Comparisons of extent of decay in southern red oaks (Quercus falcate Michx.) revealed that trees injected with 2.4-D decayed sooner than girdled trees. Internal examinations of treated trees revealed that girdling and injection permitted growth of heartwood-and sapwood-decaying fungi a condition necessary for woodpecker nest cavity excavation. As a result of the delayed decay, girdling produces better woodpecker habitat in southern red oak. Girdled southern red oaks remain standing longer for woodpeckers to use for foraging and nesting sites. Number of snags required to support various percentages of woodpecker population maximums are presented.
Conner, Richard N.; Kroll, James C.; and Kulhavy, David L., "The Potential of Girdled and 2,4-D-Injected Southern Red Oaks As Woodpecker Nesting And Foraging Sites" (1983). Faculty Publications. 285.