Living with Snakes: the Eastern Indigo
There is no doubt that many people are uncomfortable when they see snakes but seeing an 8 foot one will strike terror in their minds. This reaction has probably cost the lives of many indigo snakes in our area. The largest of all North American snakes this harmless non-venomous snake actually consumes venomous ones as well as rodents and other animals we consider pests. But the site of this large, possibly hissing, snake in someone’s yard will certainly bring out a shovel, or pistil, and end the potential threat.
Indigos (Drymarchon corias ) are absolutely one of the most beautiful snakes in our area. Their smooth blue/black scales give the animal a “rainbow-metallic” sheen when in the sunlight; similar to the colors produce with gasoline on water. It is often confused with the Southern Black Racer (Coluber constrictor) but can be distinguished from this species but the reddish coloration under the skin (as opposed to the white chin of the racer) and, of course it’s size. Indigos are a foot long at birth and grow rapidly. They also have less timid disposition than the Southern Racer. Though they will bite they tend not to be more aggressive than the racer. Indigos are known in some parts of the south as the “bull snake” – possibly due to their resemblance to bull whips of the frontier days.
Gibbons and Dorcas report the range of the Eastern Indigo Snake including all of Florida, portions of southern Georgia, a narrow area of Alabama along the Florida border, extreme southeast Mississippi, and the peninsula area of southern Texas. They prefer dry, well drained soils in habitats such as longleaf pine, turkey oak, and palmetto fields. They seem to prefer similar habitats as the gopher tortoise and are one of the many animals that share the gopher’s burrow during bad weather. They tend to be more active during daylight hours and may be seen basking near a gophers burrow on a sunny day during winter months.
They feed on a variety of prey and are non-constrictors – preferring to actually bite and swallow their prey directly. They are known to prey on rattlesnakes, cottonmouths, and copperheads and tend to attack these prey by biting their heads. The fact that they feed on venomous snakes may reduce the number of humans who try to kill them. One story involved Indigos that were part of a re-stocking project in south Alabama by a PhD candidate at Auburn University. The student released Indigos in the Conecuh Forest and tracked them using radio tags. Several of his snakes moved towards a local church retreat camp. Concerned that the inhabitants of the camp would see the large snakes and try to kill them forced him to rush to the location. When he arrived he was told that yes, they had seen the snakes and they were heading towards the maintenance shed. The reason for their attraction the shed was it housed several copperheads that the indigos in turn consumed. This made the inhabitants of the camp happy and they now respect, and welcome, the indigos. Education will be a major player in spreading this thought across our area.
When encountered indigos rarely strike but reports of bites have occurred and from those who have been bit, this large snake can be quite painful – so care should be taken. They may hiss and flatten their heads appearing aggressive but in most cases they tend to “run away” from humans.
In 1978 the Eastern Indigo was listed as a threatened species under the Endangered Species Act. The causes of its decline include: loss of habitat (non-fire and development), the pet trade, and using gasoline in gopher burrows to capture either gophers or rattlesnakes, and collisions on highways; as you can imagine it is difficult for an 8 foot snake to get completely off the road when crossing. The animal is still found in peninsula Florida and recent reports suggest that are adapting to human neighborhoods where rodents and other snakes can be found. They are rare in southern Georgia and have not been verified in Alabama or Northwest Florida since 1998 (reported by the Alabama Chapter – Partners in Amphibian and Reptile Conservation; November 2010). Auburn University is currently experimenting with a release program in the Conecuh Forest just north of Santa Rosa and Okaloosa counties and an “all call” has gone out in Northwest Florida. Anyone who believes they have seen this snake in our area should contact Rick O’Connor at the Escambia County Extension Service (email@example.com) and, if possible, obtain a good photograph as well as a GPS location. Important in the photograph will be the head region to observe coloration.