Habitat Use and Population Biology of the Northern Redbelly Snake at Oaklake Field Station, SD

Habitat use and population biology of the northern redbelly snake (Storeria occipitomaculata occipitomaculata) were studied at the Oak Lake Field Station to enhance existing knowledge and future management efforts for this species in eastern South Dakota. The redbelly snake is listed as a monitored species in South Dakota, species of special concern in Nebraska and protected species in Iowa. Forty three snakes were caught by hand and from drift fences from May-August 2003. Three snakes (7%) were recaptured during the sampling period. Time duration between recaptures ranged from 1-63 days and all three recaptures occurred within 50m of their first collection. Nearly twice as many females (65%) as males (35%) were collected. Snout to vent length ranged from 97 to 245 mm (mean=185 mm) and body mass (WW) ranged from 1.0-10.7 g (mean =4.4 g). Air and ground temperatures at collection locations ranged from 17.8ºC to 29.6ºC. Over half (65.8%) of captured snakes were found on northerly aspects with soil moisture at collection sites ranging from 0%-100% (mean=56%). Many snakes (63%) were captured on unpaved roads consisting of 90% or greater sand and gravel. Vegetation cover at collection sites ranged from 0%-100% (median=38.8%). Those sites with vegetation were dominated by grasses and forbs. No snakes were found between 1200 hrs-1600 hrs throughout the summer and more than half of snakes were captured late during the growing season (58.1% during August). This study enhances our understanding of redbelly snake habitat use and demographics in eastern South Dakota. Future efforts will focus on descriptions of hibernacula and population estimates for the Oak Lake Field Station