Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany.
Center for Adaptive Rationality, Max Planck Institute for Human Development, Berlin, Germany.
Nat Ecol Evol. 2018 Oct;2(10):1610-1618. doi: 10.1038/s41559-018-0658-4. Epub 2018 Sep 3.
Individual foraging is under strong natural selection. Yet, whether individuals differ consistently in their foraging success across environments, and which individual- and population-level traits might drive such differences, is largely unknown. We addressed this question in a field experiment, conducting over 1,100 foraging trials with subpopulations of guppies, Poecilia reticulata, translocated across environments in the wild. We show that individuals consistently differed in reaching and acquiring food resources, but not control 'resources', across environments. Social individuals reached and acquired more food resources than less-social ones and males reached more food resources than females. Yet, overall, individuals were more likely to join females at resources than males, which might explain why individuals in subpopulations with relatively more females reached and acquired, on average, more food resources. Our results provide rare evidence for individual differences in foraging success across environments, driven by individual- and population-level (sex ratio) traits.
个体觅食受到强烈的自然选择。然而，个体在不同环境中的觅食成功率是否存在一致的差异，以及哪些个体和种群特征可能导致这种差异，在很大程度上尚不清楚。我们在一个野外实验中解决了这个问题，该实验对跨越环境的 1100 多次食性试验进行了研究，试验对象是丽鱼科鱼，也就是俗称的孔雀鱼的一个亚种 Poecilia reticulata。我们发现，个体在不同环境中始终存在获取食物资源的差异，但在控制“资源”方面没有差异。社交个体比非社交个体获取更多的食物资源，雄性比雌性获取更多的食物资源。然而，总体而言，个体更有可能选择雌性个体而不是雄性个体作为食物资源的获取对象，这可能解释了为什么在具有相对更多雌性个体的亚种群中，个体平均能够获得和获取更多的食物资源。我们的研究结果提供了在不同环境中觅食成功率存在个体差异的罕见证据，这是由个体和种群（性别比例）特征驱动的。
