摘要:

Because of their small body size, tamarins are potentially vulnerable to a wide range of predator species. This paper examines the general patterns of predator avoidance of the Avila-Pires saddle-back tamarin (Saguinus fuscicollis avilapiresi) and the red-cap moustached tamarin (Saguinus mystax pileatus) in the upper Urucu river, Amazonas, Brazil. One highly stable mixed-species group of these species suffered an average of 1 attack by carnivorous raptors every 8.8 days of activity. Although none of these attacks was successful, tamarins occasionally fall prey to raptors or terrestrial predators. The two tamarin species exhibited a high degree of coordination in their anti-predation tactics. Saddle-back tamarins accounted for most of the vigilance and detection of terrestrial and scansorial threats, whereas moustached tamarins scanned for and detected most aerial and arboreal threats. Of the two species, however, moustached tamarins contributed a significantly greater proportion of scanning time after predation attempts, during pre-retirement periods and at other times. Moreover, their substantially larger groups (1.6 times larger than those of saddle-back tamarins) accounted for a further increase in their effective vigilance effort. The anti-predation benefits gained by saddle-back tamarins from joining mixed-species groups with moustached tamarins thus appeared to be greater than the reverse, because the latter provide greater protection to the group, particularly against aerial sources of threat. However, the greater vigilance of saddle-back tamarins towards potential terrestrial predators cannot be discounted, because these may on rarer occasions pose a real threat to either species. Collective protection against predators may thus represent an important factor maintaining the widespread and bilaterally reinforced interspecific associations observed with Amazonian tamarins.

ISSN:0015-5713    

DOI:10.1159/000156732

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Interactions between tourists and Barbary macaques (Macaca sylvanus) at Queen’s Gate, Gibraltar, are described. Interaction rates are high, with 99.6 interactions/h at peak times. Macaques spend 13.2% of their day interacting with tourists and 41.9% inactive. An overall ratio of 3.2:1 between human-initiated and macaque-initiated interactions was found. Of interactions involving humans, 85% concerned tourists. Diurnal activity patterns of the macaques were adapted to tourist visitation patterns. Old animals initiated more food-related interactions than younger ones. Infants/juveniles were the commonest class in contacts with humans and vehicles. Interactions involving more than one macaque were rare. High interaction rates were recorded for mothers and babie

ISSN:0015-5713    

DOI:10.1159/000156733

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156734

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156735

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156736

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156737

出版商:S. Karger AG    

年代:1993

数据来源: Karger