The federally threatened and state-threatened eastern indigo snake (Drymarchon couperi) is the longest native snake in North America. Today, this unique reptile is found only in disjunct populations in the extreme southeast, with most occurring in Florida and Georgia.
The population SCCF monitors appears to be the last barrier island population known to science.
Project Details
Population Monitoring
SCCF works with the Orianne Society, J.N. "Ding" Darling National Wildlife Refuge, and Florida State Parks to help assess the remaining populations of eastern indigo snakes in Pine Island Sound.
PIT Tagging
Our biologists mark and tag snakes with Passive Integrated Transponders (PIT) tags so movements can be documented.
Outreach
SCCF trains permittees to capture and process snakes and teaches volunteers to identify and document eastern indigo snakes, and educate others about keeping them safe.
Eastern Indigo Snake Facts
- Eastern indigo snakes are non-venomous. Learn about venomous snakes in Southwest Florida.
- They can reach over 8 feet in length (average is 5-7 feet)
- Their scales are bluish-black, and reddish-orange, brown, or tan on the throat, cheeks, and chin
- They have the largest home range of any snake in the U.S. A male's range can be up to 2 miles!
- They like upland, grassland areas near the edge of hammocks during the dry season and go into shadier, wetter areas over the summer
- They're frequent visitors of gopher tortoise burrows
- They often bask in the sun on cooler days
- They breed in winter. Sightings during summer are uncommon due to the intense heat
Threats to Eastern Indigo Snakes
- Vehicle strikes. These diurnal snakes may travel long distances and are prone to crossing roads. They are mostly non-existent in areas with roads.
- Habitat loss and fragmentation
- Pollutants and biomagnification of toxins in prey
- Poaching and fear-based illegal killing
History
The eastern indigo snake was once common on Sanibel and Captiva Islands but has been extirpated for over 20 years.
One of the last known eastern indigo snakes was hit by a bicycle on the Indigo Trail (named after the indigo snake) on the J.N. “Ding” Darling National Wildlife Refuge in February 1999. Over 10 years later, an eastern indigo snake swam to Captiva. Unfortunately, it was killed in a landscaping accident.
Surveys, trapping protocols, and educational programs asking island residents to document new specimens have failed in verifying any remaining snakes on Sanibel and Captiva.
The current population SCCF monitors inhabits small islands that are less developed.
The first eastern indigo snake of this project was brought to SCCF staff on Feb. 6, 2012, after the snake was found with unknown injuries. After a remarkable recovery at CROW, SCCF released it back into the wild on April 19, 2012. The Orianne Society asks that indigo snakes be given names, and the person who found the injured snake chose the name Kurt.
The main reason that the eastern indigo snakes we monitor are able to survive is the lack of busy roads and full-size vehicles on the islands they inhabit. Most of both islands are held in state park land, with large un-bisected tracts of land.
Report Eastern Indigo Snake Sightings
If you think you've seen an eastern indigo snake, take a photo without disturbing them to record their location and report it to SCCF at indigo@sccf.org or 239-472-3984.
Eastern indigo snakes resemble the very common southern black racer (Coluber constrictor priapus) and Florida watersnakes (Nerodia fasciata pictiventris), so be aware that there are other black snakes in the area.
