Red-Cockaded Woodpecker Cavity-Tree Damage by Hurricane Rita: An Evaluation of Contributing Factors

Abstract

Picoides borealis (Red-cockaded Woodpecker) is an endangered species inhabiting pine savannas of the southeastern United States. Because the intensity of hurricanes striking the southeastern United States is likely to increase as global temperatures rise, it is important to identify factors contributing to hurricane damage to Red-cockaded Woodpecker cavity-trees. Our objectives were to examine the effects of landscape-level factors on wind damage to cavity-trees and assess the relative risk of wind damage for different tree species and trees with different types of cavities. We evaluated wind damage to cavity-trees from Hurricane Rita on the Angelina, Sabine, and Davy Crockett national forests in eastern Texas. Basal area and number of cavity-trees in a cluster were identified as factors influencing the likelihood of damage to a cavity-tree. The likelihood of damage increased with decreasing basal area and an increasing number of cavity trees in a cluster. The increase in damage associated with an increase in the number of cavity-trees in a cluster likely reflects an increase in cluster area with more cavity-trees and the maintenance of lower basal areas in clusters to meet the habitat requirements of Red-cockaded Woodpeckers. Therefore, increasing basal area is not a reasonable management option because clusters will become unsuitable for Red-cockaded Woodpeckers. A higher proportion of trees with natural cavities were damaged than trees with artificial cavities in all three forests. A higher proportion of Pinus echinata (Shortleaf Pine) cavity-trees were damaged than Pinus palustris (Longleaf Pine) or Pinus taeda (Loblolly Pine) cavity-trees. Longleaf Pine cavity-trees were more likely to snap at the cavity, compared to a higher likelihood of wind throw for Shortleaf and Loblolly Pine cavity-trees. Restoring Longleaf Pine habitat and allowing stands to develop under lower tree densities could decrease the likelihood of damage to cavity-trees and the impact of hurricanes on Redcockaded Woodpeckers.