Abstract
The Eastern Indigo Snake (Drymarchon couperi) is a large, non-venomous snake endemic to the southeastern coastal plains of the U.S. that is federally listed as threatened because of habitat loss and fragmentation. To implement effective management strategies, we must better understand the life history and movement patterns of this species. Our understanding of D. couperi remains limited, however, as previous studies focused on central and northern populations. To address this knowledge gap, we used radio telemetry to study D. couperi detectability, home range size, seasonal variation, habitat preferences, and shelter use in southss est Florida. We conducted this study in Collier County, Florida, USA, an environment with comparatively stable year-round temperatures, higher hydrological variations, and expansive saline environments relative to other areas in the range of the species. These D. couperi were most active during midday hours (1000-1400) and breeding seasons (October-March). These snakes prioritized upland features dominated by Gopher Tortoise (Gopherus polyphemus) burrows but would occasionally use wetland habitats including mangrove swamps. These snakes also maintained large annual home ranges (female mean = 110 ha; male range, 207-233 ha) similar to the most northern populations. Understanding the diverse behaviors of D. couperi is essential to the overall conservation of the species throughout its range. Current survey protocols, which encourage surveying snakes at sunrise and sunset during summer months, may not be appropriate for animals in southern Florida and could result in mismanagement of D. couperi if these patterns were replicated in similar locations.
