Influence of nesting habitat on breeding Song Thrushes Turdus philomelos
Capsule Habitat significantly influences nest-site choice, breeding output and daily nest failure rates in Song Thrushes. Aims To describe nesting habitat of a stable Song Thrush breeding population, investigate habitat influence on breeding, and examine what variables influence nest-site selection by comparing habitat variables in nesting sites with random non-nesting sites. Methods Nesting habitat data were collected throughout Ireland in 2001-03 during a detailed study in County Cork and by volunteers across the country. Results Most nests were located 1.3-2.4 m from the ground. Nests built in April were significantly higher than those built in May. Nest-sites were mostly in trees, bushes or hedgerows and we highlight the role of garden habitat for nesting. Clutch size was significantly higher (mean +/- sd) on farmland (4.5 +/- 0.7) than in garden and parkland (4.0 +/- 0.5) and woodland (4.0 +/- 0.6). The number of hatched chicks was significantly greater in hedgerows (4.1 +/- 0.9) than in trees (3.2 +/- 0.7), but not in bushes (3.7 +/- 0.9), while the number of fledged chicks was significantly lower in nests in trees (3.2 0.7) than in hedgerows (4.2 +/- 0.8) and bushes (3.8 +/- 0.7). Daily nest failure rates were significantly lower for nests in trees and partly concealed nests across different nest periods. Nesting sites had significantly denser vegetation than non-nesting sites. Conclusion Dense vegetation is an important deciding factor for Song Thrushes when choosing a nest-site and may be an important consideration in conservation measures striving to maintain or restore Song Thrush populations.
Author(s): Kelleher, KM; O'Halloran, J
Journal: Bird Study