Influence of Food Resource Availability on the Activity Time of Raccoon Dogs ( <i>Nyctereutes procyonoides</i> ) in Urban Parks in Tokyo

Urbanization results in the reduction and fragmentation of green spaces, which function as wildlife habitats. However, some wildlife has adapted to urbanization by changing their ecology and behaviors. The raccoon dog (<i>Nyctereutes procyonoides</i> ) has established itself in urbanized environments due to its flexible ecology including activity time and feeding habits. However, there have been few studies on the mechanism of its adaptation to urbanized environments. In this study, we evaluated the relationship between raccoon dog activity time and food resources and the degree of urbanization in the western area of Tokyo, the most populated region of Japan. Results showed that raccoon dogs tend to increase their daytime activity and use artificial food resources according to the degree of urbanization, but this is seasonally dependent. This suggests that the activity time and feeding habits of raccoon dogs are linked to their adaptation to urbanized environments. Specifically, daytime activity may provide an advantage for access to artificial food resources. Therefore, with increasing urbanization, activity time and feeding habits may change. Given that wild mammals, such as raccoon dogs, may alter their activity time and feeding habits in response to urbanization and that these changes may be interrelated, examining activity time and feeding habits in conjunction is essential.