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.

寄生虫是群居动物面临的主要风险之一，而海鸟因常营密集巢群，素来极易遭受体外寄生虫（ectoparasite）侵染。蜱虫（Ticks）在全球所有生物地理区域均可寄生海鸟，且对雏鸟的危害尤为突出；但目前学界对影响蜱虫向雏鸟传播的生态因子的研究极少、认知匮乏。本研究发现，蓝脚鲣鸟（Sula nebouxii）育雏种群中的蜱幼虫丰度，随局部巢群同步性、巢群密度以及栖息地结构发生变化：其丰度随当地繁殖同步性提升而升高，与局部巢密度呈线性及二次相关关系，且在研究区域的南端——该区域拥有适宜蜱虫生存的多砾石生境——达到峰值。此外，随着雏鸟日龄增长，蜱虫侵染程度先升后降。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状况。