Predation Risk and the Organization of the Parus Guild

Abstract

Many studies indicate that interspecific competition restricts the use of foraging sites in mixed-species winter flocks of tits. However, predation is a strong mortality factor for members of the tit guild and predation risk may restrict the selection of foraging sites and organisation of the mixed-species tit flock. We evaluated pygmy owl (Glaucidium passerinum) predation can North European tits and goldcrests. A literature analysis of six areas showed clearly that pygmy owls feed more heavily on those species that forage on exterior tree parts (coal tit P. ater and golderest Regulus regulus)