Relationships among red-cockaded woodpecker group density, nestling provisioning rates, and habitat
We examined Red-cockaded Woodpecker (Picoides borealis) food provisioning rates of nestlings during the 1992 and 1993 breeding seasons on the Vernon Ranger District of the Kisatchie National Forest in Louisiana. Provisioning rates were monitored at nest trees in moderate (9.8 groups/2 km radius, n=10) and low (5.9 groups/2 km radius, n=10) density populations. Habitat around each cluster was measured within three radii (100 m, 400 m, and 800 m) to evaluate the possible influence of habitat quality on group density and nestling provisioning rates. We tested the ' hypothesis that habitat quality and provisioning rates would be similar in areas with different densities of woodpecker groups. We failed to detect differences in nestling provisioning rates between woodpecker groups in moderate versus low group densities. Woodpecker groups from areas where group densities were moderate attempted to nest significantly more often than woodpecker groups occurring in low densities. Hardwood midstory vegetation was more abundant in areas with low woodpecker group density. Old-growth pines, which are known to be important for cavity excavation, were present in habitat around cavity-tree clusters of moderate-density groups, but generally absent in areas where group density was low. Woodpecker group density may be related to hardwood midstory conditions and the abundance and spatial distribution of remnant old pines.