Moult location and diet of auks in the North Sea inferred from coupled light-based and isotope-based geolocation

Marine ecology progress series

Michael P. Harris^2¹  Kjell Einar Erikstad^3,4²  Sarah Wanless^2³  Francis Daunt^2⁴  Hallvard Strøm^5⁵  Katie St. John Glew^1⁶ 

[1] Hydrology, Bush Estate, Penicuik EH26 0QB, UK^2;Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway^4;Centre for Ecology &Norwegian Institute for Nature Research, Fram Centre, 9296 Tromsø, Norway^3;Norwegian Polar Institute, Fram Centre, Postbox 6606 Langnes, 9296 Tromsø, Norway^5;Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton SO143ZH, UK^1

关键词: Isoscape;    Trophic ecology;    Foraging;    Moult;    Atlantic puffin;    Common guillemot;    Razorbill;   

DOI  :  10.3354/meps12624

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

Many pelagic seabirds moult their feathers while at sea, which is an energetically costly behaviour. Mortality rates during moult can be high, so spatial and trophic ecology during this critical period is important for understanding demographic patterns. Unfortunately, individual foraging behaviours specifically linked to at-sea moulting are commonly unclear. This paper combines 2 different approaches to geolocation: data from bird-borne geolocation loggers and stable-isotope assignment using carbon and nitrogen isotope maps (isoscapes). Coupling 2 geolocation processes allows some uncertainties associated with isotope-based assignment to be constrained. We applied this approach to quantify species-specific foraging locations and individual trophic variability during feather regrowth in 3 sympatric auk populations breeding on the Isle of May, Scotland (common guillemot Uria aalge, razorbill Alca torda and Atlantic puffin Fratercula arctica). Inferred foraging areas during moult differed between species and feather types. Guillemots likely underwent moult within the southern North Sea, razorbills along the east coast of England and into the southern North Sea and puffins off the east coast of Scotland. Estimates of individual trophic position varied considerably within feather types (up to 1 trophic level difference between individuals), among feather types grown during different time periods and across the 3 species, with guillemots consistently foraging at higher trophic positions than razorbills and puffins. Used in combination, these methods better constrain foraging areas during moulting, and provide a technique to explore individual differences and flexibility in foraging strategy, which is valuable information for both seabird conservation and marine spatial planning.

【 授权许可】

Unknown