Pérez-Cembranos Ana, Pérez-Mellado Valentín
Department of Animal Biology, Universidad de Salamanca, Campus Miguel de Unamuno, s/n., 37007, Salamanca, Spain,
Anim Cogn. 2015 May;18(3):629-37. doi: 10.1007/s10071-014-0831-3. Epub 2014 Dec 21.
Even in solitary foragers, conspecifics can provide reliable information about food location. The insular lizard Podarcis lilfordi is a solitary species with high population densities that sometimes aggregate around rich food patches. Its diet includes novel and unpredictable resources, such as carcasses or plants, whose exploitation quickly became widespread among the population. We tested the use of social information by lizards through some field experiments in which they had to choose one of the two pieces of fruit. Probably due to local enhancement, lizards preferred to feed on the piece of fruit where conspecifics or lizard-shaped models were already present. Conspecifics' behaviour, but also their mere presence, seems to be a valuable source of information to decide where to feed. Lizards also showed a strong attraction to conspecifics, even in the absence of food. Maybe the presence of a group is interpreted as an indirect cue for the presence of food. The group size was not important to females, but males had a significantly higher attraction towards groups with three conspecifics. We discuss some characteristics of P. lilfordi at Aire Island that can explain the development of the observed social foraging, as well as their possible consequences.
即使在独居觅食者中，同种个体也能提供有关食物位置的可靠信息。伊维萨岛蜥蜴（Podarcis lilfordi）是一种独居物种，种群密度较高，有时会聚集在丰富的食物斑块周围。其饮食包括新奇且不可预测的资源，如尸体或植物，对这些资源的利用很快在种群中广泛传播。我们通过一些野外实验测试了蜥蜴对社会信息的利用情况，在实验中它们必须从两片水果中选择其一。可能由于局部增强效应，蜥蜴更喜欢在已经有同种个体或蜥蜴形状模型存在的那片水果上取食。同种个体的行为，甚至仅仅是它们的存在，似乎都是决定在哪里觅食的宝贵信息来源。蜥蜴即使在没有食物的情况下也对同种个体表现出强烈的吸引力。也许群体的存在被视为食物存在的间接线索。群体大小对雌性蜥蜴不重要，但雄性蜥蜴对有三个同种个体的群体吸引力显著更高。我们讨论了伊维萨岛伊维萨岛蜥蜴的一些特征，这些特征可以解释观察到的社会觅食行为的发展及其可能产生的后果。
