The Jollyville Plateau Salamander (JPS), Eurycea tonkawae, is a species of salamander endemic to Texas, the United States. It is a candidate for protection under the Endangered Species Act. This report assesses the JPS population abundances at Lanier Spring, Long Hollow Creek at Wheless Spring, and Ribelin Spring in Austin using a mark-recapture method. The maximum likelihood estimation method was used to obtain the population size estimates under two models, the M₀ model and the M[subscript t] model. The M₀ model assumes that every animal has the same capture probability in the population for each sampling period while the M[subscript t] model allows capture probabilities to vary by time. Simulations were performed by using an MCMC algorithm based on the M₀ model. Between 2007 and 2009, the population size estimates for JPS (>16mm snout-vent length, (SVL)) at Lanier Spring varied between 86 and 554 under the M₀ model, between 80 and 549 under the M[subscript t] model, and between 76 and 564 using MCMC simulations. During 2007 monitoring periods, the population size estimates for JPS (>16mm SVL) at Ribelin Spring varied between 105 and 236 under the M₀ model, between 104 and 196 under the M[subscript t] model, and between 105 and 265 using MCMC simulations. During 2007 and 2008 monitoring periods, the population size estimates for JPS (>16mm SVL) at Wheless Spring varied between 368 and 1087 under the M₀ model, between 339 and 1075 under the M[subscript t] model, and between 411 and 1098 using MCMC simulations. Different estimation methods yielded consistent estimates. No clear population trends were detected due to the big fluctuations in estimates in this study. / text
| Identifer | oai:union.ndltd.org:UTEXAS/oai:repositories.lib.utexas.edu:2152/ETD-UT-2010-05-1299 |
| Date | 29 November 2010 |
| Creators | Luo, Liming, 1976- |
| Source Sets | University of Texas |
| Language | English |
| Detected Language | English |
| Type | thesis |
| Format | application/pdf |
Page generated in 0.0028 seconds