Kestrel Species Action Plan
Bethan Cox of the Pembrokeshire Biodiversity Partnership has initiated a species action plan to aid kestrels (Falco tinnunculus) in this county.
Kestrels have shown a 30% decline in numbers in Britain over the last decade or so. Food and nest sites are the usual forces that govern raptor numbers and in the case of the little kestrel, predation by bigger raptors may also be a problem.
The species action plan will involve putting up 50 nest boxes for kestrels around Pembrokeshire. These will be placed where there is suitable habitat including farmland in the Tir Gofal agri-environment scheme. By careful placement of the potential new nest sites, we hope to help the kestrel population, and by monitoring the boxes, to learn more about them and their needs. In addition, the species will be used as an indication of the success of the agri-environment scheme.
Volunteers from the Wildlife Trust of South and West Wales have constructed 50 nestboxes at kestrel specification (nice view, open plan dining area etc) and Bethan and Jon Hudson recently put up the first box in a tree in mid Pembs. It will be a great thrill to see these lovely little falcons take up in the boxes. If you are interested in helping with this project by monitoring or offering a site please send an email to Bethan.Cox@Pembrokeshire.gov.uk
WWBIC is helping this project by mapping suitable habitat for kestrels across the county. It has been a great application of our new software from ESRI, particularly the spatial analyst extension which analyses grid data. The exercise has helped us establish grids for the region at varying scales which match the reference of the British National Grid. The project is our first step towards ecological models which predict the occurrence of different species on the basis of their preferred habitats. For grids at certain scales we have started to load environmental information such as mean annual temperature and altitude. These same measures may then be readily used in future distribution models for different species.
We started by giving each phase 1 vegetation type a code rating from a kestrel's point, ranging from 0 (not suitable at all) to 10 (kestrel heaven). We took expert advice on this from Bob Haycock and Matt Sutton at CCW. Bob kindly supplied us with the Pembrokeshire breeding atlas data for kestrels from the 1980s and the 2000s.
For each tiny grid square we then summed all the foraging habitat ratings for all squares accessible within a 1.5km radius, because this is the foraging range of a kestrel when breeding. The result was a very smooth map with some very obvious 'green' areas ranked high for kestrel feeding habitat....
This feeding habitat rating, at the tetrad level (the 2km by 2km grid used by the Pembrokeshire Breeding Bird Atlas), showed the strongest positive correlation with where the kestrels are currently recorded. We found weaker correlations with distance from large raptors, Tir Gofal farm extent, mean annual temperature, altitude, wind speed etc.
The GIS offers a great tool for selecting best sites for kestrels. This selection by spatial analyst highlights all grid squares where feeding habitat is above average and which are further than 2km from a nesting large raptor. These areas are thought to offer the best nesting habitat for Kestrels in the county, but will not necessarily contain natural nest sites.
Using this valuable information we were able to identify specific geographical areas suitable for boxes across Pembrokeshire. Once in place, these nestboxes can then be monitored for kestrel breeding attempts and success at rearing young. By careful siting of the boxes in varying environmental conditions and observing what happens at each we hope to be able to answer some of the questions of why kestrels have declined across Britain.
The project is being funded by Pembrokeshire Coast National Park Authority and the Countryside Council for Wales.
