Spatiotemporal dynamics of urban green spaces and human–wildlife conflicts in Tokyo

Although urban green spaces are increasingly important both for humans and wildlife, an increase in urban green spaces may also increase human-wildlife conflicts in urban areas. However, few studies have examined the relationship between the size of green spaces and the level of conflicts with wildlife in multiple taxa, including invertebrates and vertebrates. To better understand current pest statistics and predict changes that will occur as the area of green spaces increases, we analysed a dataset compiling the number of pest consultations in 53 metropolitan districts in Tokyo over a 20-year period and its relationships with the area of green space. Stinging insects (e.g., wasps) made up over 50% of pest consultations, followed (in order) by rats and other nuisance animals (e.g., snakes). The number of consultations per unit population did not correlate, or was even negatively correlated, with the proportions of green spaces (mainly forest) for many indoor pests, but did positively correlate for some outdoor pests, such as wasps and snakes. Therefore, wasps and snakes can increase when urban green spaces increase. Because even minor nuisances are relevant for urban lifestyles, considerations of ways to minimise conflicts with wildlife are critical for urban green space management.