Competition for Red-cockaded Woodpecker Roost and Nest Cavities: Effects of Resin Age and Entrance Diameter

Ansra.Cr.-competition for roost and nest cavities was investigated in a Texas population of Red-cockaded Woodpeckers (Picoides borealis) in longleaf pine (Pinus pahstris) habitat. Twenty-two percent of all examined cavities were occupied by Red-cockaded Woodpeckers, and 46% were occupied by other species. Red-cockaded Woodpeckers did not roost in the open or in sub-optimum cavities due to the presence of other species, with one temporary exception. Southern flying squirrels (Glaucomys volans) were a potential competitor. Similar to Red-cockaded Woodpeckers, flying squirrels preferred cavities with small entrance diameters, and their use of cavities was not hampered by the presence of a resin barrier or woodpecker cluster status (active vs inactive). Other potentially competing species were either rare or restricted to enlarged cavities no longer used by Red-cockaded Woodpeckers. These data suggest that competition for cavities is not an important factor in this particular population of Texas Red-cockaded Woodpeckers during the period prior to breeding. Received 3 Nov. 1988, accepted I May 1989.