RED-COCKADED WOODPECKER NESTING SUCCESS, FOREST STRUCTURE, AND SOUTHERN FLYING SQUIRRELS IN TEXAS

For several decades general opinion has suggested that southern flying squirrels (Glaucomys volans) have a negative effect on Red-cockaded W oodpeckers (Picoides borealis) through competition for cavities and eg g/nestling predation. Complete removal of hardwood trees from Red-cock aded Woodpecker cavity tree clusters has occurred on some forests beca use southern flying squirrel abundance was presumed to be associated w ith the presence and abundance of hardwood vegetation. In some locatio ns, southern flying squirrels have been captured and either moved or k illed in the name of Red-cockaded Woodpecker management. We determined southern dying squirrel occupancy of Red-cockaded Woodpecker cavities in loblolly (Pinus taeda)-shortleaf (P. echinata) pine habitat (with and without hardwood midstory vegetation) and longleaf pine (P. palust ris) habitat (nearly devoid of hardwood vegetation) during spring, lat e summer, and winter during 1990 and 1991. Flying squirrel use of Red- cockaded Woodpecker cavities was variable and was not related to prese nce or abundance of hardwood vegetation. Woodpecker nest productivity was not correlated with flying squirrel use of woodpecker cavities wit hin clusters. In addition, we observed six instances where Red-cockade d Woodpeckers successfully nested while flying squirrels occupied othe r cavities in the same tree. Our results suggest that complete removal of hardwoods from woodpecker cluster areas in loblolly and shortleaf pine habitat may not provide benefits to the woodpeckers through reduc tion of flying squirrel numbers. Reduction of hardwood midstory around cavity trees, however, is still essential because of the woodpecker's apparent innate intolerance of hardwood midstory foliage.