Bornean bristlehead (Pityriasis gymnocephala)

Also known as: bald-headed crow, bald-headed wood-shrike, bristled shrike, bristled starling, bristlehead
Synonyms: Barita gymnocephala
KingdomAnimalia
PhylumChordata
ClassAves
OrderPasseriformes
FamilyPityriaseidae
GenusPityriasis (1)
SizeLength: 22 - 26 cm (2)
Weight115 - 150 g (2)
Top facts

The Bornean bristlehead is classified as Near Threatened (NT) on the IUCN Red List (1).

The Bornean bristlehead (Pityriasis gymnocephala) is an enigmatic bird, meriting not only its own genus, but also its own family (Pityriaseidae) (2).

The bald crown of the Bornean bristlehead is endowed with extraordinary yellow-orange skin growths. In addition to this, the feathers of the lower throat are bristly and the feathers of the grey ear-coverts are of the same stiff texture. The common name of this species is taken from these highly unusual features (3) (4) (5).

Although the Bornean bristlehead is a medium-sized passerine, its black bill is disproportionately large and is hooked at the tip (2) (3) (4). The thick-set body and short tail give the Bornean bristlehead a top-heavy appearance (6). Although the Bornean bristlehead is mostly blackish in plumage, its face, throat, nape and thighs are bright red (3) (4) (5). A white patch is also visible on the wing when the bird is in flight (3).

Male and female Bornean bristleheads differ slightly in appearance, with the black flanks of the male being spotted with red in the female (3) (4). Juvenile Bornean bristleheads also show some differences from the adult birds. The thighs of the juvenile are black rather than red, and the ear-coverts are red instead of grey. In addition to this, the bristles of the head are undeveloped (3) (7).

The Bornean bristlehead makes a very wide and distinctive variety of calls. This species is highly sociable and the most frequently heard vocalisation is a nasal, whining contact call made as individuals of a flock communicate. A ‘pit-pit-peeoo’ call is also heard very often between members of a group. In addition, flock members sometimes whistle to each other, with every individual giving a single loud whistling call within the space of two to three seconds (3) (7).

As its name suggests, the Bornean bristlehead is endemic to the island of Borneo. Within this range, the species is widespread but patchily distributed below elevations of 600 metres, and occurs locally up to 1,000 metres (2) (8).

A bird of tropical moist forest, the Bornean bristlehead is typically associated with lowland primary rainforest and peat swamp forest (6) (8) (9). Despite this, it also often inhabits mature secondary and selectively logged forests, as well as coniferous forest, Acacia groves and upland heath forest (‘kerangas’ forest) (2) (9).

The Bornean bristlehead shows a preference for the mid-storey of forest with relatively small trees and dense undergrowth (4).

The Bornean bristlehead is rarely encountered and is considered to be uncommon even in prime habitat. The apparent scarcity of this species may, in part, be explained by the tendency of flocks to range over large areas (6). This behaviour suggests that the Bornean bristlehead is nomadic in nature, maintaining large home ranges (10).

As a naturally gregarious species, the Bornean bristlehead is usually encountered in flocks of six to ten birds. It moves slowly through its lowland rainforest habitat in an ungainly fashion (3). Flocks of the Bornean bristlehead often associate with other large forest birds, notably the black magpie (Platysmurus leucopterus) (7).

These flocks of Bornean bristleheads spend much of their time searching leaves and tree trunks for invertebrate prey (3). Caterpillars, cicadas, beetles and other large insects are the principle sources of food for the Bornean bristlehead (2) (3) (7). Occasionally, small reptiles and amphibians are also taken as prey (2). Although the Bornean bristlehead has been seen to feed on fruit, this is considered to be a small part of the overall diet (3).

The breeding biology of the Bornean bristlehead remains a mystery, with very little information known (3). Although the nest of this species has never been found, there is a description of an egg taken from a female specimen that was collected in 1896. This egg was largely white with grey and brown spots (11). Evidence of breeding, such as carrying of nesting material, has been observed in May, August and October (3) (7), suggesting that this species may have quite an extended breeding season (3). However, further fieldwork is necessary to unearth the exact details of this aspect of the life of the Bornean bristlehead (2).

The principal threat to the Bornean bristlehead is habitat loss through deforestation. Destruction of forest in lowland Borneo continues at a rapid rate, including in protected areas. Rates of forest loss in Kalimantan (Indonesia) have been particularly rapid, with illegal logging and land conversion being major threats there (2) (9).

Additionally, the Bornean bristlehead is at risk from forest fires, which similarly destroy available habitat. As this species is tolerant of disturbed forest, these threats may be slightly alleviated. However, habitat destruction remains a major concern for the conservation of the Bornean bristlehead, and the species is believed to be undergoing a population decline (9).

Although there are no known specific conservation measures currently in place for the Bornean bristlehead, it occurs within several protected areas (9). The Danum Valley Conservation Area, located in Sabah (Malaysia), is one of the Bornean bristlehead’s strongholds. This unusual bird has also been recorded in Lambir Hills National Park and Samunsam Wildlife Sanctuary in Sarawak, Tawau Hills National Park in Sabah, and Ulu Temburong National Park in Brunei (3).

Recommended measures for the conservation of the Bornean bristlehead include surveys to measure its population trends and studies into its exact habitat requirements. It will also be important to work towards protecting the remaining peat swamp forests which it inhabits (9).

Find out more about the Bornean bristlehead and its conservation:

More information on conservation in Borneo:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. IUCN Red List (July, 2013)
    http://www.iucnredlist.org/
  2. del Hoyo, J., Elliott, A. and Christie, D. (2009) Handbook of the Birds of the World. Volume 14: Bush-Shrikes to Old World Sparrows. Lynx Edicions, Barcelona.
  3. Colenutt, S. (2002) Little known Oriental bird: Bornean bristlehead. Oriental Bird Club Bulletin, 35: 75-77.
  4. Ahlquist, J.E., Sheldon, F.H. and Sibley, C.G. (1984) The relationships of the Bornean bristlehead (Pityriasis gymnocephala) and the black-collared thrush (Chlamydochaera jefferyi). Journal für Ornithologie, 125(2): 129-140.
  5. Moyle, R.G., Cracraft, J., Lakim, M., Nais, J. and Sheldon, F.H. (2006) Reconsideration of the phylogenetic relationships of the enigmatic Bornean bristlehead (Pityriasis gymnocephala). Molecular Phylogenetics and Evolution, 39(3): 893-898.
  6. Smythies, B.E. (1960) The Birds of Borneo. Oliver and Boyd, London.
  7. Sheldon, F H., Moyle, R.G. and Kennard, J. (2001) Ornithology of Sabah: history, gazetteer, annotated checklist, and bibliography. Ornithological Monographs, 52: 1-278.
  8. BirdLife International (2001) Threatened Birds of Asia: The BirdLife International Red Data Book. BirdLife International, Cambridge, UK.
  9. BirdLife International - Bornean bristlehead (October, 2012)
    http://www.birdlife.org/datazone/speciesfactsheet.php?id=5868
  10. Witt, C.C. and Sheldon, F.H. (1994) A review of the status and distribution of the Bornean bristlehead. Kukila7(1): 54-67.
  11. Bartlett, W.J. (1896) Egg of Pityriasis gymnocephala. Ibis, 38: 158-159.