|
The northern red-legged frog (''Rana aurora'') is a species of amphibian, whose range is the coastal region stretching from southwest British Columbia to southern Mendocino County in Northern California, and is protected in British Columbia, Oregon and California.〔''California Wildlife, Volume I: Amphibians and Reptiles'', ed. by D.C. Zeiner et al., published by the California State Department of Fish and Game, May 2, 1988〕 As a member of the genus ''Rana'', this species is considered a true frog, with characteristic smooth skin and a narrow waist. This frog requires still waters for breeding, and is rarely found at any great distance from its breeding ponds or marshes. Northern red-legged frog adults may attain a length of ; they have dark facial masks and single characteristic light stripes along their jawlines.〔Stebbins, R.C. ''Amphibians and Reptiles of North America'', McGraw Hill, New York (1954)〕 The northern red-legged frog has long, powerful legs well adapted to jumping. It is one of two amphibian species classified as red-legged frog, the other species being the California red-legged frog (''Rana draytonii''); however, the latter species is found from southern Mendocino County southerly to Baja California. In some systems of taxonomy, this species is classified as ''Rana aurora aurora''. ==Range== The northern red-legged frog is found in western Oregon, western Washington and southwestern British Columbia, including Vancouver Island.〔 In California, its range includes every coastal county from southern Mendocino County northward. While it occurs primarily in the Northern California coastal mountain ranges, it is not found above an elevation of 1200 m. It also occurs somewhat less commonly in the southern Cascade Range.〔 ==Habitat== The still waters of ponds, marshes or stream pools are essential for northern red-legged frog breeding habitat;〔(U.S. Department of Agriculture Northern Red-legged Frog profile (2003) )〕 moreover, this species of frog is considered unusually highly oriented to its aquatic habitat, with a clear preference for thickly vegetated shoreline.〔''Red-legged Frog observations in the coastal ranges and development impact analysis'', Lumina Technologies, Tiburon (1997)〕 ''R. aurora'' requires cover, since it is subject to predation by various fishes, snakes, birds, mammals, and even certain other amphibians. When this frog senses danger, it will quickly plunge to depths of one meter or more to seek safety in the benthic zone of a pond. Adults leave the breeding pond soon after the breeding activity is concluded, and may migrate about one half kilometer to their summer locations, which are likely to be riparian zones. In the northern part of their range, adults may hibernate. Juveniles are slower to leave the breeding ponds, but also tend to find cover in riparian areas, and may readily migrate about one half kilometer by summertime. Mature ''R. aurora'' specimens prey upon terrestrial insects, but will also take small snails and crustaceans;〔(Amphibian Declines: The Conservation Status of United States Species, edited by Michael Lannoo ©2005 website excepted from University of California Press )〕 also, they will consume worms, tadpoles, small fish. and even small frogs of other species. The tadpolee are herbivorous. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Northern red-legged frog」の詳細全文を読む スポンサード リンク
|