Additional Evidence of the Decline of the Tree Sparrow in Japan, Based on Bird Banding Data

A previous study has demonstrated that the population size of the Tree sparrow Passer montanus in Japan is declining. To confirm this, we examined reports on the number of tree sparrows banded in Japan from 1987 to 2008. If the population size of the tree sparrow is actually diminishing, then the numbers banded should also reflect this. Results showed that the number of tree sparrows banded over this period decreased by more than half, and support previous studies documenting the decline of the tree sparrow in Japan.