Department of Psychology, University of Tennessee, Knoxville TN, USA.
Department of Ecology &Evolutionary Biology, University of Tennessee, Knoxville TN, USA.
Sci Rep. 2017 Feb 23;7:43014. doi: 10.1038/srep43014.
Mixed-species groups are common and are thought to provide benefits to group members via enhanced food finding and antipredator abilities. These benefits could accrue due to larger group sizes in general but also to the diverse species composition in the groups. We tested these possibilities using a novel feeder test in a wild songbird community containing three species that varied in their dominant-subordinate status and in their nuclear-satellite roles: Carolina chickadees (Poecile carolinensis), tufted titmice (Baeolophus bicolor), and white-breasted nuthatches (Sitta carolinensis). We found that chickadees and titmice were more likely to obtain seed from the novel feeder with greater diversity of species composition in their mixed-species flocks. For successful chickadee flocks, furthermore, the latency to obtain seed from the novel feeder was shorter the more diverse their flocks were. These results in a natural setting indicate that diversity, per se, can benefit individuals in mixed-species groups in biologically meaningful contexts such as finding food in novel places.
混合物种群体很常见，人们认为它们通过增强食物寻找和抗捕食能力为群体成员带来益处。这些好处可能源于更大的群体规模，但也可能源于群体中不同物种的组成。我们在一个包含三个物种的野生鸣禽群落中使用一种新颖的喂食器测试来检验这些可能性，这三个物种在其支配-从属地位和核-卫星角色方面存在差异：卡罗莱纳山雀（Poecile carolinensis）、绒冠山雀（Baeolophus bicolor）和白胸吸汁雀（Sitta carolinensis）。我们发现，山雀和绒冠山雀在混合物种群体中，其物种组成的多样性越大，就越有可能从新型喂食器中获取种子。此外，对于成功的山雀群体，它们的群体多样性越大，从新型喂食器中获取种子的潜伏期就越短。这些在自然环境中的结果表明，多样性本身可以在寻找新地方的食物等具有生物学意义的情况下，使混合物种群体中的个体受益。
