Dataset for: In the bleak mid-winter: The value of brownfield sites for birds during the winter
This data was used to investigate the value of brownfields sites for birds during the winter in the metropolitan county of Greater Manchester in the UK by 1) calculating bird diversity (species richness and species evenness) and bird density estimates 2) investigating bird-habitat associations for brownfield sites, and making comparisons with other broad land-uses. Moreover, the data was used to explore the extent to which brownfield sites have been recipient to land-use change in the county in comparison to other land-uses in order to make broad inferences regarding the impact on bird density during the winter. This was undertaken from the year 2000 to 2009, a period of prolific urban redevelopment within the county. Specifically, the dataset includes records of the birds present in six land-use categories (brownfield sites, green space, pre-2000 housing, post-2000 housing, industrial, commercial) in Greater Manchester during winter 2010. In addition, it includes data regarding the land coverage of the aforementioned land-uses in Greater Manchester for 2000 and 2009. Methodology: 171 x 1 km grid squares were identified within the M60 ‘ring-road’ motorway, and two sampling locations were chosen randomly in each square. The land-use present at each sampling location was identified by eye using aerial images from Google Earth and categorised into one of six categories (brownfield site, green space, pre-2000 housing, post-2000 housing, industrial, commercial). A point count took place at each sampling location to record all birds seen and heard, together with an on-site habitat survey which recorded the presence/absence of 14 tree and shrub species within 20 m of the sampling location. Land-cover variables were also recorded within 200 m of each sampling location using Google Earth images. This was achieved by superimposing a 10 x 10 square grid (each square measured 20 x 20 m) over Google Earth images, centred above each sampling location. From here, the area of grass, tree, water, and impervious land cover was measured by quantifying the percentage of cross points that fell onto each type of land cover. In order to quantify changes in the land coverage of the six land-uses between 2000 and 2009, the 1 km squares were further subdivided into 5x5 squares and the land-use at each cross-point was identified for both years using the historical image function on Google Earth. The area of land in the study area covered by each land-use was calculated for both years.