Knowledge regarding the influence of individual traits on interaction patterns in nature can help understand the topological role of individuals within a network of intrapopulation interactions. We tested hypotheses on the relationships between individuals’ positions within networks (specialization and centrality) of four populations of the mouse opossum Gracilinanus agilis and their traits (i.e., body length, body condition, tail length relative to body length, sex, reproductive condition, and botfly parasitism) and also seasonal effects in the Brazilian savanna. Individuals with lower body length, better body condition, and relatively shorter tail were more specialized (i.e, less connected within the network). Individuals were also more specialized and less connected during the warm-wet season. The relationship between individuals’ position in the network and body traits, however, was independent of season. We propose that specialization may arise not only as a result of preferred feeding strategies by more capable individuals (i.e., those with better body condition and potentially prone to defend and access high-quality food resources) but also because of morphological constraints. Smaller/younger individuals (consequently with less experience in foraging) and short-tailed individuals (less skilled to explore the vertical strata of the vegetation) would feed only on a subset of the available food resources and consequently become more specialized. Moreover, individuals are more specialized during the warm-wet season because of high competition (population-dense period) and higher ecological opportunities (resource-rich period). Therefore, our study reveals the relevance of individual traits in shaping interaction patterns and specialization in populations.

中文翻译：

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形态特征解释了新热带有袋动物资源消耗网络中的个体位置

关于个体特征对自然界相互作用模式的影响的知识可以帮助理解个体在群体内相互作用网络中的拓扑作用。我们测试了关于小鼠负鼠四个种群网络中的个体位置（专业化和中心性）与其特征（即体长、身体状况、相对于体长的尾长、性别、繁殖状况、和马蝇寄生）以及巴西稀树草原的季节性影响。体长较短、身体状况较好、尾巴相对较短的个体更加专业化（即网络内的联系较少）。在暖湿季节，人们的专业性也更强，联系也更少。然而，个体在网络中的位置和身体特征之间的关系与季节无关。我们认为，专业化的出现不仅可能是由于更有能力的个体（即那些身体状况更好并且可能倾向于保护和获取高质量食物资源的个体）偏好的喂养策略的结果，而且还因为形态的限制。较小/年轻的个体（因此觅食经验较少）和短尾个体（探索植被垂直层的技能较差）将仅以可用食物资源的子集为食，因此变得更加专业化。此外，由于竞争激烈（人口密集期）和更高的生态机会（资源丰富期），暖湿季个体更加专业化。