Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany.
Department of Evolutionary Ecology, Leibniz-Institute of Zoo and Wildlife Research, Berlin, Germany.
J Anim Ecol. 2019 Dec;88(12):1950-1960. doi: 10.1111/1365-2656.13086. Epub 2019 Sep 9.
Responding to the information provided by others is an important foraging strategy in many species. Through social foraging, individuals can more efficiently find unpredictable resources and thereby increase their foraging success. When individuals are more socially responsive to particular phenotypes than others, however, the advantage they obtain from foraging socially is likely to depend on the phenotype composition of the social environment. We tested this hypothesis by performing experimental manipulations of guppy, Poecilia reticulata, sex compositions in the wild. Males found fewer novel food patches in the absence of females than in mixed-sex compositions, while female patch discovery did not differ regardless of the presence or absence of males. We argue that these results were driven by sex-dependent mechanisms of social association: Markov chain-based fission-fusion modelling revealed that less social individuals found fewer patches and that males reduced sociality when females were absent. In contrast, females were similarly social with or without males. Our findings highlight the relevance of considering how individual- and population-level traits interact in shaping the advantages of social foraging in the wild.
对他人提供的信息做出反应是许多物种的一种重要觅食策略。通过社会觅食，个体可以更有效地找到不可预测的资源，从而提高觅食成功率。然而，当个体对某些表型比其他表型更具有社交反应性时，他们从社交觅食中获得的优势可能取决于社交环境的表型组成。我们通过在野外对孔雀鱼（Poecilia reticulata）的性组成进行实验操纵来检验这一假设。与混合性别组成相比，雄性在没有雌性的情况下找到的新食物斑块较少，而雌性无论是否有雄性存在，其发现斑块的情况都没有差异。我们认为这些结果是由依赖于性别的社会关联机制驱动的：基于马尔可夫链的分裂-融合模型表明，社交性较低的个体发现的斑块较少，而且当雌性不存在时，雄性会减少社交性。相比之下，雌性无论有无雄性存在，其社交性都相似。我们的研究结果强调了考虑个体和种群水平特征如何相互作用以塑造野生社交觅食优势的重要性。
