Indigo Snake Capture Methods: Effectiveness of Two Survey Techniques for Drymarchon Couperi in Georgia

Drymarchon couperi (Eastern Indigo Snake), a federally threatened species of the southeastern Coastal Plain, has presented challenges for surveyors, with few reliable methods developed for its detection or monitoring. Surveys for D. couperi at potential underground shelters conducted in late fall through early spring have been relatively successful when performed by experienced surveyors, especially in the northern portions of the range. However, trapping efforts for D. couperi conducted throughout the range have met with limited success. To further evaluate detection methods, we completed trapping and surveying from December 2002 to April 2004 in areas known to support D. couperi in southeastern Georgia. We captured 18 D. couperi through surveys of potential underground shelters from December 2002 to March 2003 (14 person-hours per capture) and six individuals through trapping (141 trap days or 27 in-field person-hours per capture). Trapping was most successful during early fall, a period when surveys are often less effective compared to those conducted in late fall through early spring. We recommend a combination of surveys from mid-fall through March in conjunction with trapping, especially from late-summer through fall in the northern portions of the snake’s range. We also recommend further experimentation with alternative trap designs and survey methods for D. couperi.