Species Spotlight: The Eastern Indigo Snake
The eastern indigo snake (Drymarchon couperi) is the longest native snake in the United States. Adults are typically 60-84 inches (152-213 cm), but the longest eastern indigo reached 110.4 in. Male snakes grow longer than females. They are a shiny blueish-black color with some red or orange scales around their chins and sides of face. Juveniles have more red scales on their heads, but otherwise look very similar to adults. Their scales are mostly smooth, but adults have ridges on some of them.
The snakes feed mostly on small mammals, birds, amphibians, eggs, and reptiles, including other snakes and baby alligators. Eastern indigos do not use constriction to hunt; instead they use their large size and powerful jaws to attack and eat their prey. Biologists believe that the eastern indigo is mostly immune to rattlesnake venom. They are non-venomous and usually show no aggression to humans unless they are cornered. When feeling threatened, they flatten their heads, hiss, and make a rattling sound with their tails. Actual bites are very rare.
The eastern indigo’s range extends from South Georgia, throughout Florida, and in some areas of Alabama and Louisiana as well. It is found most commonly in Florida and Georgia’s sandhill plant communities where oaks and longleaf pines are common. The eastern indigo is also found in pine flatwoods, hardwood forests, moist hammocks, and around cypress swamps. They change habitats seasonally, searching for dens in the winter, using gopher tortoise burrows as their dens. They are only active during the day and can tolerate cold temperatures better than other snake species.
Eastern indigos breed from November to April. They lay their eggs in gopher tortoise burrows from May through August. A single clutch is four to 12 eggs. When they hatch, the baby eastern indigos are typically 16 in. long. Parthenogenesis is a type of asexual reproduction which may be possible for eastern indigo snakes.
The eastern indigo snake is listed as a threatened species by the US Fish and Wildlife Service. The species may already be extirpated (locally extinct) within Alabama. The destruction, fragmentation, and degradation of their habitat is the main threat facing the eastern indigo. Eastern indigo snakes lose more than 5% of their habitat yearly in Florida alone. They are frequently killed or injured by people hunting for rattlesnakes. The illegal process of “gassing” is also responsible for many of the deaths of eastern indigos. Gassing involves pouring gasoline into gopher tortoise burrows to flush out rattlesnakes. Pollution, vehicle strikes, and pet trade capturing also contribute to eastern indigo deaths.
Why is the eastern indigo important?
Eastern indigo snakes are at the top of the food chain; their health ensures the health of their habitat. Top predators play an important role in the food chain, keeping other species from overpopulating and harming the ecosystem. Population recovery efforts release captive-bred snakes into the wild, as well as restore and protect their native habitat. You can help the recovery of the eastern indigo snake by donating here.