Sixteen Conservation Focus Areas (Figure E1), distributed throughout portions of the historic and current range of the eastern indigo snake were identified, to provide our partners with a potential conservation scenario to consider to implement recovery efforts. Populations within these areas, if protected and managed for eastern indigo snakes under this scenario, could improve the status of the species. The areas were chosen because they contain potentially viable populations or because they will contribute to the connectivity of occupied eastern indigo snake habitat and thus increase dispersal between populations and improve opportunities for new population establishment. Preservation and enhancement of habitat within each focus area is important to maintain and expand the distribution of eastern indigo snake populations range-wide. Conservation Focus Areas in the historic range, represent important elements of the species’ historic distribution and representation, were selected to prevent further range collapse. Unoccupied areas may require varying degrees of rehabilitation (e.g., prescribed fire, gopher tortoise translocations) to restore habitat suitability prior to future recolonization or reestablishment efforts. These potential areas would require long-term protection and management so that existing and newly-established populations achieve and maintain viability.
Conservation Focus Areas were selected based on a review of the historical/current distribution and habitat requirements of the species. Data were incorporated from a review of the current literature, primarily Enge et al. (2013, entire); comments provided by of eastern indigo snake experts; and an eastern indigo snake habitat model (Appendix C). The primary factors used in delineating boundaries of Conservation Focus Areas within specific physiographic provinces were presence of: (1) intact, unfragmented (by major roads or river systems), naturally-functioning habitat representative of that area’s physiographic province that meet the medium or higher threshold for habitat fragmentation (25% of habitat is >20K acres patch size; or 50% is >10K acres patch size; or 75% >5K acres patch size ); (2) areas that in their totality, support genetic and ecological integrity of the species by including areas throughout the historical and current range of the eastern indigo snake and in both the Gulf Coastal Plain and Atlantic Coastal Plain; (3) areas that contain multiple, large acreages (greater than 2,500 ac (1,000 ha)) of conservation land such as public lands or property with conservation easements capable of adequate management (e.g., prescribed fire, wildlife corridors); and (4) diverse habitat types (e.g., scrub, sandhills, riverine sand ridges, etc.) as identified by our eastern indigo snake habitat model (Appendix C).
Physiographic provinces were used as described by Brooks (1981) for Florida and Wharton (1978) for Georgia. A discussion of the habitat types used by eastern indigo snakes in these physiographic provinces is provided below in the discussion of each individual Conservation Focus Area. Conservation Focus Areas were given names that would be identifiable to the general public by using a geographic area name or, as in the case of Fort Stewart and Okefenokee, the name of a major Federal landholding. Conservation Focus Areas may include entire watersheds and thus are composed of both public and private lands.
CONSERVATION FOCUS AREAS
PANHANDLE
Western Panhandle
The Western Panhandle Conservation Focus Area includes parts of Covington and Escambia counties in Alabama, and parts of Okaloosa, Santa Rosa, and Walton counties in Florida. Most of this Conservation Focus Area lies within the Western Highlands Physiographic Province, while the more southerly portions closer to the Gulf Coast are within the Coastal Lowlands. This area, close to the western margin of the species’ range, includes large and well-managed (e.g. regular prescribed fire) public lands both in Alabama and Florida (Conecuh National Forest, Blackwater River State Forest, Choctawhatchee River Wildlife Management Area (WMA), Eglin Air Force Base); and a privately-owned nature preserve dedicated to the preservation of native biodiversity (Nokuse Plantation). It contains approximately 845,607 ac (342,205 ha) of potential eastern indigo snake habitat. The most recent verifiable eastern indigo snake record for the region was at Eglin Air Force Base in 1999; a credible (but not verified by photo or specimen) eastern indigo snake sighting was reported from close to the base boundary in 2011 (Enge et al. 2013). The decline of eastern indigo snakes in this region may have resulted from a dramatic decline in gopher tortoise populations, going back to the mid 1900’s and coinciding with a period of heavy human predation on tortoises. Currently, an eastern indigo snake reintroduction effort is underway on the Conecuh National Forest, Alabama (Stiles et al. 2013, entire). In this region, eastern indigo snakes require tortoise burrows for cool-season shelter sites and other aspects of their ecology.
Apalachicola National Forest and Vicinity
The Apalachicola National Forest and Vicinity Conservation Focus Area occupies parts of Franklin, Gadsen, Leon, Liberty, and Wakulla counties in Florida. The Apalachicola National Forest (ANF) is located almost entirely within the Delta Plain and Coastal Strip physiographic regions, however the northeastern section, a large block of xeric sandhill (called the Munson Sandhills), is part of the Paleodelta Relics region (also known as the Woodville Karst Plain). North of the ANF an extensive sand ridge that is a part of the Quincy Hills physiographic region occurs on the east side of, and parallel to, the Apalachicola River in Liberty County. Apalachicola Bluffs and Ravines Preserve (owned by The Nature Conservancy) is located on this sand ridge, is actively managed for longleaf pine-wiregrass, and supports a gopher tortoise population. The Munson Sandhills and Apalachicola Bluffs and Ravines supported eastern indigo snake populations into the late 1980s-to-mid-1990s (Enge et al. 2013). Much of the western half of the ANF is too poorly-drained (i.e., mesic savannas and flatwoods, swamps) to support eastern indigo snakes, however this Conservation Focus Area contains 424,274 ac (171,698 ha) of potential eastern indigo snake habitat. In this part of their range, eastern indigo snakes require tortoise burrows excavated in well-drained xeric sands for cool-season shelter sites and other aspects of their ecology. If snake reintroductions are attempted in the Florida panhandle within the historic range of the species, the Munson Sandhills and Apalachicola River sandhills will be likely areas to consider for the effort.
NORTH FLORIDA
Suwannee River
The Suwannee River Conservation Focus Area includes portions of Alachua, Columbia Gilchrist, Lafayette, Levy, and Suwannee counties in Florida. This Conservation Area is located within the Northern Peninsula Plains, Suwannee River Valley and Newberry Sand Hills physiographic provinces and includes a portion of the Brooksville Ridge. The northern part of this area includes significant xeric sandhill habitats along the Suwannee River in Suwannee and Lafayette counties. The southern portion encompasses the northern extent of the Brooksville Ridge in Levy County. Approximately 406,732 ac (164,599 ha) of potential eastern indigo snake habitat occurs in this Conservation Focus Area. There are recent eastern indigo snake records for the rolling sandhills of Goethe State Forest, Watermelon Pond Wildlife and Environmental Area, and Ashton Biological Preserve in southwestern Alachua County; Troy Springs Conservation Area; Lafayette Blue Springs State Park in Levy County; Ichetucknee Springs State Park and Little River Conservation Area in Suwannee County; and Twin Rivers State Forest in Madison County. Habitat management of longleaf pine–wiregrass communities is ongoing at conservation tracts throughout this Conservation Focus Area. In this region, eastern indigo snakes require gopher tortoise burrows excavated in well-drained xeric sands for cool-season shelter and other aspects of their ecology.
Trail Ridge
The Trail Ridge Conservation Focus Area occurs in portions of Clay and Putnam counties, Florida. Trail Ridge is the largest of several long, low north-trending ridges in central Florida and is among the most distinctive landforms in an area of otherwise low topographic relief. The ridges are complexes of sand dunes formed during the Pleistocene and contain 110,031 ac (44,528 ha) of potential eastern indigo snake habitat. The Trail Ridge Conservation Focus Area is composed of portions of three physiographic regions: Duval Upland, Interlachen Sand Hills and Okefenokee Upland. In this Conservation Focus Area, eastern indigo snakes are thought to require gopher tortoise burrows excavated in well-drained xeric sands for cool-season shelter and other aspects of their ecology. Conservation lands in this region known to support eastern indigo snake populations include Camp Blanding Joint Training Center, Belmore State Forest, Etoniah Creek State Forest, and Gold Head Branch State Park.
PENINSULAR FLORIDA
Brooksville Ridge and Vicinity
The Brooksville Ridge and Vicinity Conservation Focus Area includes all of Citrus County and portions of Gilchrist, Hernando, Levy, Marion, and Sumter counties, Florida. It is situated within 10 different physiographic regions and encompasses 589,489 ac (238,558 ha) of potential eastern indigo snake habitat. The Brooksville Ridge, an ancient, linear dune line that extends from Levy County to southern Hernando County, is characterized by high-quality tracts of longleaf pine sandhills. Elevations along the ridge range from 70 to 300 ft (230 to 984 m) above sea level. This region is a recognized stronghold for the species in Florida (Enge et al. 2013). Although at this latitude eastern indigo snakes do not absolutely require gopher tortoise burrows, many indigo populations in this region are associated with xeric sandhills and large tortoise populations, and at these sites it is likely that they exhibit frequent use of tortoise burrows. Other habitats utilized by snakes in this region include scrubby and mesic pine flatwoods, hydric hammocks, and depressional wetlands. Conservations lands within this Conservation Focus Area with recent eastern indigo snake records include Marjorie Carr Cross Florida Greenway, Chassahowitzka National Wildlife Refuge, Chassahowitzka WMA, Ross Prairie State Forest, Goethe State Forest, Crystal River State Park, Weekiwachee Preserve, Lake Panasoffkee WMA, Half Moon WMA, Halpata Tastanaki Preserve, Annutteliga Hammock (a conservation land administered by the Southwest Florida Water Management District), Rainbow Springs State Park, and six different tracts comprising the Withlacoochee State Forest.
Gulf Coast
The Gulf Coast Conservation Focus Area occupies in portions of Charlotte, DeSoto, Hardee, Hillsborough, Lee, Manatee, and Sarasota counties, Florida. It is located primarily within the DeSoto Slope physiographic region, but also occurs within a portion of the Bone Valley Uplands region. The area is composed of a mix of dry prairie, pinelands, freshwater marsh, wet prairie, and hardwood swamp. Eastern indigo snakes do not depend on gopher tortoise burrows in this area and snake populations occur in various habitats. However, it’s likely that tortoise burrows are used where the species overlap. A significant portion of the natural habitat has been converted to pasture and cropland, however approximately 773,207 ac (312,906 ha) of this Conservation Focus Area represent potential eastern indigo snake habitat. Conservation lands in the region with potential habitat and recent records for eastern indigo snakes include Babcock Ranch Preserve, Myakka River State Park, and Duette Preserve. Babcock-Webb WMA also has potential habitat for the species.
Everglades
The Everglades Conservation Focus Area occurs in portions of Broward, Collier, Monroe, and Miami-Dade counties, Florida. This Conservation Focus Area is within the Big Cypress Swamp, Everglades, Southern Atlantic Coastal Strip, and Ten Thousand Islands physiographic regions. It is located in southernmost peninsular Florida and contains 657,004 ac (265,880 ha) of potential eastern indigo snake habitat. In this area, eastern indigo snakes are locally distributed and uncommon, inhabiting pine rocklands, hardwood hammocks, wetland margins, mangroves, and disturbed habitats. Eastern indigo snakes do not depend on gopher tortoise burrows in this area (in fact, natural tortoise populations are absent from most of this predominantly wetland region). Conservation lands in this region known to support eastern indigo snake populations include Everglades National Park, Big Cypress National Preserve, Rookery Bay National Estuarine Research Preserve, and Fakahatchee Strand Preserve State Park.
Ocala
The Ocala Conservation Focus Area occurs in portions of Lake, Marion, Putnam, and Volusia counties, Florida. It is situated within portions of Crescent City-Deland Ridge, Lynne Karst, Ocala Scrub, and St. John’s Offset Physiographic regions, lies between the Ocklawaha and St. Johns Rivers in central Florida and includes the Ocala National Forest where eastern indigo snakes have been documented in recent surveys (Enge et al. 2013). This Conservation Focus Area includes a significant part of the Big Scrub, a notable ecological area that supports many scrub endemic species. Uplands of approximately 445,997 ac (180,489 ha) of potential eastern indigo snake habitat include oak scrub, sand pine scrub, longleaf pine sandhills, xeric hammocks, and some mesic pine flatwoods. This area supports a very large gopher tortoise population (over 10,000+ individuals) and uplands are actively managed using prescribed fire. Eastern indigo snakes are widespread in this region but do not appear to be especially common. It is not known to what extent the eastern indigo snake depends on gopher tortoise burrows in this area, but it’s likely that tortoise burrow use is common where the species overlap.
Osceola Plain
The Osceola Plain Conservation Focus Area occurs in Osceola County, Florida. It is part of the Holopaw-Indian Town Ridges and Swales and Kissimmee Valley physiographic province, a region of palmetto prairie and scrubby flatwoods habitats. The Conservation Focus Area contains approximately 238,384 ac (96,470 ha) of potential eastern indigo snake habitat. Eastern indigo snakes do not depend on gopher tortoise burrows in this area, but it’s likely that tortoise burrow use is common where the species overlap. Conservation lands in this region with recent eastern indigo snake records include Bull Creek Wildlife Management Area, Three Lakes Wildlife Management Area, and Triple N Ranch Wildlife Management Area.
Lake Wales Ridge
The Lake Wales Ridge Conservation Focus Area occurs in Glades, Hardee, Highlands, and Polk counties, Florida. This south-central Florida Conservation Focus Area is centered on an ancient dune system which runs (north-to-south) for about 150 mi (240 km) and includes Lake Wales Ridge, Carlton Ranch Ridge, and Bombing Range Ridge physiographic regions. Intact habitats on the Lake Wales Ridge itself are predominantly scrub (oak scrub, sand pine scrub) and scrubby flatwoods, with lesser areas of sandhill habitat. Although at this latitude eastern indigo snakes do not absolutely require gopher tortoise burrows, many snake populations in this region are associated with xeric sandhills and large tortoise populations, and at these sites snakes exhibit frequent use of tortoise burrows (Layne and Steiner 1996, Bauder 2018). This region of approximately 645,361 ac (261,168 ha) of eastern indigo snake potential habitat is recognized as a significant population stronghold, despite historic habitat loss and fragmentation. Conservation lands eastern indigo snake populations in this Conservation Focus Area include the Avon Park Bombing Range, Lake Wales Ridge Wildlife and Environmental Area, Lake Wales Ridge State Forest, Highlands Hammock State Park, and Archbold Biological Station.
Merritt Island and Vicinity
The Merritt Island and Vicinity Conservation Focus Area occurs in Brevard County, Florida. This Conservation Focus Area, along the Atlantic Coast of central Florida, includes Merritt Island, as well as inland habitats located to the west, and on both sides of Interstate 95, in Brevard County. Physiographic regions within this area include Cape Canaveral, Central Atlantic Coastal Strip, and St. Johns Wet Prairie. Conservation lands supporting eastern indigo snake populations include Merritt Island National Wildlife Refuge, Seminole Ranch Conservation Area, Buck Lake Conservation Area, Salt Lake Wildlife Management Area, Fox Lake Sanctuary, and Cape Canaveral National Seashore. Although this Conservation Focus Area encompasses brackish estuaries and marshes, the remaining habitats consisting of approximately 132,709 ac (53,706 ha) of coastal dunes, oak scrubs, pine flatwoods, oak hammocks, cabbage palm hammocks, and swamps are considered potential eastern indigo snake habitat. Eastern indigo snakes in this region are not dependent on the presence of tortoise burrows and use a wide variety of refuge types including debris piles, small mammal burrows and armadillo burrows. The eastern indigo snake population in this region has been well-studied including research using radio-telemetry (Breininger et al. 2004, 2011, 2012).
SOUTHEAST GEORGIA
Fort Stewart
The Fort Stewart Conservation Focus Area occurs in Candler, Bryan, Bulloch, Evans, Liberty, Long, and Tattnall counties, Georgia. It is located primarily within the Sea Island Flatwoods physiographic province of southern Georgia and includes all of the Fort Stewart Military Installation. This area includes extensive xeric sand ridge habitats adjacent to the Canoochee River and xeric sandhills associated with Beard’s Creek, an Altamaha River tributary. Habitats within this Conservation Focus Area include fire-managed longleaf pine sandhills that support large sizeable tortoise populations, mesic pine flatwoods, blackwater creek swamps and isolated depressional wetlands. Approximately 260,253 ac (105,432 ha) of potential eastern indigo snake habitat occurs within this Conservation Focus Area. The eastern indigo snake population on the Fort Stewart Military Installation has been monitored via mark-recapture methods for 15 years (1999-2014) (Stevenson et al. 2009, Hyslop et al. 2012) and was the site of a recent radio-telemetry study examining home range and habitat use (Hyslop 2007). There are numerous recent eastern indigo snake records for this area. Eastern indigo snakes in this region require gopher tortoise burrows excavated in well-drained xeric sands for cool-season shelter and other aspects of their ecology.
Altamaha River Sandhills
The Altamaha River Sandhills Conservation Focus Area occurs in Appling, Candler, Coffee, Emanuel, Glynn, Jeff Davis, Long, McIntosh, Montgomery, Tattnall, Telfair, Toombs, Wayne, and Wheeler counties, Georgia. It is located primarily within the Tifton Uplands with more southerly portions within the Sea Island Flatwoods physiographic province. It includes eastern indigo snake and gopher tortoise habitats within the Altamaha River Drainage from the lower Ocmulgee River and lower Oconee River (and their perennial tributaries) southeasterly and downstream along the Altamaha River to close to the coast. Approximately 620,253 ac (251,008 ha) of potential eastern indigo snake habitat occurs within this Conservation Focus Area.
Because of the widespread distribution of the eastern indigo snake and local robust populations, this region has long been recognized as a population stronghold for the species in Georgia. This Conservation Focus Area includes some xeric sand ridge habitats that, historically, have been fire-suppressed or planted for commercial forestry; active management efforts are currently underway to restore these sites to longleaf pine – wiregrass habitats (e.g., Long and McIntosh counties). Eastern indigo snakes in this region require gopher tortoise burrows excavated in well-drained xeric sands for cool-season shelter and other aspects of the snakes’ ecology. There are numerous recent eastern indigo snake records for this area, and substantial acreage of public and conservation lands within this Conservation Area which include the Griffin Ridge Wildlife Management Area, Orianne Indigo Snake Preserve, Sansavilla Wildlife Management Area, and Townsend Wildlife Management Area. Even so, acquisition and/or protection of additional eastern indigo snake habitat is needed, especially along the Ohoopee River and Little Ocmulgee River.
Alapaha River Sandhills
The Alapaha River Sandhills Conservation Focus Area occurs in Berrien, Coffee, Echols, Irwin, Lanier, Lowndes, and Turner counties, Georgia. It is located within the Tifton Uplands and Okefenokee Plains physiographic provinces of southern Georgia. This Conservation Focus Area includes vast areas of xeric sand ridge habitats, some of which are intact and in good condition with large numbers of gopher tortoises, adjacent to the Alapaha River. It also includes sandhills within the upper Satilla River Drainage along 17-Mile River. Approximately 283,837 ac (114,865 ha) of this Conservation Focus Area is considered potential eastern indigo snake habitat. Eastern indigo snakes in this region require gopher tortoise burrows excavated in well-drained xeric sands for cool-season shelter and other aspects of the snakes’ ecology. There are numerous recent eastern indigo snake records for the Alapaha River Sandhills although public conservation lands within this Conservation Focus Area are limited to Alapaha River Wildlife Management Area, a Georgia Forestry Commission Conservation Easement in Berrien County, Grand Bay Wildlife Management Area, and Moody Air Force Base. Acquisition and/or protection of additional eastern indigo snake habitat are needed.
Cabin Bluff
This small Recovery Area is located entirely within Camden County and extends to the Atlantic Coast (Sea Islands Coastal Marsh and Sea Island Flatwoods physiographic provinces). Habitats here include a matrix of sandy uplands, pine flatwoods, wetlands and coastal marshes between the lower Satilla River and the Crooked River. Approximately 24,663 ac (9,981 ha) of this Conservation Focus Area is considered potential eastern indigo snake habitat. The region supports a large gopher tortoise population and is one of the few sites in Georgia where eastern indigo snakes occur in coastal habitats. Eastern indigo snakes in this region require gopher tortoise burrows excavated in well-drained xeric sands for cool-season shelter and other aspects of the snakes’ ecology. Public conservation lands are very limited to Crooked River State Park although the nearby Kings Bay Navy Base may offer suitable habitat within this Conservation Focus Area. Acquisition and/or protection of additional eastern indigo snake habitat are needed.
Okefenokee and Vicinity
The Okefenokee and Vicinity Conservation Focus Area occurs in Brantley, Camden, Charlton, Clinch, Glynn, Ware, and Wayne counties, Georgia; and a small area of Nassau County, Florida. It is located mostly within the Okefenokee Swamp and Okefenokee Plains physiographic provinces, but also includes part of the Bacon Terraces. This area includes all of the Okefenokee National Wildlife Refuge (ONWR) and sandy uplands on the east side of the refuge associated with Trail Ridge; and areas of sandhill habitats north of ONWR and within the Satilla River and St. Mary’s River Drainages. Recent field work has provided data documenting eastern indigo snakes from the east side of ONWR (Enge et.al. 2013), however, eastern indigo snakes are not currently known to inhabit any of the pine islands within the swamp interior, or any refuge lands on the west or north sides of the swamp. This Conservation Focus Area consists of approximately 351,861ac (142,395 ha) of potential eastern indigo snake habitat. Eastern indigo snakes in this region require gopher tortoise burrows excavated in well-drained xeric sands for cool-season shelter and other aspects of the snakes’ ecology. Outside of ONWR, there is very limited acreage of public and conservation lands within this Conservation Focus Area, and acquisition and/or protection of additional eastern indigo snake habitat is needed, especially within the Satilla River Drainage.
