PRIMATE SCIENCE RESEARCH HIGHLIGHT
Nov. 5, 1999

"Vervet monkeys get the 'word' out"
by Kristin Cook, editorial intern, Wisconsin Regional Primate Research Center

Studies of alarm calls in vervet monkeys have suggested animals can convey
specific messages in their calls, an accomplishment long thought to be
uniquely human, reports the Sept. 12, 1998 issue of Science News.

Research by Robert M. Seyfarth and Dorothy L. Cheney of the University of
Pennsylvania in Philadelphia and Peter R. Marler of the University of
California, Davis, suggests vervet monkeys give different alarm calls when
different predators are near. The researchers played recordings of
different alarm calls. The monkeys responded by looking up for eagle
alarms, looking down for snake alarms and running to safety for leopard
alarms.

More recent studies involving vervet monkeys have explored how young
vervets learn to associate different alarm calls with different predators.
Adult vervets use alarm calls mainly in response to leopards, eagles and
snakes. Young vervet monkeys, on the other hand, tend to use alarm calls
for harmless objects. The vervet infants sound eagle alarms for objects in
the air, even if they are harmless birds or falling objects.

Marc D. Hauser of Harvard University, suggests that young vervets may be
using alarm calls to question whether an object falling from the sky or an
object moving along the ground is potentially harmless. Hauser reported
that vervets who sound a generally appropriate alarm, resulting in much
commotion among the adults, are more likely to call out the correct alarm
next time, when an eagle is actually sighted, than are young vervets who
call inappropriately. Researchers are performing further investigations
into how experience and age improves predator identification and
classification.

Additional research by Dr. Hauser suggestes that vervet monkeys display
characteristics of a "language universal" in their speech.  According to
Hauser, the rapid fall at the end of an utterance signals the ending of a
particular declaration. This is called the declination of the fundamental
frequency and is widespread across languages in human speech. Hauser has
suggested that vocalizations in vervet monkeys show clear evidence of a
final fall, which coincides with the tendency of human vocalizations to
possess a final fall. This discovery further supports the theory that
animal, at least nonhuman primate vocalizations, are more similar to human
communications than we may think.

More research in the area of vervet alarm calls is being performed in order
to figure out what messages are conveyed in alarm calls and how those
messages are involved in animal communication. Further research into animal
communication can provide valuable insight into the evolution of human
cognition.

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Reference: Milius, S. The Science of Eeeeek! What a Squeak Can Tell
Researchers About Life, Society, and All That. Science News. September 12,
1998. pp 174-175.

Seyfarth, R.M., Cheney, D.L., Marler, P. Monkey Responses to Three
Different Alarm Calls: Evidence of Predator Classification and Semantic
Communication. Science. November 14, 1980. pp 801-803.

Hauser M.D. Fundamental Frequency Declination is Not Unique to Human
Speech: Evidence From Nonhuman Primates. Journal of Acoustic Society of
America. January 1992. pp 363-369.



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Primate-Science Research Highlights appears every other week and focuses
broadly on research involving non-human primates. Coverage includes
biomedicine, behavior, conservation and veterinary science. Please
submit highlights for this column to Larry Jacobsen, Primate-Science Research
Highlights editor, at jacobsen@primate.wisc.edu. A 300-word limit and
lay-language style are recommended. Primate-Science Research Highlights are
supported by a grant from the National Institutes of Health,
National Center for Research Resources.  Copyright 1999,
Wisconsin Regional Primate Research Center. No portion of this highlight
may be copied or redistributed without the consent of the editor.

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