Habitat Characteristics of Active and Abandoned Red-Cockaded Woodpecker Colonies
Active red-cockaded woodpecker (Picoides borealis) colonies in the Piedmont of Georgia are mature pine stands (mean age = 87 ± 1 yr old) with relatively sparse midstories (mean basal area = 31 ± 3 ft2/ac). Active and abandoned colony sites have similar overstory characteristics, but midstories are significantly denser in abandoned colony sites (mean basal area = 56 ± 3 ft2/ac ). Previous studies have focused on the effect of hardwoods in the midstory, but we found that increases in both pine and hardwood midstory density are associated with colony abandonment. A logistic regression model based on field data suggests that the probability of a colony becoming abandoned increases considerably when midstory basal area is > 30 ft2/ac. To maintain red-cockaded woodpecker populations, managers should keep midstory basal area in colonies below 25 ft2/ac. Treatments should be applied to entire stands and not just around individual cavity trees.