A Simple Solution, But Not That Easy
Inserting artificial cavities into mature pine trees has played a major part in the restoration of red-cockaded woodpecker populations. Installation is designed to accommodate the species’ specialized lifestyle.
Each member of a red-cockaded woodpecker family group has a roosting cavity in a separate tree; the group’s cavity trees are located in “clusters.” Forest technicians install artificial cavities to supplement existing clusters or to provide cavities in a potentially new cluster site. Redcockaded woodpeckers may occupy these new sites on their own, or birds can be translocated to the sites by biologists. The ability to provide cavities in unoccupied habitat is a powerful tool in the ongoing recovery of this species.
Artificial cavity inserts are made out of a soft wood such as cedar to minimize swelling and warping. A 10- inch tall box is built (4 inches wide, 6 inches deep) with a 1¾ inch entrance hole angled to prevent rain from entering the chamber. The outside of the box is coated with exterior wood putty to keep pine resin from getting into the cavity.
Technicians are lifted up 12 to 22 feet off the ground to chainsaw a rectangular hole in a living tree; to accommodate the insert, the tree must be at least 15 inches in diameter at the installation site. Since red-cockaded woodpeckers may use a cavity for as long as 20 years, a healthy tree with a large crown should be selected. After the insert is installed, the top, bottom, and sides of the hole are coated with the same wood putty applied to the outsides of the box.
When they excavate their cavities, red-cockaded woodpeckers also dig into the bark of pine trees to create resin wells. The sticky resin that streaks their cavity trees keeps predators like snakes from reaching their nests. When an artificial insert has been installed, a technician may cut resin wells to start the flow of sap.