Effects of broadleaved trees on birds of upland conifer plantations in North Wales

Abstract

Five-minute counts at 253 points at ecotones in exotic conifer plantations contained 3515 records of 34 songbird species in the breeding season. Habitat data were collected at these points and at another 155 where singing individuals of selected scarcer species were located. Fourteen of 22 species with sufficient data showed habitat selection, including all the migrants, which were relatively uncommon. The main trends of vegetation were due to succession and the extent of non-crop broadleaves. The latter had a greater effect on bird species occurrence. A relationship between size of patch of broadleaves and density of habitat-selective birds was such that, for a fixed area, there would be more individuals of these species if broadleaves were dispersed throughout the conifers rather than concentrated in few larger blocks. The study has methodological interest and practical application.