Annual cycles in the behaviour and energetics of North Atlantic seabirds
Energy is the central currency that drives biological processes at every hierarchical level of life and maintaining an energetic balance is therefore integral to an animal’s survival. For iteroparous species, investigating how they manage their energy budgets throughout the annual cycle, in the face...
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| Other Authors: | , , , |
| Format: | Thesis |
| Language: | English |
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2020
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| Subjects: | |
| Online Access: | http://livrepository.liverpool.ac.uk/3114298/ http://livrepository.liverpool.ac.uk/3114298/1/201209548_Sep2020.pdf |
| Summary: | Energy is the central currency that drives biological processes at every hierarchical level of life and maintaining an energetic balance is therefore integral to an animal’s survival. For iteroparous species, investigating how they manage their energy budgets throughout the annual cycle, in the face of seasonally varying intrinsic and extrinsic drivers, is critical to understanding the viability of populations. Although studying year-round energetics has previously been challenging, advances in biologging technology increasingly help to provide novel insights. Seabirds are a frequently investigated taxon within biologging studies; they are top marine predators that are often wide-ranging and many species are of high conservation concern due to a multitude of anthropogenic threats. However, despite an accumulation of knowledge regarding seabird movement and behaviour during their breeding seasons, our understanding of their year-round energetics remains fragmented. Within this thesis I therefore use a range of biologging and analytical approaches to investigate seabird behaviour and energetics throughout different key phases of the year, as well as across the entire annual cycle. Initially, using a global, multi-species, meta-analytical approach, I identify the large-scale drivers of seabird energetics during the breeding period. I demonstrate that seabird energy expenditure increases across the breeding season and also that it is higher for larger birds living at more extreme latitudes. I then focus on the North Atlantic marine ecosystem and compare the diving behaviour of common guillemots Uria aalge, razorbills Alca torda and Atlantic puffins Fratercula arctica during the period following the breeding season. Using biologging data, I identify interspecific, sex-specific and temporal differences in key dive metrics, driven by differences in body mass, post-breeding strategy and environmental conditions. Next, I combine both biologging data and statistical modelling approaches to focus on temporal changes in the ... |
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