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.