Changes in ranges of Florida Key deer—does population density matter?

The relationship between population density and range size has long been debated. While many studies have documented varying responses in range size to changes in population densities, most have been the result of experimental manipulation. We examined the effects of long-term density changes in Florida Key deer (Odocoileus virginianus clavium) on range and core-area sizes. We radiocollared Key deer as part of 2 separate research projects conducted December 1968–June 1972, and January 1998–December 2001. We used a total of 96 (females, n=62; males, n=34) and 163 (females, n=88; males, n=75) radiocollared Key deer to calculate annual and seasonal ranges and core areas, respectively. Season and age were not important factors in describing ranges and core areas of Key deer, while sex and period (early vs. current study) were important. On average, male annual ranges (=221 ha, current; =388 ha, early) were greater than female annual ranges (=42 ha, current; =101 ha, early), which might explain higher male mortality due to roadkills. Early ranges and core areas were greater (≅2x) than current ranges and core areas. We suggest that increased deer densities may have resulted in a decrease in Key deer ranges. Other factors influencing changes in Key deer ranges included increased habitat quality and Key deer domestication over the last 30 years.