Understanding migration of pelagic seabirds with stable isotopes and geolocation

• Main Author: Neto Militao, Teresa Afonso
• Other Authors: González-Solís, Jacob, Universitat de Barcelona. Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universitat de Barcelona 2016
• Subjects: Ocells marins; Migració d'ocells; Isòtops estables en ecologia; Sea birds; Birds migration; Stable isotopes in ecological research; Southern Ocean
• Online Access: http://hdl.handle.net/2445/105528; http://hdl.handle.net/10803/398988

[eng] Animal migration is an amazing widespread phenomenon that forms an essential component of the animal life history. Animals usually migrate to take advantages of changes in resource availability in space and time or to find suitable habitats for different life-history stages, which ultimately may improve their fitness. Unfortunately, migratory species are currently experiencing substantial population declines because of the several threats they are exposed to. These largely depend on their migratory patterns, and therefore its study is crucial for the effective conservation of migratory species. Despite our wealth of knowledge on avian migration, the study of migratory ecology of pelagic seabirds is still very challenging, especially in small species. Until recently, most studies on seabird migration focused on species of the Southern Ocean, while our knowledge on Mediterranean, tropical and subtropical Atlantic species is scarcer. In this thesis, we aim to fill in this gap of knowledge for a number of pelagic seabirds of the Mediterranean and the Atlantic, by studying the migratory patterns of 7 shearwaters, 4 petrels and 1 gull species. More specifically, we (1) increase our knowledge on different methodologies for seabird identification as a preliminary step to study their migratory movements; (2) evaluate the utility of stable isotopes analysis (SIA) to infer the non-breeding areas of pelagic seabirds, and; (3) reveal the migratory patterns and non-breeding areas of the study species using geolocation or a combination of SIA and geolocation data. Our findings pointed out the importance of integrating different methodologies to distinguish individuals of closely related or recently diverged species and thus overcome their identification difficulty. Furthermore, we demonstrated the utility of SIA as powerful approach to discriminate species that explore isotopically distinct areas. We verified a generally high efficiency of SIA on feathers as a geographic marker to infer the previous non-breeding area of ...