Distribution, Habitat Analysis, and Conservation of the Timber Rattlesnake in Virginia

dc.contributor.authorGarst, David Walteren
dc.contributor.committeechairHaas, Carola A.en
dc.contributor.committeememberStauffer, Dean F.en
dc.contributor.committeememberBrown, William S.en
dc.contributor.committeememberPrisley, Stephen P.en
dc.contributor.departmentFisheries and Wildlife Sciencesen
dc.date.accessioned2014-03-14T20:40:05Zen
dc.date.adate2007-07-17en
dc.date.available2014-03-14T20:40:05Zen
dc.date.issued2007-05-16en
dc.date.rdate2007-07-17en
dc.date.sdate2007-06-15en
dc.description.abstractThe timber rattlesnake (Crotalus horridus) is a forest dwelling terrestrial pit viper that utilizes several types of habitat within the forest environment. One type of habitat crucial to the species' survival in mountainous regions and at more northern latitudes is basking habitat, which typically is an exposed rocky area used by gravid females for gestation, and by other timber rattlesnakes for shedding, mating, and digesting. Understanding the range of the timber rattlesnake in Virginia will enable biologists and land managers to better manage the landscape in a way conducive to the survival and persistence of timber rattlesnakes. To improve our ability to identify and locate areas potentially containing timber rattlesnake basking habitat, I used 5 landscape-level habitat variables with logistic regression and geographic information systems (GIS) to model and map areas of western Virginia potentially containing timber rattlesnake basking habitat. Models were ranked using Akaike's Information Criterion (AIC) and were crossvalidated using the methods of Fielding and Bell (1997). Aspect, slope, elevation, landform index, and percentage of forest cover values were derived using GIS for 217 known basking sites in western Virginia. I then used data derived for the 217 known basking sites to create 22 a priori models. The best model used the variables of aspect, slope, landform index and percentage of forest cover. When I crossvalidated the top model, the kappa value, a measure of the proportion of specific agreement, and was 0.804. During field tests the predictive model was used to find timber rattlesnakes at 3 of 15 (20%) of the test sites in the Goshen Wildlife Management Area in southwestern Virginia. My predictive model has proven to be an effective tool that could be used by biologists and land managers to locate and protect timber rattlesnake basking habitat. The historic and current ranges for the timber rattlesnake in Virginia were determined using literature records, database records, place names, personal interviews, and site surveys. Historically, the timber rattlesnake ranged over the entire state. Currently, the timber rattlesnake is restricted to the mountainous regions of Virginia (not including the coastal plain population of the timber rattlesnake). The biology of Crotalus horridus and regulations and management practices used by other states within the range of the species were used to create a set of management recommendations to the Virginia Department of Game and Inland Fisheries. These recommendations include implementing (1) a no-take regulation, (2) enhanced public education, and (3) protection of critical habitat and location of new populations.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-06152007-160321en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-06152007-160321/en
dc.identifier.urihttp://hdl.handle.net/10919/33597en
dc.publisherVirginia Techen
dc.relation.haspartGARST_THESIS.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectAspecten
dc.subjectBasking Habitaten
dc.subjectTimber Rattlesnakeen
dc.subjectSlopeen
dc.subjectForest Coveren
dc.subjectGeographic Information Systemen
dc.subjectElevationen
dc.subjectManagementen
dc.subjectRangeen
dc.subjectLandform Indexen
dc.subjectLogistic Regressionen
dc.titleDistribution, Habitat Analysis, and Conservation of the Timber Rattlesnake in Virginiaen
dc.typeThesisen
thesis.degree.disciplineFisheries and Wildlife Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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