Breeding bird communities in the upland margins (ffridd) of Wales in the mid-1980s

Abstract

Capsule: The bird communities in the Welsh marginal uplands were frequently distinct from those of adjacent habitats and consisted of heterogeneous mixtures of species strongly influenced by vegetation composition and land-use. Aims: To provide a unique description of the influence of vegetation, altitude and regional position on the bird communities of upland margins and to create a baseline against which future changes in these communities may be assessed. Methods: Survey data collected at 120 sites in 1985-87 were used to identify broad relationships between habitat and bird communities. This was complemented by habitat descriptions made at exact locations occupied by individual birds. Results: Bird communities in Bracken-dominated sites, especially those with relatively high numbers of scattered trees and bushes, held more species than sites dominated by grassland and other moorland vegetation. Relationships between species and habitat were broadly consistent at both the scale of whole sites and the scale of patches occupied by individual birds. Abundance of scattered trees and bushes was important for a diverse range of passerines; extent of Gorse Ulex spp. scrub was important for several species. Geographical location and topography appeared to have secondary effects on bird communities relative to those of vegetation composition. Conclusions: The Welsh marginal uplands hold diverse bird communities, strongly affected by local vegetation composition and usually different from those of adjacent moorland, woodland and farmland. Tree Pipit Anthus trivialis, Whinchat Saxicola rubetra, Linnet Carduelis cannabina and Yellowhammer Emberiza citrinella were among the species likely to be more abundant in the upland margins than in adjacent habitats. There is a need to assess whether these communities have changed since the mid-1980s, especially in relation to high sheep grazing pressure. However, agricultural abandonment of marginal areas may occur in the future which could eventually reduce habitat availability for several bird species and reduce avian diversity in the Welsh uplands. © 2006 British Trust for Ornithology.