The Gansu leaf warbler is a small passerine bird known only from China. It belongs to the leaf warbler genus Phylloscopus within the family Phylloscopidae. It was formerly treated as a subspecies of Pallas's warbler but is now regarded as a separate species based on differences in voice and cytochrome-b gene sequences.
Region
Northeastern edge of the Tibetan Plateau
Typical Environment
This species occurs in montane regions of central-northwest China, especially Gansu and adjacent provinces such as Qinghai and northern Sichuan. It breeds in coniferous and mixed forests with dense understory, including rhododendron and willow thickets. Birds also use forest edges, scrubby slopes, and streamside vegetation where insect prey is abundant. In the non-breeding season it moves to lower elevations locally and may shift southward within China. The distribution is patchy, following suitable highland habitats.
Altitude Range
1800–3800 m
Climate Zone
Highland
Ease of Keeping
Beginner friendly: 1/5
Once treated as a subspecies of Pallas's warbler, the Gansu leaf warbler is now recognized as a full species based on distinct vocalizations and cytochrome-b genetic differences. It is confined to China, where it favors high-elevation forests and shrubby slopes. Identification in the field often relies on its high, thin song phrases and subtle plumage differences.
Temperament
active and restless
Flight Pattern
short rapid wingbeats
Social Behavior
Breeds in solitary pairs with well-defined territories. Nests are placed low in dense shrubs or on the ground in concealed sites, where the female typically handles most incubation while both adults feed the young. Outside the breeding season, it often joins mixed-species flocks with other small insectivores.
Migratory Pattern
Partial migrant
Song Description
Song consists of very high, thin, and sweet trills and whistles delivered in short phrases, distinct from Pallas’s warbler in rhythm and structure. Calls are sharp, high-pitched seeps used frequently as the bird forages in foliage.
Plumage
Small, greenish-olive warbler with clean whitish underparts, a prominent pale supercilium, and two pale wingbars; fine, pointed bill and compact structure.
Diet
Primarily takes small arthropods such as aphids, caterpillars, beetles, and spiders. It gleans prey from leaves and twigs, often hanging or hovering briefly to reach the underside of foliage. Occasional short sallies catch small flying insects. Foraging is rapid, with frequent movements through the canopy and shrub layer.
Preferred Environment
Feeds in coniferous and mixed forests, especially along edges, clearings, and riparian thickets where insect densities are high. During cooler months it uses lower-elevation woodlands, scrub, and sheltered valleys. It often forages in the mid-story but will move from understory to canopy as resources shift.
