Indigo snake
Encyclopedia
The eastern indigo snake (Drymarchon couperi) is a large nonvenomous snake with an even blue-black coloration, with some specimens having a reddish-orange to tan color on the throat, cheek and chin. This smooth- scaled snake is considered to be the largest native snake species in the United States with the longest recorded specimen measuring 9.2 feet (2.8 m). The eastern indigo snake received its name from the glossy iridescent blackish-purple sheen it displays in bright light.
in 1842. The species was considered monotypic with 12 subspecies until the early 1990s when it was elevated to full species status according to the Society for the Study of Amphibians and Reptiles, in their official names list.
The Latin name for the genus Drymarchon roughly translates to “Lord of the Forest”. It is composed of the Greek words Drymos (Δρυμός), meaning "forest", and Archon(ἄρχων), meaning "lord" or "ruler". The specific name is a Latinization of James Couper's surname. Couper brought Holbrook the first specimen from south of the Altamaha River
in Wayne County, Georgia
. Eastern indigo snakes have a number of common names including indigo, blue indigo snake, black snake, blue gopher snake, and blue bull snake.
south through Florida
and west to Louisiana
, Mississippi
, and Alabama
. The Texas indigo snake (subspecies Drymarchon melanurus erebennus) is found in southern Texas and Mexico.
Because of habitat loss, the eastern indigo snake is listed as a federally threatened species in Georgia and Florida.
The eastern indigo snake is most abundant in the sandhill plant communities of Florida and Georgia. These communities are primarily scrub oak-longleaf pine (Pinus palustris) with occasional live oak (Quercus virgianiana), laurel oak (Q. laurifolia), Chapman's oak (Q. chapmanii), and myrtle oak
(Q. myrtifolia). Other communities include longleaf pine-turkey oak (Q. laevis), slash pine (Pinus elliottii)-scrub oak, pine flatwoods, and pine-mesic hardwoods.
it can overpower. It has been known to kill its prey by wildly beating it against nearby objects. Captive specimen are frequently fed dead prey to prevent injury to the snake from this violent method of subduing its prey. Its diet
has been known to include other snakes (ophiophagy
), including venomous ones, as it is immune to the venom of the North American rattlesnake
s. Eastern indigo snakes eat turtles, lizards, frogs, toads, a variety of small birds and mammals, and eggs.
As defensive behavior the eastern indigo snake vertically flattens its neck, hisses, and vibrates its tail. If picked up, it seldom bites.
It often will cohabit with gopher tortoises
in their underground burrows, although it will settle for armadillo
holes, hollow logs, and debris piles when gopher tortoise burrow
s can't be found. Hunters, hoping to flush out rattlesnake
s, often wind up accidentally killing indigo snakes when they illegally pour gasoline
into the burrows of gopher tortoises (a practice referred to as "gassing"), even though the tortoises themselves are endangered and protected.
, this snake requires a larger enclosure than most species do, preferably with something to climb on.
Taxonomy
The eastern indigo snake was first described by John Edwards HolbrookJohn Edwards Holbrook
John Edwards Holbrook American zoologist, herpetologist, physician, and naturalist, was born in Beaufort, South Carolina, the son of Silas Holbrook, a teacher, and Mary Edwards....
in 1842. The species was considered monotypic with 12 subspecies until the early 1990s when it was elevated to full species status according to the Society for the Study of Amphibians and Reptiles, in their official names list.
The Latin name for the genus Drymarchon roughly translates to “Lord of the Forest”. It is composed of the Greek words Drymos (Δρυμός), meaning "forest", and Archon(ἄρχων), meaning "lord" or "ruler". The specific name is a Latinization of James Couper's surname. Couper brought Holbrook the first specimen from south of the Altamaha River
Altamaha River
The Altamaha River is a major river of the American state of Georgia. It flows generally eastward for 137 miles from its origin at the confluence of the Oconee River and Ocmulgee River towards the Atlantic Ocean, where it empties into the ocean near Brunswick, Georgia. There are no dams...
in Wayne County, Georgia
Wayne County, Georgia
Wayne County is a county located in the U.S. state of Georgia. As of 2000, the population was 26,565. The 2007 Census Estimate showed a population of 29,046. The county seat is Jesup.-History:...
. Eastern indigo snakes have a number of common names including indigo, blue indigo snake, black snake, blue gopher snake, and blue bull snake.
Distribution
The eastern indigo snake ranges from southern South CarolinaSouth Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
south through Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
and west to Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
, Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...
, and Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
. The Texas indigo snake (subspecies Drymarchon melanurus erebennus) is found in southern Texas and Mexico.
Because of habitat loss, the eastern indigo snake is listed as a federally threatened species in Georgia and Florida.
Preferred habitat
Eastern indigo snakes frequent flatwoods, hammocks, dry glades, stream bottoms, cane fields, riparian thickets, and high ground with well-drained, sandy soils. In Georgia, snakes prefer excessively drained, deep sandy soils along major streams, as well as xeric sandridge habitats. Xeric slash pine plantations seem to be preferred over undisturbed longleaf pine habitats. Habitat selection varies seasonally. From December to April, eastern indigo snakes prefer sandhill habitats; from May to July snakes shift from winter dens to summer territories; from August through November they are located more frequently in shady creek bottoms than during other seasons.The eastern indigo snake is most abundant in the sandhill plant communities of Florida and Georgia. These communities are primarily scrub oak-longleaf pine (Pinus palustris) with occasional live oak (Quercus virgianiana), laurel oak (Q. laurifolia), Chapman's oak (Q. chapmanii), and myrtle oak
(Q. myrtifolia). Other communities include longleaf pine-turkey oak (Q. laevis), slash pine (Pinus elliottii)-scrub oak, pine flatwoods, and pine-mesic hardwoods.
Cover requirements
Because the cover requirements of eastern indigo snakes change seasonally, maintaining corridors that link the different habitats used is important. From the spring through fall snakes must be able to travel from sandhill communities and upland pine-hardwood communities to creek bottoms and agricultural fields. In winter, indigo snakes den in gopher tortoise burrows, which are usually found in open pine forests with dense herbaceous understories. Burrows need to be in areas where there is no flooding. Eastern indigo snakes heavily use debris piles left from site-preparation operations on tree plantations. These piles are often destroyed for cosmetic reasons but should be left intact because they provide important hiding cover for both the snake and its prey. Summer home ranges for the indigo snake can be as large as 273 acres (229 ha).Food habits and behavior
The eastern indigo snake is carnivorous, like all snakes, and will eat any other small animalAnimal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
it can overpower. It has been known to kill its prey by wildly beating it against nearby objects. Captive specimen are frequently fed dead prey to prevent injury to the snake from this violent method of subduing its prey. Its diet
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
has been known to include other snakes (ophiophagy
Ophiophagy
Ophiophagy is a specialized form of feeding or alimentary behavior of animals which hunt and eat snakes. There are ophiophagous mammals , birds , lizards , and even other snakes, such as the Central and South American mussuranas and...
), including venomous ones, as it is immune to the venom of the North American rattlesnake
Rattlesnake
Rattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae . There are 32 known species of rattlesnake, with between 65-70 subspecies, all native to the Americas, ranging from southern Alberta and southern British Columbia in Canada to Central...
s. Eastern indigo snakes eat turtles, lizards, frogs, toads, a variety of small birds and mammals, and eggs.
As defensive behavior the eastern indigo snake vertically flattens its neck, hisses, and vibrates its tail. If picked up, it seldom bites.
It often will cohabit with gopher tortoises
Gopherus polyphemus
The gopher tortoise is a species of the Gopherus genus native to the southeastern United States. The gopher tortoise is seen as a keystone species because it digs burrows that provide shelter for 360 other animal species...
in their underground burrows, although it will settle for armadillo
Armadillo
Armadillos are New World placental mammals, known for having a leathery armor shell. Dasypodidae is the only surviving family in the order Cingulata, part of the superorder Xenarthra along with the anteaters and sloths. The word armadillo is Spanish for "little armored one"...
holes, hollow logs, and debris piles when gopher tortoise burrow
Burrow
A burrow is a hole or tunnel dug into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Burrows provide a form of shelter against predation and exposure to the elements, so the burrowing way of life is quite popular among the...
s can't be found. Hunters, hoping to flush out rattlesnake
Rattlesnake
Rattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae . There are 32 known species of rattlesnake, with between 65-70 subspecies, all native to the Americas, ranging from southern Alberta and southern British Columbia in Canada to Central...
s, often wind up accidentally killing indigo snakes when they illegally pour gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
into the burrows of gopher tortoises (a practice referred to as "gassing"), even though the tortoises themselves are endangered and protected.
Predators
Humans represent the biggest threat to indigo snakes. Highway fatalities, wanton killings, and overcollection for the pet trade adversely affect indigo snake populations. Snakes are taken illegally from the wild for the pet trade. Eastern indigo snakes are sometimes gassed in their burrows by rattlesnake hunters.Reproduction
Eastern indigo snakes are oviparous. The eggs are 75–100 mm (3–4 in.) long by 27–32 mm (1-1¼ in.) wide. Only 5–6 eggs are laid. The hatchlings are 600–700 mm (23½–27½ in.) long.Captivity and care
Due to its generally docile nature and attractive appearance, some people find it a desirable pet, although its protected status can make owning one, depending on location, illegal without a permit. Only a few states require permits to own an eastern indigo snake but a federal permit is required to buy one from out of state anywhere in the US. The permit costs $100; information about obtaining one can be found by doing a web search. Most states allow unrestricted in-state sales. To thrive in captivityCaptivity (animal)
Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals or wild animals. This may include for example farms, private homes and zoos...
, this snake requires a larger enclosure than most species do, preferably with something to climb on.