Final Report, Translocation as a Management and Restoration Technique for the Threatened Florida Scrub-jay (Aphelocoma coerulescens)

Mumme, Ronald; Below, Theodore

Abstract: The Florida scrub-jay (Aphelocoma coerulescens) is restricted to the oak scrub of peninsular Florida. Although loss of habitat is the major problem facing this threatened species, habitat protection alone is unlikely to ensure its continued survival. Because Florida scrub-jays are extremely sedentary and are often found in isolated fragments of suitable habitat, many existing populations are too small to be viable indefinitely. For these reasons, a successful management plan for the species should incorporate both habitat protection and the translocation of jays from healthy populations to isolated areas of suitable habitat where jays either are absent or have been recently extirpated. Prime candidates for such translocations are the "surplus" nonbreeding helpers that comprise roughly a third of the adult population of jays. Although physiologically capable of breeding, non breeding helpers are unable to do so because all suitable oak scrub habitat within a local population is usually occupied and defended by other jays. The purpose of this project was to evaluate translocation as a management technique for the Florida scrub-jay. Between 1987 and 1995, 20 Florida scrub-jays (14 nonbreeding helpers plus 3 breeding pairs) were removed from a color-banded population of jays at Archbold Biological Station in Highlands County and translocated to suitable but unoccupied habitat at Rookery Bay National Estuarine Research Reserve in Collier County. Although 9 (45%) of the translocated birds emigrated from Rookery Bay or died in the first 8 weeks following translocation, 11 remained and eventually settled at Rookery Bay. Successful nesting first occurred in 1989, and from 1991 through 1997 the population remained relatively stable with 6- 10 individuals and 1-3 breeding pairs. Measures of nesting success, juvenile survival, and adult survival at Rookery Bay were all comparable to those from Archbold Biological Station. However, because of high rates of mortality or emigration by females fledged at Rookery Bay, from 1991 through 1997 the population sex ratio was strongly biased toward males. Our results indicate that translocation of Florida scrub-jays is a viable technique for management and restoration of this threatened species. However, because of the scarcity of suitable translocation sites, the high rates at which jays emigrate or die following translocations, and the potential negative impacts on source populations, translocation should be pursued only under unusual circumstances. It should not be considered an acceptable substitute for the protection of existing populations and should be viewed only as a technique for the restoration of jays to unoccupied portions of their historic range.