When species coexist, it is expected that they will reduce competition through niche partitioning or spatial segregation. We investigated the importance of niche partitioning versus spatial segregation across a seabird community where food and foraging constraints vary seasonally. Spatial clustering of seabird density in the western Irish Sea occurred in both seasons, with hotspots of seabird occurrence significantly higher in summer (Moran's I: 0.29) than winter (Moran's I: 0.19). A positive correlation between seabird density and feeding guild richness suggested a role for niche partitioning in reducing competition. This correlation was significantly stronger in summer than winter (Z‐test, p < 0.05), suggesting that when foraging range is constrained during the breeding season, interspecific competition is reduced through increased niche partitioning. Reduced spatial clustering and weaker correlations between density and feeding guild richness in winter suggests that spatial segregation plays a greater role in reducing interspecific competition outside the breeding season. This study demonstrates the relative importance of niche partitioning and spatial segregation, highlighting niche partitioning as a response to constraints on foraging range during the breeding season.

中文翻译：

---

中心地带觅食推动海鸟的利基划分

当物种共存时，预计它们将通过生态位划分或空间隔离减少竞争。我们调查了在食物和觅食限制随季节变化的海鸟群落中，生态位分配与空间隔离的重要性。在两个季节中，爱尔兰西部海域海鸟密度的空间聚集都发生，夏季（Moran I：0.29）海鸟出现的热点明显高于冬季（Moran I：0.19）。海鸟密度与行会丰富度之间呈正相关关系，这表明利基分配在减少竞争中发挥了作用。夏季的相关性明显强于冬季（Z检验，p <0.05），这表明在繁殖季节限制觅食范围时，种间竞争通过增加利基分配而减少。空间聚类的减少以及冬季密度与饲喂行会丰富度之间的相关性较弱，这表明空间隔离在减少繁殖季节以外的种间竞争方面发挥了更大的作用。这项研究证明了生态位分配和空间隔离的相对重要性，强调了生态位分配是繁殖季节对觅食范围限制的一种反应。