Rhabdotorrhinus exarhatus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Bucerotiformes Bucerotidae

Scientific Name: Rhabdotorrhinus exarhatus (Temminck, 1823)
Common Name(s):
English Sulawesi Hornbill
Penelopides exarhatus (Temminck, 1823)
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
Taxonomic Notes: Rhabdotorrhinus exarhatus (del Hoyo and Collar 2014) was previously placed in the genus Penelopides.

Assessment Information [top]

Red List Category & Criteria: Vulnerable A4cd ver 3.1
Year Published: 2017
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): O'Brien, T., Kinnaird, M., Mulyawati, D., Lambert, F. & Holmes, D.
Facilitator/Compiler(s): Derhé, M., Symes, A., Westrip, J.
This species has been uplisted to Vulnerable because it has a rapidly declining population owing to destruction of its forest habitat and hunting.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is endemic to Sulawesi, Indonesia. Race R. e. exarhatus occurs in northern Sulawesi and Lembeh island; race R. e. sanfordi occurs in southern Sulawesi and the islands of Muna and Butung.
Countries occurrence:
Additional data:
Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:415000
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:No
Upper elevation limit (metres):650
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The global population size has not been quantified, but the species is reported to be locally common (del Hoyo et al. 2001).

Trend Justification:  The population is suspected to be declining rapidly owing to ongoing habitat destruction (16.9% forest loss per ten years during 1985-1997; 36.1% loss per ten years during 1997-2001 on Sulawesi [based on D. A. Holmes in litt. 1999 and Kinnaird and O’Brien 2007]) and hunting for food and for keeping as pets (del Hoyo et al. 2001).
Current Population Trend:Decreasing
Additional data:
Number of mature individuals:UnknownContinuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:No
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:The species occurs in lowland primary forest, occasionally tall secondary forest, usually below 650 m asl but sometimes up to 1,100 m asl. Family groups sometimes in more open habitats (del Hoyo et al. 2001). Diet consists mainly of fruit (85%), also some small animals, mainly invertebrates. Forages mostly through foliage below the canopy. In Gorontalo, Sulawesi, the species has been observed foraging in primary and abandoned selectively logged forest, including those in fairly close proximity to human settlements (D. Mulyawati in litt. 2010). It requires large forest trees for breeding (del Hoyo et al. 2001, F. Lambert in litt. 2011), nesting in natural cavities or old woodpecker holes. Nests in some sites used by Knobbed Hornbill Aceros cassidix.
Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):19.4
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): The species is threatened with habitat destruction, with forest on Sulawesi being lost at a rate of 16.9% per ten years during 1985-1997; and 36.1% per ten years during 1997-2001 (based on D. A. Holmes in litt. 1999 and Kinnaird and O’Brien 2007). The species's specialised breeding requirements (including a dependence on large trees) makes them particularly vulnerable to forest loss and degradation (e.g. Winarni and Jones 2012). Hunting, both for food and for keeping as pets, is also a serious threat (del Hoyo et al. 2001). MacKinnon and MacKinnon (1980) documented a dramatic crash in the population at Tangkoko in 1978-1979 which may have been driven by disease introduced by domestic poultry into wild populations (T. O’Brien and M. Kinnaird in litt. 2006).

Conservation Actions [top]

Conservation Actions: Conservation measures underway
None is known

Conservation measures proposed
Conduct further surveys to clarify its distribution and status. Monitor trends in the population. Protect remaining extensive tracts of forest, extend existing protected areas where appropriate, and strictly control hunting in protected areas. Lobby for improved logging practices that leave patches of old growth or large trees. Design and implement hornbill conservation programmes aimed at reducing hunting levels.

Amended [top]

Amended reason: Edited Threats Information text. Added a reference and a Facilitator/Compiler.

Citation: BirdLife International. 2017. Rhabdotorrhinus exarhatus (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2017: e.T22682504A117181682. . Downloaded on 19 August 2018.
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