Report 552
Review of Seabird Demographic Rates and Density Dependence
Horswill, C. & Robinson, R.A.
This report and the accompanying material details demographic information on the 32 species of seabird and sea duck thought to be most vulnerable to off-shore renewable developments in the UK.


This report presents individual species accounts for a selection of British seabirds, sea ducks, divers and grebes. Each account gathers the most up to date published estimates on the following demographic parameters: age-specific survival, age-specific productivity, age of recruitment, incidence of missed breeding, and natal and adult breeding dispersal. Particular attention has been given to regional variation in demographic rates, indicating the extent to which estimates may be applied to other less-well studied colonies. Where possible, the intrinsic and extrinsic factors that influence demographic rates are also detailed.
The reported rates should enable population models that assess the impacts of offshore wind farms to be developed as reliably and realistically as possible. Where sufficient data could not be gathered using UK examples, data from colonies outside of the UK have been presented, or a proxy species has been identified. The evidence for density-dependent regulation of seabird demographic rates is also reviewed using examples from the UK, as well as non-UK studies on similar species.

Download supplemental information:

  • Supporting Information (ZIP, 1963 kb) Please Note: If you are unable to access the ZIP file, please contact JNCC for the supplemental information in separate PDF file format.


You will need the free Adobe Acrobat Reader to view this document.
ISSN 0963-8901
Please cite as: Horswill, C. & Robinson, R.A., (2015), Review of Seabird Demographic Rates and Density Dependence, JNCC Report 552, ISSN 0963-8901