(871) Phylloscopus humii praemium
The Crowned Willow-Warbler.
Phylloscopus humii praemium Mathews and Iredale, Aus. Av. Record, iii, p 44 (1915) (Russia). Phylloscopus superciliosus. Blanf. & Oates, i, p. 409. Phylloscopus mandellii. Id., ibid., p. 411.
Vernacular names. Daotisha koro (Cachari).
Description. Similar to P. 7i. humii but very much darker.
Colours of soft parts and measurements as in P. 7i. humii.
Distribution. Breeding from the Ob to Kamchatka in Siberia as far South as Lake Baikal and Baikalia, Mongolia, N. China and a great part of Tibet and North-West China. In Winter South to Bengal. Assam, Burma, South China and the Indo-Chinese countries- It also straggles into Russia and Eastern Europe and rarely into Western Europe and Great Britain.
I cannot separate P. mandellii. As far as I know, no form of P. humii breeds South of Tibet in Sikkim and certainly none breed in the Khasia Hills. The very dark head and rich coloration on which Oates relies as distinguishing features seem to be individual characters which crop up in both races all over their habitat.
Nidification. Similar to that of P. h. humii, making a ball-nest of grass lined with hair and placed on bank under the shelter of a bush, fern or patch of grass. The eggs cannot be distinguished from those of Hume's Willow-Warbler. Hartert gives the measurements of fifty eggs as follows: average 14.0 x 11.25 mm. : maxima 16.0 x 12.0 mm.; minima 13.0 x 11.0 mm.
Specimens of birds nesting in Tibet and obtained in abraded breeding-plumage are very difficult to place, but seem to me to be of this race. In the South of Tibet and Sikkim there are no authentic records of its having bred but in Ladak and N. E. Tibet it is not uncommon, though apparently very local. These latter birds have hitherto been recorded as P. h. humil but may possibly prove to be P. h. superciliosus.
Habits. Similar to those of Hume's Willow-Warbler.
* It is unfortunately impossible to use the name P. inornatus of Blyth for the Crowned Willow-Warbler, as Blyth himself stated subsequently that it does not apply to this species.