Department of Biology, University of Maryland, College Park, Maryland, USA.
Am J Primatol. 2011 Sep;73(9):852-60. doi: 10.1002/ajp.20952. Epub 2011 Mar 31.
Forming interspecific associations is one of many strategies adopted by primates in order to avoid predation. In addition to improved predator detection and avoidance, benefits of interspecific associations relate to improved foraging efficiency. In this study we tested these two hypotheses explaining associations between the endangered golden-headed lion tamarin, Leontopithecus chrysomelas and the sympatric Wied's marmoset, Callithrix kuhlii. We estimated predation risk by recording the number of encounters between lion tamarins and potential predators in cabruca agroforest (shaded cacao plantation) and in mosaic forest (a mix of cabruca, primary and secondary forest). To evaluate if the association between the two species was related to foraging benefits we recorded the number of associations between the two species when the lion tamarins were eating and when they were not eating. To test if the association occurred to improve predator detection and avoidance, we evaluated if associations between the species were more frequent in areas with higher predation risk and during the part of the day when predation risk is higher. We also compared the number of associations 3 months before birth events and 3 months after, when the lion tamarins are more susceptible to predation. Predation risk, mainly by raptors, was significantly higher in cabruca than in mosaic forest (0.17 and 0.05 encounters with predators per hour of observation, respectively). Associations were significantly more frequent after birth events and during the part of the day when predation risk was also higher (5-6 am until noon). We did not observe any direct evidence of foraging-related advantages of interspecific associations for the lion tamarins. The tamarins did not associate more when they were foraging. Our findings suggest that lion tamarins are more exposed to predation in cabruca than in mosaic forest and associations between lion tamarins and Wied's marmosets are related to predation avoidance.
形成种间联系是灵长类动物为了避免被捕食而采用的多种策略之一。除了提高对捕食者的检测和避免能力外，种间联系的好处还与提高觅食效率有关。在这项研究中，我们测试了这两个假设，以解释濒危的金头狮狨（Leontopithecus chrysomelas）和同域分布的黄头黑白柽柳猴（Callithrix kuhlii）之间的联系。我们通过记录狮狨与潜在捕食者在 cabruca agroforest（遮荫可可种植园）和 mosaic forest（cabruca、原生林和次生林的混合）中的相遇次数来估计捕食风险。为了评估这两个物种之间的联系是否与觅食利益有关，我们记录了当狮狨在进食时和不进食时这两个物种之间的联系次数。为了测试这种联系是否发生以提高对捕食者的检测和避免能力，我们评估了在捕食风险较高的地区以及在捕食风险较高的一天中的那个时间段，物种之间的联系是否更频繁。我们还比较了出生事件前 3 个月和出生后 3 个月的联系次数，因为此时狮狨更容易受到捕食。在 cabruca 中，狮狨面临的捕食风险（主要来自猛禽）明显高于 mosaic forest（观察每小时与捕食者相遇的次数分别为 0.17 和 0.05）。出生事件后，以及捕食风险较高的时间段（上午 5 点至中午 12 点），联系更加频繁。我们没有观察到狮狨之间种间联系与觅食相关的任何直接优势。当狮狨觅食时，它们的联系并不多。我们的研究结果表明，狮狨在 cabruca 中比在 mosaic forest 中更容易受到捕食，而狮狨和 Wied 的狨猴之间的联系与避免捕食有关。
