Black-headed Bulbul Microtarsus melanocephalos Scientific name definitions

16–18 cm; 20–30 g. Small, active, brightly colored bulbul with very small legs. Whole head is black with metallic blue-green sheen; upperparts dark olive to yellow-olive, feathers of lower back and rump bright yellow with blackish bases (strongly barred effect when raised or ruffled), long uppertail-coverts bright yellow; rounded tail rich yellow at base and tip, broad black subterminal band; wings blackish, bright olive-yellow outer webs of secondaries and tertials forming large solid panel on inner wing, contrasting with black primaries (two-toned effect); breast and flanks dark olive to yellow-olive, rest of underparts bright yellow; plumage color individually variable, some birds with greenish wash overall, others brighter yellow; iris pale cobalt-blue (often looks white at distance); bill black; legs brownish black or dusky. Differs from Andaman Bulbul (Microtarsus fuscoflavescens) in obviously black-hooded appearance, conspicuous two-toned wing, and darker subterminal tailbar. Rare gray morph has slaty neck, breast and belly, with vent, undertail-coverts and inner wing variably yellowish or white; in some areas (e.g., eastern Thailand) another morph occurs, with dull orange or yellow-green replacing yellow. Sexes alike. Juvenile is much duller, with less pronounced wing pattern, dark olive or brownish head and throat, yellow parts of plumage darker and greener, base of rump feathers brown; feathers of uppertail-coverts and undertail-coverts shorter, iris brownish or dull bluish gray. Subspecies <em>hyperemnus</em> is supposedly similar to nominate but with upperparts much darker, underparts slightly darker, bill stouter; baweanus differs in slightly larger size and longer tail (gray morph predominates); hodiernus is larger, with longer wing, gray-tipped tail, and lacks yellow tones in plumage.

Editor's Note: This article requires further editing work to merge existing content into the appropriate Subspecies sections. Please bear with us while this update takes place.

Usually considered conspecific with the Andaman Bulbul (Microtarsus fuscoflavescens). Island subspecies hyperemnus, baweanus and hodiernus poorly differentiated and in need of review; at other extreme, one recent regional guide (1 Eaton, J. A., B. van Balen, N. W. Brickle, and F. E. Rheindt (2016). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea. Lynx Edicions, Barcelona, Spain. Close ) comments that all three may merit treatment at species level, hyperemnus “because of pronounced differences in ecology, biometrics and coloration”, baweanus “because of predominance of gray-morph birds”, and hodiernus “because of moderately deep mtDNA divergence and lack of widespread yellow morph”. Forms described as chalcocephalus (Bantam district, in Java) and cinereoventris (Tippera district, in Bangladesh) shown to be variations of gray morph of present species, and “B. immaculatus” found to be a variant of the yellow type. Proposed subspecies major (Northeastern India) was described on basis of inaccurate measurements and is invalid. Four subspecies provisionally recognized.

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.

Broadleaf evergreen forest, mixed deciduous forest and peatswamp-forest, often where fairly open and at edges along roads, clearings, waterways, etc.; occurs also in second growth (at all stages of regeneration after disturbance), mature tree orchards and plantations in vicinity of natural habitat, bamboo, canebrakes, wooded gardens, scattered trees in Imperata grassland, back mangroves and well-developed coastal scrub. Often reaches peak density in lowlands, but in some regions commoner on lower slopes at 400–800 m; occasionally ascends to 1,600 m, rarely higher (one record at 2,450 m, another at 2,580 m).

Resident, but partially nomadic. Flocks roam and disperse over wide area in non-breeding season; rarely disappears entirely from a site, but paucity of recaptures suggests that many individuals are mobile. Seasonal altitudinal movements noted in some regions, e.g., northeastern India and northern Bangladesh.

Fruits; some invertebrates. Figs (Ficus) feature prominently in diet, at Kuala Lompat (Peninsular Malaysia) include forest-edge banyans (F. benjamina or F. microcarpa), high-crown fruiting F. glabella and F. sumatrana and seven other species, with range of mean minimum diameter 5.4–14.8 mm; other recorded items include fruit of Rubiaceae, Callicarpa pentandra (Verbenaceae), Clausena excavata (Rutaceae), Mallotus macrostachyus and Macaranga (Euphorbiaceae), and Trema orientalis (Ulmaceae). Invertebrates taken include, among others, dragonflies (Odonata) and alate termites (Isoptera); two woodlice (Isopoda) found in one stomach, a grasshopper (Orthoptera) in another. Many insects (including dragonflies) and small fruit identified among food items delivered to nestlings. Ripe fruit picked from bushes and trees. Often reported as aerial-sallying for flying insects, often darts out, catches prey, and returns to same or nearby perch; also gleans small amount of invertebrate food from branches. Usually inconspicuous, but restless; in pairs or small parties moving through tall trees, often also in midstory or lower at edges. Rarely, if ever, descends to ground (has very small legs). Sometimes visits fruiting or flowering shrubs and trees in scattered flocks containing up to 20 individuals (usually fewer than ten).

Flight call a single emphatic “tchimp” or “tchep”; similar calls when perched include distinctive, emphatic, downward-inflected “chew” or “chiw”, often repeated irregularly every few seconds. Presumed song a similar, often lengthy, series of well-spaced very short, thin, sweet metallic “tink” notes that meander slightly in pitch and emphasis, the whole sequence somewhat disjointed and off-key, typically rising and then falling hesitantly; generally longer, lower and slower than that of the Andaman Bulbul (Microtarsus fuscoflavescens). In India said to give melancholy double whistle (verification needed). Lacks boisterous vocalizations of typical members of genus.

Season January–September, usually March–June. Nests singly or in loose clumps of pairs, these clumps probably temporary and breeding not always synchronized, but one group of four pairs in Selangor (Malaysia) had full clutches of eggs simultaneously; one inter-nest distance measured 40 m. Nest a loosely constructed open cup, sometimes more compact and firmly made, in India described as made of tough creeper stems and twigs interwoven with few blades of coarse grass, often with outer layer of dead leaves, and lined with fine grass stems; in Thailand and Malaysia made of grass, creeper stems, plant fibers and much dead leaf material, and often lined with black fibers (possibly fungal hyphae); one in Borneo was of grass and vegetable fibers, another was built from dead twigs and other plant fibers; placed 1–6 m up (but usually low) in bush or tree, often in upright fork or cane fronds, recorded sites e.g., thorny bush and rhododendron (Melastoma malabathricum) in clearing, creepers and hanging vines, leaf axil of a ginger (Zingiberaceae), nodal branch tuft of bamboo, branch fork or main fork of forest sapling, similar fork in dense thicket of rubber (Hevea) saplings, outer-branch fork of plantation rubber, and in two instances exotic conifer planted at forest edge. Clutch 1–3 eggs, in Peninsular Malaysia usually two; no information on incubation and fledging periods; both pair-members tend nestlings and fledglings; fledged broods of two in Malaysia.

Not globally threatened. Locally common throughout much of range, tolerating fair degree of habitat degradation; very rare in southern China and rare in India, with very few recent records. Gray morph was once locally fairly common in northeastern India, and remains regular in Java; it is commonest morph on Bawean Island, and only morph on Maratua Island. This species has been recorded in a large number of national parks, including Nam Bai Cat Tien (Vietnam), Khao Yai (Thailand), Taman Negara (Peninsular Malaysia), Kerinci-Seblat (Sumatra) and Ujung Kulon (Java).