A 10-year Population Survey of a Red-Cockaded Woodpeckers on a 5,181-Hectare Study Site, Apalachicola National Forest, Florida

Labisky, Ronald; Hovis, Julie; Sargent, Robert

Submitted as final report for Florida Fish and Wildlife Conservation Commission Project NG86-028. The status and population ecology of the endangered red-cockaded woodpecker (Picoides borealis) was investigated on a 5,181-ha tract of longleaf pine (Pinus palustris) and slash pine (P elliottii) forest in the Apalachicola National Forest, Florida, during the 10 years 1980-1989. The number of clusters, active and abandoned, increased from 42 in 1981 to 47 in 1989; the increase of 5 clusters, all active, included 2 previously unlocated clusters ( 1987) and 3 new clusters (1987 and 1988). Two of these new clusters were established through "budding," and the third apparently was a product of pioneering. There was a net gain of only I active cluster between 1981 (N = 40) and 1989 (N = 41); the number of active clusters was lowest in 1985 (N = 34) and greatest in 1988 (N = 42). The number of living cavity trees averaged 5.5 per cluster annually. The annual mortality rate of cavity trees averaged less than 4% annually, except for the greater than 19% loss of cavity trees attributable to Hurricane Kate in 1985. The rate of nestling production within active clusters averaged 73% for the 10 years 1980-1989, ranging from a low of 62% in 1985 to a high of 93% in 1989. Sixty-eight (62%) of 109 individual nest cavities produced nestlings in greater than 2 years; these cavities yielded 85% of the total production of nestlings. Nestlings were produced in I individual nest cavity for I 0 consecutive years. The amount of suitable foraging habitat within a 1.2-km radius of active clusters averaged 193.7 ha (SD = 1.5, N = I 0) annually, and was substantially greater than areal foraging habitat requirements previously reported for this population. Thus, changes in cluster status and nestling production observed during the I 0-year period more likely were related to demographic and behavioral factors rather than to habitat loss by clear cutting. Management practices in effect between 1980 and 1989 were sufficient to sustain the resident red-cockaded woodpecker population on the study site. However, these findings may not be applicable to those areas of the Apalachicola National Forest characterized by lesser stocking rates or different timber harvest regimes.