Date of Award
Master of Science (MS)
Native shortgrass prairie ecosystems have undergone drastic changes since European settlement, resulting in fragmentation of native prairie. With this reduction in available native habitat, it has become increasingly important to conserve the remaining patches of native prairie and the biodiversity within them. In order to apply proper management and conservation strategies to conserve what remains, we must have baseline bio logical information about each of the species present. Few studies exist that focus on the status of amphibians and reptiles in the shortgrass prairie ecosystem. Of particular importance are species whose populations are at risk. The prairie rattlesnake (Crotalus viridis) is a species that is commercially exploited as the focal species of the annual Sharon Springs Rattlesnake Roundup in western Kansas. Unfortunately, information is lacking regarding the potential effects of commercial harvest on rattlesnake populations. The goals of this study were to gain insight into the possible effects of harvest on prairie rattlesnake populations, to develop harvest recommendations, to increase the knowledge of the natural history of this species in the short grass prairie ecosystem, and to conduct a baseline survey of the amphibians and reptiles of the Smoky Valley Ranch, a Nature Conservancy shortgrass prairie preserve in Logan County, Kansas. I collected demographic data from samples of snakes brought to the Sharon Springs Rattlesnake Roundup in 2000 and 2001. These data were compared with similar data collected by Dr. Henry Fitch of the University of Kansas in previous years. The results indicated a shift toward smaller and younger individuals comprising the bulk of the sample, an increased proportion of females, and an apparent increase in the reproduction of younger snakes. These results are expected in a harvest biased toward large individuals. Secondly, in 2000 and 2001, I collected data on the habitat use and movement patterns of prairie rattlesnakes from an unexploited population on the Smoky Valley Ranch. Using traditional capture techniques and radiotelemetry, I collected data associated with 27 individuals at 64 capture sites. Of these sites, 68% were in open grass containing few forbs and 56.3% of all capture sites contained rodent burrows. Sample sizes limited statistical analyses, but radiotelemetry provided useful anecdotal information. Concurrently with the above study, I conducted a baseline survey of the amphibian and reptile species that occur on the Smoky Valley Ranch. Using the traditional visual encounter surveys (VES), aural surveys, road cruising, and drift fence/funnel trap arrays, I documented 24 species of amphibians and reptiles on the ranch. Catch per unit effort (CPUE) values for each sampling method were calculated for each species within each of the 4 major habitat types present on the ranch. An index of relative abundances was created using the CPUE values.
Copyright 2004 Curtis J. Schmidt
Schmidt, Curtis J., "Natural History and Status of the Exploited Prairie Rattlesnake (Crotalus Viridis) in Western Kansas and a Herpetofaunal Inventory of the Smoky Valley Ranch, Logan County, Kansas" (2004). Master's Theses. 2923.