Decrease in nest holes of Norway rats in planting zones along sidewalks in an urban center of Tokyo

Abstract

I investigated the distribution of nest holes of Norway rats in the planting zone along sidewalks of the Showa Street that passes through Taito-Ku and Chiyoda-Ku, Tokyo. The holes disappeared in three survey sites among four in the Taito-Ku area from the year 2016 to 2018. Also, they disappeared in six sites among eight in the Chiyoda-Ku area from the year 2013 to 2018. Possible causes of the disappearance include physical blockage of planting zones by asphalt cover, waste reduction projects by local governments, and renewal of buildings to larger ones. The urban renewal reduces roadside stores, which serve food source for rats by putting garbage in plastic bags on roadside.