RED-COCKADED WOODPECKER NEST-CAVITY SELECTION - RELATIONSHIPS WITH CAVITY AGE AND RESIN PRODUCTION

We evaluated selection of nest sites by male Red-cockaded Woodpeckers (Picoides borealis) in Texas relative to the age of the cavity when on ly cavities excavated by the woodpeckers were available and when both naturally excavated cavities and artificial cavities were available. W e also evaluated nest-cavity selection relative to the ability of natu rally excavated cavity trees to produce resin, which is used by the wo odpeckers to maintain a barrier against predation by rat snakes (Elaph e spp.). Longleaf pines (Pinus palustris) selected by breeding males a s nest trees produced significantly greater resin yields at 2, 8, and 24 h post-wounding than cavity trees used for roosting by other group members. This preference was observed in loblolly pine (I! taeda) and shortIeaf pine (P. echinata) cavity trees only at the 2-h resin-sampli ng period. When only naturally excavated cavities were available, Red- cockaded Woodpeckers in both longleaf pine and loblolly-shortleaf pine habitat selected the newest cavities available for their nest sites, possibly as a means to reduce parasite loads. When both naturally exca vated and artificial cavity inserts were available, Red-cockaded Woodp eckers continued to select the newest cavity for nesting in loblolly-s hortleaf pine habitat but not in longleaf pine habitat. Resin producti on in existing longleaf pine nest trees remained sufficient for contin ued use, whereas resin production in loblolly pine and shortleaf pine nest trees decreased through time, probably because of woodpecker acti vity at resin wells. For these latter tree species, breeding males swi tched to newer cavities and/or cavity trees with higher resin yields.