NATURAL HISTORY

EASTERN INDIGO SNAKE } Drymarchon Couperi

NOTE: In 2016 biologists released a study determining that the species till then known as the “eastern indigo snake” is in fact two separate species — the eastern indigo snake, Drymarchon Couperi, and the Gulf Coast indigo snake, Drymarchon kolpobasileus. Relatively little is known about the Gulf Coast indigo snake and how its natural history differs from that of the eastern indigo, described below.

FAMILY: Colubridae

DESCRIPTION: The nonvenomous eastern indigo snake is the longest snake in the United States, ranging in size from 60 to 84 inches long. Its body, including the belly, is shiny and bluish-black in color. Its chin and the sides of its head are reddish- or orange-brown in color. Juvenile indigo snakes look very similar to adults but have more red featured along their heads.

HABITAT: Eastern indigo snakes inhabit pine flatwoods, hardwood forests, moist hammocks and areas surrounding cypress swamps. They require a variety of habitats to complete their annual cycle of breeding, feeding and sheltering. Gopher tortoise burrows are an important part of these snakes' habitat because the snakes use them for shelter from the winter cold and to escape dehydrating environments.

RANGE: This snake can be found in Florida, as well as southern areas of Georgia, Alabama and Mississippi.

MIGRATION: Eastern indigo snakes are not believed to migrate, though they do have a much smaller range in the winter than in the summer months.

BREEDING: Eastern indigo snakes breeding from November to April and nest from May to August. Females lay four to 12 eggs yearly or bi-yearly, with the eggs hatching 90 days after being laid.

LIFE CYCLE: There is no information about indigo snakes' lifespan in the wild, although one captive individual lived 25 years and 11 months.

FEEDING: Eastern indigo snakes' diet consists of a variety of species, including small mammals, birds, toads, frogs, turtles and their eggs, lizards and small alligators. Eastern indigo snakes also eat other snakes, including venomous species.

THREATS: Threats to eastern indigo snakes include habitat destruction and degradation, collection for the pet trade, road mortality, climate change and sea-level rise, and mortality from toxic chemicals used to collect rattlesnakes.

POPULATION TREND: Due to habitat destruction and degradation, populations of indigo snakes have been steadily declining, although an exact current population count is uncertain.

Photo of eastern eastern Indigo snake by Florian Denis/Flickr