Data and code for: Behavioral plasticity shapes participation in a mixed-species flocking community of birds

Behavioral plasticity can modulate the costs and benefits of sociality, and thus may play a prominent role in mediating competition and facilitation during social interactions in mixed-species groups. However, investigations of assembly patterns of mixed-species groups typically treat species' behavioral attributes as static rather than dynamic features that can change in social contexts. We investigate four axes of behavioral plasticity that may modulate interaction within mixed-species groups: 1) species' selective preference for joining certain groups, 2) species' ability to flexibly change their behavior in response to groupmates' behavior, and 3) shifts and/or 4) expansions of species' niche occupancy when foraging with conspecifics versus when foraging with heterospecifics. We assess variation in these axes of behavioral plasticity in an Australian mixed-species avian community. All species had selective preferences for flocks of certain strata, and some flexibly matched their flockmates' foraging strata. Three species exhibited patterns of niche shift, and one species showed niche expansion. These findings suggest that species converge in strata in mixed-species flocks despite the potential for increased competition and emphasize that species can plastically react to changes in their social environment in numerous ways. Acknowledgment of such plasticity is likely integral to understanding the nuances of heterospecific interactions.行为可塑性（behavioral plasticity）可调控社会性的成本与收益，因此在混合种群群体（mixed-species groups）的社会互动过程中，可能在介导竞争与易化作用方面发挥关键作用。然而，现有针对混合种群群体集群模式的研究，通常将物种的行为属性视为静态特征，而非可随社会情境动态变化的属性。本研究探讨了四类可能调控混合种群群体内部互动的行为可塑性维度：1）物种对加入特定群体的选择性偏好；2）物种响应集群同伴行为而灵活调整自身行为的能力；3）当与同种个体（conspecifics）觅食相较于与异种个体（heterospecifics）觅食时，物种生态位占用（niche occupancy）的偏移；以及4）当与同种个体觅食相较于与异种个体觅食时，物种生态位占用的扩展。我们在澳大利亚混合物种种鸟类群落中，评估了上述四类行为可塑性维度的变异情况。所有物种均对特定层位的鸟群表现出选择性偏好，部分物种可灵活匹配其集群同伴的觅食层位（foraging strata）。共有三个物种呈现出生态位偏移（niche shift）的模式，另有一个物种表现出生态位扩展（niche expansion）。本研究结果表明，尽管存在竞争加剧的潜在可能，但物种在混合种群鸟群的层位上趋于趋同；同时也强调，物种可通过多种方式对社会环境的变化产生可塑性响应。认识到这类行为可塑性，对于理解异种间相互作用（heterospecific interactions）的细微差异至关重要。