White-crowned Hornbill ( Berennicornis comatus )

Originally thought by some to be closely related to White-crested Hornbill of West Africa, which is then placed in this genus. Until recently placed alone in the subgenus Berenicornis within the genus Aceros, as it shares distinct all-black adult female plumage with Rufous-necked Hornbill. It is now considered unique in its own genus, as plumage, behavior and voice are all markedly distinct.

Size 80-100 cm. young male 1250-1360 g; female 1470 g. Large hornbill with white spiky crest and white graduated tail, wings with white trailing edge. Male has white neck and underparts, blue bare skin around eye and throat; black bill has small casque.

The female is smaller with all-black body except for the white crest. Juveniles of both sexes have white underparts, head and neck, similar to adult male, but with grey streaks on head and breast and dull greenish-yellow bill, proximal half of tail is black and the rest whites.

The call is a characteristic series of mellow double and triple cooing notes, falling in pitch “ho-ho ho-hoo-hoo”

Ecology and habits


Found in large expanses of primary rainforest; extends into adjacent closed secondary forest and riverine areas, also recorded in nearby cultivation.

Mainly in the lowlands, up to 900 m elevation, recorded to 1,680 m. It is a shy and  unobtrusive bird that stays hidden inside the canopy of large trees. It rarely flies high above the forest; instead it flips from tree to tree on short flights at canopy level. The diet has a large proportion of animal food; it actively hunts in the trees, probing the bark and vines for prey and even drops down to the ground regularly.

The prey is insects, snakes, lizards and small bird’s chicks and eggs, mice. It also takes fruits, mainly lipid-rich drupes and capsules, also some figs, In southern Thailand fruit food, other than figs, includes Oncosperma horridum (Arecaceae), Litsea spp (Lauracaea), Aglaia spectabilis, Chisocheton ceramicus (Meliaceae), Horsfieldia tomentosa  and Myristica elliptica (Myristicaceae) and Sterculia sp (Sterculiaceae).

It is apparently sedentary and territorial, but somewhat social with co-operative activities reported during breeding. Surveys found that the home range is small, only some 1-10 km2

Breeding ecology


 

The nesting season is largely aseasonal; egg-laying has been recorded in Jan, Mar, Jun, Oct and Dec. In southern Thailand, nesting season begins in May and finishes in Aug; nests of this hornbill are 5-22 m (average 11 m) above the ground, mostly in tall trees of Dipterocarpaceae (Hopea, Shorea) and Syzgium sp (Myrtaceae).

Most nests are found near streams. Co-operative during the nesting period, 3-8 birds may gather around a other females and enters the nest where she lays probably 2 eggs. One or more males and helpers will bring food to the nest. In southern Thailand, at least ten breeding pairs had only one helpers, usually females.

Otherwise not much is known about the nesting practice; incubation and nestling periods are not known, but in southern Thailand the nesting cycle is 103-113 days (average 105 days) and 1-2 chicks fledge