Pityriaseidae – Bristlehead

The Bornean Bristlehead also variously known as the Bristled Shrike, Bald-Headed Crow or the Bald-headed Wood-shrike. The featherless crown is deep yellow and covered in short, 3–4 mm long, bristle-like skin projections, giving it a bald appearance from afar. This gives the species its common name ‘bristlehead’. The genus name Pityriasis comes from the Greek meaning ‘having dandruff’ and the specific name gymnocephala is also from the Greek, meaning ‘bald-headed’. Red flank patches are present in all females and some males, but can be covered by the wings when perched. There is a white wing-patch at the base of the primaries, visible in flight. It has a massive heavy black hooked bill and a short tail, giving it a chunky appearance. It is the only member of the passerine family Pityriaseidae and genus Pityriasis. It is an enigmatic and uncommon species of the rainforest canopy of the island of Borneo, to which it is endemic.

The relationships of this species have been controversial. At times it has been placed in the Prionopidae, the Cracticidae, the Artamidae or even the Corvidae. A more recent suggestion has been to include it in the Tephrodornithidae, a new family that includes Hemipus and Tephrodornis – more taxonomic research is needed.

Bornean Bristlehead Pityriasis gymnocephala – ©Dubi Shapiro

It is a medium-sized (25 centimetres in length) generally black or dark grey bird, with red thighs and a red head, throat and neck, grey ear-coverts and a featherless yellow crown. Juveniles have black thighs, red ear-coverts, a red eye-ring, just a few red feathers on the head and undeveloped ‘bristles’.

It is a noisy species making a variety of unmusical calls, including distinctive high-pitched nasal whining notes interspersed with harsher notes, chattering noises, whistles, honks and chortles.

Endemic to the island of Borneo, throughout the lowlands of which it has been recorded up to 1200m, though its distribution is sparse, patchy and unpredictable. It may be found in both primary and secondary lowland forests, including peat swamp forests, mixed dipterocarp forests and mangroves

It is a sociable species which often moves steadily in small garrulous flocks of 6–10 birds in the mid and upper canopy of the forest, sometimes accompanied by other large forest birds such as malkohas, babblers, drongos, trogons, woodpeckers and hornbills in mixed-species feeding flocks. Its movements in the canopy are slow and heavy and it flies with a fast, shallow wing-beat.

Bornean bristleheads feed primarily on animal prey, mainly large insects and other arthropods, but also small vertebrates like lizards and frogs. Prey is gleaned from foliage, twigs, branches and trunks at canopy to mid-levels of the forest. It occasionally takes fruit.

Breeding behaviour is largely unknown, though an oviduct egg was described as being white with grey and brown spots and with dimensions of 31 x 25 mm. A sighting of two apparent females feeding a fledgling has been interpreted as suggesting communal breeding. Birds have also been seen in flight carrying nesting material.

It is at risk as the lowland forest it mostly inhabits is disappearing at an alarming rate.