Home ranges of Red-Cockaded Woodpeckers in coastal South Carolina
Total observed ranges of 24 groups of Red-cockaded Woodpeckers (Picoides borealis) varied from 34 to 225 ha and averaged 86.9 ha. Groups defended portions of these ranges from adjacent groups year-round. Home ranges were derived from total observed ranges by subtracting extraterritorial areas and areas receiving limited use. The percentage of year-round home-range boundaries determined by intergroup conflicts varied from 0% to 54% and averaged 23.6%. Year-round home ranges averaged 70.3 ha and varied from 30 to 195 ha. The portion of year-round home ranges used in all sampling periods varied from 15% to 65% and averaged 30.5%. The amount of potential foraging habitat per group for all groups within 2,000 m of a study group's colony, a measure of population density relative to available habitat, accounted for 70% of the variation in size of year-round home ranges (P < 0.0001). Various measures of group size and habitat quality were weakly related to size of year-round home ranges. Measures of group size and population density together accounted for 80% of the variation in size of year-round home ranges.