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Sulu Hornbill Anthracoceros montani
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This hornbill faces the possibility of imminent extinction. It has a tiny population probably now confined to just one island. It is likely to be declining very rapidly owing to the continuing loss and degradation of the few remaining forest tracts in its range, and levels of exploitation. For these reasons, it is listed as Critically Endangered.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

c.70 cm. Blackish hornbill with wholly white tail. Black bill and casque, bare blackish skin around eye and small patches near bill-base. Glossy dark greenish upperparts. Iris cream-coloured in male and dark brown in female. Pale tip to casque-less bill in juvenile, and sometimes whitish-tipped primaries. Voice Series of loud cackling and shrieking calls.

Distribution and population
This species is endemic to three islands in the Sulu archipelago in the Philippines. Described as common to abundant in the late 19th century, it has undergone a drastic decline, and persists with certainty only on Tawi-tawi. Recent evidence suggests that its population is extremely low, perhaps numbering fewer than 20 pairs in the main mountain range. During a visit in February and June 2009, four individuals were reported in contiguous areas over two days on Tawi-tawi (I. Sarenas in litt. 2010). An estimated 250-300 km2 of forest remained on Tawi-tawi in 2001, although much of this included selectively logged forest (Mallari et al. 2001), and further declines have been noted since. Fortunately, the rate of clearance for oil palm plantations is lower than was feared previously. The species is thought to be extinct on Jolo (Sulu), but this requires confirmation. It is almost certainly extinct on Sanga-sanga. Local reports from 1995 suggested that it may visit the small islands of Tandubatu, Dundangan and Baliungan, though these hold very little primary forest (D. Allen in litt. 2012) and are unlikely to sustain resident populations.

Population justification
The population is estimated to number a minimum of 40 individuals, equivalent to 27 mature individuals.

Trend justification
Described as common to abundant in the late 19th century, this species is suspected to have undergone a very rapid decline over the last ten years, and persists with certainty only on Tawi-tawi. Here, extremely rapid conversion of habitat to oil palm plantations was predicted to cause near-total forest loss, but to date these predictions have not been vindicated.

It inhabits primary dipterocarp forest, typically on mountain slopes (although this may simply reflect a constraint enforced by forest loss), occasionally visiting isolated fruiting trees over 1 km from the nearest forest. It requires large trees for nesting.

Jolo (Sulu) and Sanga-sanga have apparently been almost completely deforested. By the mid-1990s, rapid clearance of primary forest on Tawi-tawi had rendered remaining lowland patches highly degraded, although plans to replace these with oil-palm plantations seem to have stalled, while the rate of logging has slowed with the remainder of forest being confined to rugged mountainous areas. Conversion to rubber plantations remains a threat to existing forest (D. Allen in litt. 2012). There have been examples of known sites being cleared for agriculture (I. Sarenas in litt. 2010). High gun ownership in the recent past may have resulted in it being shot for food and target practice. Young may continue to be harvested for food, and the species may be collected for trade. Hunting pressure on Tawi-tawi may well have increased in recent years (I. Sarenas in litt. 2010).

Conservation Actions Underway
CITES Appendix II. Military activity and insurgency continue to present a serious obstacle to conservation work in the Sulus. There are no formal protected areas in the archipelago. A proposal exists to provide conservation funding for the Tawi-tawi/Sulu Coastal Area, although neither the outcome nor the likely benefits to the species is known. A draft a municipal resolution for the banning of hunting or capture of Tawi-tawi endemics has been developed and was planned to be passed in July 2010 (I. Sarenas in litt. 2010). Conservation Actions Proposed
Conduct surveys in all remaining forest patches in the Sulus to identify key sites. Urgently establish formal protected areas in the centre-west of Tawi-tawi to conserve populations in the main mountain range. Clarify the proposal for conservation funding for the Tawi-tawi/Sulu Coastal Area. Continue and expand environmental awareness programmes and establish captive-breeding populations for future supplementation/reintroduction.

BirdLife International. 2001. Threatened birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.

Collar, N. J.; Butchart, S. H. M. 2013. Conservation breeding and avian diversity: chances and challenges. International Zoo Yearbook.

Collar, N. J.; Mallari, N. A. D.; Tabaranza, B. R. J. 1999. Threatened birds of the Philippines: the Haribon Foundation/BirdLife International Red Data Book. Bookmark, Makati City.

Diesmos, A. C.; Pedregosa, M. D. G. 1995. The conservation status of threatened species of bleeding-hearts (Columbidae) and hornbills (Bucerotidae) in the Philippines.

Mallari, N.A.D., Tabaranza, B.R. and Crosby, M.J. 2001. Key conservation sites in the Philippines: A Haribon Foundation and BirdLife International directory of Important Bird Areas. Bookmark, Makati City, Philippines.

Further web sources of information
Alliance for Zero Extinction (AZE) species/site profile. This species has been identified as an AZE trigger due to its IUCN Red List status and limited range.

Click here for more information about the Alliance for Zero Extinction (AZE)

Detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001).

Explore HBW Alive for further information on this species

View photos and videos and hear sounds of this species from the Internet Bird Collection

Text account compilers
Benstead, P., Bird, J., Butchart, S., Derhé, M., Lowen, J., Symes, A. & Khwaja, N.

Allen, D. & Sarenas, I.

Recommended citation
BirdLife International (2016) Species factsheet: Anthracoceros montani. Downloaded from on 21/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 21/10/2016.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Sulu hornbill (Anthracoceros montani) 0

Key facts
Current IUCN Red List category Critically Endangered
Family Bucerotidae (Hornbills)
Species name author (Oustalet, 1880)
Population size 27 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 590 km2
Country endemic? Yes
Links to further information
- Additional Information on this species