Humans represent the biggest threat to the eastern indigo snake. Summer home ranges for the indigo snake can be as large as . The Burmese pythons flexible diet makes it a competitor for the States endangered Indigo snake. The threatened eastern indigo snake is also present on the island. Highway fatalities, wanton killings, and overcollection for the pet trade adversely affect indigo snake populations. The eastern indigo snake was first described by John Edwards Holbrook in 1842. The Texas indigo snake is listed as a threatened species by the state of Texas. These include the eastern indigo snake, southern hognose snake and the mimic glass lizard. The Indigo snake (Drymarchon corais) is a species of snake of the family Colubridae. The eastern indigo snake, "Drymarchon corais couperi" is another species of this genus.