Mosquitero de Sichuán Phylloscopus yunnanensis

Small plump leaf warbler. A “Pallas’s-type” leaf warbler: stout, with a pale rump, crown stripe, and prominent brow stripes. Olive-yellow above with a faint gray wash on the nape. Chinese is distinguished from Pallas’s by its paler, more faded-looking brow and crown stripes, less yellow suffusion all over the body, less compact appearance, and less obvious or absent upper wingbar. Extremely similar Gansu Leaf Warbler and Lemon-rumped Warbler can be difficult to separate; note Chinese’s slightly more elongated and less rounded appearance, a lack of a distinct hook under the end of the brow stripe, less contrasting and more yellowish head patterning, and paler yellowish secondaries. Forages actively, often hovering and hopping about at mid-level. Breeds in montane broadleaved deciduous or mixed forest; moves to lower elevations in winter. On average, found at lower altitudes than Lemon-rumped and Gansu. Lengthy song is unique and bizarre, with a twanging, grating quality: “btrichi-btrichi-btrichi.” Call is an explosive “wip!”, often repeated in medium-length series on the breeding grounds.