Age differences in the responses to adult and juvenile alarm calls by bonnet macaques (Macaca radiata)

Citation
U. Ramakrishnan et Rg. Coss, Age differences in the responses to adult and juvenile alarm calls by bonnet macaques (Macaca radiata), ETHOLOGY, 106(2), 2000, pp. 131-144
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences","Neurosciences & Behavoir
Journal title
ETHOLOGY
ISSN journal
0179-1613 → ACNP
Volume
106
Issue
2
Year of publication
2000
Pages
131 - 144
Database
ISI
SICI code
0179-1613(200002)106:2<131:ADITRT>2.0.ZU;2-7
Abstract
This study examined the differential responses to alarm calls from juvenile and adult wild bonnet macaques (Macaca radiata) in two parks in southern I ndia. Field studies of several mammalian species have reported that the ala rm vocalizations of immature individuals are often treated by perceivers as less provocative than those of adults. This study documents such differenc es in response using field-recorded playbacks of juvenile and adult alarm v ocalizations. To validate the use of playback vocalizations as proxies of n atural calls, we compared the responses of bonnet macaques to playbacks of alarm vocalizations with responses engendered by natural alarm vocalization s. We found that the frequency of flight, latency to flee, and the frequenc y of scanning to vocalization playbacks and natural vocalizations were comp arable, thus supporting the use of playbacks to compare the effects of adul t and juvenile calls. Our results showed that adult alarm calls were more p rovocative than juvenile alarm calls, inducing greater frequencies of fligh t with faster reaction times. Conversely, juvenile alarm calls were more li kely to engender scanning by adults, a result interpreted as reflecting the lack of reliability of juvenile calls. Finally, we found age differences i n flight behavior to juvenile alarm calls and to playbacks of motorcycle en gine sounds, with juveniles and subadults more likely to flee than adults a fter hearing such sounds. These findings might reflect an increased vulnera bility to predators or a lack of experience ill young bonnet macaques.