Abstract

The Willow Tit Poecile montana population in Britain is in serious, long- term decline. It is likely that several factors are responsible for this decline, although those related to habitat change or degradation are thought to be among the most important. So far, there is little evidence that nest predation or competition has had a major effect on this species. This paper presents the results from a long-term study of Willow Tit nests in natural sites in northwest England.The results suggest that avian competition, and particularly nest predation, may be important contributory factors in the Willow Tit’s decline, at least in some areas of Britain.