Longleaf pines used for cavities by red-cockaded woodpeckers
I studied characteristics and availability of young (≤80 yr old) and old (≥100 yr old) longleaf pines (Pinus palustris) used and not used for cavities by red-cockaded woodpeckers (Picoides borealis), and the associated population densities of red-cockaded woodpeckers in Osceola and Ocala national forests (NF) in Florida, and in Francis Marion NF in South Carolina. In Francis Marion NF old noncavity trees were common (17/ha); 6% of the cavity trees were young; decayed heartwood was frequent in old (97%) and young (86%) cavity trees (P = 0.299), but rare in young noncavity trees (9%); and population density was high (8.3 colonies/1,000 ha). In Osceola and Ocala NF, respectively, old noncavity trees were rare (<1/ha); 65 and 76% of the cavity trees were young; decayed heartwood was frequent in old cavity trees (80 and 90%), but less so in young cavity trees (27 and 32%) (P ≤ 0.007); young cavity trees had faster growth rates than young noncavity trees (P ≤ 0.001); and population densities were low (1.7 and 1.4 colonies/1,000 ha). Red-cockaded woodpeckers may have been using the easiest trees to excavate. The order of preference appeared to be trees with decayed heartwood and then fast-growing trees with sound heartwood. Because decay increases with tree age and decayed trees are the most preferred, older trees apparently provide red-cockaded woodpeckers with more and better opportunities for cavity excavation than younger trees. Results support past recommendations of providing longleaf pines >95 years old to red-cockaded woodpeckers for cavity excavation.