title: Avian predation upon a mixed community of common voles (Microtus arvalis) and wood mice (Apodemus sylvaticus).
abstract: Pellets of diurnal avian predators (mainly kestrels and buzzards) were analysed to prove the hypothesis of selective predation for a mixed population of small rodents. It was found that voles heavily predominated as prey over mice (up to a factor of 19 during winter). Within both prey species, predation focussed on distinct parts of the populations: during winter the heaviest specimens were preferentially captured, during summer the subadults were in an exposed position. In the voles, an additional predominance of males occurred (up to a factor of 5.2 during summer). These findings verify the assumption of Errington (1956) that speciments of a low social rank are susceptible to the highest risk of predation.
authors.affiliation: Physiologische Ökologie, Zoologisches Institut der Universität Köln, Weyertal 119, D-5000, Köln 41, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Halle
keywords: Pellet analysis; Selective avian predation; Small rodent populations; Social rank; Varying vulnerability