Cooperative Fish and Wildlife Research Units Program: Georgia
Education, Research and Technical Assistance for Managing Our Natural Resources

Delany, M. F., C. T. Moore, and D. R. Progulske, Jr. 1995. Territory size and movements of Florida grasshopper sparrows. Journal of Field Ornithology 66:305-309.


Florida Grasshopper Sparrows (Ammodramus savannarum floridanus) (n = 73) were color-banded and monitored on the U.S. Air Force Avon Park Range in southcentral Florida, 1989-1992, to obtain information on minimum area requirements and movements of this endangered subspecies. Estimates (100% convex polygon) of 30 breeding territories averaged 1.8 ha (SD = 0.96) and ranged from 0.6 to 4.8 ha. The mean territory size (95% convex polygon) of mated males was not significantly (P = 0.159) greater than that of unmated males. Population density was 0.0371-0.0614 territories/ha. Adults were sedentary, 21 of 25 resighted or recaptured individuals occupied the same breeding territories for 2-4 successive years. The maximum territory size and minimum population density suggest a minimum viable population of 50 breeding pairs may require 240-1348 ha of prairie habitat. Information on the breeding biology and winter ecology of the Florida Grasshopper Sparrow is needed to assess recovery efforts.