Literaturdatenbank
Literaturdatenbank |
|
 |
|
Lechowicz, C. , Aspects of the population dynamics of sympatric graptemys barbouri and graptemys ernsti in the lower choctawhatchee river of alabama and florida. Paper presented at Turtle Survival Alliance 2007 Annual Meeting.
Added by: Admin (13 Dec 2008 22:23:45 UTC) |
| Resource type: Proceedings Article BibTeX citation key: Lechowicz2007 View all bibliographic details  |
Categories: General Keywords: Emydidae, Ernährung = nutrition, Graptemys, Graptemys barbouri, Graptemys ernsti, Graptemys nigrinoda, Graptemys pulchra, Habitat = habitat, invasive Arten = invasive species, Morphologie = morphology, Nordamerika = North America, Schildkröten = turtles + tortoises, Systematik = taxonomy Creators: Lechowicz Collection: Turtle Survival Alliance 2007 Annual Meeting |
Views: 6/853
Views index: 15% Popularity index: 3.75% |
| Abstract |
|
Map turtles (Genus: Graptemys) are the most diverse group of turtles in the United States, including 12 species, and are differentiated into two recognizable groups, the broad-headed and narrow-headed species, based upon the head width of adult females due to diet (Ernst and Barbour et al. 1994). The discovery of two broad-headed map turtle species (Graptemys barbouri and Graptemys ernsti) in the Choctawhatchee River system in south Alabama has raised many questions concerning competitive exclusion and niche partitioning, while the existence of hybrids (Graptemys barbouri x ernsti) adds another level of complexity to this enigma (Godwin 2002). When only one Graptemys sp. is found in a Gulf Coast River system, then it is of the broad-headed group. Gulf Coast Rivers containing two sympatric Graptemys species are known to represent both head width groups, such as the Alabama River system, with a narrow-headed (G. nigrinoda) and broad-headed species (G. pulchra). This instance of two similar species occupying the same river is unique opportunity to study exclusion and/or rapid adaptation. The main objective of this project is to quantify the sex ratios of pure G. barbouri and G. ernsti in the Choctawhatchee River and compare them to the sex ratios in hybrid zones with a mark-recapture study. All map turtles will be photographed to compare the marginal scute, head and chin patterns. The morphology of hybrids will be carefully examined to identify any similar characteristics that can be described. Also, any expansion of hybrids in this river system since 2002 will be documented.
Added by: Admin |