Banded broadbill

In The Birds of Asia, ca. 1850

The banded broadbill was described as Eurylaimus javanicus by the American naturalist Thomas Horsfield in 1821 based on specimens from Java. It is the type species of the genus Eurylaimus, which was created for it.[4] The generic name Eurylaimus comes from the Ancient Greek ευρυς (eurus), meaning broad, and λαιμος (laimos), meaning throat. The specific name javanicus comes from Java, the island on which it was discovered.[5] Banded broadbill is the official common name designated by the International Ornithologists' Union (IOU).[6] Other common names for the species include Javan broadbill.[7] The species is called takau rimba in Malay and Nok Phaya Paak Kwaang laay leuang in Thai.[8]

The banded broadbill is one of two species currently placed in the genus Eurylaimus, in the typical broadbill family Eurylamidae, a family of nine tropical species native to Southeast Asia.[9] Based on a 2017 study by the Brazilian researcher Alexandre Selvatti and colleagues, its closest relative is the black-and-yellow broadbill. These two species are most closely related to a clade formed by the black-and-red and silver-breasted broadbills, and all three genera form a sister clade to the genus Sarcophanops. This clade is sister to one formed by the long-tailed broadbill and dusky broadbill. Both of these clades are sister to the Grauer's broadbill. The following cladogram shows phylogenetic relationships among the Eurylaimidae, based on the above study:[lower-alpha 1][11]

Four subspecies of the banded broadbill are currently recognised by the IOU:[6]

• E. j. pallidus Chasen, 1935: Found from southeastern Myanmar to Vietnam and the Malay Peninsula.[6] Populations from the northern Malay Peninsula are sometimes separated as E. j. friedmanni.[12]
• E. j. harterti van Oort, 1909: Found on Sumatra, the Riau Archipelago, Bangka Island, and Belitung.[6] The population from Belitung was previously recognised as E. j. billitonis, but this is not generally accepted anymore.[12] It is larger than the nominate subspecies, with light blue-green irises, darker underparts, a more reddish upper back, and pink vent.[13]
• E. j. javanicus Horsfield, 1821: Also known as the Javan broadbill, it is the nominate subspecies and found on Java.[6]
• E. j. brookei Robinson & Kloss, 1919: Found on Borneo and the northern Natuna Islands.[6]

All the subspecies excluding javanicus are sometimes split as a separate species, which would make the current species monotypic (having only one subspecies).[13]

In Kaeng Krachan National Park, Thailand

The banded broadbill is a striking, large-bodied bird, with a length of 21.5–23.0 cm (8.5–9.1 in). The weight of adults of pallidus from the Malay Peninsula was 65.1–95.0 g (2.30–3.35 oz), with males weighing slightly more than females. If seen clearly, the species is unlikely to be confused with any other bird. It may be mistaken for black-and-yellow broadbill, which differs in its smaller size, black head, and contrasting white collar.[13]

Adult males of the nominate subspecies have a glossy purple-red head, which turns black towards the lores and base of the bill. The chin, throat, and ear-coverts are slightly lighter, with a black band across the neck. The top of the head is glossy maroon black and turns grey towards the back of the neck. The upper back is maroon-tinged dark brown, with most of the back black, except for a central line of yellow streaks. The primary feathers are dark brown, with thin yellow edges that are present as a yellow line on the bend of the wing. The remaining wing-coverts are blackish, with yellowish markings. The secondaries have bright yellow edges to their outer margins that form a well-marked, trapezoidal patch on the wing. The underparts are pale pinkish-violet to wine-red, with a grey tinge to the chin and upper breast and a pure grey breast-band. The tail is dark black and has white spots on the underside, while the undertail-coverts are pale yellow and the rump has a variable black and yellow pattern. The brilliant turquoise blue beak is broad and hooked, edged green or black. The irises are pale yellow in javanicus and sapphire blue in all other subspecies, while the legs are pale pinkish-brown to light greyish-blue with dull black feathering.[8][13]

Females are similar to males, but can be told apart by their lack of a neckband and greyer heads and underparts, although the neckband is faint or absent in males as well on Borneo and Java. Juveniles have pale brown heads, brown upper backs, dark brown wings, and black tails. They have a marked yellow supercilium that widens towards the back of the neck to become a broken collar, while the ear-coverts have narrow yellow streaks. The upper back has irregular yellow spots and the back and rump are largely yellow. The wings have yellowish markings like those of adults. The throat is yellowish with pale dark streaks and is separated from the breast by a yellowish-white strip, the rest of the underparts being a pink-tinted yellow. The bill is orangish-brown. As juveniles age, the yellow on the body is gradually replaced with purple-pink, starting with the head and side of the neck. In Malaysia, moulting has been observed in all months except January and February and peaks from May to August. The primary feathers nearest the body are moulted first, with those further away mounting later.[8][13]

Reddish colours in the banded broadbill's plumage are caused by the biological pigment 2,3-didehydro-papilioerythrinone, which is also found in the black-and-yellow broadbill, black-and-red broadbill, and Sarcophanops species. The yellow in the species' plumage is caused by the carotenoid 7,8-dihydro-3′-dehydro-lutein, which is also present in the plumage of the black-and-yellow broadbill.[14]

Despite the banded broadbill's distinctive and conspicuous coloration, it is generally hard to observe due to its lethargic habits and is generally only seen due to its loud song.[13] It is known to make wing and gaping displays similar to those of the black-and-yellow broadbill. Wing displays include raising the wings slightly above the back and then slowly opening and closing the flight feathers, and are made after singing, foraging, or in response to playback. They may include just one wing and are sometimes complemented with a tail wag. Gaping displays are conducted by opening and closing the bill measuredly without making any sounds. They displays are performed both when alone and in the presence of other banded broadbills, and have been observed being performed near nests. They are also sometimes accompanied by soft calls.[15]

The International Union for Conservation of Nature, which splits the banded broadbill into two species, classifies javanicus as being near-threatened and the other subspecies as being of least concern.[1][16]