Drymarchon couperi

Wüster et al. (2001) using morphological evidence, demonstrated that D. couperi is a distinct species (Crother 2017). Krysko et al. (2016a) supported recognition of D. couperi as distinct from D. melanurus and suggested that D. couperi is split into 2 distinct genetic lineages (termed "Atlantic" and "Gulf," but see Fig. 2 for map) that correspond to historical biogeography and sea level changes in peninsular Florida. Subsequently, Krysko et al. (2016b) erected a new species, D. kolpobasileus, to represent the Atlantic lineage. However, re-evaluation by Folt et al. (2019) from a broader genetic perspective cast doubt on the 2-species hypothesis, and D. kolpobasileus was synonymized into D. couperi. D. kolpobasileus is currently recognized by SSAR.

This species is restricted to the Coastal Plain of the southeastern U.S. An estimated 95% of longleaf pine forest, the primary habitat used by this species, was destroyed due to logging, agriculture, and development. Development continues to be a threat. Habitat degradation continues in the forms of long-term fire exclusion, the loss of gopher tortoises (Gopherus polyphemus) from the landscape, which provide crucial refuge sites in xeric habitats, and fragmentation by roads. The population declined by over 50% from historical levels and was extirpated from the entire western extent of the historical range. The population is presumably continuing to decline due to threats.

The current range includes southeastern Georgia, throughout Florida, and one reintroduced population in southern Alabama (Diemer and Speake 1983, Krysko et al. 2019, Chandler et al. 2023). In Florida, it is primarily found in the peninsula and is likely extirpated from the Panhandle except at Apalachicola Bluffs and Ravines Preserve where it has been reintroduced (Krysko et al. 2019, Chandler et al. 2023). In Alabama, it is being reintroduced in Conecuh National Forest in the south-central part of the state (Chandler et al. 2023). Using Global Biodiversity Information Facility (GBIF) (2025) records from 2005-2025, range extent is estimated to be 283,532 km² (RARECAT 2025).

The historical range extended throughout the lower Coastal Plain of the southeastern United States, from southern South Carolina through Georgia and Florida to the Florida Keys, and west to southern Alabama and perhaps southeastern Mississippi (Diemer and Speake 1983). The species is apparently very rare or extirpated in Alabama, western Florida, Mississippi, and South Carolina.

USFWS (2019) determined there were 51 extant natural populations and two extant reintroduced populations.

Historical declines are primarily due to habitat loss of mature longleaf pine habitat due to conversion to slash pine (Pinus elliottii) and sand pine (P. clausa) plantations for lumber and paper industries, citrus groves and other agriculture, and mining (Moler 1992, Krysko et al. 2019). An estimated 95% of historical longleaf pine habitat was lost in the 1800s and 1900s (Ware et al. 1993). Habitat loss continues and relatively few sites have been adequately restored. By virtue of the loss of gopher tortoises (Gopherus polyphemus) from the landscape, which provide important refuges, habitat suitability continues to decline (Moler 1992, Bolt et al. 2023, USFWS 2024). Florida Fish and Wildlife Conservation Commission (FWC) allowed tens of thousands of tortoise burrows to be entombed prior to 2008, and continues to allow the destruction of habitat and tortoise burrows for development (FWC 2024). FWC provides permits for the relocation of over 10,000 tortoises annually, a quantity greater than the capacity of authorized recipient sites (Miller 2021, Turner 2021, FWC 2024). The removal of stumps and fallen trees also eliminates another source of refuge sites for this snake (Moler 1992, Bolt et al. 2023). Habitat fragmentation from roads is a continuing threat with ongoing impacts. Long-term fire exclusion from fire-adapted habitats is also an ongoing threat reducing habitat quality (FNAI 2010). Multiple diseases impact this species and may be impacting overall health of individuals with unknown consequences at the population level (Bogan, Jr. et al. 2024).

Gassing of gopher tortoise burrows, which also incidentally killed this species, is considered a past threat after it was made illegal in Florida in 1978 (USFWS 1998, FWC 2024). Similarly, commercial collection for the pet trade is now illegal and has drastically declined (USFWS 1998).