in the displayer. Includes:
Chest beating
Ground or wall slapping
Drumming
Throwing objects
Foot stomping
Kicking
Clapping
Branch whipping
Strut walking
Pursed-lip tense face
Other
Vocalization: Scream, grunt, bark, etc.
Solitary behavior: Active physical motions such as in play but
without a partner, including rolling, sliding,
swinging, spinning, etc.
Contact: The focal animal is in direct physical contact
with another group member.
Social play: The focal animal is engaging in play behavior
with another group member (non-aggressive) such
as chasing, wrestling, mouthing, etc.
Aggression: Chase, hit, grab in aggressive manner
(different than social play).
Sexual behavior: Oral-genital contact, genital-genital contact,
digital-genital contact, masturbation.
Locomotion: Continuous horizontal or vertical movement of
at least 1 body length during the interval.
Rest: In an inactive state for a minimum of 10
seconds.
Miscellaneous behavior:Digging up enclosure, coprophagy,
regurgitation, regurgitation and reingestion.
Gold, K. (b) Gorilla development study. Nationwide, 10/82-10/86.
Purpose: To investigate infant development in gorillas.
Sampling: One/zero sampling during 15 second intervals.
Trial=twelve 15 second intervals with a two
minute pause (five minutes total).
Session=Twelve trials (60 minutes). Focal
animal sampling.
Ethogram key words:Development.
Behaviors:
Approach:* Focal animal moves toward another (or another
toward focal) to within proximity.
Withdraw:* One animal retreats from another in a
non-passive fashion. Must be the result of an
approach.
Leave by other:** An animal leaves proximity of another, but not
as an result of an approach.
Touch:* Physical contact with non-focal animal other
than in categories below.
Lift/hold:** Weight support contact.
Carry:** Infant is transported by another animal.
Ventro-ventral contact:**Infant's ventrum in contact with other's.
Dorso-ventral contact:**Infant's ventrum in contact with other's
back, shoulders, or back of neck.
Proximate:** Within arm's reach of another (arm length of
larger animal).
Near:** Out of arm's reach of another, but within
fifteen feet.
Social play:* Physical play with a partner including "rough
and tumble" play such as tickling, wrestling,
chasing. Score TOUCH in addition if it occurs.
Genital inspect*: Close observation, touching, sniffing or
manipulation of genital area of self or other.
Sexual behavior*: Mounting, pelvic thrusting, mock copulation,
with a partner or inanimate object.
Nipple contact:** Infant's mouth on nipple, with or without
actual suckling visible.
Environmental exploration: Investigation such as touching,
sniffing, close visual inspection of parts of
exhibit, habitat or cage other than gorillas or
loose objects, toys. Does not include aimless
oral or manual activities.
Object contact: Contact with toys or any loose object.
Mouthing: Using tongue, lips, teeth to explore
environment, objects or animals. May include
biting, chewing, food or non-food. May be
during a play bout.
Solitary play: Active physical motions such as in play, but
without a partner. Includes rolling, sliding,
swinging, spinning, etc.
Self-directed behavior:Self clasp, self groom, self suck,
scratching, rubbing, etc.
Play face: Open mouthed, slack lipped "smile" exposing
teeth. May be accompanied by head shake,
patting, mouthing or play biting.
Locomotion: Continuous horizontal or vertical movement of
at least one body length during trial.
Rest: In an inactive state for five seconds or more.
Vocalization: Belch
Cough/grunt
Growl
Hoot
Bark
Scream
Whine/whinny
Pant
Display: Chest beat
Throwing
Slapping/tearing
Whipping
Thumping/Slamming
Strut Walk
Threat face
Out of sight: Observer is unable to see focal animal.
Contact with human:Any contact with a person. Must be initiated
by focal animal in order to be scored.
* note initiator/recipient
** note non-focal animal
Gould, J. E. University of West Florida and The Zoo, Gulf Breeze,
Florida.
Purpose: Collection of behavior, posture/locomotion, and
location data, primarily to document
socialization and group formation involving a
previously isolated adult male.
Sampling: Focal instantaneous time samples, at one minute
intervals when observing two gorillas
(male-female dyad) and 30 second intervals
when observing one gorilla. These data are
supplemented with audiotaped notes, written ad
lib notes, and still and video photography.
Ethogram key words:Activity budgets/General behaviors, Social
behavior, Sexual behavior, Display/Agonistic behavior,
Introductions/Socialization, Abnormal/Stereotypic behavior,
Vocalizations.
Behaviors:
Positional Behaviors:
Posture:
Lie:
Lying down: Specify dorsal, ventral, lateral.
Leaning: Legs under body and body less than 45 degrees
from horizontal--specify ventral or lateral and
on which arm or arms.
Sit:
Sitting: Resting on buttocks--specify any support or
suspension with hands.
Squatting: Knees bent, buttocks above heels--specify any
support or suspension with hands.
Standing, quadrupedal
/pronograde
Standing, tripedal
Standing,
bipedal/upright
Crouching: Quad stand with limbs flexed/bent.
Locomotion:
Walk:
Walking, quadrupedal
/pronograde: (knuckles?)
Walking, tripedal
Walking,
bipedal/upright
Run:
Running, quadrupedal
/pronograde
Running, tripedal
Running,
bipedal/upright
Other:
Climbing: Specify up, down, left or right.
Hanging by hand(s)
Swinging by hand(s)
Brachiating: Progressing by swinging from one hold to
another by the arms.
Jumping
Spinning
Sliding
Rolling: Sideways.
Somersaulting: Head over heels.
Eating, drinking, and eliminating activity:
Eat:
Eating: Specify type of food.
Gathering: Gathering food in heaps.
Foraging: Wandering in search of food.
Sharing food: With another gorilla.
Symbolically eating
Drink:
Drinking water
Drinking milk
Nursing
Eliminate:
Defecating
Attending to feces
Handling feces
Passing gas
Urinating
Attending to urination
Handling urine
Object-oriented activity (specify if play):
Look (specify object/food):
Glancing: Briefly observing sideways out of corner of
eyes.
Looking: Observing directly.
Watching/staring: Prolonged and attentive observing; curiosity?
Manipulate (specify object/food and body part used):
Smelling
Mouthing
Reaching
Touching
Fiddling
Grasping/grabbing
Clasping/hugging/
cuddling/embracing:In arms.
Releasing
Patting
Swiping
Slapping
Hitting
Kicking
Barging
Pushing
Pulling
Throwing
Swishing/splashing: Water.
Holding: Specify hands, feet, mouth, back, etc.
Carrying: Specify hands, feet, mouth, back, etc.
Other:
Approaching
Moving away
Retreating: Withdrawing from apparent danger (e.g., snake).
Avoiding/evading
Fleeing/escaping
Grimacing: e.g., at water spray.
Swatting insects
Killing insects
Catching insects
Nest building
Tool using: Specify tool and object acted on.
Tool manufacturing:Specify tool and method.
Self-oriented activity (specify if play):
Manipulate:
Non-genital self-manipulating:
Autogrooming: Picking through own hair with fingers and/or
lips.
Rubbing
Scratching
Picking: Specify nose, eye, etc.
Finger tapping
Hand clapping
Chin slapping: See chest-beating sequence below.
Hair pulling: Stereotypic/abnormal?
Genital self-manipulating:
Masturbating
Bottom bouncing: By female.
Self-inspecting: Visually.
Finger licking: May be associated with menstruation.
Finger smelling: May be associated with estrus.
Stereotypic/Abnormal activity (may not be abnormal unless behavior
is stereotypic; could include preceding behaviors listed under
"manipulate"):
Rocking
Swaying: Side to side.
Shuffling
Pacing
Self-biting
Self-grasping
Turning back
Sitting in corner: As though in bed.
Jawing: Opening and closing mouth.
Grinding teeth
Regurgitating and
reingesting
Coprophagy: Eating dung.
Drinking urine
Other:
Sleeping: Eyes closed, no movement for 3 minutes.
Resting: Specify if eyes are closed--see sleeping.
Yawning
Looking: At self; specify body part if possible.
Self recognition: In mirror or other reflector.
Sitting or standing
in water
Running through water
Splashing in water
Chest-beating sequence:Release of accumulated tension associated
with excitement as in sexual excitement, play,
mild irritation, impatience, frustration,
lonesomeness, novelty, or when in conflict
between aggression and flight; this is the
apparent primary function and cause; for
additional functions as well as descriptions
and components to be specified--see below under
"inter-individual oriented activity" both
"interact" and "aggress-defend."
Inter-individual oriented activity (specify if play):
Look:
Glancing: Briefly observing sideways out of corner of
eyes.
Looking: Observing directly.
Watching: Prolonged and attentive observing.
Staring: Listed below under "reproductive" and
"aggressive acts".
Interact (nonagonistic behavior, includes play; note that several
of these behaviors also occur in agonistic interactions--see below
under "aggress-defend"):
Non-contact:
In vicinity:1-5 meters.
In proximity:Within arm's length; approximately
1 meter.
Approaching:Moving towards.
Displacing:Taking place of another.
Lunging:Incipient charge: abrupt advance of 0-3
steps.
Charging:Running is lateral, not forward, if
there is conflict between charge and retreat.
Chasing:Pursuing rapidly.
Throwing material:Specify material.
Standing off:Rigid/strut quad stance, facing
each other; often associated with tight-lipped
face--see below under "other," can be sexual
initiation by female toward male or vice versa.
Moving away
Retreating:Withdrawing from what is dangerous
or disagreeable.
Avoiding/evading
Fleeing/escaping
Chest-beating
sequence:See above.
Reaching/inviting:Arm extended, hand open, palm
up; initiates play; see also under
"reproductive".
Arm-over response:Palm down.
Smelling
Imitating
Teasing
Playface/pleasure
face:Relaxed, open mouthed.
Play biting
Play walking
Play running
Play chasing
Play fleeing
Bouncy gait
Contact:
Touching:Non-genital.
Hand holding
Grasping/grabbing
Clasping/hugging/
cuddling/embracing: In arms.
Releasing
Giving
Taking
Leaning on
Grooming:Picking through hair of another with
fingers and/or lips.
Tagging
Patting
Swiping
Slapping
Hitting
Kicking
Pummelling
Barging
Pushing
Pulling
Wrestling/grappling
Mouthing:Taking an arm or shoulder between
teeth and appearing to bite, but applying no
pressure; can be intimidation by dominant male
and thus agonistic.
Reproductive:
Charging parallel:By male, sometimes preceded
by chest-beating display, usually followed by
standing off.
Standing off:See above under "non-contact".
Staring:Can be sexual initiation by female
toward male, often associated with standing off
and head shaking, may be tight-lipped.
Head shaking:See below under "aggress-defend:
submissive displays".
Inviting:Extended arm with hand open and palm
up by female while staring at male; another
variation is drumming on hindquarter or ground
by female while staring at male.
Offering/presenting:Prone position: female
crouches, backs up toward male to display her
genitalia, and looks back at him; supine
position: female lays on back and makes
rhythmic pelvic movements, also often inviting
as above.
Inspecting genitalia
Manipulating gen.
Oral-genital contact
Mounting:Specify dorso-ventral or
ventro-ventral.
Pelvic thrusting
Paternal/maternal
caring:e.g., nursing.
Disciplining
Aggress-Defend (agonistic behavior, aggressive or defensive
interaction--see also behaviors listed above under "interact"):
Aggressive acts:
Non-contact:
Staring:Furrowed brow?
Staring openmouthed
/threat face: Specify if teeth showing.
Staring bared-
teeth scream face/
threat face
Head jerking or
snapping:Toward antagonist; specify if audible
snap of jaws.
Forward lunging:Incipient charge: abrupt
advance of 0-3 steps.
Bluff charging:If conflict between charge and
retreat; then lateral running.
Throwing non-fecal
material
Throwing feces
Physical contact:
Hitting
Barging
Grappling
Biting
Etc.:See "interact: contact" behaviors above.
Threat Displays (Domination):
Chest-beating
sequence:Intimidation to repel intruders; for
functions other than aggress-defend, see above
under "interact" and "self-oriented activity".
Consists of rhythmic beating, with alternating
cupped hands, of the chest, but also abdomen
and thighs, as well as cheek drumming with
mouth open, chin drumming with backs of
fingers, and rhythmic beating of ground, floor,
logs, etc.; chest-beating is only one of 9
actions which do not necessarily all occur
together, or in the following order; full
sequence exhibited only by silverbacked males
and infrequent--specify components present:
Hooting
Symbolically feeding
Rising bipedally
Throwing vegetation
Chest-beating
Leg kicking
Running sideways bipedally then quadrupedally
Slapping and tearing vegetation
Ground thumping (or beating/slapping other
inanimate object, e.g., wall)
Strut standing: Very stiff quad posture, elbows bent outward,
shoulders hunched, sometimes head diverted to
side, brief sideways glances at opponent;
commonly with tight-lipped/lip-in/tense-mouth
face; may occur at end of chest-beating
display.
Strut walking: As above, with short-stepped quadrupedal
walking.
Strut running: May be followed by striking a barrier or
another animal with shoulder or forearm.
Submissive displays (Submission):
Turning head away: Also used to indicate aggression is not
intended.
Head shaking: Also used to appease when unsure and during
sexual initiation by female while staring at
male; relatively rare; specify if lower jaw
relaxed.
Cowering: Crouching on abdomen; head lowered, arms and
legs tucked under; protects body.
Other:
Pursed-mouth/pout/
light-distress face:Watch out, I'm ready to get
mad; or male during copulation.
Tight-lipped/lip-in/
tense-mouth face:Usually with periodic quarter
turns of head and sideways glancing; situations
of uncertainty, tension, courtship; or female
during copulation.
Grimacing
Fear grinning
Vocalizing: Specify, see vocalizations below.
Piloerecting: Erecting body hair, especially on back and
head.
Marking: e.g., by urinating.
Observer-oriented activity (specify if play):
Look:
Glancing: Briefly observing sideways out of corners of
eyes.
Looking: Observing directly.
Watching/staring: Prolonged and attentive observing; curiosity?
Interact (non-agonistic behavior, includes play; see
"inter-individual oriented activity" above for additional behaviors
and descriptions):
Listening
Pursed-mouth/pout/
light-distress face
Tight-lipped/lip-in/
tense-mouth face
Chest-beating sequence
Vocalizing: Specify, see "vocalizations" below.
Exchanging/giving
Imitating
Signing: Specify: e.g., chest tap, head tap, hand clap.
Aggress-Defend (see "inter-individual oriented activity" above for
listing of specific behaviors):
Aggressive Acts
Threat displays
(Dominance)
Submissive displays
(Submission)
Vocalizations:
Aggressive Calls:
Roar/threat bark: Simple, mono-syllabic, sudden loud outburst
of low-pitched harsh sound. Strong aggression
of silverback male to predator (including
human) or other group. Always followed by some
type of aggressive behavior.
Growl: Deep guttural prolonged noise resembling growl
of dog and not loud. Mild aggression in
stationary group associated with "annoyance."
Pant series: Rapid sequence of forced expulsions of air, of
very low frequency, seems whispered, resembles
pig grunt (see below). Mild threat within
group.
Mild alarm calls:
Question bark: Three notes, low-high-low, as in "who are you?"
Very mild alarm or curiosity.
Hiccup bark: Resembling di-syllabic spurt of noise like a
hiccup. Very mild alarm of curiosity.
Fear and Alarm Calls:
Silence: Sudden cessation of all sound emission, vocal
and mechanical. Most extreme form of fear,
e.g., to sounds of approaching poachers.
Screams: Shrill and prolonged emission of extremely loud
sound. Aggressive disputes within group;
copulating female.
Wraagh/alarm bark: Explosive, monosyllabic outburst of loud
sound, abrupt beginning and end. Sudden
alarming situation; loud noise; very close or
sudden contact; not accompanied by aggression.
Distress calls:
Cries: Wails, sobs, screeches and hooting types of
distress calls; can build to screams or shrieks
(temper tantrums). Infant separated or in
difficulty.
Whines: Very soft, prolonged plaintive sound, like that
of puppy. Danger of injury or abandonment; not
limited to infants.
Group coordination vocalizations:
Pig grunts: Short, rough, guttural grunts (av. 9-10),
resembling grunting of pigs feeding at a sty.
Mild aggression in moving group, e.g., right of
way dispute during feeding; silverback when
pursuing female before copulation or when
guiding group movements; disciplinary
enforcement.
Hoot bark: Like bark of dog but more "who-who" than
"woof-woof" or "wah-wah" sound; like hiccup and
question barks but two, not one or three
syllables. Alerting to mild alarm; group
movement initiation.
Belch vocalization:Deep, prolonged rumble, like soft belch; most
commonly long, di-syllabic throat-clearing
(ummm-ummm) sound, with second note lower than
first; at times more complex, like croons,
purrs, hums, moans, wails, or howls. Feeding;
group contentment; localization; useful in
allaying gorilla apprehension among human
observers.
Intergroup communication:
Hoot series: Given with or without a terminating chest-beat
or other elements of that sequence. Prolonged
series (av. 10-15) of "hoo hoo hoos",
low-pitched, quiet at start of series, building
up. Intergroup encounters with aggressive
component; intergroup communication/vocal
probing/social space echolocation.
Miscellaneous vocalization:
Chuckles: Raspy expirations verging between pants and
grunts. Social play, tickling.
Copulatory pants: Rapid series of soft, short duration hoots,
becoming more prolonged and merging into long
howl-like note. Silverback copulating. Also
dove-coos by both sexes.
Whinnies: Resembles raspy neighing of horse. May be
anomalous; ailing animal.
Harcourt, A. H. (1979a). Social relationships among adult female
mountain gorillas. Animal Behaviour,
27:251-264.
Purpose: To examine relationships among adult female
mountain gorillas.
Sampling: Ad lib sampling, using behavioral checksheet,
including intitiator/recipient, bout lengths.
Ethogram key words:Social behavior, Field study, Gorilla g.
beringei.
Behaviors: (Also see Harcourt, A. H. (1977). Social
relationships of wild mountain gorilla. Ph.D.
thesis, University of Cambridge.)
Proximity: Within 2m or 5m of partner.
Touching: More than 5 sec.
Body contact: Excludes grooming.
Grooming: More than 5 sec.
Agonism:
Avoid:Actions ranging from simply leaning away
from an approaching animal to cringing under an
attack or getting up and leaving.
Pig-grunts:Antagonistic, coughing-type
vocalization.
Chest beating
Strut runs
Harcourt, A. H. (1979b). Social relationships among adult male and
female mountain gorillas in the wild.
Animal Behaviour, 27:325-342.
Purpose: To examine relationships among adult male and
female mountain gorillas.
Sampling: Continuous ad lib sampling, using behavioral
checksheet, including intitiator/recipient,
bout lengths; plus activity and location scans
at 15 minute intervals.
Ethogram key words:Social behavior, Field study, Gorilla g.
beringei.
Behaviors: (Also see Harcourt, A. H. (1977). Social
relationships of wild mountain gorilla. Ph.D.
thesis, University of Cambridge.)
Proximity: 2m and 5m.
Grooming: Only those lasting > 5 sec.
Agonism:
Approach-retreat:Non-aggressive approach
followed by retreat.
Approach
Retreat
Avoid:Movement away within 1 to 2 sec following
the other's approach, but not to beyond 2 m
Supplanted:Movement away within 1 to 2 sec
following the other's approach, to beyond 2 m.
Threat display:Includes chest-beating,
ground-thumping, foliage-slapping, strutting
and running.
Hooting
Attacks:Hits, kicks, and bites.
Pig grunt:Sharp grunt.
Harcourt, A. H. & Stewart, K. J. (1981). Gorilla male
relationships: Can
differences during
immaturity lead to
contrasting
reproductive tactics in
adulthood? Animal
Behaviour, 29:206-210.
Purpose: To examine relationships among adolescent males
and group leaders and tendency to remain in
natal group.
Sampling: Ad lib sampling, using behavioral checksheet,
including intitiator/recipient, bout lengths.
Ethogram key words:Social behavior, Field study, Gorilla g.
beringei.
Behaviors: (Also see Harcourt, A. H. (1977). Social
relationships of wild mountain gorilla. Ph.D.
thesis, University of Cambridge.)
(Also see Stewart, K. J. (1981). Social
development of wild mountain gorillas. Ph.D.
diss., University of Cambridge.)
Proximity
Contact
Grooming
Hoff, M. P., Nadler, R. D., & Maple, T. L. (1981a). Development of
infant
independence
in a captive
group of
lowland
gorillas.
Developmental
Psychobiol-
ogy, 14,
251-265.
Purpose: To supplement the data available on infant
development of gorillas.
Sampling: One/zero sampling, one minute intervals in 1st
3 and last 5 months; focal animal continuous
sequential activity record for remainder of the
18 month study using 30 minute samples.
Ethogram key words:Development.
Behaviors:
Ventro-ventral: Animals' ventral surfaces in contact.
Dorso-ventral: One animal's ventrum pressed against another
animal's dorsum. Herein used exclusively in
"back ride" position (infant lying on mother's
back).
Ventral-dorso: As above. Herein used exclusively as infant's
dorsum against its mother's ventrum.
Other contact: Any form of contact excluding ventro-ventral,
dorso-ventral and ventro-dorsal.
Proximate: Animals not in contact, but within 3 ft (1 m)
(arm's length) of one another.
Distant: Animals between 3 and 15 ft (1 and 5 m) apart.
Far distant: Animals beyond 15 feet (5 m) apart.
Leave: Moving from a position of contact to proximate,
distant or far distant.
Return: Reestablishing contact with another animal.
Scored for the animal reestablishing contact,
regardless of which animal left.
Social approach: Animal moving from distant or far distant to
proximate (contact not established).
Follow: Moving behind and in the same direction as
another animal.
Restrain: Prevent another animal from moving away.
Struggle: Animal attempting to leave another while being
restrained.
Retrieval: Move another animal into closer spatial
proximity as defined by the above contact
variables.
Nipple contact: Animal's mouth placed on another's nipple with
or without suckling.
Wean: Remove an infant from the nipple.
Remove: Move another animal into a position of less
close spatial proximity as defined by the above
contact variables.
Social examination:Inspect another animal with fingers, feet,
and/or mouth (includes stare).
Object examination:Inspection and/or manipulation of articles in
the environment (does not include solitary play
using objects).
Protect: Saving an animal from possible harm (by
retrieval, crouching over the animal, holding
arm up, etc.).
Hoff, M. P., Nadler, R. D., & Maple, T. L. (1981b). Development of
infant play
in a captive
group of
lowland
gorillas
(Gorilla
gorilla
gorilla).
American
Journal of
Primatology,
1, 65-72.
Purpose: To supplement the data available on infant
play, and particularly of development of infant
play in gorillas.
Sampling: One/zero sampling, one minute intervals in 1st
3 and last 5 months; focal animal continuous
sequential activity record for remainder of the
18 month study using 30 minute samples.
Ethogram key words:Development.
Behaviors:
Infant solitary play:Initially consisted of ground slapping...at
7th month consisted of gymnastic play.
Mother-infant play:Typically involved gently nudging with finger,
arm, or leg by the mother, and wrestling with
and mouthing of the mother by the infant. Play
was often exhibited in a discontinuous,
reciprocal fashion.
Infant-infant play:
Active social play:"Rough and tumble" play.
Typically consisted of chasing, lunging,
tackling, vigorous wrestling, falling on the
other, and vigorous mock biting.
Moderate social play:Typically involved lying
on the play partner, light bouncing on the
partner's stomach, or mild pulling.
Lockard, J. S. Ethogram for longitudinal study of Seattle's
Woodland Park gorillas. University of
Washington.
Purpose: To develop a longitudinal database on captive
gorillas.
Sampling: 15 minute continuous focal-animal samples,
divided into 30, 30-second intervals, of all
behaviors; with location scans at 5 minute
intervals.
Ethogram key words:Activity budgets/General behaviors, Social
behavior, Sexual behavior, Development, Maternal behavior,
Display/Agonistic behavior, Vocalizations.
Behaviors: (Only an abbreviated ethogram is presented
here. A manuscript describing the full
ethogram, and detailing the data collection
process, is presented in Appendix 1.)
NonSocial Behaviors:
Locomotive Behaviors:
Quadrupedal:
Stand: On all four extremities.
Walk: Forward progression or backward motion.
Lateral walk: Forward progression with sideways deviation
(species characteristic).
Run: (Conventional definition.)
Tripedal stand/walk/
run: On three extremities.
Bipedal stand/walk/
run: On two lower extremities.
Sit: Buttocks in contact with ground or supported by
heels with the back vertical.
Handstand: (Conventional definition.)
Lie: Reclines on substrate.
Circle: Spin, roll, somersault in self play
(conventional definitions).
Climb: Movement up/over an object.
Jump: Vertical spring from substrate.
Fall: Tumbles abruptly from one position to another.
Hang: Suspended by one or both arms from elevated
surface.
Scoot: Swings legs between hand placement while in a
sitting posture.
Slide under: Squeezes beneath object in reclined position.
Self-directed Behaviors (while stationary):
Urinate/defecate:(Conventional definitions.)
Collect/discard stool:Manually gathers feces eats/or drops.
Cradle foot: While reclined, holds lower extremity in arm.
Self maintenance:Manual grooming of face and body.
Rest: Reclined with eyes closed.
Pat: Hit self with hand.
Regurgitate: Manually collects vomit, eats/or discards.
Shake: Repeatedly moves hand/or head in self play.
Adult self nurse:Mouths own nipple.
Food and/Environment Directed Behaviors:
Consume: Eat/drink.
Forage: Search for, uproot, tear off and/or pick up
edible items.
Chase birds: Rapidly following fleeing individual(s).
Pull/rock object:Manipulates object.
Pry: Attempts to open door/window with hand or
object.
Thread: Attempts to manually insert object through
opening.
Drape: Covers body part with bough or object (e.g.,
burlap).
Nest build: Arranges objects (straw, branches, burlap) in
rim around and/or under body.
Hold object(s): Supports objects in mouth or extremity(ies).
Lick/sniff: Tongue touch or smells object.
Shred object: Tears apart or peels object with hands or
mouth.
Rub: Touches object with back and forth motion.
Drop object(s): Releases object from mouth or extremity(ies).
Tool dig: Uses object to disturb substrate.
Lift/sift: Manually scoops soil and discards.
Brush substrate: Smooth and/or clear area with hand.
Look at/up: Eyes fixed on (environmental) object.
Noncontact Social Behaviors:
Facial displays:
Yawn: Tips head back, exposing mouth cavity fully or
partially while inhaling.
Attention: Active, direct or over-the-shoulder observation
of conspecifics/humans in area.
Relaxed face: Eyes neutral and mouth closed, surveys
environment and visible other(s) without
obvious attention.
Estrus gaze: Hard, fixed gaze by female conspecific toward
male conspecific.
Stare face: Head tipped slightly downward, eyes hard and
fixed. Lips pursed or curled back, may scream
or roar.
Uneasy face: Refrains from direct stare at other. May have
mouth tightly compressed and or head turned to
side.
Pout face: Lower lip pursed and protruding slightly.
Pulled down lip corners and hollow cheeks may
be seen.
Fear grimace: Head tilted slightly back, eyes darting back
and forth. Lips curled back at mouth corners,
exposing gums and teeth.
Sneer: Upper lip drawn back.
Head shake: Moves head back and forth.
Play/laughter face:Mouth open and corners rounded. Exposed
teeth and gums, and laughing motions without
vocalizations may be seen.
Vocalizations:
Roar: Sudden, loud outburst of low-pitch sounds from
open mouth.
Growl: Deep, guttural prolonged sound.
Pant: Repeated, rapid exhalations.
Bark: Dog-like sound.
Scream: Shrill, loud, prolonged sound.
Wraagh: Abrupt, monosyllabic explosion of loud sound.
Pig grunt: Series of short, rough guttural pig-like
sounds.
Belch: Soft, deep prolonged rumble.
Hoot: Series of distinct hoo-hoo sounds.
Chuckle: Series of raspy, successive expirations.
Sexual grunt: By male when copulation is averted/terminated
before fruition.
Raspberries: Lips extended, rapid exhalation.
Staccato grunt: Similar to pig grunt. Grunts emitted on
inhalation as well as exhalation.
Hoot-whine: High volume hoot with level dropping
considerably to a narrow band of prolonged
sound.
Postural displays:
Strut displays: Stiff quadrupedal stance, arms bent outward at
elbow (species characteristic). Frontal
oblique, or parallel variants.
Strut display w/motion:As defined above, while walking alone or
in parallel with other.
Running display: Bipedal or tripedal run with outswept arm (hand
holding object or empty).
Reach for: Extends extremity in direction of other.
Throw: Manually tosses object.
Catch: While stationary, grabs thrown object.
Arm swing: Sweeps arm out towards other.
Chest/body pound:Rapidly beats body with open, slightly cupped
hands.
Kick at: Rapidly extends hindlimb out and back in
direction of other.
Hit surface: Strikes substrate/structure with hand or
object.
Social forage: Coordinated foraging with other(s).
Social sniff: Explores body part, excreta or secretion of
other.
Wave: Flaps hand or arm in air.
Hand clap: Brings palms together rapidly.
Head jerk: Moves head quickly in direction of other.
Lunge: Rapid, short quadrupedal jump toward other.
Self protect: At approach of other, cowers, flinches or
blocks body with arm.
Approaches: Runs or walks to stationary other.
Leaves: Runs or walks from stationary other.
Chases: Behind other, both running.
Conflict intervention:Supports one of two (or more) disputing
others.
Leads/follows: In front of other, both walking.
Supplant: Concedes location to approaching other.
Proximity: Other in nearby location (within 30-60 cm).
Contact Social Behaviors:
Agonistic/play interactions:
Strike: Use of extremity in brief, sharp contact with
other; e.g., hit, poke, kick.
Grab: Manually seize other suddenly.
Wrestle: Grabs and hits other. May roll on ground, each
individual grappling, mouthing and slapping
other.
Mockbite: Teeth in contact with other without
penetration.
Bite: Seizes other with teeth.
Push/pull: Shoves away/draws other closer with extremity.
Steal: Grabs object from possession of other.
Body press: Uses chest to restrain crouched other.
Sexual interactions:
Present: Remains stationary with ano-genital area
towards other.
Probe: Explores genital area of other with hand or
mouth.
Probe avert: Activity that foils successful probe; sitting,
distraction, cowering, threatening, or exiting.
Mount: Assumes position for copulation dorsal-ventral,
ventral-ventral, or variation. Male may use
hind limb in restraint of female.
Mount avert: Activity that foils successful mount; sitting,
distraction, cowering, threatening, or exiting.
Copulation: (Conventional definition) with multiple
thrusts; may see ejaculatory pause.
Adult/young interactions:
Nurse: Suckles nipple(s) of female.
Nurse prevent: Activity that prevents young from nursing;
blocking nipple, nipping at, and/or pushing
away.
Hold infant: Support young against body with arm(s) while
stationary.
Hold/carry solicit:Young holds arms above head in proximity to
older other.
Carry infant: Supports young against body with hand/arm while
moving; variants (e.g., dorsal carry, leg
carry).
Pick up: Manually lifts young.
Release: Relinquishes hold on young.
Shift: Moves young to another position on body.
Retrieve: Pulls young back.
Shake: Abrupt manual movement of young.
Kidnap: Grabs young from other.
Infant cling: Young self-supported by holding onto other.
Drag infant: Manually pull infant while moving along
substrate.
Swing: Rhythmically moves suspended young by arms.
Other contact affiliative interactions:
Allogroom: Uses mouth/or hand to inspect/pick pelage of
other.
Social lick: Mouth to body part, excreta or secretion of
other.
Caress: Gently rubs mouth or hand over body part of
other.
Repose together: Sit or recline in contact with other.
Tickle: (Conventional definition.)
Kiss: Mouth briefly touches facial area of other.
Hug: Embraces other with arm.
Social climb: Ascends/or descends other.
Fall off: Loses hold on other.
Jump on/off: Abrupt ascent/descent of other.
Solicit: Begs food or object from other.
Offer: Extend food or object to other.
Mannchen, K. (1980). A method of analysis of the activity patterns
of lowland gorillas (Gorilla gorilla
gorilla) at the Miami Metro Zoo. Animal
Keepers' Forum, 465-471.
Purpose: To determine if there were differences in
behavior of 5 lowland gorillas.
Sampling: One/zero Hansen's checklist, 15 minute samples,
100 samples per gorilla.
Ethogram key words:Activity budgets/General behaviors.
Behaviors:
Activities:
On ground
Climbing
Elevated
Walking
Running
Sitting
Standing on all fours
Kneeling on elbows
Standing bipedally
Lying down
Yawning
Sleeping
Manipulating with hands
Manipulating with mouth
Wearing something on head
Drinking
Urinating
Eating
Bowel movement
Nesting
Grooming self
Social interactions:
Grooming another
Contact passive
Contact active
Playing
Transport
Nursing
Sexual responses:
Masturbation
Presenting
Copulation
Ejaculation
Initiating sexual encounter
Emotionally aggressive and submissive behaviors:
Thigh beating
Chest beating
Charging display
Tight lips
Strutting walk
Beating on objects
Throwing objects
Grinding teeth
Smashes object
Pucker hooting
Grumble
Staring
Chasing
Hitting
Grappling
Mock biting
Biting
Screaming
Coalitions
Turning of head
Head shaking
Cowering
Dominant supplanting
Subordinate supplanted
Abnormal behaviors:
Stereotyped rocking
Coprophagy
Regurgitation reingestion
Pacing
Maple, T. L. & Hoff, M. General Gorilla Ethogram.
Ethogram key words:Activity budgets/General behaviors, Social
behavior, Sexual behavior, Development, Maternal behavior,
Display/Agonistic behavior.
Behaviors:
Contact variables:
Ventro-ventral:Common usage.
Dorso-ventral:M dorsal, I ventral (i.e.,
back-ride position).
Ventro-dorsal:Vice-versa above.
Other contact:Any contact other than above or
"touch".
Proximate:Out of contact, within arm's
(Mother's) length of other.
Distant:Farther than one arm's length from the
other, less than 15 feet.
Far distant:Beyond 15 feet from other animal.
Hold:Animal clinging to another.
Touch:Momentary contact with hand (this
behavior is scored independently of other
contact variables).
Maternal behaviors:
Back ride:Infant riding on her mother's back,
"jockey style."
Hanging walk:Animals VV, mother walking
quadrupedally.
Tripedal walk:Mother holding infant with one
arm while walking.
Crutch walk:Infant in mother's lap, M move
using arms as crutches.
Protect:Save from possible harm; by retrieve,
crouching over infant, holding arm up, etc.
Retrieve:Move another animal into closer
contact.
Restrain:Prevent another from moving away.
Wean:Remove infant from nipple.
Punish:Mother preventing infant from moving
into closer position with her (includes pushing
animal into the ground).
Extended arm carry:Mother carrying infant away
from her body and off the ground.
Extended arm drag:Mother carrying infant away
from her body but along the ground.
Infant behavior:
Whimper
Scream
Nipple contact:Infant's mouth on mother's
nipple.
Struggle:Infant attempts to leave while mother
restrains.
Arm out:Infant holding arm out to mother (i.e.,
when mother moves away).
Crawl:Animal moving on hands and knees.
Individual behaviors:
Active play
Solitary play
Auto groom:Pick through own hair with fingers
and/or lips.
Self manipulation:As manipulate but
self-directed.
Eat
Defecate
Urinate
Postural/movement:
Lie
Sit
Squat
Quadrupedal stand
Quadrupedal walk
Bipedal stand
Bipedal walk
Bipedal walk w/support:Walking bipedally while
holding some supporting substrate.
Climb
Leave:Move from other.
Social approach:Move from Distant to Proximate.
Return:Move back into contact within 15 seconds
of leaving.
Follow:Moving after another animal.
Chase:Following another animal at a run
(usually in play).
Displace:Take another's place.
Retreat:Move away from another as it approaches
and follows.
Turn away:Turn bodily away from another as it
approaches.
Walk by:One animal walks by another, becoming
proximate or in contact only for a moment.
Crawl:Animal moving on hands and knees.
Stand with support:Animal standing bipedally
while holding some supporting substrate.
Perch:Animal off the ground and not moving
(i.e., lie on climbing apparatus).
Run
Gallop
Arm-in-arm:Hip hold. Animals walking
tripedally holding each other around the body
shoulder (arms entwined).
Play behaviors:
Initiate social play:Animal responsible for
beginning social play bout.
Passive social play:Less than whole body
involvement, often gentle rocking, mouthing, or
wrestling.
Active social play:Whole body involvement,
including rough wrestling, rolling, chasing.
Play hit:Animal standing or sitting and
repeatedly hitting another (usually during
active social play).
Side-by-side play:Parallel play - animals
proximate and both engaged as in active social
play.
Play movement:Attempted play imitation
(non-reciprocated).
Play face:Grin (teeth together, lips pulled
back over teeth).
Aggressive displays:
Cough:Vocal threat, usually in series of three
or more.
Quadrupedal stiff stance:Animal standing, stiff
manner, with elbows turned inward (in tension
situation).
Stiff walk:As above, but walking quadrupedally.
Head divert:Head turned away from object being
threatened.
Tight lip:Lips compressed together.
Lunge:Animal rushing at another in short, fast
run (without hit).
Lunge with hit:As above, including a hit with
hand or foot.
Chest beat:Slapping chest alternatively with
hands.
Wall beat:As above, but directed toward
inanimate object in the environment (i,e.,
wall, pole).
Ground slap:Thumping the ground with one or
both hands.
Vegetation:Plucking a piece of vegetation and
placing it between the lips (without chewing).
Hand clap
Throw vegetation:Tossing vegetation and/or rock
at beginning of lunge sequence.
Openmouth bared teeth:Lips pulled back over
teeth, mouth open.
Sexual behaviors:
Mount:Assume sexual position.
Thrust:Rhythmic pelvic movements against
another animal.
Penile erection
Genital examination:Animal manipulating
another's pelvic region with fingers and/or
mouth.
Present:Animal turning its hindquarters toward
another.
Other behaviors:
Manipulate:That is, rub, rock, pat, scratch,
turn, rock, bounce, etc., behavior directed
toward another.
Groom:Picking through another's hair with
fingers or lips.
Object examination:Examining objects in the
environment in any way except stare.
Social examination:Examining another with
fingers, feet, mouth, includes stare.
Confiscate food:Take food from another.
Confiscate object:Take object from another.
Confiscate infant:Animal gaining control of
infant from another (original animal may still
be in contact with infant).
Mouth:Excludes biting.
Stereotypy: Repetitive motions or vocalizations, or
abnormal maintenance of a posture, for which
there is no obvious biological significance.
Meder, A. (1985). Integration of hand-reared gorilla infants in a
group. Zoo Biology, 4, 1-12.
Purpose: To document the introduction and integration
processes of hand-reared gorilla infants into a
group.
Sampling: Period I: ad lib sampling
Period II: focal animal sampling for 5 hours
per 4 weeks.
Distances sampled at 5 minute intervals.
Contacts were noted.
Ethogram key words:Development, Introductions/Socialization.
Behaviors: (following Meder's dissertation, 1982)
Stand facing: Stand in front of partner quadrupedally and
look at him directly for several seconds.
Display: Specific behavior including stiff stance,
piloerection and tense lips, mostly combined
with further elements mentioned in Schaller
(1963) and Meder (1982).
Smell: Bring the nose very close to partner's body for
at least one second.
Genital investigation:Touch ano-genital region of partner with
finger or lips or smell it.
Touch with hand: Extend one hand toward partner and touch him
briefly.
Touch with body: Sideswipe partner while moving past him.
Run toward: Run in the direction of partner from a
distance.
Run after: Follow partner for several meters while
running.
Hit: Slap partner with one hand once.
Beat: Slap partner with both hands alternately.
Push: Press one hand against partner briefly.
Tear: Grasp partner and pull him briefly into
oneself's direction.
Play: Nonaggressive interaction with more than 3 s of
body contact and both partners participating
actively with such patterns as hit, push,
tear, hold, bump against partner, play-face
(mouth open widely, teeth not visible).
Back-ride: Rest on the back of partner, who is either
standing quadrupedally or walking or climbing,
for several seconds.
Meder, A. (1986). Physical and activity changes associated with
pregnancy in captive lowland gorillas (Gorilla
gorilla gorilla). American Journal of
Primatology, 11, 111-116.
Purpose: To quantitatively determine changes in social
behavior and locomotor activity in 5 lowland
gorillas.
Sampling methods: Frankfurt:
Whole group observed ad lib, as well as focal
animal sampling.
Stuttgart:
Focal animal sampling, nine 5 minute samples
per female, per observation block.
Ethogram key words:Activity budgets/General behaviors, Social
behavior, Pregnancy, Behavior during.
Behaviors: (following Meder's dissertation, 1982)
Long social play: Nonaggressive interaction with at least 10
seconds of body contact and with both partners
participating actively. Behavior patterns
included hitting, pushing, tearing, holding,
and bumping against the partner. The play face
(mouth open widely, teeth generally not
visible) was exhibited frequently.
Threat: Noncontact aggression consisting of a display
directed toward the partner: staring at him or
following him while showing the display posture
(stiff stance, piloerection, tense lips).
Social contact: Behaviors directed toward a group member by the
focal animal. This included all forms of
physical contact as well as threat. A new
contact was noted when at least three seconds
had elapsed since the last contact to the same
partner had been broken.
Locomotion: A move of the focal animal from one place to
another with at least three steps. A new
locomotion was noted when the female had rested
in one place for at least ten seconds.
Meder, A. (1990). Sex differences in the behaviour of immature
captive lowland gorillas. Primates, 31, 51-63.
Purpose: To investigate behavioural development of
immature gorillas and differences in terms of
sex and different rearing conditions.
Sampling methods: Scan sampling (1 minute intervals) was used for
all solitary and some social behaviors. All
social behaviors were observed with continuous
focal animal sampling. One observation block
consisted of 10 hours of scan sampling
distributed over the day and 5 hr of focal animal
sampling in the afternoon within one week.
Ethogram key words:Activity budgets/General behaviors, Development.
Behaviors: (not defined)(following Meder's dissertation, 1982)
115 behavior patterns were included, including:
Behavior of subject toward objects
Behavior toward own body
Behavior toward conspecifics
Behavior toward visitors
Locomotion
Body movements
Vocalizations
Location
Asleep
Nest building
Allogrooming
Self-grooming
Aggressive behavior:Biting, slapping, pushing, pulling.
Social contact
Play
Mitchell, R. W. (1989). Functions and social consequences of
infant-adult male interaction in a captive
group of lowland gorillas (Gorilla gorilla
gorilla). Zoo Biology, 8, 125-137.
Purpose: To investigate the behaviors of captive male
lowland gorillas to infant, of the infant to
the males, and of the infant's mother to the
behavior of the males and infant.
Sampling: Ad lib.
Ethogram key words:Development, Paternal behavior.
Behaviors:
Simple actions: The majority of simple actions described have
been "used in
other studies as undefined elements in
definitions of higher order action patterns, or
were presented without definition, so do not
require definition here" - see Estrada, 1984,
Tilford & Nadler, 1978.
Combinations of simple actions:
Dragging:When an animal grabbed an infant in
contact with its mother and ran while holding
onto the infant, thereby pulling both the
infant and its mother behind it.
Collecting:When an animal pulled or pushed,
toward itself, an infant.
Kidnapping:When an animal moved away with an
infant when the kidnapper was not the primary
caregiver.
Caressing:When an animal gently moved its hand
around the head of another animal.
Cuddling:When an animal embraced another
whereby at least one of the animals involved
had his or her arms around the other.
Episodes:A sequence of social actions that
occurs when one organism performs temporally
close social actions toward another organism.
Nadler, R. D., Collins, D. C., Miller, C., & Graham, C. E. (1983).
Menstrual
cycle patterns of hormones and sexual behavior in gorillas.
Hormones and Behavior, 17, 1-17.
Purpose: To investigate possibility that different
aspects of sexual activity might be
differentially associated with two hormone
peaks.
Sampling methods: 30 minute daily tests (midmorning and
midafternoon) of sexual behavior initiated on
the day after the first day of menses and for
each cycle continued to the next period of
menses. Tests consisted of introducing female
with male.
Ethogram key words:Sexual behavior.
Behaviors:
Copulation: Genital-genital contact, dorso-ventral or
ventro-ventral, accompanied by a series of
rhythmic pelvic thrusts executed by the male.
Male solicitations:Male approaches female, followed by male
pulling female toward him, preparatory to
covering the female.
Covering: Male, standing quadrupedally, assumes position
behind and above the female so as to
approximate their genitals, with or without
grasping the female's sides or hips, generally
in the dorso-ventral position.
Male display: Charge directed at or parallel to the female,
with or without prior chest- or wall-beating
and accompanied or not by hitting or kicking
the female.
Male success: Male solicitation that is followed by female
presenting.
Female presenting: Quadrupedal stance, ranging from legs extended
to crouching, in which female's genitals are
directed toward the male.
Male success index (MSI):Proportion of days on which male
solicitations were successful, multiplied by
100.
Female solicitation:Female approaches the male, followed by
presenting, but not preceded by male
solicitation or male display.
Female success: Female solicitation followed by copulation.
Female success index (FSI):Same but for females.
Attractivity, proceptivity, and receptivity: [Defined as according
to Beach (1976)].
Attractivity: Frequency of male solicitation
days.
Proceptivity: Frequency of female solicitation
days.
Receptivity: MSI.
Nadler, R. D. (1985). Sex-related behavior of immature wild
mountain gorillas. Developmental
Psychobiology, 19, 125-137.
Purpose: Providing data on sex-related behavior of
immature wild mountain gorillas, to supplement
Schaller's work.
Sampling methods: Ad lib sampling incidentally to a study of
mother-infant relations. All observed
sex-related behaviors were recorded, including
identity of participants, positions of bodies,
# of pelvic thrusts, other repetitive acts of
genital stimulation or the duration of such
behavior, and group activity at time.
Ethogram key words:Sexual behavior, Field study, Gorilla g.
beringei.
Behaviors:
Positions: Dorso-ventral or ventral-ventral.
Genital stimulation:Principally when animal executed thrusts
against the body of another, included all
positions. Episode defined as a single bout or
multiple bouts in which bouts occurred within a
few minutes of each other.
Thrusting: Rhythmic pelvic movements.
Ogden, J. J., Hoff, M., & Maple, T. L. Zoo Atlanta.
Purpose: To study enclosure utilization and general
patterns
of adaptation to new enclosures in lowland
gorillas.
Sampling method: 15 minute continuous focal samples of all
behaviors, with location scans at 15 minute
intervals.
Ethogram key words:Activity budgets/General behaviors, Social
behavior, Sexual behavior, Development, Maternal behavior,
Display/Agonistic behavior, Abnormal/Stereotypic behavior.
Behaviors:
Solitary behaviors [no actor/recipient]:
Stand:Includes bipedal and quadrupedal (note
bipedal in
comments if possible). (back legs are both
straight).
Locomote:Any moving of the animal's entire body
including walking, running [bipedal or quad].
Sit:Includes squat and leaning on one elbow.
Lie: Dorsally, ventrally, or on side (includes
lying with one shoulder touching ground, or
leaning ventrally on both elbows).
Climb
Autogroom:Pick through own hair with fingers
and/or lips.
Masturbation
Solitary play:Self-motion play.
Feed/forage:Manipulating the substrate or food
item while intermittently transferring items to
the mouth or chewing a food item. Note item
eating (i.e., browse, monkey chow, fruit, tree
branch). Includes drinking, but note if
drinking from stream or lixit.
Object manipulate:The handling of available
objects with hands, feet, or mouthing;
examining except stare. [Note: score this
category if sorting through straw or
manipulating branches/browse without movement
to mouth]. Note object being manipulated.
Carry/hold:The carrying or holding of object
with hands or feet. Either while locomoting
or while stationary. (Or carrying on back
while walking). Note object.
Social Behaviors - note actor/recipient:
Approach:Approach another to within one arm's
length.
Displace:Take place of other.
Move away:Move away from another, either from
within contact or within arm's length.
In contact:In contact with another, any
posture. Note posture.
Sexual behavior:Includes mount, insertion,
genital inspection, etc. Note in comment
section.
Social playMotion play; social play involving
object manipulation should be noted as SP/OM.
Groom-social:Pick through hair of other with
fingers and/or lips (excludes scratching).
Displays/Threats/Vocalizations: (note actor/recip where known]
Rumble/belch vocal.
Cough vocalization:Vocal threat; usually in
series of three or more.
Quad. stiff stance:Animal standing; stiff
manner; with elbows turned inward (in tension
situation).
Stiff walk:As above, but walking quadrupedally.
Tight lip:Lips compressed together.
Openmouth bared teeth:Lips pulled back over
teeth, mouth open.
Agonism:Includes biting, fighting, hitting,
slapping, lunge with hit; any aggression with
contact. Time interval between bouts of 15
seconds.
Lunge:Animal rushing at another in short, fast
run (without hit).
Chest beat:Slapping chest alternately with
hands (includes beating of thighs by females).
Wall beat:Beat/slap directed toward inanimate
object in environment (note object).
Ground slap:Thumping ground with one or both
hands.
Hand clap
Throw objectTossing object at beginning of
lunge sequence.
Abnormal Behavior (non-social; no actors/recip):
Self-biting:Usually of arms, legs, torso,
hands.
Self-clasping/Embracing, or use of hands or
feet to
self-grasping:hold onto a part of body.
Stereotyped pacing
Rocking:Often associated with self-clasping.
Coprophagia:Ingestion of fecal material (not
necessarily their own).
Regurgitation/
reingestion:Regurgitation and reingestion of
feeding matter.
Out of viewNote substrate if known, tunnel if
known.
OtherAny behavior of interest not listed here;
explain in comments.
Maternal/infant behavior:
Active social play:Whole body movement,
including rough wrestling, rolling, chasing.
Passive social play:Less than whole body
movement, often gentle rocking, mouthing or
wrestling.
Initiate play:Animal responsible for beginning
social play bout.
Retrieve:Retrieve another while moving away.
Remove:Move another into a lesser contact
(e.g., VV to OC).
Restrain:Prevent another from moving away.
Wean:Remove infant from nipple.
Social examination:Examining another with
fingers, feet, mouth; includes stare.
Nipple contact
Manipulate:Rub, rock, pat, scratch, turn, rock,
bounce, etc.; behavior directed toward other.
Self-manipulation:As manipulate only
self-directed.
Struggle:Infant attempts to leave while Mother
is restraining.
Contact Variables:
Ventro-ventral:Common usage.
Dorso-ventral:M dorsal, I ventral; i.e., back
ride position.
Ventral-dorso:As above, but vice-versa.
Other contact:Any contact other than above or
"touch".
Proximate:Out of contact, within arm's length.
Distant:Greater than arm's length but less than
15 feet.
Far distant:Greater than 15 feet from another
animal.
Maternal Transport:
Tripedal walk:Mother holding infant with one
arm while walking.
Hanging walk:Animals VV, mother walking
quadrupedally.
Extended arm drag/carry: Mother carrying infant
away from her body and along/or off the ground.
Back ride:Infant riding on mother's back,
"jockey style".
Crutch walk:Infant in mother's lap, M move
using arms as crutches.
Other transport
positions
Quiatt, D., Miller, L., & Cambre, R. (1986). Overt behavior
correlates
of menstruation and
ovulation in a lowland
gorilla. In D. M. Taub
and F. King (Ed.),
Current perspectives in
primate biology (pp.
32-41). New York: Van
Nostrand Reinhold.
Purpose: To investigate whether observations of social
behavior might help pinpoint ovulation
sufficiently to increase chances of successful
artificial insemination.
Sampling: Eight weeks of data collection, during each of
two summers. Most days 1 hour of observation
in the morning and 1 in the afternoon,
scheduled when gorillas were most active
(during 2 hours following morning feeding and 2
hours preceding afternoon feeding).
Frequencies/rates resulted.
Ethogram key words:Social behavior, Sexual behavior.
Behaviors:
Displacement: One individual "causes" another to move away
from the location he/she has been occupying.
The first may or may not replace the second in
space. Cause may be assumed from apparent
intent of the displacer (e.g., gaze or eye
aversion) or attentiveness of the displaced
individual. Rather than infer cause, and to
insure consistency, displacement recorded as
whole body movement of one individual which was
one or more feet away from the other, when the
other is in movement and has approached within
six feet.
Proximity: One individual moves to within arm's reach of
another and remains without other interaction
for at least 5 seconds. If the approached
individual moved off before 5 seconds was up,
we scored the behavior as "Displacement."
(Note the qualifier, "without other
interaction." This is what distinguished
"Proximity" as an observational unit.)
Contact: Any tactile communication other than
"Examination," e.g., touching, brushing,
hitting, sitting, lying in contact, etc.
Groom: No grooming of either animal occurred, so
eliminated this.
Examination: An inspection of one animal by another or a
self-inspection. Examinations involved
looking, touching, smelling, mouthing, and
combinations thereof.
Display: A stereotypical hammering of the chest with the
knuckles. We noted two levels of intensity:
(1) a low level, without accompanying
locomotion or other signs of agitation - 1 or 2
taps or a series of light taps (the displaying
individual might be sitting or lying), and (2)
a rapid series of forceful chest-pounding while
the displaying individual was standing and
perhaps locomoting. Many such displays were
directed toward spectators. If a display
involved contact with the window, we noted that
contact.
Riess, B. F., Ross, S., Lyerly, S. B., & Birch, H. G. (1949). The
behavior of two captive specimens of the lowland gorilla
Gorilla gorilla gorilla (Savage & Wyman). Zoologica, 111-118.
Purpose: To provide basic information on lowland
gorillas, comparable to that of Carpenter's.
Sampling: During three-minute periods of observation all
behaviors which occurred were checked. 30
minute observation periods. Sequences were
noted.
Ethogram key words:Activity budgets/General behaviors, Social
behavior.
Behaviors:
42 behaviors divided into the following five categories
Posture and locomotion:
Walking, pronograde
Walking, upright
Running, pronograde
Running, upright
Standing, pronograde
Standing, upright
Sitting
Climbing
Swinging by hands
Hanging
Sliding
Left-handedness
Right-handedness
Lying down
Sleeping
Nest building
Eating, drinking and elimination:
Gathering food in heaps
Sharing food with cage mate
Drinking water
Drinking milk
Regurgitation of milk
Handling of feces
Attention to urination
Self-oriented activity:
Self-manipulation (non-genital)
Manipulation of genitalia
Manipulation of objects
Manipulation of food (non-eating)
Attitude toward stream of water
Self-grooming
Inter-individual behavior:
Chasing
Wrestling
Grooming
Inspection and manipulation of genitalia
Presenting
Mounting
Pelvic thrusts
Chest thumping
Vocalizing
Dominance
Observer-oriented behavior:
Throwing of feces
Throwing of non-fecal material
Attentional responses
Vocalization
Schaller, G. (1963). The mountain gorilla: Ecology and behavior.
Chicago: University of Chicago Press.
Purpose: To provide the first systematic examination of
behavior of wild mountain gorillas.
Sampling methods: Ad lib field notes.
Ethogram key words:Activity budgets/General behaviors, Sexual
behavior, Social behavior, Display/Agonistic behavior,Field study,
Gorilla g. beringei.
Behaviors:A separate ethogram is not provided, but behavioral
descriptions
are integrated into the text. The reader is
referred to the book.
Schildkraut, D. & Akers, J. Boston MetroParks Zoos.
Purpose: To compile baseline and comparison data on a
pair of gorillas before and after their move
from Cincinnati Zoo to Stone Zoo.
Sampling methods: All occurrences.
Ethogram key words:Activity budgets/General behaviors, Social
behavior.
Behaviors:
Social behaviors:
Play:Wrestling, chasing, running past and
cuffing each other, gentle slapping and
grabbing, bipedal jostling (time + frequency).
Initiator listed first. Note: a play bout
must be separated by a 10 second interval or
another behavior to constitute another
frequency.
Groom:Animal mouths and manipulates the fur of
another.
Touch:Animals in contact when not engaged in
any other defined activity (time + frequency).
Initiator listed first.
Arm's length:Animal is within arm's reach of
another and not engaged in any other defined
activity (time + frequency). Initiator listed
first.
Displace:One animal approaches another, and the
2nd animal moves away before they are within
arm's reach (frequency). Initiator listed
first.
Fight:Rough hitting or biting accompanied by
screaming.
Self Behaviors:
Display:A single incidence of banging/kicking
doors and walls OR a series of events which
includes chest beating, stamping feet, running
and pulling chain, loud clapping. The display
is usually performed bipedally and ends in
running a short distance (frequency).
Self-groom:One animal mouths and manipulates
its own fur for more than 5 seconds
(frequency). Note: self-groom does NOT
include licking fingers during the process of
regurgitation and reingestion.
Self-play:Sliding on the floor when wet,
turning in circles on all fours, clapping
softly and shaking head or limbs, rolling on
back and slapping feet with hands, hanging
upside down from chain or ladder, squirting
self with water spout, grabbing hose from
keeper, putting food on head and "laughing",
swinging on ladder, somersaults, spitting into
hands or on floor, pushing food along the
floor, wiggling chain, standing on hands and
walking up the wall, sticking out tongue,
pushing food out of cage, self-tickling. AW =
a behavior typical of the female where she
scoots along the floor on her rear end for
short distances. The female also puts her
knuckles or fingers in her eyes and walks about
the cage "as if she were blind" (frequency).
Regurgitation andFood or fecal material is
eaten, regurgitated back into the
reingestion:hands or floor and eaten again
(frequency).
Cage change:Animal moves from cage I to cage II
through doorway (frequency).
Schildkraut, D. (a), Boston MetroParks Zoos.
Purpose: To determine the dominance relationship between
an adult male and female pair of gorillas, with
particular regard to its possible effect on
their breeding behavior.
Sampling methods: Frequency and sequential recording, three
ten-minute intervals per day.
Ethogram key words:Activity budgets/General behaviors, Social
behavior, Sexual behavior.
Behaviors:
Gigi crosses into Sam's exhibit
Sam sits and calls at Gigi's door
Grooming
Feeding/stealing/
bribing with food
Spatial displacement
Aggressive behavior:Such as hitting, biting, etc.
Threats: Specifically directed at the other gorilla -
not at staff or public.
Social encounters
Breeding
Schildkraut, D. (b), Boston MetroParks Zoos.
Purpose: Ethogram for introduction of three peer-raised
juvenile gorillas to a mother-infant pair.
Sampling methods: Frequency recording, one hour per day, five
days per week, over a twelve month period.
Ethogram key words:Introductions/Socialization, Social behavior,
Development, Maternal behavior.
Behaviors:
Self-directed behaviors:
Self-grooming
Sleeping
Sliding
Walking:Specify bipedal or quadrupedal.
Swinging
Spinning
Handstands
Hand clapping
Hand shaking
Eating
Urinating
Defecating
Object manipulation:Specify the object and
indicate how object is manipulated, i.e.
thrown, banged, put on head, etc.
Stare
R & R:Regurgitation and reingestion of food.
Coprophagy:Eating feces.
Noncontact social behaviors:
Quadrupedal straight leg stance
Open mouth threat
Chest beating
Bluff charges
Vocalizations
Approach:Move toward another animal.
Affiliate:Sits within one arm's length of
another.
Displace:One animal moves out of the way as
another approaches.
Contact social behaviors:
Wrestling
Tumbling
Charging with hitting
Chasing
Tickling
Hitting
Pushing
Biting
Mounting
Copulating
Grooming others
Sit/touch:Sits or reclines in contact with
another animal.
Mother/infant behaviors:
Nursing:Specify which breast (right or left).
Carrying:Specify v-v, v-d, d-v, arm, leg,
thigh, etc.
Retrieve:Mother retrieves infant.
Restrain:Mother prevents infant from leaving
her.
Struggle:Infant struggles to get away from
mother.
Other:
Follow:May be used when any animal follows
after another. Often seen in mother/infant
pairs.
Cage change:Used when introductions take place
to indicate that an animal has moved from one
cage to another.
Schildkraut, D. (c), Boston MetroParks Zoos.
Purpose: Observations on the behavior of an isolated
adult male gorilla.
Sampling methods: Frequency recording, three ten-minute periods
per day.
Ethogram key words:Activity budgets/General behaviors.
Behaviors:
Staring: Watching or looking at something.
Groom/body part: Specify part of body being groomed.
Slide on floor: Usually occurs when cage floor is wet.
Object manipulation
in quiet play: Playing with objects while in a stationary
position.
Object slapping: Beating or slapping on an object with hands or
feet - specify which he uses, and the object.
Bluff charges: Incomplete charges, specify target (i.e., zoo
keeper).
Charges with hitting:Usually hits the front glass or the side
walls. Specify target.
Sitting
Climbing
Running
Sleeping: Specify on floor or platform.
Eating
R & R: Regurgitation and reingestion.
Coprophagy: Eating feces.
Chest beating
Facial threat: Usually open mouth.
Threat vocalization
Threat stance
Schildkraut, D. (d), Boston MetroParks Zoos.
Purpose: Observations on the introduction of an adult
male/female pair.
Sampling methods: Positions mapped at beginning, after 5 min.,
and at end of observation period. All
occurrences of the following behaviors were
recorded, noting actor and recipient.
Ethogram key words:Introductions/Socialization.
Behaviors:
Full body display
Head display: Usually done from a sitting position.
Charge
Charge with slam
Lunge
Rattle/bang door: From a stationary position.
Approach door: Moving toward the door in a non-threatening
manner, i.e. not charging.
Sitting at door
Passing objects
through door
Physical contact: Touching the other animal.
Withdrawal from
door area
Display with chest
beating
Schildkraut, D. (e), Boston MetroParks Zoos.
Purpose: Gorilla Enclosure Utilization Checksheet.
Sampling methods: 15 minute continuous focal samples of all
behaviors, with scans at 15 minute intervals of
locations.
Ethogram key words:Activity budgets/General behaviors, Social
behavior, Sexual behavior, Development, Maternal behavior,
Display/Agonistic behavior, Abnormal/Stereotypic behavior.
Behaviors:
Same as those listed by Ogden, J. J., Hoff, M. and Maple, T. L.
with two additions:
Diarrhea
Ventral/ventral embrace
Smalley, S. L. (1979). Comparative analysis of aggressive and other
social behavior of captive lowland gorillas
and free living mountain gorillas.
California Anthropologist, 9, 1-28.
Purpose: To compare the interactions and behaviors of
captive gorillas to those of free living
mountain gorillas.
Sampling methods: Interactions were recorded during or
immediately after behavioral sequences. Group
was observed as a whole, interactions given
priority over solitary behaviors.
Ethogram key words:Activity budgets/General behaviors, Social
behavior, Display/Agonistic behavior, Field study, Gorilla g.
beringei.
Behaviors:
Aggression: For purposes of study defined as dominance: one
gorilla is considered dominant over another if
the first displaces the second, with or without
physical contact.
Other behaviors recorded (definitions unclear):
Feeding
Chestbeating
Self-grooming
Mutual grooming
Object carrying/holding
Running
Rising as part of a display
Rubbing of underarms
Copulation
Sexual presentation
Watts, D. P. (1988). Environmental influences on mountain gorilla
time budgets. American Journal of
Primatology, 15, 195-211.
Purpose: To investigate mountain gorilla time budgets
and the effect which characteristics of their
food supply and other ecological factors have
on them, including sex differences.
Sampling: Focal sampling to collect time budget data,
durations recorded.
Ethogram key words:Activity budgets/General behaviors, Field study,
Gorilla g. beringei.
Behaviors: (See also Watts, D. P. (1983). Foraging
strategy and socioecology of mountain gorillas.
Ph.D. Diss., University of Chicago.)
Feeding: Preparation and ingestion of food. Feeding
bouts began when a stationary individual,
either on arrival at a feeding spot or after
having engaged in some other activity there for
at least 5 seconds, started to prepare food for
ingestion (which included chewing). They ended
when the individual ceased preparation and
ingestion for at least five seconds or shifted
position by at least 1 m.
Moving: All locomotor activity other than shifts of
position of less than 1 m during feeding and
resting and locomotion during play.
Resting: Stationary, nonsocial behavior during which
animals were not feeding (sleeping,
autogrooming, etc.)
Social: Social interactions with a measurable duration,
including play, allogrooming, sexual behavior,
and some forms of agonistic behavior.
Other: Other subsistence behavior, including nest
building, and, for females, nursing. Because
it was usually impossible to be certain whether
a female was nursing when she had her back
turned, and because "other" activities occupied
only a tiny fraction of observation time, they
are not discussed below.
Watts, D. P. (1990). Mountain gorilla life histories, reproductive
competition and sociosexual behavior and
some implications for captive husbandry.
Zoo Biology, 9, 185-200.
Purpose: To draw implications from the data on wild
mountain gorillas to apply to captive
management and husbandry of captive lowland
gorillas.
Sampling: All occurrences sampling of below behaviors.
Ethogram key words:Sexual behavior, Field study, Gorilla g.
beringei.
Behaviors: (See also Watts, D. P. (1983). Foraging
strategy and socioecology of mountain gorillas.
Ph.D. Diss., University of Chicago.)
Sociosexual behavior:Heterosexual mounts with thrusting, with or
without intromission.
Copulations: Mounts in which one or both partners thrust and
positioning by both suggests that intromission
occurred.
Woods, S. Denver Zoo, Enrichment Study.
Purpose: Investigate effects of enrichment protocols and
general activities.
Sampling: Focal animal, behavioral checksheet.
Ethogram key words:Enrichment, Activity budgets/General behaviors.
Behaviors:
Aggressive interaction - with another gorilla:
Display threat
Physical attack
Chase
Displacement
Other -- urinate, ambiguous, etc.:
Drink
Sexual activity - mating attempts, solicit
Playful social interaction
No observation:
Not visible
Bad observation (cannot see behavior)
Stereotypic or undesirable behaviors:
Regurgitation/reingestion
Coprophagy
Masturbation
Self-grooming (must be manual and visual)
Manipulate:
Manipulate, investigate, With objects or
exhibit features (takes precedence over
play:public orientation).
Manipulation of
enrichment items
Travel:
Quadrupedal walking
Quadrupedal running
Climbing
Eat while traveling
(has priority)
Public orientation:
Intently watching
humans
Display: e.g., chest beating, charging, hitting
glass, baring teeth.
Gesturing: e.g., clap, treat sign.
Vocalizing: (can see chest vibrate).
Idle:
Sit or squat
Stand
Recline
Intently watching
another animal:(has priority)
Feed:
Foraging: Searching in or under hay, eating
hay, seeds, nuts.
Foraging while intently
watching public
Grass
Eating from enrichment
objects
Eating anything else
Eating while intently
watching public
Browse
Object contact:
Structural features: Walls, doorways, back
fence, front glass, platforms.
Furnishings: Trees, shelves, net, ropes, log,
rocks, poles.
Enrichment objects
Other portable objects
Outside: Includes doorway to outside yard.
Up: On shelves, trees, net.
Wood, G., Forthman, D. L., & Ogden, J. J. Ethogram for enrichment
study, Zoo Atlanta.
Purpose: To study general activity budgets with a focus
on
those behaviors likely to be affected by
presentation of enrichment items.
Sampling method: Group scans at 2 minute intervals, for hour long
observation periods.
Ethogram key words:Enrichment, Activity budgets/General behaviors,
Social behavior, Display/Agonistic behavior.
Behaviors:
Position and activity:
Lie: Dorsally, ventrally, or side (includes
lying with 1 shoulder touching ground, or
leaning ventrally on both elbows).
Sit:Includes squat and leaning on one elbow.
Stand:Includes bipedal and quadrupedal (back
legs are both straight).
Locomote:Any moving of the animal's entire body
including walking, running [bipedal or quad].
Climb:Climbing a substrate.
Hang/swing:Hanging or swinging from a
substrate.
Solitary behaviors:
Autogroom:Pick through own hair with fingers
and/or lips.
Object manipulate:Manipulating available
non-food item with hands, feet, or mouth: e.g.,
branches, rocks, or bark (if not attempting to
eat such items).
Carry/hold:Carrying or holding a non food item
with hands, feet, or draped across back.
Either while locomoting or stationary.
Solitary play:Self-motion play.
Masturbation:Manipulating genitals.
Social Behaviors - note actor/recipient:
Proximity:Within one arm's length to another
group member.
Social contact:In contact with another group
member.
Social groom:Pick through another's hair with
fingers or lips.
Social play:Includes all motion social play
behaviors: chase, somersault, hit, etc.
Sex:Includes mount, insertion, genital
inspection, etc.
Displays/Threats:
Quad. stiff stance:Animal standing; stiff
manner; with elbows turned inward (in tense
situation).
Stiff walk:As above, but walking quadrupedally.
Tight lip:Lips compressed together.
Bared teeth/openmouth:Mouth open with lips
pulled back over teeth.
Agonism:Aggression with contact, including:
biting, fighting, hitting, slapping, and lunge
with hit.
Lunge:Animal rushes at another (without hit).
Chest beat:Slapping chest alternately with
hands (includes beating of thighs by females).
Wall beat:Beat/slap wall or other substrate.
Throw object:Throwing an object, frequently
exhibited before lunge.
Abnormal Behavior:
Self-biting:Usually of arms, legs, torso,
hands.
Self-clasping/Self-embracing, or holding onto a
body part.
self-grasping:
Stereotyped pacing:Pacing, walking in circles.
Rocking:Often associated with self-clasping.
Coprophagia:Ingestion of any fecal material.
Regurgitation/
reingestion:Regurgitation and reingestion of
feeding matter.
Out of view:Note substrate if known, tunnel if
known.
Other:Any other behavior of interest not
listed.
Feeding behavior:
Carry/hold food:Carry or holding food or
enrichment item. Note item.
Foraging:Gathering and collecting food items.
Note item.
Process food:Processing, preparing, stripping,
peeling, seek, remove pith, sucking, husking,
and chewing. Some processing may take place
inside the buccal cavity (e.g., peeling). Note
item.
Yamagiwa, J. (1986). Activity rhythm and the ranging of a solitary
male mountain gorilla (Gorilla gorilla
beringei). Primates, 27, 273-282.
Purpose: Description of activities, ranging behavior and
responses to neighboring groups by a lone male
gorilla.
Sampling
(of behavioral info): Focal sampling, each activity was scored in
every 10 minutes by 10 second observations.
Ethogram key words:Activity budgets/General behaviors, Field study,
Gorilla g. beringei.
Behaviors:
Feeding
No move
Locomotion
Others:
Chest-beating display?
INDEX
Abnormal/Stereotypic behavior 7, 27, 48, 54, 92, 107
Activity budgets/General behaviors 3, 7, 25, 27, 37, 50, 54, 73, 79,
81, 87, 88, 92, 97, 99, 100, 102, 105, 107, 108, 109, 113, 115
Birthwatch 46
Development 5, 27, 41, 52, 70, 72, 73, 81, 86, 88, 89, 92, 103, 107
Display/Agonistic behavior 7, 27, 38, 54, 73, 81, 92, 99, 107, 108,
113
Enrichment 111, 113
Environment change, Influence of 25, 48
Field study1 37, 39, 41, 45, 67, 68, 69, 91, 99, 108, 109, 110, 115
Gorilla g. beringei 37, 39, 41, 45, 67, 68, 69, 91, 99, 108, 109,
110, 115
Introductions/Socialization 38, 54, 86, 103, 106
Maternal behavior 27, 73, 81, 92, 103, 107
Noise disturbance, Effects of 50
Paternal behavior 89
Post-occupancy evaluation 7, 48
Pregnancy, Behavior during 41, 87
Sexual behavior 7, 27, 45, 54, 73, 81, 90, 91, 92, 96, 99, 102, 107,
110
Social behavior 3, 7, 26, 27, 54, 67, 68, 69, 73, 81, 87, 92, 96,
97, 99, 100, 102, 103, 107, 108, 113
Vocalizations 27, 39, 54, 73
1 Studies not designated as field studies were conducted in
captivity.
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