Gansu Leaf Warbler (Phylloscopus kansuensis)

[order] PASSERIFORMES | [family] Phylloscopidae | [latin] Phylloscopus kansuensis | [UK] Gansu Leaf Warbler | [FR] Pouillot du Gansu | [DE] Kansulaubsanger | [ES] Mosquitero de Gansu | [NL]

Subspecies

Physical charateristics

This bird looks like a warbler but is scarcely bigger than a Goldcrest and has a dazzling array of yellow stripes in its plumage – two in each wing and no less than three through its head. On top of all that it keeps hovering in front of you like a humming bird, showing off a neat, square yellow rump. The only species which comes close to matching this suite of pale markings is the Yellow-browed Warbler but this isn’t so dainty and lacks both the yellow rump and the pale central crown stripe.

Range

Eurasia : Northcentral China

Habitat

Breeds in middle and lower middle latitudes of east Palearctic, in taiga towards north of range at high altitudes optimally at 2000-3000 m in western Himalayas, up to 4000 m in C and E Nepal and further east.
Frequents uneven-aged taiga-type forest rich in thick undergrowth ascending to upper limits, stunted conifers, and open woodlands with shrubby meadows, but sings from tops of tall trees where available, and nests in pines 3-4 m above ground.

Reproduction

Breeds Jun-July in USSR. Nest site is on ground, in or against tussock, mound, windfall debris, or among tree roots. Nest is a domed structure with side entrance, of dry grasses, moss, rotten wood, plant fibre, and rootlets, lined with finer material. 4-7 eggs are laid, incubation 11-14 days, by female.

Feeding habits

Insects and a few other invertebrates. Highly active when foraging, impression being enhanced by constant fluttering and wing-flicking which perhaps serve to disturb prey. Picks or snatches items from twigs and leaves of trees and bushes, sometimes after short flight. Often pursues insects in agile flight, during and twisting.

Conservation

Although this species may have a restricted range, it is not believed to approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
A rare vagrant to the West Palearctic from Siberia. The breeding range includes much of eastern Asia, north of the Himalayas and the normal wintering area is in south east Asia including India and Indochina.

Migration

Northern populations are long-distance migrants, southern populations make shorter, mainly altitudinal movements. Main movements are through eastern Asia.
Regular autumn vagrant to north-west Europe; increasingly frequent since 1960s, previously rare. Occurrences involve mostly 1st-years and probably result chiefly from westward displacement in anticyclonic conditions, with reverse migration as possible additional factor. A few birds may occasionally overwinter.

Distribution map