Eastern Indigo Snake: In Depth
Eastern indigo snakes were listed as threatened because of dramatic population declines caused by over-collecting for the domestic and international pet trade as well as mortalities caused by rattlesnake collectors who gassed gopher tortoise burrows to collect snakes. The pressure from collectors has declined in response to effective law enforcement, but collecting still remains a concern. Since its listing as a threatened species, habitat loss and fragmentation by residential and commercial expansion have become much more significant threats to the eastern indigo snake. Human population growth increases the risk of direct mortality of the eastern indigo snake from property owners, domestic animals, and highway mortality. Pesticides that bioaccumulate through the food chain present a hazard to the snake as well.
Considering the low numbers of this species, any additional threats to its survival could cause local extirpations. Extensive tracts of wild land are the most important refuge to sustain a breeding population of eastern indigo snakes. Even with continued habitat destruction and alterations, this species likely will persist in most localities where large, unfragmented pieces of natural habitat remain. Unfortunately, current and anticipated future habitat fragmentation probably will result in a large number of isolated, small groups of indigo snakes. Fragmented habitat patches probably cannot support a sufficient number of individuals to ensure viable populations.
The eastern indigo snake is secure within Everglades National Park where it is widely distributed and relatively uncommon in pine and tropical hardwood forests and, to a lesser extent, in coastal habitats and freshwater marshes. Preservation of these habitats is the best assurance of the continued existence of the snake within these park areas.
Status of the Eastern Indigo Snake in Southern Florida National Parks and Vicinity
Todd M. Steiner, Oron L. Bass, Jr., and James A. Kushlan, 1983