Does red-cockaded woodpecker excavation of resin wells increase risk of bark beetle infestation of cavity trees?
The red-cockaded woodpecker (Picoides borealis) is unique among North American woodpeckers in that it nests and roosts almost exclusively in living pines (Pinus spp.) The red-cockaded woodpecker makes daily excavations at small wounds, termed "resin wells," around the cavity entrance and on the bole of the cavity tree from which resin flows down the tree. The woodpecker also flakes off loose bark, which results in a smoother surface on the pine tree's bole. These behaviors result in a resin barrier that serves as an effective deterrent against rat snakes, which prey on the red-cockaded woodpecker. A pine tree's resin provides its primary defense against the southern pine beetle (Dendroctonus frontalis). The authors discuss whether the red-cockaded woodpecker's depletion of a pine tree's resin increases the risk of bark beetle infestation. The article addresses results for longleaf (Pinus palustris), loblolly (P. taeda), and shortleaf (P. echinata) pines.