Interspecific interactions with foraging Red-cockaded Woodpeckers in south-central Florida

Interspecific competition for Red-cockaded Woodpecker (Picoides borealis) c avities has been well documented and may be one factor contributing to the species' decline. Other forms of interspecific interactions have rarely bee n documented over most of the species' range and have received little atten tion. During 806 hours of Red-cockaded Woodpecker foraging observations in south-central Florida we documented 306 interspecific interactions with 19 species. We observed fewer non-foraging interactions (98) than foraging int eractions (208). Red-cockaded Woodpeckers lost 70 (71%) of the non-foraging interactions and 177 (85%) of the foraging interactions. Most non-foraging interactions (64%) were with non-woodpecker species, several of which freq uently and consistently dominated Red-cockaded Woodpeckers. Together, Easte rn Kingbirds (Tyrannus tyrannus), Great Crested Flycatchers (Myiarchus crin itus), Eastern Bluebirds (Sialia sialis), and Pine Warblers (Dendroica pinu s) won 45 of their 48 (94%) non-foraging interactions with Red-cockaded Woo dpeckers. Most foraging interactions (97%) were with other woodpecker speci es. Red-bellied Woodpeckers (Melanerpes carolinus) were involved in 172 (85 %) of these interactions, of which they won 168 (98%). We found no relation ship between the rate of interactions and the habitats or the local landsca pe in which these interactions occurred. Red-cockaded Woodpeckers did not a ppear to move to different and possibly less productive foraging sites afte r being usurped. In south-central Florida, where hardwood basal areas are r elatively low in Red-cockaded Woodpecker habitat, the foraging niche of the se two species may overlap to a greater extent than elsewhere in their rang e.