Slender-billed Oriole Oriolus tenuirostris Scientific name definitions

21–25 cm; 72–92 g. Male nominate race has head golden-yellow apart from broad black band extending from lores around eye and across back of head; mantle and back golden-olive, rump duller; remiges black, outer primaries tipped yellowish-white and narrowly edged white, inner primaries, secondaries and tertials broadly edged golden-olive and tipped bright yellow, upperwing-coverts golden-olive; tail has outermost rectrices mostly yellow and inner pair black, the intervening feathers with amount of yellow decreasing towards inner pair; throat and underparts entirely golden-yellow; iris red; bill livid pink; legs slaty blue. Distinguished from very similar O. chinensis mainly by much narrower black band on nape, duller (not golden-yellow) mantle and back (but similar in colour to female of O. chinensis), and longer, more decurved and more slender bill. Female is very similar to male but slightly darker above, dark colour sometimes extending onto crown and obscuring nuchal band, rump olive; yellow underparts have narrow dark streaks. Immature is yellowish-green above, creamy white on chest to yellowish on belly, entire underside heavily streaked black ; bill black. Race <em>invisus</em> is smaller than nominate, inner secondaries with larger yellow tips.

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Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Montane forests, e.g. open pine (Pinus) forest, mixed pine-oak (Pinus-Quercus) forest, dry open semi-evergreen or broadleaf evergreen forests, also forest edge, bamboo, plantations, gardens, groves, tea-shade trees, clearings and open country with scattered tree clumps; up to 1500 m in Thailand, but to 2100 m in India and Bhutan, and at 2500–4300 m in China. In non-breeding season found down to 600 m in open evergreen broadleaf forests and secondary growth.

Generally resident, but some migratory; status in many areas poorly known, partly because of taxonomic uncertainties (formerly treated as conspecific with O. chinensis) and patchy records. Probably resident in Bhutan and NE India (Arunachal Pradesh, Nagaland); resident Myanmar, Laos, NW Vietnam and parts of Thailand; probably only a breeding visitor in China (Yunnan). Non-breeders occur to the W in E Nepal, Sikkim, hills of S Assam, possibly also Bihar, West Bengal and Bangladesh, and to the S in parts of Thailand and Indochina (limits uncertain).

Fruits, e.g. figs (Ficus) and Trema orientalis, also nectar, e.g. of Salmalia and Erythrina; also insects. Forages alone or in pairs high up in trees; rarely, descends to ground to take caterpillars.

Song  a variety of mellow fluty “wheeow” notes usually preceded by 2 or 3 short high “kick” notes (like those of a Dendrocopos woodpecker), alternatively as “chuck, tarry-you”. Calls  include a rather harsh mewing note, also short nasal notes and harsh snarling sounds.

Season Apr/May–Jun. Nest a moderately deep open cup of grass stems, leaves, roots, seed down, slender strips of bark and other fine material, lined with fine grass, down, hair and feathers, suspended hammock-like from thin, horizontal forked branch at variable height, usually in outer edge of well-foliaged tree canopy, sometimes attached to creepers on oak, and often near nest of Black Drongo (Dicrurus macrocercus); nest and nest-site like those of O. kundoo. Clutch 2–4 eggs, very similar to those of O. kundoo but nearly always have a warm pink to yellowish-pink tinge with red, light chestnut, purple-brown or blackish spots, often with reddish haloes, 26·1–29·6 × 19–21·7 mm. No other information.

Not globally threatened. Fairly common to common in much of range of c. 1,000,000–10,000,000 km². Almost extinct in some areas in China owing to hunting and to trapping for the cagebird trade and taxidermy. Occurs in various protected areas, e.g. Mae Wong National Park, in Thailand, and other reasonably secure sites, and thought therefore not to be at any immediate risk.