Literaturdatenbank
Literaturdatenbank |
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Garber, S. D. (1994). Reproductive strategies, winter behavior and ecology, and conservation of the north american wood turtle (clemmys insculpta). Unpublished thesis thesis, Thesis Rutgers University.
Added by: Admin (23 Aug 2008 15:32:58 UTC) Last edited by: Beate Pfau (08 Nov 2008 16:46:01 UTC) |
| Resource type: Thesis/Dissertation BibTeX citation key: Garber1994a View all bibliographic details  |
Categories: General Keywords: Clemmys, Emydidae, Fortpflanzung = reproduction, Glyptemys, Glyptemys insculpta, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises Creators: Garber Publisher: Thesis Rutgers University |
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| Abstract |
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We observed two North American wood turtle (Clemmys insculpta) populations in Connecticut for 20 years, from 1974 through 1993. 133 different wood turtles were observed a total of 1,176 times. We studied sexual stategies, winter behavior and ecology, and conservation. The hypothesis that some species have a flexible mating system favoring outbreeding during periods of population decline is presented. We test the hypothesis that during and after a population bottleneck if organisms choose mates of disparate ages, outbreeding is promoted by insuring mating between less-related individuals. We found during a wood turtle population bottleneck, that random matings do not occur with regard to age; male turtles breed with females that are significantly older than those generally available in the population. We found age-dependent mate selection moderates the detrimental effects of a bottleneck by conserving genetic heterozygosity and allelic diversity, which supports our hypothesis, hereafter called the "sexy grandmother hypothesis." We studied winter behavior and ecology and concluded wood turtles are on land during the summer and overwinter in rivers where they remain through November, December, and January. Of river, marsh, and pond habitats, the highest dissolved oxygen concentrations occur in river water during the winter. Turtles bask on land during the warmer days of late winter and early spring. Turtles are alert and capable of activity all winter. As the air and water warm up turtles spend more time on land and travel farther from the water. We document the high correlation between human recreation and wood turtle decline. Human and turtle demographics were monitored. Our data suggest that the wood turtle populations remained stable when people were denied access to the study site. When the property was opened to recreation (hiking, fishing) the turtles declined steadily; the total number declined 100% in 10 years. Throughout our study the size of the forest remained the same, road building was restricted, and air and water quality were constant. We conclude that recreation in parks and preserves threatens the longterm survival of this species. As wilderness areas become mixed-use recreation areas, the remaining wood turtle populations will suffer. Without proper management, the increasing recreational use of parks, reservoirs, and wildlife reserves may adversely affect the longterm survival of the wood turtle, ultimately leading to its extinction in the wild.
Added by: Admin Last edited by: Beate Pfau |