Extinction risks and cofactors of amphibia

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Conservation of biodiversity is the scale dependent in the planning process. At first, priority areas are screened extensively on the national or regional scale by using a simple habitat model. The second step is to design a conservation area in the landscape scale. We developed habitat models for amphibias in this two scales and discussed usefulness of the models in conservation1.Risk assessment in national scale and phylogeographic studyPresence and absence data were available for the clouded salamander and in Shiga and Osaka Prefecture. Logistic models were used to estimate the potential habitat for these two species. Habitat suitability was estimated using Ecological-Niche Factor Analysis for species in which only presence data are available. Future risks were evaluated for these animals by overlaying land use planning maps with the potential habitat maps. To identify regional population units of H.nebulosus, 420 base pairs were sequenced within the mitochondrial DNA control region … More . Results indicate substantial phylogeographic structuring and strong population-level separations. Four groups were detected among this species.2.Risk assessment in landscape scaleA habitat model in landscape scale (1 km x 2 km range) was built for the clouded salamander by using a result of ecological survey and a 1/2,500 vegetation map and 10 m DEM. This model was used to estimate extinction risk of the salamander in several scenarios of land change. The risk assessment of metapopulation allows a sophisticate evaluation of environmental impacts in complex landscapes such as Satoyama in Japan.3.Influence of small dams on the movements of Japanese giant salamander.A.japonicus move to up stream before their breeding season. But it is predictable that the movement is prevented by small dams. We surveyed. a seasonal movement of A.japonicus and examined the effect of small dams on the movement in Hatuka river of Muko river system in western Japan. We surveyed in 1523 m section of the river that include six dams, and marked 104 individuals. More than 10 individuals moved up stream over each of the dams. But the fact that many individuals were observed just under dams that are taller than 30 cm and 30° in the inclination suggests that A.japonicus cannot pass over those dams without a bypass or a foothold4.Avoidance responses of (Hynobius nebulosus mediated by predator chemical cue.We studied antipredator behavior of the clouded salamander (H.nebulosus)larvae. In our experiment, we tested the effects of predatory newt and crayfish, non-lethal effects of tadpole and effects of inexperience fish We found that H.nebulosus can recognize predators not based on visual cue but kairomones emitted by the predator. larvae did not respond to kairomones of predatory fish Carassius auratus which did not inhabit in temporary pool, therefore it suggested that H.nebulosus do not have avoidance response to predator not inhabit the same habitat. Less