At 10000 ft. in Kullu - Manali District of Himachal Pradesh, India At 10000 ft. in Kullu - Manali District of Himachal Pradesh, India At Biskeri (11000 ft.)in Kullu - Manali District of Himachal Pradesh, India At Biskeri (11000 ft.)in Kullu - Manali District of Himachal Pradesh, India

Hume's Leaf Warbler (Phylloscopus humei) or Hume's Warbler is a small leaf warbler which breeds in the mountains of central Asia from the Hindu Kush and Karakoram east and north to the Tien Shan in China and the Altay Mountains in Mongolia. The completely allopatric subspecies mandellii - sometimes separated as Mandell's Warbler - occurs in the eastern Tibetan Plateau (Alström 2006). This warbler is migratory and winters mainly in India.

This is a common bird of mountain woodlands at altitudes of up to 3,500m. The nest is built on the ground. Like most Old World warblers, this small passerine is insectivorous.

It was recently split (Sangster et al., 2002) from the Yellow-browed Warbler (Phylloscopus inornatus), based on differences in morphology (Shirihai & Madge, 1993), bioacoustics (Alström & Olsson, 1988; Irwin et al., 2001), and molecular characters (Irwin et al., 2001). The Western Hume's Leaf Warbler's range overlaps with that of the Yellow-browed Warbler in the western Sayan Mountains (Ernst, 1996), but the species apparently do not hybridize (Irwin et al., 2001). The divergence between the two species has been tentatively estimated at roughly 2,5 mya, and that between the P. h. humei and P. h. mandelli at about 1 mya (Irwin et al., 2001).

This tiny warbler is prone to vagrancy as far as western Europe in October, despite a 3000km distance from its breeding grounds. It is a rare vagrant in late autumn and winter in Great Britain.

The Hume's Leaf Warbler is one of the smallest warblers, and shares greenish upperparts and off-white underparts with typical leaf warblers. It is very similar to the Yellow-browed Warbler, sharing a long supercilium, crown stripe and well-marked tertials. However, it has only one prominent wing bar, only a faint second wing bar and duller colours. It also has dark legs and lower mandible.

This bird is not shy, although its arboreal life style makes it difficult to observe. It is constantly in motion. Its song is buzzing and high pitched. The best distinction from the Yellow-browed is the more disyllabic call. While the Eastern and Western Hume's Leaf Warblers already show noticeable differences in mtDNA sequence and calls, their songs do not differ (Irwin et al., 2001); they are reproductively isolated only by allopatry and not usually considered separate species.

This bird is named after Allan Octavian Hume.