Foraging and movement ecology of two sympatrically breeding Antarctic storm-petrels

风暴海燕是世界上数量最多的远洋海鸟之一，因此构成了海洋生态系统的重要组成部分。然而，由于它们体型较小，生活在远洋，其营养生态很难研究，特别是在它们在公海度过的非繁殖期。以前对黑腹风暴海燕(Fregetta Tropica)和威尔逊风暴海燕(Ocean Ocean Anicus)在繁殖期的营养位置和食性进行了研究，发现BbSP在较高的营养位置捕食比WSP更多的鱼。此外，稳定同位素分析(SIA)为它们的非繁殖活动提供了一些线索。然而，到目前为止，它们的非繁殖营养位置和分布还没有得到充分的研究。在这个项目中，我们计划在过去几十年开展的工作的基础上，实施已经在试点项目和其他海燕物种中被证明成功的方法。利用与基线无关的SIA、GPS和GLS标签，对南极洲乔治王岛繁殖季节收集的食物内容和形态和繁殖参数数据进行元数据库编码，我们的目标是进一步揭示黑腹海燕和威尔逊风暴海燕的觅食和运动生态。我们打算使用基线独立的SIA来研究所研究物种在繁殖期内和繁殖期外的营养位置，包括成体和雏鸟，并研究观察到的饲料和营养位置的差异如何影响繁殖成功。我们将在繁殖季节为成虫配备GPS标签，以发现繁殖期间的觅食范围，并为其配备GLS标签，以研究非繁殖活动。我们的目标是测试物种之间营养位置的差异如何与鸟类和它们的猎物分布的差异有关，觅食生态在繁殖季节之间是如何变化的，以及与非繁殖季节相比如何。由于这些信息中的大部分仍是未知的，这项研究将为未来对行为变异性的分析设定基线。

Storm-petrels are among the world’s most abundant pelagic seabirds, and thus form an important part of marine ecosystems. However, due to their small size and pelagic lifestyle, their trophic ecology is hard to study, especially during the non-breeding period which they spend on the open ocean. The trophic position and diet of black-bellied storm-petrels (Fregetta tropica) and Wilson's storm-petrels (Oceanites oceanicus) during the breeding period has been studied previously, revealing that BBSP forages at a higher trophic position consuming more fish than WSP. Additionally, stable isotope analyses (SIA) have shed some light upon their non-breeding movements. However, their non-breeding trophic position and distribution have so far remained understudied. In this project, we plan to build upon the body of work carried out over the past decades, and implement methods already proven successful in a pilot project and other petrel species. Using baseline-independent SIA, GPS and GLS tags, metabarcoding of diet contents and morphological and breeding parameter data collected during the breeding season on King George Island, Antarctica, we aim to further unravel the foraging and movement ecology of black-bellied and Wilson’s storm-petrels. We intend to use baseline-independent SIA to study the trophic position of the studied species both during and outside of the breeding period, for both adults and chicks, and to study how differences in observed diets and trophic position affect breeding success. We will equip adults with GPS tags during the breeding season to discover foraging ranges during the breeding period, and with GLS tags to study the non-breeding movements. We aim to test how differences in trophic positions between the species are connected to differences in distribution of the birds and their prey, how the foraging ecology changes among breeding seasons, and how it compares to the non-breeding season. As much of this information is still unknown, this study will set a baseline for future analyses of behavioural variability.