The influence of local habitat and landscape composition on cavity-nesting birds in a forested mosaic

Abstract

Forest management influences both stand and landscape structure. While research exists on stand-scale habitat relationships for cavity-nesting birds, there are few studies at the landscape scale. In a managed forest, we characterised the influence of local vegetation on the occurrence of cavity-nesting bird species and determined whether landscape scale variables explained any of the remaining variation. We selected three spatial extents for investigation based on the species’ natural history: (1) local (100 m radius); (2) meso-scale (300 m radius); (3) macro-landscape (1000 m radius). Variables at the larger scales generally explained little of the species occurrence once we controlled for local factors. The occurrence of boreal chickadees, red-breasted nuthatches, hairy woodpeckers, and yellow-bellied sapsuckers was explained by variables solely at the local scale. Two species most commonly associated with younger stands, northern flicker and downy woodpecker, were influenced by variables at both the meso-scale and macro-landscape scales, although the amount of variance explained by the greater of these extents was small. We speculate that the comparatively strong influence of meso-scale variables may be due to the larger home range size of these two species. Sites that are appropriate at the stand level could remain unoccupied if the area of suitable habitat is not extensive enough to contain an entire home range.