洪水

Northern Kyushu was caught in heavy rains, rivers around overflowed and their catchment areas met unparalleled flood in the end of June, 1953. In August we went to Onga Village, Hinashiro Village and Zend6ji Town, in which the damages were most tremendous, along the Onga and Chikugo rivers in Fukuoka Prefecture, and investigated the effects of the flood on the habitations of the domestic rats, Norway rat Rattus norvegicus, and house rat Rattus rattus, in those areas. Norway rats were captured in Togo Town of unflooded area and in the higher and dried part of Nakabaru Village of flooded area but in the above mentioned villages and town in which water came over several metres, only house rats were got, Norway rats being never met. Therefore it seems that in the flooded areas the Norway rats decreased exceedingly in number, having been drifted or drowned, as the water invaded their dwelling places of ground level, though the house rats survived, escaping to the higher places in the house such as rafters of the ceiling. The peasants observed that abundant individuals of rats were drifted and arrived, being alive or dead, to the foot of the hill situated down the Onga river. Most of them are considered to be Norway rats. Hinashiro Village and. Zendoji Town along the Chikugo river are used to be flooded almost annually in summer, so the Norway rats, living in ground level, are thought to be very few in number or to be lacking absolutely, because they can not dwell habitually in such area.