Data from: Tick infestation of chicks in a seabird colony varies with local breeding synchrony, local nest density and habitat structure

Parasites are a major risk for group-living animals and seabirds are notoriously susceptible to ectoparasite infestations because they commonly nest in dense colonies. Ticks parasitize seabirds across all biogeographical regions and they can be particularly harmful to nestlings, but the ecological factors that affect their transmission to chicks are little studied and poorly understood. Here we show that abundance of tick larvae in blue-footed booby (Sula nebouxii) broods varies with local nest synchrony and density, and also with habitat structure: abundance increased with local breeding synchrony, was linearly and quadratically related to local nest density, and was highest toward the southern end of the study area which has suitable (boulder-rich) habitat for ticks. Also, with increasing chick age infestation first increased and then declined. The results of this study highlight how local physical and social environmental factors influence infestation of seabird nestlings by ticks.寄生虫对群居动物而言是一类主要威胁，而海鸟因通常营高密度集群巢穴，素来易受体外寄生虫（ectoparasite）侵染。蜱虫（ticks）在全球所有生物地理区域均可寄生海鸟，且对雏鸟具有尤为显著的危害，但影响其向雏鸟传播的生态因子迄今仍鲜有研究、认知匮乏。本研究发现，蓝脚鲣鸟（Sula nebouxii）各繁殖窝中的蜱幼虫丰度随局部巢群繁殖同步性、巢群密度以及生境结构发生变化：其丰度随本地繁殖同步性提升而升高，与本地巢群密度呈线性及二次相关关系，且在研究区域南部达到峰值——该区域拥有适宜蜱虫生存的多砾石生境。此外，随雏鸟日龄增长，侵染程度先升后降。本研究结果揭示了局域物理与社会环境因子如何影响蜱虫对海鸟雏鸟的侵染情况。