Development of a Camera-Installed Nest Box for Small Mammals and Its Application in Reproductive Schedule Estimation for the Okinawa Spiny Rat

Reproduction in the endangered Okinawa spiny rat is primarily limited to autumn and winter, with subadults emerging predominantly between December and March. This finding was derived from a novel camera-installed nest box system deployed on Okinawa Island, which captured 850 images of rats over six months. By analyzing the distribution of body size (measured as eye distance) using a Gaussian mixture model, researchers identified two distinct clusters: subadults (11% of individuals) and adults (89%). The seasonal emergence pattern suggests that weaning occurs mainly during winter, providing critical insights into the species' reproductive ecology. This non-invasive method offers a scalable approach for studying small mammals in their natural habitats.

Kotaka, N., Yasuda, M., & Shimada, T. (2021). Development of a Camera-Installed Nest Box for Small Mammals and Its Application in Reproductive Schedule Estimation for the Okinawa Spiny Rat. Mammal Study, 47(2). https://doi.org/10.3106/ms2021-0025