Distribution Maps

When a species is selected, a short species account and an overview of the tetrad distribution maps is displayed. All species recorded in the 2007-11 survey period are included. For some non-resident species, where adequate data are available, a histogram of monthly counts is displayed.

Interactive tetrad map: The following distribution maps are can be selected:

• Breeding in the 2008-11 surveys
• Breeding in the 1987-9 surveys
• Select both to show the changes in breeding distribution between the survey periods
• Relative abundance in April - July
• Relative abundance in November – February

For some commoner migrant species that normally neither breed nor winter in Berkshire:

• Frequency of occurrence in March – June
• Frequency of occurrence in July – October

Overlays can be selected to display OS grids, broad habitat classes and some topographical features.

Click on a tetrad to display the tetrad designation and the number of species recorded (a list of species can be displayed by clicking on the arrow to the right). A Google map for the tetrad can be opened in a separate window.

The Compare maps button allows side by side comparisons of different seasons or different species.

Interactive google map: The tetrad breeding and abundance distributions are shown against Google Maps’ roadmap and satellite views, with their useful zoom facility.

Species richness maps: The overall tetrad species richness is displayed for all wintering species and for all breeding species. Maps are also provided for species of conservation concern, together with the changes between the 1987-9 and 2007-11 surveys. Overlays can be selected to display OS grids, broad habitat classes and some topographical features.