FWS Focus

Overview

Characteristics
Overview

The eastern indigo snake is a large, non-venomous snake in the family Colubridae. Native to the southeastern United States, it is the longest native snake species in the country. The generic name, Drymarchon, translates to "lord of the forest."

Threats

Habitat fragmentation and loss due to land use changes, especially urbanization, including residential and commercial development, and road construction and expansion. Vehicle strikes, human persecution, invasive species invasive species
An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.

Learn more about invasive species
, and predation pose further threats, and sea level rise is also an increasing risk.

Scientific Name

Drymarchon couperi
Common Name
Eastern Indigo Snake
Blue Indigo Snake
Blue Bull Snake
FWS Category
Reptiles
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Life Cycle

Characteristics
Life Span

Eastern indigo snakes may live for 8 to 12 years in the wild, become sexually mature around 3.5 years of age, and breed from October through January.

Reproduction

The eastern indigo snake lays eggs that are 3–4 inches long by 1 inch wide. Females will lay a single clutch of 4 to 14 eggs from late April through early June. Eastern indigo snakes usually do not reach maturity until they are 3 to 5 years old and around 5 to 6 feet in length. Females can retain live sperm for long periods, potentially over 4 years, and can choose when to release the sperm to fertilize the eggs. Mating season is at a peak from October through January.

Characteristic category

Habitat

Characteristics
Habitat

The eastern indigo snake lives in portions of Florida and southeastern Georgia in longleaf pine sandhills, scrub, pine flatwoods, tropical hardwood hammocks, and coastal dunes. Gopher tortoise burrows are important to these snakes' habitat for shelter.

Forest

A dense growth of trees and underbrush covering a large tract.

Characteristic category

Food

Characteristics
Food

The eastern indigo snake eats a wide variety of prey, including turtleslizardsfrogstoadsfish, small birds, mammals, and eggs. It consumes other snakes, including venomous ones, as it is immune to the venom of the North American rattlesnakes. While eastern indigo snakes depend on gopher tortoises for their burrows, they are also known to eat small tortoises.

Characteristic category

Behavior

Characteristics
Behavior

Eastern indigo snakes move seasonally between upland and lowland habitats, especially in the northern portions of their range. Throughout their range, eastern indigo snakes use below-ground shelter sites for refuge, breeding, feeding, and nesting. They depend on gopher tortoise burrows in xeric sandhill habitats throughout the northern part of the species’ range for overwintering shelter sites. Adults move long distances and have large home ranges; from several hundred to several thousand acres.

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

Mature adult eastern indigo snakes weigh from 2 pounds to over 10 pounds. This is the longest species of snake native to the United States and reaches up to 8.6 feet. Eastern indigo snakes are moderately heavy-bodied and almost entirely iridescent bluish-black with the chin and sides of the head colored reddish, orange-brown, or cream.

Geography

Characteristics
Range

Eastern indigo snake populations occur in portions of Florida as well as southern areas of Georgia and Alabama. Historically, this snake was found throughout Florida and in the coastal plain of Georgia, Alabama, and Mississippi.

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Timeline

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