Taraborelli Paula, Moreno Pablo, Torres Maria E Mosca
EEA BARROW, Centro Regional Buenos Aires Sur, INTA and CONICET, CC 50- CP 7500, Buenos Aires, Argentina.
Grupo de Investigaciones de la Biodiversidad (GIB), IADIZA, CCT-Mendoza, CONICET, CP 5500, Mendoza, Argentina.
Behav Processes. 2019 Oct;167:103914. doi: 10.1016/j.beproc.2019.103914. Epub 2019 Jul 23.
Group vigilance is a cooperative behaviour in social species that reduces individual risk of predation. Lama guanicoe is a social species of camelid performing cooperative vigilance, but little is known about the vigilance behaviour of different social units. We analysed the vigilance behaviour in different types of social units of L. guanicoe, to better understand the complexity of this behaviour. The best supported models for both the frequency of vigilance and the proportion of time vigilant included the type and size of social units as the most important predictors that affect the vigilance behaviour. Solitary males devoted proportionally more time in vigilance behaviour than family, mixed or bachelor groups, whereas females in female groups spent more time vigilant than guanacos in mixed groups. Frequency of vigilance was higher in family individuals and solitary males than in bachelor or mixed groups. It is likely that that in family and females groups, the presence of offspring would increase the vigilance behaviour to detect possible predators. Topography and habitat characteristics that determine the predation risk, affected vigilance behaviour of mixed groups and solitary males. Our results suggest that vigilance behaviour should not be generalized for this species, since there are differences between the types of social units, probably related to intrinsic characteristics of each one and the perception of risk.
群体警戒是群居物种中的一种合作行为，可降低个体被捕食的风险。原驼是一种具有合作警戒行为的群居骆驼科动物，但对于不同社会单位的警戒行为知之甚少。我们分析了原驼不同类型社会单位的警戒行为，以更好地理解这种行为的复杂性。对于警戒频率和警戒时间比例，得到最佳支持的模型都将社会单位的类型和规模列为影响警戒行为的最重要预测因素。独居雄性在警戒行为上投入的时间比例比家庭群体、混合群体或单身群体更多，而雌性群体中的雌性比混合群体中的原驼花更多时间警戒。家庭个体和独居雄性的警戒频率高于单身或混合群体。在家庭群体和雌性群体中，后代的存在可能会增强警戒行为以发现潜在捕食者。决定捕食风险的地形和栖息地特征影响了混合群体和独居雄性的警戒行为。我们的结果表明，该物种的警戒行为不应一概而论，因为不同社会单位类型之间存在差异，这可能与每个单位的内在特征以及对风险的认知有关。
