Feeding habitat and nest-site selection of breeding Great Spotted Woodpeckers Denrocopos major

Abstract

We studied within-territory habitat and nest-site selection of breeding Great Spotted Woodpeckers Dendrocopos major, by means of radio-telemetry, to test the general notion that this woodpecker is able to utilize a variety of forest habitats . The birds (4 males and 3 females) were monitored in the Varaldskogen study area, a managed, boreal forest of south-central Scandinavia. An 85% home-range estimate averaged 20 ha (range 7-43 ha, n = 4 birds) and breeding pairs lived in separate territories with extensive intersexual overlap of home-ranges. The habitats being used for feeding varied considerably from dry, open clearcuts to moist old-forest stands . When feeding observations were combined for all birds (n = 85 observations), older stands and wet vegetation types were preferred, whereas clearcuts and middle-aged stands were used according to their availability . The birds spent about equal time arboreal and ground feeding. Surface feeding in Scots pine canopies and swamp vegetation constituted half of the observations . Nest sites (n = 36) were preferentially located in older stands of deciduous and spruce trees. In general, our findings confirm the notion that Great Spotted Woodpeckers are flexible in their choice of feeding habitat during breeding. However, the results indicate a certain preference for older forest stands and swamp vegetation types, which we suggest is linked to the availability of important insect prey groups.