Effects of cavity-entrance restrictors on red-cockaded woodpeckers

The U.S. Forest Service has installed restrictors on cavity entrances of red-cockaded woodpeckers to limit access by larger cavity-dwelling competitors. This study tested the hypothesis that restrictors have no adverse effects on red-cockaded woodpeckers. Entrance restrictors were placed on openings to 20 cavities used by roosting red-cockaded woodpeckers, and 20 were left nonrestricted in the Bienville National Forest, Mississippi. No difference was found between treatments in subsequent cavity use by red-cockaded woodpeckers. We examined possible effects on bill wear of birds using cavities with the metal restrictors. We recorded evidence of damage to bills and measured bill lengths of 14 birds captured from cavities with restrictor plates compared to 20 birds from cavities without restrictors. No significant difference was found. These data indicate restrictors do not negatively affect red-cockaded woodpeckers.