Recent declines in populations of woodland birds in Britain: a review of possible causes

Published on 01 March 2005 in Main articles

ABSTRACT Large declines in the breeding populations and contractions of breeding range have occurred in several woodland birds in Britain in recent decades. Data from the BTO’s Common Birds Census indicate that 10 out of 32 woodland species declined by more than 50% between 1966 and 1999, while 5 species increased by more than 50% over the same period.The declining species differ substantially in their ecology and life-history patterns. No single general explanation can be identified for the declines and it is likely that multiple factors have exerted a combined effect on several of the species. Seven factors emerge from this review as especially relevant and worthy of further study: (i) pressures on migrants during migration or in winter; (ii) climate change on the breeding grounds; (iii) general reduction in invertebrate food supplies; (iv) impacts of land use on woodland edges, habitats adjacent to woodland and hedgerows; (v) reduced management of lowland woodland; (vi) intensified habitat modification by deer; and (vii) increased predation pressure from Grey Squirrels Sciurus carolinensis, Great Spotted Woodpeckers Dendrocopos major and corvids.ird populations in the wider countryside of Britain underwent large changes in the second part of the twentieth century. The majority of specialist farmland birds declined in the 1970s and 1980s, largely as a result of agricultural intensification (Chamberlain et al. 2000; Fuller 2000). It is less widely appreciated that populations of some woodland birds in Britain have also declined considerably in recent decades, with Lesser Spotted Woodpecker Dendrocopos minor, Marsh Tit Parus palustris, Willow

Click here to download the full article.