Abstract
This study analyzed the contexts of three types of agonistic calls (Growl, Threat rattle, Vibrato growl) in Formosan macaques and their responses to predators and alarm calls at Mt. Longevity. Under natural condition, 112 five-minute scan samplings and 100 twenty-minute behavior samplings were collected to record agonistic behaviors and agonistic calls of macaques. In addition, 11 dog-presence tests and 102 playback experiments were successfully conducted from January 2003 to April 2004.
Of 385 agonistic events, 61.8% comprise of vocal bouts contained units belonging to single type of agonistic calls, and 31.8% bouts were mixed units contained more than one type of agonistic calls. Among these three single types of agonistic calls, Vibrato growl was used most frequently during conspecific interactions (44.3%); Threat rattle was used toward human (51.7%) and dogs (94.4%). During intraspecies conflicts of macaques, the vocal rates of three single type agonistic calls decreased from adult males, adult females and juveniles to infants. The average units per bout of Growl was higher than that of Threat rattle and Vibrato growl (p<0.0002). However, the agonistic interactions explain the different functions of the three types of agonistic calls. Growl was frequently accomplished with chase of callers (45.6%), while flee was usually expressed by receivers (57.9%). When monkeys uttered Threat rattle or Vibrato growl, open mouth threat was the most frequent behavior expressed by callers (80.5% and 73.1%), while evade was most frequent behavior expressed by receivers (43.9% and 31.9%). Growl conveyed messages about intense callers and contexts, and receivers avoided damage through fleeing. These results support Smith (1981) hypothesis referential signal carry information about external objects, contexts or a caller internal state as reflected in the probability of its subsequent behavior pattern. Receivers are able to attribute a certain meaning and express appropriate responses by the combination of signal structure and the context in which they are exposed the call.
Six different acoustic features of alarm calls existed between adult males and juvenile males. Alarm calls from Juveniles have higher Maximal, Median and Modulation Fundamental Frequencies than from adult males (p<0.0001). But alarm calls from juveniles have lower Highest Frequency, Total Range of Frequency and Duration of each Unit than from adult males (p<0.005). The results support current theory that the duration and fundamental frequency reflect body size.
In the playback experiments, macaques responded stronger to alarm calls from adult males than from juvenile males (p<0.0001). The average response score of macaques toward alarm calls from playback experiments was highest from infants, followed by juveniles, adult females and adult males. Adult macaques often responded to playbacks by looking in the direction of the loudspeaker. Juveniles and infants most often responded to playback calls by escape and startle. In playback experiments of alarm calls from adult males, F troop had significant different responses in three different places, strongest in the unfamiliar place (p<0.0001). The presents of dog elicited macaques with stronger responses than playback of dog barks (p<0.0001).
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0902104-141126 |
| Date | 02 September 2004 |
| Creators | Chuang, Chih-wen |
| Contributors | M. J. Hsu, G. Agoramoorthy, H. W. Chang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0902104-141126 |
| Rights | restricted, Copyright information available at source archive |
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