To effectively implement conservation programs for eastern indigo snakes we need to use a science based approach. Our science staff conducts research projects that provide the information needed to inform our applied conservation programs. We are developing close relationships with many universities including University of Georgia, University of Florida, University of Massachusetts, University of Idaho, and Idaho State University. These relationships allow us to work with some of the greatest scientists and graduate students in the world. We are currently conducting and planning a number of studies that will help us better implement our applied conservation initiatives:

Determine the Effectiveness of Dogs at Surveying Eastern Indigo Snakes.

CJ, the Eastern Indigo snake detector dog, sniffs a gopher tortoise burrow, photo credit Dirk Stevenson

CJ indicates on an Eastern Indigo snake shed, photo credit Dirk Stevenson

Eastern Indigo Snake Genetics

We are working with the University of Florida to examine range-wide patterns in eastern indigo snake genetics. The results from this study will provide the information needed to determine appropriate source populations for our captive breeding and reintroduction efforts.

Conservation Planning

We are working with the University of Massachusetts to develop a conservation planning tool for the Altamaha River Drainage in Georgia. The project is a multi-scale habitat model that predicts the distribution and connectivity of winter and summer habitat for eastern indigo snakes. The results from this study will help us prioritize land protection, restoration, and management efforts.

Factors Causing Snake Decline

Though there are many factors have influenced eastern indigo snake declines, we believe that habitat loss and fragmentation, gopher tortoise declines, and subsidized predation are among the biggest current threats. Project Orianne is researching facets of these factors as follows:

• Habitat Loss, Fragmentation, and Alteration: This is arguably one of the most important causes of eastern indigo snake decline as the species requires a large expanse of natural habitat that contains both overwintering and foraging habitats. Due to the abundance of private land and small parcel sizes, the Southeastern Coastal Plain is a patchwork of different land uses with little continuity across the landscape. Specifically, urban and rural development, agriculture, roads, altered fire regimes, forestry, and conversion to pine plantations have fragmented habitats and are potentially causing negative impacts to eastern indigo snakes. Project Orianne is conducting research in South Florida using radio telemetry, Geographic Information Systems (GIS), and spatial analysis techniques to determine the impacts of varying levels of habitat fragmentation and loss on indigo snake movements and habitat selection.

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  Gopher tortoise, photo credit Dirk Stevenson
  Gopher Tortoise Declines: Declines in gopher tortoise populations are likely having a negative effect on eastern indigo snakes due to the snake’s reliance on tortoise burrows for overwintering sites; particularly in the portion northern range. Project Orianne is conducting a thermal ecology study to determine how important gopher tortoise burrows are for eastern indigo overwintering habitat and how this varies across the range of the snake. Specifically, we are examining the physical environment (e.g. temperature, moisture) that gopher tortoise burrows provide for eastern indigo snakes and their nests.

• Subsidized Predation: Given that the Southeastern Coastal Plain is such a fragmented and disturbed region, predators that do well in proximity to humans (i.e., subsidized predators) are likely much more abundant than they would have been historically. Potential subsidized predators in the region include raccoons, opossums, armadillos, crows, hogs, coyotes, foxes, fire ants, and feral cats and dogs. These predators may have an especially pronounced impact on egg and juvenile age classes of eastern indigo snakes. Project Orianne will be looking at the effects of subsidized predation on both eggs and juveniles; potentially by time-lapse videography to monitor predation on nests and juvenile snakes.

Population Viability of Eastern Indigo Snakes Little is known about the population biology of eastern indigo snakes. We are working with the University of Florida to determine population growth rates and the factors that affect survival. The results from this study will be incorporated into broader analyses that examine the population viability of eastern indigos. Base viability models will be used to predict the effects of threats on snake populations, help determine the life stages that are most sensitive to threats, and determine how large of an area is needed to conserve this species (i.e., how large the Preserve should be).

Juvenile Eastern Indigo Snake Ecology. 

A juvenile Eastern Indigo snake, photo credit Steve Winters

knowledge of general snake ecology is that of young age classes. However, understanding the ecology of juvenile eastern indigo snakes is critical for us to determine the factors causing their decline and for modeling population viability. We plan to begin a project on juvenile ecology of eastern indigos within the next year.

Gopher Tortoise Reproduction.

Adult and juvenile tortoises, photo credit Dirk Stevenson

Gopher tortoises are long-lived, low reproductive output animals and their presence is critical to the persistence of eastern indigo snakes in the northern portions of their range. Adult tortoises could live for many years even if their offspring where not surviving long enough to become adults. We are planning a study that will examine the reproductive biology of gopher tortoises in the Preserve. Specifically, we are interested in determining whether juvenile tortoises are being recruited into the breeding population. The results from this study will help us determine if active measures need to be taken to improve gopher tortoise survival within the Preserve.