Annual and seasonal consistency in the feeding ecology of an opportunistic species, the yellow-legged gull Larus michahellis

Marine Ecology Progress Series

Lurdes Morais¹  Vera Fidalgo¹  Alexandra Baeta¹  Jo#xe3o C. Marques¹  Jaime A. Ramos¹  Stefan Garthe¹  Vitor H. Paiva¹  Filipe R. Ceia¹  Paulo Cris#xf3stomo¹  Eduardo Mourato¹ 

关键词: Activity patterns;    Generalist seabirds;    Foraging specialization;    Habitat use;    GPS tracking;    Stable isotopes;   

DOI  :  10.3354/meps10586

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: This study investigated the extent to which the plasticity of a generalist, opportunistic species allows individuals to shift their feeding ecology and foraging niche, throughout the annual cycle, and between 2 years of contrasting diet and oceanographic conditions during the breeding season. The spatio-temporal variations in the foraging niche of an overpopulated gull species—the yellow-legged gull Larus michahellis population at Berlenga Island (Portugal)—were assessed using blood (plasma and cells) and different feathers for stable isotope analyses (δ¹³C and δ¹⁵N) from 52 breeding adults in 2 consecutive years (2011 and 2012). In addition, GPS loggers were deployed on 11 individuals (and removed after several foraging trips) to infer the foraging behaviour of this species during the incubation period. Results suggest inter-annual differences in the feeding ecology and foraging behaviour of birds during the breeding season that were associated with the availability of food resources around the colony. Despite the high feeding plasticity and opportunistic behaviour of yellow-legged gulls, individual birds exhibited short- and long-term consistency in their feeding ecology, with exception of the period between winter and pre-laying. Our results support the hypothesis that individual feeding preferences throughout most of the annual cycle are an intrinsic characteristic of this population, and potentially of related opportunistic and generalist species.

【 授权许可】

Unknown