Variation in Resin-well Construction as an Indicator of Predation Load and Breeder Experience in Red-cockaded Woodpecker Populations

Abstract

The pine forest of the southeastern coastal plain supports a rich assemblage of cavity nesting birds. Unlike some regions, most primary and secondary cavity nesters experience high rates of nest predation. Rat snakes (Elaphe spp.) are proficient tree climbers and are well-documented nest predators throughout the red-cockaded woodpecker's (Picoides borealis) range. Nesting success of this species, however, is relatively high. This woodpecker is well-known for excavating cavities in living pine trees as well as excavating moderate to small holes or resin wells above and below its cavities, and scaling loose bark from around them. These behaviors create a surface around the cavity entrance that is difficult for snakes to climb. Despite these protective behaviors, snakes successfully depredate some nests. This suggests that variation may exist in individual woodpecker investment in cavity protective behaviors. To explore the usefulness of resin-well construction on cavity trees as an indicator of predation an...