The role of naturally occurring waterholes in determining the distribution of Florida Key Deer

The purpose of my research was to test the hypothesis that the availability of fresh, naturally occurring water may limit the distribution of Florida Key Deer (Odocoileus virginianus clavium). More specifically, I was trying to determine if there was enough fresh, drinkable water for the deer on each of the islands. To test the hypothesis, I developed a model that simulated likely seasonal fluctuations in fresh water availability in naturally occurring waterholes within the Key Deer range. I estimated 60 scenarios representing different weather (precipitation and evaporation) conditions, different literature estimates of the daily water requirement of Key Deer and also different upper salinity thresholds for drinkable water. Results showed that 1) even under the most favorable conditions in terms of fresh water availability, there was not enough fresh, drinkable water for the deer on any of the islands. Results also showed that 2) high salinity was important in determining the fresh water availability to the deer, in addition to the lack of water volume. Although these results suggest a prolonged seasonal shortage of fresh, naturally occurring water on each of the islands, deer were present on all of the islands during all seasons. One possible reason for the lack of correlation between Key Deer distribution and naturally occurring waterholes is the availability of man-made water sources (e.g. birdbaths, swimming pools)