PLATE 84: THRUSHES I
Pale Thrush Turdus pallidus
22–24 cm
ID In Mongolia, this distinctively grey-headed, rufous-sided thrush is likely to be confused only with Eyebrowed Thrush, but lacks latter’s prominent white supercilium. Adult male has darker, more contrasting coloration. Voice Song is a three-note repetitive whistle, interspersed with brief chitters. Also gives thin tzee and stronger chrrri-ii-ip calls, and low ko-ko-ko. Habitat Nests in montane pine and deciduous forest with thickets and secondary growth. Occurs in other habitats on migration. Behaviour Feeds in fruiting trees as well as on ground. Status Very rare breeding visitor in Hentii and Khangai mountain ranges, and rare passage migrant through breeding range, presumably late April to mid-September.
Eyebrowed Thrush Turdus obscurus
21–23 cm
ID Similar in general coloration to Pale Thrush but with diagnostic white supercilium. Sexes similar but adult male has deeper colour. 1st-winter is similar to adult female but has pale wing-bar and is duller. Voice Song is a simple, repeated, trisyllabic whistled phrase consisting of rather abrupt notes. Also makes high thin seep contact calls, and a briefer sip-sip. Habitat Nests in moist montane spruce and birch forest and willow thickets near rivers and streams. Migrants also occur in steppe and desert. Behaviour Rather shy. Feeds on ground but quickly flies into cover if disturbed. Status Scarce breeding visitor in Hövsgöl, Khangai and Hentii ranges, and uncommon passage migrant countrywide, late April to late September.
Siberian Thrush Geokichla sibirica
20–23 cm
ID Overall slate-grey plumage of adult male, with contrasting white supercilium, is unmistakable. 1st-winter male similar to adult male but duller with paler markings. Adult female is plain olive-brown above with heavy black scaling below, creating possible confusion with White’s Thrush. However, the latter is notably larger with longer bill and tail and is densely scaly above as well as below. Scaly female rock thrushes are much smaller and more compact, and occur in open (vs. forested) habitats. Voice Song has been described as ‘rich, whistled phrases…tve-kwi-tring or similar’. Calls include a low clucking when flushed, a high-pitched tsee and a quiet zit. Habitat Breeds in dense coniferous and mixed forest with dense understorey shrubs. Occurs in steppe and arid mountains on migration. Behaviour Rather shy and skulking, but may flock with other thrushes on migration. Status Very rare and local breeding visitor, known to nest only in northernmost Hövsgöl and Selenge provinces, and rare passage migrant through all major mountain ranges, late April to early September. Taxonomy Formerly placed in genus Zoothera.
