The area is split into grid cells 100 m X 100 m. This grid is projected on a transverse mercator projection with a central meridian of -2.2666 and grid cell ID numbers(FID) run from bottom left to top right

Bird counts; Bathymetry and Elevation

The dataset comprises seabird count data gridded into 100 m x 100 m grid cells collected during a survey of up to 1 km from the coastline of Alderney, Channel Islands, during the summer breeding season (April to July) in 2013. A survey to record the distance and bearing to any seabirds and their group level (Large gulls, Large auks, European shags) was undertaken on 64 occasions. All birds observed were recorded up to 6 days a week from three land-based vantage points. Four 15 minute scans, carried out using binoculars, were conducted at the same time of day each morning. The scan which contained the most number of birds was incorporated into the result set in order to capture all of the individuals in the area including diving birds. The other scans were discarded. The distance was estimated using a rangefinder, the bearing recorded using a compass and a scope was used for further identification. The data were collected and analysed by Victoria Warwick Evans (University of Liverpool) in collaboration with the Alderney Wildlife Trust in order to understand the environmental drivers behind the near-shore fine-scale distribution of seabirds. Publicly available environmental data were also used to test the importance of environmental variables. These included depth (from an admiralty chart); substrate type (from a report published by the Alderney Commission for Renewable Energy); distance to land, intertidal zone and seabird nests, calculated using ArcGIS. The data are also held in the archive system of the British Oceanographic Data Centre.

University of Liverpool Department of Earth, Ocean and Ecological Sciences
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