In a previous study conducted during the dry season at La Selva Biological Station, Costa Rica, mean perch height of libellulid dragonfly species (Odonata: Libellulidae) correlated with male body size, and interactions between species suggested a size-dependent competitive hierarchy. Here, I report on a wet-season study that examined whether seasonal changes in community composition affect these patterns. Males were captured, photographed, and marked, perch heights among individuals and species on natural and artificial perches (25, 50, and 100 cm) were compared, and the frequencies of aggressive interactions between species were analyzed. I also examined the responses of Micrathyria atra and Micrathyria mengeri males to decoys of these species placed in their territory at different heights (50 or 100 cm). Although the wet season community differed from the dry season community (Jaccard dissimilarity = 0.778), there was still a significant correlation between species perch height and body size, on both natural and artificial perches. Interspecific interactions supported the size-dependent competitive hierarchy hypothesis: smaller species that perched low avoided attacks by larger species. These patterns were confirmed in the decoy experiment. The larger M. atra, which perches at ∼100 cm, attacked decoys at 100 cm almost exclusively, and attacked decoys of the smaller M. mengeri more than conspecifics. In contrast, M. mengeri (which perches at 50 cm) only attacked decoys placed at 50 cm. Although community membership changed, the correlation between body size and perch height was maintained by a size-dependent competitive hierarchy in both dry and rainy seasons.

中文翻译：

---

确认热带齿科动物（Odonata：Libellulidae）的体型和鲈鱼高度之间的关系：雨季对比和实验测试

在先前在哥斯达黎加 La Selva 生物站进行的旱季研究中，蜻蜓科蜻蜓物种（蜻蜓目：蜻蜓科）的平均栖息高度与雄性体型相关，物种之间的相互作用表明存在依赖于尺寸的竞争等级。在这里，我报告了一项雨季研究，该研究检查了社区组成的季节性变化是否会影响这些模式。捕获、拍照和标记雄性，比较自然和人工栖息地（25、50 和 100 厘米）上的个体和物种之间的栖息高度，并分析物种之间侵略性相互作用的频率。我还研究了 Micrathyria atra 和 Micrathyria mengeri 雄性对放置在其领土上不同高度（50 或 100 厘米）的这些物种的诱饵的反应。尽管雨季群落与旱季群落不同（Jaccard 差异 = 0.778），但自然和人工栖息地的物种栖息高度与体型之间仍然存在显着相关性。种间相互作用支持依赖于大小的竞争等级假设：较小的物种栖息在较低的避免较大物种的攻击中。这些模式在诱饵实验中得到证实。较大的 M. atra 栖息在约 100 cm 处，几乎完全攻击 100 cm 处的诱饵，并且比同种攻击更小的 M. mengeri 的诱饵。相比之下，M. mengeri（栖息在 50 厘米处）只攻击放置在 50 厘米处的诱饵。虽然社区成员发生了变化，