Eastern Indigo Snake
Eastern indigo snake. Eastern indigo snake. © Dirk J. Stevenson

Stories in Florida

An Apex Predator Returns

Absent for 35 years, the eastern indigo snake is back. The reintroduction of eastern indigo snakes in North Florida could be as significant as the reintroduction of wolves to Yellowstone.

The longest snake native to the United States, the eastern indigo grows 9 feet long, sleek as a stair banister, with conspicuous black-blue scales. It’s non-venomous, docile even when cornered and, at least as far as its diet goes, fond of its fellow snakes, particularly the venomous kind. A daytime hunter, it was once a common sight throughout Florida, Georgia, southern Alabama and southeastern Mississippi. By 1978, however, its numbers had so declined it was one of the earliest entries on the list of protected wildlife under the Federal Endangered Species Act, victim to human antipathy, cars and the steady degradation of its habitat.

Eastern indigos had been noticeably absent at the Conservancy’s Apalachicola Bluffs and Ravines Preserve (ABRP) since the last ones were spotted 1982. As an apex predator, the species plays a vital role in the natural balance, a consumer of otherwise unchecked species, especially snakes. Many endemic species at ABRP, particularly songbirds, have likely suffered from the imbalance.

When the first 12 zoo-raised eastern indigos were released to the ABRP, it symbolized success for a partnership 35 years in the making that, in addition to the Conservancy, includes Central Florida Zoo’s Orianne Center for Indigo Conservation, Auburn University, the Florida Fish and Wildlife Conservation Commission, the U.S. Fish and Wildlife Service, the Orianne Society, the Joseph W. Jones Ecological Research Center, National Fish and Wildlife Foundation, Gulf Power, the Fish and Wildlife Foundation of Florida, the U.S. Forest Service and Florida Department of Environmental Protection.

 The Nature Conservancy's David Printiss holding an eastern indigo snake prior to its reintroduction stands with partners in conservation. © Bill Boothe, PhotoNaturalist/NatureInFocus.com (CC BY 2.0)
Reintroduction Indigo snake release with partners from Florida Fish & Wildlife Conservation Commission © Bill Boothe

Apalachicola Bluffs was not an arbitrary choice for the snakes’ return. Originating, poetically enough, with a tract of land called the Garden of Eden, the preserve today is one of Florida conservation’s greatest success stories. After 35 years of restoration efforts by the Conservancy and its partners, it is now a fully restored Florida  longleaf pine landscape, a vast forest system that once flourished throughout the state, north to Virginia and west to Southern Texas, but is now reduced to only 5 percent of its original map.

FL Longleaf Pine Forest
Indigo Habitat Longleaf pine forest at Apalachicola Bluffs and Ravines Preserve where the snakes are released. © Katherine Blackmore

“Patient restoration efforts, including groundcover restoration, prescribed burns and replanting, have fully restored the ABRP, part of a region that is now considered one of the five most important biological hotspots in North America,” said David Printiss, the North Florida Program Manager for the Conservancy.

A lush mosaic of habitats, the preserve is forested with pines, cut with ravines and streams, and carpeted in mile after mile of waving wiregrass. As this flora returned, so did the gopher tortoises, bobwhite quail and Florida pine snakes. The only missing piece was the eastern indigo.

 Several groups heading out to release eastern indigo snakes.
Release Date TNC staff and partners head out to release eastern indigo snakes. © Fran Perchick/TNC

Bred and raised by Central Florida Zoo’s Orianne Center for Indigo Conservation (OCIC), each reintroduced eastern indigo snake was tagged with a subcutaneous radio transmitter and a Passive Integrated Transponder (PIT) tag. The tags help scientists measure survival rate, reproduction, preferred habitats and the distance the snakes cover. The data from the tags is monitored full time by scientists at Auburn University in Alabama.

“Auburn has a long history with eastern indigos, dating back to the 1970s, including two earlier reintroductions in Alabama,” said David Steen, assistant research professor overseeing the monitoring program.

In the next 10 years, the plan is to release approximately 300 eastern indigos into the preserve, said Michele Elmore, lead biologist for the U.S. Fish and Wildlife Service.

“For the first time in a long time, other parts of the Panhandle are being restored to the point that they, too, will be ready for reintroductions,” she said. “Our ultimate goal is to establish and protect enough viable populations so that we can remove the eastern indigo from the list of protected wildlife.”

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 Chief Veterinary Officer of the Central Florida Zoo, Dr. James Bogan conducts the transmitter procedure with the eastern indigo snake. © Central Florida Zoo (CC BY 2.0)
Tracking the Indigos Chief Veterinary Officer of the Central Florida Zoo, Dr. James Bogan conducts the transmitter procedure with the eastern indigo snake. © Central Florida Zoo