Literaturdatenbank
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Pitt, A. L., & Nickerson, M. A. (2013). Potential recovery of a declined turtle population diminished by a community shift towards more generalist species. Amphibia-Reptilia, (early view).
Added by: Admin (06 Jan 2014 18:25:10 UTC) |
| Resource type: Journal Article DOI: 10.1163/15685381-00002883 BibTeX citation key: Pitt2013 View all bibliographic details  |
Categories: General Keywords: Emydidae, Graptemys geographica, Habitat - habitat, Kinosternidae, Nordamerika - North America, Schildkröten - turtles + tortoises, Sternotherus odoratus, Trachemys scripta Creators: Nickerson, Pitt Collection: Amphibia-Reptilia |
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| Abstract |
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Keywords: Graptemys geographica; Sternotherus odoratus; harvested turtle population; Trachemys scripta elegans; community composition; habitat degradation Models suggest that a declined turtle population may rebound if the cause of decline is remedied and adult mortality is reduced, but recovery time will likely be slow. In 2005-2007, we reexamined a river turtle community which included a population of Northern Map Turtles (Graptemys geographica) that had been reduced by approximately 50% between 1969 and 1980 likely as a result of harvesting, and had failed to rebound by 2004 despite no evidence of continued harvesting. Comparisons of population estimates for G. geographica showed no significant differences between 2005 and 2006 ( z = 1 . 79 , P = 0 . 073 ) or between 2006 and 2007 ( z = 1 . 07 , P = 0 . 284 ). However, the population estimate for 2007 was not significantly different from the population estimate for 1969 ( z = 0 . 48 , P = 0 . 629 ) but was significantly higher than the population estimate for 1980 ( z = 2 . 96 , P = 0 . 003 ), suggesting the population had returned to its pre-decline (1969) size. While the recovery of the G. geographica population demonstrates that a previously harvested river turtle population may rebound if no further harvesting occurs, the recovery period will be extensive, thus confirming model predictions. Furthermore, the turtle community composition was shifting towards a higher relative abundance of generalist species and a lower relative abundance of specialist species – a pattern that can be expected with habitat degradation, another threat which may present new challenges to G. geographica, a dietary specialist.
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