Selectivity of Wintering Habitat for the Tokyo Daruma Pond Frog: Comparison of wintering environments in the paddy fields of multiple areas

We investigated the overwintering habitats and environments of the endangered Tokyo daruma pond frog, Pelophylax porosus porosus, in the paddy of multiple areas. The frogs overwintered underground in every district. Overwintering habitats differed among areas; frogs overwintered in paddy fields in areas where paddy fields were dominated, whereas they chose different fields in areas with mixed fields. The frogs avoided wet fields and overwintered on adjacent ridges and slopes. There was no significant difference in the soil moisture content (volume water content) of the different areas in which frogs over wintered. Moreover, when the wintering and non-wintering environments of the same paddy field were compared, the soil water content during wintering was significantly lower. These results suggest that the frogs avoid overwintering in fields with high soil moisture and prefer dry soil habitats.