Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- 1 Introduction
- 2 Effects of fisheries on ecosystems: just another top predator?
- 3 Physical forcing in the southwest Atlantic: ecosystem control
- 4 The use of biologically meaningful oceanographic indices to separate the effects of climate and fisheries on seabird breeding success
- 5 Linking predator foraging behaviour and diet with variability in continental shelf ecosystems: grey seals of eastern Canada
- 6 Distribution and foraging interactions of seabirds and marine mammals in the North Sea: multispecies foraging assemblages and habitat-specific feeding strategies
- 7 Spatial and temporal variation in the diets of polar bears across the Canadian Arctic: indicators of changes in prey populations and environment
- 8 Biophysical influences on seabird trophic assessments
- 9 Consequences of prey distribution for the foraging behaviour of top predators
- 10 Identifying drivers of change: did fisheries play a role in the spread of North Atlantic fulmars?
- 11 Monitoring predator–prey interactions using multiple predator species: the South Georgia experience
- 12 Impacts of oceanography on the foraging dynamics of seabirds in the North Sea
- 13 Foraging energetics of North Sea birds confronted with fluctuating prey availability
- 14 How many fish should we leave in the sea for seabirds and marine mammals?
- 15 Does the prohibition of industrial fishing for sandeels have any impact on local gadoid populations?
- 16 Use of gannets to monitor prey availability in the northeast Atlantic Ocean: colony size, diet and foraging behaviour
- 17 Population dynamics of Antarctic krill Euphausia superba at South Georgia: sampling with predators provides new insights
- 18 The functional response of generalist predators and its implications for the monitoring of marine ecosystems
- 19 The method of multiple hypotheses and the decline of Steller sea lions in western Alaska
- 20 Modelling the behaviour of individuals and groups of animals foraging in heterogeneous environments
- 21 The Scenario Barents Sea study: a case of minimal realistic modelling to compare management strategies for marine ecosystems
- 22 Setting management goals using information from predators
- 23 Marine reserves and higher predators
- 24 Marine management: can objectives be set for marine top predators?
- Index
- References
16 - Use of gannets to monitor prey availability in the northeast Atlantic Ocean: colony size, diet and foraging behaviour
Published online by Cambridge University Press: 31 July 2009
- Frontmatter
- Contents
- List of contributors
- Preface
- 1 Introduction
- 2 Effects of fisheries on ecosystems: just another top predator?
- 3 Physical forcing in the southwest Atlantic: ecosystem control
- 4 The use of biologically meaningful oceanographic indices to separate the effects of climate and fisheries on seabird breeding success
- 5 Linking predator foraging behaviour and diet with variability in continental shelf ecosystems: grey seals of eastern Canada
- 6 Distribution and foraging interactions of seabirds and marine mammals in the North Sea: multispecies foraging assemblages and habitat-specific feeding strategies
- 7 Spatial and temporal variation in the diets of polar bears across the Canadian Arctic: indicators of changes in prey populations and environment
- 8 Biophysical influences on seabird trophic assessments
- 9 Consequences of prey distribution for the foraging behaviour of top predators
- 10 Identifying drivers of change: did fisheries play a role in the spread of North Atlantic fulmars?
- 11 Monitoring predator–prey interactions using multiple predator species: the South Georgia experience
- 12 Impacts of oceanography on the foraging dynamics of seabirds in the North Sea
- 13 Foraging energetics of North Sea birds confronted with fluctuating prey availability
- 14 How many fish should we leave in the sea for seabirds and marine mammals?
- 15 Does the prohibition of industrial fishing for sandeels have any impact on local gadoid populations?
- 16 Use of gannets to monitor prey availability in the northeast Atlantic Ocean: colony size, diet and foraging behaviour
- 17 Population dynamics of Antarctic krill Euphausia superba at South Georgia: sampling with predators provides new insights
- 18 The functional response of generalist predators and its implications for the monitoring of marine ecosystems
- 19 The method of multiple hypotheses and the decline of Steller sea lions in western Alaska
- 20 Modelling the behaviour of individuals and groups of animals foraging in heterogeneous environments
- 21 The Scenario Barents Sea study: a case of minimal realistic modelling to compare management strategies for marine ecosystems
- 22 Setting management goals using information from predators
- 23 Marine reserves and higher predators
- 24 Marine management: can objectives be set for marine top predators?
- Index
- References
Summary
Large seabirds such as northern gannets Morus bassanus have very flexible time–activity budgets; this means that changes in variables such as foraging-trip duration could provide a rapid indicator of changes in food supply, an indicator that could not be obtained from smaller species. Moreover, larger birds often have longer foraging ranges, giving them the potential to integrate information about changes in food availability over large areas of ocean. There is insufficient information on temporal variation in fish stocks exploited by far-ranging species to determine how the birds' foraging ecology varies with prey abundance, but comparing colonies of different size potentially presents an opportunity to examine empirically how foraging ecology varies in relation to prey availability. For gannets in Britain and Ireland, there were major differences between colonies in foraging and food-provisioning behaviour, but the relationship between trip duration and foraging range was remarkably constant. Moreover, there was a strong relationship between trip duration and the square root of colony size, which was very similar within colonies between years and between colonies within a single year. This relationship could provide a powerful tool for gauging the importance of changes in trip duration in terms of changes in per-capita prey availability. Over 4 years, annual variation in diet at one colony to some extent reflected variation in trip durations and foraging locations, although one year was anomalous and a combination of trip duration and diet provided a much more complete picture than either did on their own.
- Type
- Chapter
- Information
- Top Predators in Marine EcosystemsTheir Role in Monitoring and Management, pp. 236 - 248Publisher: Cambridge University PressPrint publication year: 2006
References
- 5
- Cited by