Using satellite imagery to aid the implementation of a recovery plan for a declining farmland bird.

Abstract

Numbers of Grey Partridges Perdix perdix have declined since the 1950s due in part to agricultural intensification, loss of gamekeepers and available nesting cover. The Game Conservancy Trust, lead partner for the Grey Partridge Biodiversity Action Plan, will undertake to achieve three objectives: halt the population decline by 2005, double current breeding estimate to 150,000 pairs by 2010 and extend the range of the species. Land managers throughout Britain have been recruited, on a voluntary basis, both to implement management practices designed to increase Grey Partridge numbers and monitor the effect of this management. In order to put into context the density of Grey Partridges within their area, 'target' populations were calculated for their holdings. Land cover data was used to classify kilometre squares throughout Britain into optimal, sub-optimal and unsuitable Grey Partridge habitat, based on approximations of past habitat. Overlaying this with the area of land each manager covered allowed minimum expected numbers of Grey Partridges to be calculated. This contributed to a management document that puts local Grey Partridge recovery in the control of each land manager.