Yellow-browed Warbler

The Yellow-browed Warbler, Phylloscopus inornatus, is a diminutive leaf warbler of the family Phylloscopidae. It is a sprite of the avian world, measuring a mere 9.5–11 cm in length and tipping the scales at a lightweight 4–9 grams. This species is characterized by its vibrant yellow supercilium and double wing bars, with the upperparts donning a greenish hue and the underparts a clean white.

Identification Tips

When attempting to identify the Yellow-browed Warbler, look for its distinctive yellowish-white wing bars on the greater and median coverts, and the yellow margins on the tertial feathers. The bird's supercilium is a striking yellow, and some individuals may exhibit a faint green central crown stripe. Its size is slightly larger than the Pallas's leaf warbler but smaller than a chiffchaff.

Habitat

This warbler favors lowland and montane forests and woodlands, and during the winter months, it may venture into more open wooded areas.

Distribution

The breeding range of the Yellow-browed Warbler spans from the western Ural Mountains to eastern Siberia, Mongolia, and Northeast China. In winter, it migrates to the warmer climes of tropical South Asia and Southeast Asia, with some individuals reaching western Europe.

Behaviour

The Yellow-browed Warbler is an active bird, almost always on the move, flitting through the canopy. It is not particularly shy, but its arboreal lifestyle can make it a challenge to observe.

Song & Calls

The song of this warbler is a delightful high-pitched medley of whistles. Its call is a piercing "tseeweest," surprisingly loud for such a small bird.

Breeding

Nests are constructed within dense vegetation, often at the base of a tree or stump. The female lays two to four eggs, occasionally more, which hatch after 11–14 days. The young fledge at 12–13 days old.

Similar Species

The Hume's leaf warbler, P. humei, is the most similar species, with which it shares part of its range. However, the Hume's leaf warbler has duller colors, a faint second wing bar, and dark legs and lower mandible. Their vocalizations are also distinct.

Diet and Feeding

Insectivorous by nature, the Yellow-browed Warbler forages for insects among the foliage.

Conservation Status

The IUCN lists the Yellow-browed Warbler as Least Concern, indicating a stable population across its broad range.