Home ranges and social behaviour of the Downy Woodpecker Picoides pubescens in Winter.

Few detailed studies have been performed on winter social behaviour of temperate-zone woodpeckers, in contrast to other resident forest birds. We collected information on individually colour-ringed Downy Woodpeckers (Picoides pubescens) in central Ohio, North America, during December 1989 and January 1990. Woodpeckers were generally seen with one or two conspecifics in the vicinity. Male-female associations were observed more often than expected by chance. Woodpeckers tended to space out individually within their sex class, but they tolerated members of the opposite sex. However, there were no signs of territorial defense or permanent pair bonds. Such loose social structure has not been documented in resident birds before. Our observations contradict earlier reports of individual territoriality in the Downy Woodpecker, while they are compatible with other studies on intersexual competition and niche divergence.