Literaturdatenbank
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Hrycyshyn, G. E. (2007). Survival probabilities and density of four sympatric species of freshwater turtles in florida. Unpublished thesis , University of Florida, Gainesville.
Added by: Sarina Wunderlich (30 Jun 2012 22:01:05 UTC) |
| Resource type: Thesis/Dissertation BibTeX citation key: Hrycyshyn2007 View all bibliographic details  |
Categories: General Keywords: Emydidae, Habitat = habitat, Kinosternidae, Nordamerika = North America, Pseudemys, Pseudemys nelsoni, Pseudemys peninsularis, Schildkröten = turtles + tortoises, Sternotherus, Sternotherus minor, Sternotherus odoratus Creators: Hrycyshyn Publisher: University of Florida (Gainesville) |
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Views index: 19% Popularity index: 4.75% |
| URLs http://purl.fcla.edu/fcla/etd/UFE0022630 |
| Abstract |
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Turtles are important, and often neglected, components of their ecosystems, and many turtle species are endangered. I studied four species of common freshwater turtles over a five year period in Wekiwa Springs State Park (WSSP), Apopka, Florida. These four turtle species were the Peninsula Cooter (Pseudemys peninsularis), Florida Red-bellied Cooter (P. nelsoni), Loggerhead Musk Turtle (Sternotherus minor minor) and Stinkpot (S. odoratus). For each species I estimated annual recapture probabilities, population density, biomass, annual survival probabilities and realized population growth rate using capture-mark-recapture data from March 2000 to November 2005. My density estimates showed significant declines throughout the study for both Pseudemys species, and non-significant increases in density for both Sternotherus species. These findings are not directly corroborated by the estimated realized population growth rates, which suggest that P. peninsularis populations are increasing non-significantly, and P. nelsoni populations are declining non-significantly. I postulate that the apparent disagreement between the realized population growth rate and density estimates arises from the need to account for temporal variability in estimates of realized population growth rate. Overall my findings suggest that none of these turtle species are in danger, and the apparent declines in both Pseudemys species appear to stabilize toward the end of the study. There are numerous environmental factors that could impact the future health of the spring ecosystem and these turtle populations. These include invasion by the aquatic plant Hydrilla verticillata, which necessitates management activities that many disturb the turtles, increased nitrate pollution and increased water usage and therefore decreased spring output. I recommend monitoring of these turtle populations to ensure that should population declines occur appropriate management actions can be taken.
Added by: Sarina Wunderlich |