Although lowland tropical rain forests were once widely believed to be the archetype of stability, seasonal variation exists. In these environments, seasonality is defined by rainfall, leading to a predictable pattern of biotic and abiotic changes. Only the full annual cycle reveals niche breadth, yet most studies of tropical organisms ignore seasonality, thereby underestimating realized conditions. If human‐modified habitats display more seasonal stress than intact habitats, then ignoring seasonality will have particularly important repercussions for conservation. We examined the seasonal dynamics of Amazonian mixed‐species flocks, an important species interaction network, across three habitats with increasing human disturbance. We quantified seasonal space use, species richness and attendance, and four ecological network metrics for flocks in primary forest, small forest fragments, and regenerating secondary forest in central Amazonia. Our results indicate that, even in intact, lowland rain forest, mixed‐species flocks exhibit seasonal differences. During the dry season, flocks included more species, generally ranged over larger areas, and displayed network structures that were less complex and less cohesive. We speculate that—because most flocking species nest during the dry season, a time of reduced arthropod abundance—flocks are simultaneously constrained by these two competing pressures. Moreover, these seasonal differences were most pronounced in forest fragments and secondary forest, habitats that are less buffered from the changing seasons. Our results suggest that seasonality influences the conservation value of human‐modified habitats, raising important questions about how rain forest organisms will cope with an increasingly unstable climate.

中文翻译：

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低地亚马逊雨林中人为改变景观上的羊群互动网络的季节性动态

尽管低地热带雨林曾经被广泛认为是稳定的原型，但存在季节性变化。在这些环境中，季节性由降雨决定，导致可预测的生物和非生物变化模式。只有整个年度周期才能揭示利基的广度，但是大多数对热带生物的研究都忽略了季节性，因此低估了已实现的条件。如果人为改变的栖息地比完整的栖息地表现出更多的季节性压力，那么忽略季节性将对保护产生特别重要的影响。我们研究了三个人类栖息地不断增加的生境中亚马逊河混合物种群（一个重要的物种相互作用网络）的季节动态。我们量化了季节性空间的使用，物种丰富度和出勤率，以及四个生态网络指标，分别针对亚马逊中部的原始森林，小型森林碎片和再生次生森林的羊群。我们的结果表明，即使在完整的低地雨林中，混合物种的羊群也表现出季节性差异。在干旱季节，鸡群包括更多种类，通常分布在较大的区域，并且显示的网络结构较不复杂且缺乏凝聚力。我们推测-由于大多数植绒物种在干旱季节筑巢，这是节肢动物数量减少的时期-羊群同时受到这两个相互竞争的压力的制约。此外，这些季节差异在森林碎片和次生森林中最为明显，次生森林在变化的季节中较少得到缓冲。