Behaviour and survival time after the release process of hand-reared and treated raccoon dogs

Raccoon dogs (Nyctereutes procyonoides) are the most commonly rescued and rehabilitated mammal in Japan. However, few studies have monitored their post-release behaviour or survival. To address this gap, we tracked ten individuals using telemetry (radio and GPS) and camera traps for 24 months following their rescue and release into suburban areas. Five were hand-reared, and five were treated for scabies (hereafter treated). Three pairs of raccoon dogs were formed: one pair between two treated animals, another between a hand-reared and a treated animal, and the third between a hand-reared animal and a wild animal. Moreover, reproductive behaviour was confirmed in the second pair. Two hand-reared raccoon dogs died within 34 days, while two treated individuals disappeared within eight days, and another was likely dead after approximately 476 days. Comparing our results to those of a previous study involving ten individuals rescued from suburban areas and released into mountain areas, our results showed a statistically longer survival time than that reported in the previous study. This study is the first to demonstrate that hand-reared and treated raccoon dogs can survive in the wild and engage in reproductive behaviour, emphasising the release environment as one of the key factors influencing their survival.