Japanese Leaf Warbler

The Japanese Leaf-Warbler is sized between 12–13 cm in length. They typically have darker green upper body feathers, with an under body (or belly) with lighter green feathers. They have a very short and black (with a hint of yellow) beak, as well as extremely small legs that vary from pale yellow to orange-brown. The bird has a clear yellowish-white eyebrow stripe above the bird's dark eyes. Adults are bright olive-green (with a white wingbar and greenish tail). Both sexes look alike. Juveniles are roughly similar, yet duller in color (more grey-brown).

This species lives in mixed and deciduous forests, as well as in coniferous woods and thickets. It is usually found between 1500 and 2500 meters in elevation, but most often below 2200 meters. It nests in thick undergrowth, rhododendron bushes, and scrub above the tree line. In winter, it is seen below 1800 meters in woodlands, rainforests, secondary growth, plantations, and gardens. It also occurs in shrublands, wetlands, and cultivated areas, as well as artificial terrestrial habitats. The species depends on thick vegetation for nesting and foraging.

Its diet is made up mostly of insects and their larvae. Common food items include midges, ants, grasshoppers, caterpillars, beetles, spiders, and small snails. In autumn, it may also eat berries. The warbler usually forages alone or in pairs but can join mixed groups of birds outside of the breeding season. It searches for food in trees, shrubs, and on the ground, and it sometimes catches insects while flying.