Development of a Camera-Installed Nest Box for Small Mammals and Its Application in Reproductive Schedule Estimation for the Okinawa Spiny Rat Kotaka, Nobuhiko and Yasuda, Masatoshi and Shimada, Takuya, Mammal Study, 47, 77-85 (2022), DOI:http://dx.doi.org/10.3106/ms2021-0025