DECLINE OF THE RED-COCKADED WOODPECKER (PICOIDES-BOREALIS) IN SOUTHEASTERN OKLAHOMA

A search of 4600 ha of the McCurtain County Wilderness Area (MCWA), Ok lahoma, in 1989-1990 yielded 15 groups of red-cockaded woodpeckers (Pi coides borealis). The number of groups and number of individuals in a 3795-ha area that was surveyed in 1977 and 1989-1990 declined by 62% a nd 75%, respectively. The productivity of the population was low durin g 1989-1990; 0.69 young were fledged per nesting attempt. To assess th e adequacy of foraging habitat, forest structure was measured in an ar ea with a high density of groups (1.95/km2) in 1990 and in an area whe re the group density had declined from 2.92 groups/km2 in 1977 to 0.74 groups/km2 in 1990. Forest structure in both areas was adequate but a pproached the limits recommended in the Red-cockaded Woodpecker Recove ry Plan. To determine if isolation of groups was related to population decline, we estimated nearest neighbor distances from cluster locatio ns (a cluster is the cavity trees used by a group of woodpeckers) in 1 977 and 1990. Cluster sites had longer nearest neighbor distances in 1 977 than in 1990, which may indicate that isolation by distance reduce s the influx of dispersing breeders from elsewhere in the population. Periodic fires occur naturally in the MCWA but have been suppressed si nce 1926. Re-establishment of a fire regime is important in maintainin g the integrity of the MCWA and may be beneficial to its red-cockaded woodpecker population.