Good at hiding

The Kayakuguri lives in the high-altitude mountain forests of Japan, but is a wandering bird (a bird that moves within Japan depending on the season) that moves to warmer areas such as flatlands in the winter. Its brown body color blends in with the trees in the forest, and it rarely appears in open areas.
It is thought that during the wintering period, they burrow into the grass and do not come out easily, which is why they got their name. In Japanese, the grass called "Kaya" and "kuguri" means to burrow into.