Correlates of Common Buzzard Buteo buteo density and breeding success in the West Midlands

Abstract

Buzzard density and breeding success in relation to habitat and Rabbit Oryctolagus cuniculus abundance was studied in the West Midlands from 1994 to 1996. We found densities of 81 and 22 territorial pairs per 100 km2 in two areas 40 km apart; the former is the highest density yet recorded in Europe. High Buzzard breeding densities were associated with high proportions of unimproved pasture and mature woodland within estimated territories. Buzzards laid earlier clutches at lower altitudes and with high proportions of unimproved pasture close to nests. Large clutches and high numbers of fledged young were associated with high Rabbit abundance close to nests. Most nest failures occurred during incubation and were probably mainly due to corvid predation. Brood reduction was associated with low proportions of deciduous woodland close to nests and small clutch sizes, although the causes of chick mortality were uncertain. Rabbits were the main prey item found at nests with passerines, especially young corvids, also appearing frequently.