Foraging behaviour of the middle spotted woodpecker Dendrocopos medius in Sweden

Abstract

During winter and spring the oak Quercus robur, was the tree species most utilized by middle spoiled woodpeckers. In March, saptrees, mainly maples Acer platanoides, were preferred for a short period. In winter the birds foraged in the crowns of oaks but in spring they preferred lower stem parts. Dead branches were utilized more in winter than in spring. The birds mostly used a gleaning and probing technique, which may render the species more senstitive to severe weather conditions than other woodpecker species. Arthropods collected from trees were mostly spiders, beetles, thrips or springtails. The nestlings were mainly fed on scale insects and larvae of moths and sawflies. The oak habitat specialization is believed to be caused by competition for food with other gleaning forest birds. Food shortage might possibly occur during periods of bad weather, causing increased mortality.