Literaturdatenbank
Literaturdatenbank |
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Aresco, M. J., & Shealy, R. M. (2006). Graptemys ernsti - escambia map turtle. In P. A. Meylan (Ed.), Biology and Conservation of Florida Turtles Vol. 3, (pp. 273–278).
Added by: Sarina Wunderlich (06 Jul 2014 16:10:28 UTC) |
| Resource type: Book Article BibTeX citation key: Aresco2006b View all bibliographic details  |
Categories: General Keywords: Apalone mutica, Habitat - habitat, Nordamerika - North America, Schildkröten - turtles + tortoises, Trionychidae Creators: Aresco, Meylan, Shealy Collection: Biology and Conservation of Florida Turtles |
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| Abstract |
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The Escambia map turtle, Graptemys ernsti, has the most restricted range of any turtle species found in Florida. The species, described in 1992, was formerly considered a geographic variant of the Alabama map turtle, G. pulchra. Graptemys ernsti is restricted to parts of the Escambia, Yellow, and Shoal rivers and their tributaries in the western Florida panhandle and adjacent Alabama. This map turtle, like its close relatives, is a riverine species with remarkable sexual dimorphism. Adult females attain lengths over twice those of adult males and have broad heads with greatly expanded alveolar surfaces of the jaws. Small juveniles of both sexes and adult males are primarily insectivorous, whereas females feed almost exclusively on freshwater mussels and snails. The introduced Asiatic clam, Corbicula fluminea, is the primary prey of female G. ernsti. Graptemys ernsti is strongly aquatic and is found exclusively in the main channels of rivers and large to mediumsized creeks and is not typically found in river floodplain swamps. The scarcity of molluscs in blackwater streams originating in the lower Coastal Plain may account for the absence of G. ernsti in the Blackwater and Perdido rivers and their tributaries. Although it is currently the most abundant turtle in certain portions of the rivers in which it occurs, it may be sensitive to habitat degradation and other threats. The primary threats include the use of all-terrain vehicles (ATVs) on sandy riverbanks used as preferred nesting sites, indiscriminant shooting of basking adults, water pollution, dam construction, river channelization, and removal of snags used as basking sites. Because G. ernsti occurs in such a small area, all threats to this species should be minimized and it should be closely monitored for any future changes in population status and demographic structure.
Added by: Sarina Wunderlich |