VU
Knobbed Hornbill Rhyticeros cassidix



Taxonomy

Taxonomic note
Rhyticeros cassidix (del Hoyo and Collar 2014) was previously placed in the genus Aceros.

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.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - A4cd

Red List history
Year Category Criteria
2016 Vulnerable A4cd
2012 Vulnerable A4cd
2009 Least Concern
2008 Least Concern
2004 Least Concern
2000 Lower Risk/Least Concern
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

Migratory status not a migrant Forest dependency High
Land mass type Average mass -
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 432,000
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals unknown not applicable not applicable 0
Population trend Decreasing suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations - - -
Percentage in largest subpopulation - - -
Generation length (yrs) 19 - - -

Population justification: The global population size has not been quantified, but the species is reported to be locally very common (del Hoyo et al. 2001, Kinnarid and O'Brien 2007).

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. Holmes in litt. 1999 and Kinnaird and O’Brien 2007]) and hunting for food, gold mining and fires (del Hoyo et al. 2001).


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Indonesia N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Indonesia Bogani Nani Wartabone
Indonesia Popayato - Paguat
Indonesia Lembeh
Indonesia Morowali
Indonesia Gunung Ambang
Indonesia Gunung Manembo-nembo
Indonesia Mambuliling
Indonesia Gunung Klabat
Indonesia Tanjung Binerean
Indonesia Tangkoko Dua Sudara
Indonesia Likupang
Indonesia Nantu
Indonesia Puncak Botu
Indonesia Mahawu - Masarang
Indonesia Gunung Dako
Indonesia Gunung Sojol
Indonesia Kepulauan Togean
Indonesia Lore Lindu
Indonesia Rawa Aopa Watumohai
Indonesia Buton Utara
Indonesia Lambusango
Indonesia Mekongga
Indonesia Routa
Indonesia Tanjung Peropa
Indonesia Bantimurung Bulusaraung
Indonesia Karaeng - Lompobattang
Indonesia Feruhumpenai - Matano
Indonesia Muna Timur
Indonesia Tangale
Indonesia Balantak

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Dry suitable resident
Forest Subtropical/Tropical Moist Lowland major resident
Forest Subtropical/Tropical Moist Montane suitable resident
Altitude 0 - 1800 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Reduced reproductive success, Species mortality
Biological resource use Logging & wood harvesting - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Ecosystem degradation, Ecosystem conversion
Energy production & mining Mining & quarrying Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species disturbance, Ecosystem degradation
Natural system modifications Fire & fire suppression - Increase in fire frequency/intensity Timing Scope Severity Impact
Past, Likely to Return Minority (<50%) Slow, Significant Declines Past Impact
Stresses
Ecosystem degradation, Reduced reproductive success

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - Non-trivial Recent
Other household goods - - Non-trivial Recent
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2022) Species factsheet: Rhyticeros cassidix. Downloaded from http://www.birdlife.org on 30/09/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 30/09/2022.