Habitat selection by Marsh Tits Poecile palustris in the UK

The Marsh Tit Poecile palustris is a small, hole-nesting woodland passerine whose national population in the UK has declined by more than 50% in the last 25 years. To investigate possible causes for the species long-term decline, we examined habitat selection by Marsh Tits at three scales. For individual foraging birds, winter time budgets and foraging behaviour, recorded using instantaneous sampling, differed little between Marsh and Blue Tits Cyanistes caeruleus, but Marsh Tits spent more time in the understorey and more time lower down in both the woodland canopy and the understorey. At the scale of breeding territories, the characteristics (numbers by size class, vegetation density, species richness) of trees and shrubs were compared using 100 + 10-m sample transects of ten territories in each of four woods. The characteristics of the trees differed significantly between woods whilst those of the shrubs did not, suggesting that the characteristics of shrubs were more important in territory selection by Marsh Tits than were those of trees. Furthermore, in one of the four woods (Wytham Woods, Oxfordshire), Marsh Tits were largely absent from areas with dense tree canopy, but poor shrub cover.

SHELLEY A. HINSLEY, JANE E. CARPENTER et al., Ibis 149 (s2), 224-233