木曽川河口域の干拓地におけるカエル類の分布

抄録

In our country, it is reported that a decrease in the rice field in various places causes the extinction of frogs populations. Fresh large-scale development of a rice field by the reclamation by drainage development is being done on one side. It provides important information as an example for the conservation biodiversity to grasp the distribution movement of the frogs in the creative area of the new rice field environment. We explained the tendency of the inhabiting distribution of the frogs in the reclaimed land of mouth area of the Kiso river which reclamation by drainage proceeded through gradually from the Edo Period middle, and added a consideration about that regulation factor. The whole distribution tendency was divided into three of the type that it is distributed in the whole of the reclaimed land (Hira japonica, Rana limnocharis), the type that it is distributed by the fixed tendency (Rana nigromaculata, Rana porosa brevipoda) and a type to be confined for just a little distribution (Rana japonica). Specially, we thought that the existence of the shrubbery zone was the regulation factor of the distribution of nigromaculata and Rana porosa brevipoda.