The federally threatened eastern indigo snake (Drymarchon couperi), native to the southeastern Coastal Plain of the United States, has experienced population declines caused primarily by habitat loss, degradation, and fragmentation. To examine spatial and habitat use requirements of the species, we radiotracked 32 eastern indigo snakes from 2002 to 2004 on Fort Stewart Military Installation and adjacent private lands in Georgia. We estimated annual and seasonal home ranges and evaluated a priori hypotheses examining morphometric and ecological factors (sex, body size, location) associated with intraspecific differences in home range size. We analyzed habitat use hierarchically by examining use across the study area and within home ranges. Annual home range size varied from 33 ha to 1,528 ha (average minimum convex polygon: truex¯2003=378 ha; truex¯2004=340 ha). Individual home range size was most influenced by sex (males with larger home ranges) followed by body size. Compositional analysis of habitat use suggested positive selection for wetland, evergreen forest, and pine‐hardwood (mixed) forest, with an avoidance of roads and deciduous forests. Seasonally, indigo snakes used the highest diversity of habitats as they moved from xeric uplands (sandhills) in winter and early spring to wetlands and uplands other than sandhills in summer; however, snakes continued to use sandhill habitats (35–58% of locations seasonally) with gopher tortoise (Gopherus polyphemus) burrows throughout the warmest months. In Georgia, management and conservation of the eastern indigo snake should include conservation of large tracts of undeveloped land, containing a matrix of xeric uplands with suitable underground shelters and adjacent wetland habitats. © 2013 The Wildlife Society.

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Demographic data provide a basis for understanding the life history and ecology of species, factors which are vital for informing conservation efforts; however, little is known regarding the population ecology of most snake species, including the threatened Eastern Indigo Snake (Drymarchon couperi). We used 11 years (1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)) of capture-mark-recapture (CMR) and 2.5 years (2003)(2004)(2005) of radiotelemetry data from southeastern Georgia, USA, in a CMR modeling framework to estimate apparent survival, capture and transition probabilities, and evaluate factors influencing these parameters. The model-averaged estimate of overall apparent annual survival probability was 0.700 (±0.030 SE) and is comparable to that obtained from known fate analysis (radiotelemetry) at the same site. Body size positively influenced survival, regardless of sex. Capture probability differed seasonally by sex, suggesting lower capture probability for females in fall and males in winter. There was no evidence for effect of precipitation or site-specific differences in survival. Model averaged estimate of annual adult survival estimated using multistate CMR models was 0.738 ± 0.030 and 0.515 ± 0.189 for subadults. We estimated population growth rate (k) and elasticity (proportional sensitivity) of k to vital rates using a stage-structured matrix population model. Population growth rate ranged from 0.96 to 1.03 depending on the value of the probability of transitioning from subadult to adult stage. The k was proportionally most sensitive to changes in adult survival rate, followed by subadult survival. Our results suggest that protecting adult snakes and their habitats would result in the highest likelihood of long-term population stability and growth.

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