CR
Tooth-billed Pigeon Didunculus strigirostris



Taxonomy

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
C2a(i) A2cde+3cde; B1ab(ii,iii,v); C2a(i); D A2cde+3cde; B1ab(ii,iii,v); C2a(i); D1

Red List history
Year Category Criteria
2019 Critically Endangered C2a(i)
2018 Critically Endangered C2a(i)
2016 Critically Endangered C2a(i)
2015 Critically Endangered C2a(i)
2014 Critically Endangered C2a(i)
2013 Endangered A2cde;B1ab(ii,iii,v);C2a(i)
2012 Endangered A2cde;B1ab(ii,iii,v);C2a(i)
2008 Endangered A2c,d,e; B1a+b(ii,iii,v); C2a(i)
2004 Endangered
2000 Endangered
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

Migratory status not a migrant Forest dependency High
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 2,900 medium
Number of locations 11-100 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 50-249 medium inferred 2014
Population trend Decreasing medium 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) 50-79 - - -
Decline (10 years/3 generation past and future) 50-79 - - -
Number of subpopulations 2 - - -
Largest subpopulations 1-89 - - -
Generation length (yrs) 6.6 - - -

Population justification: The low number of recent records and lack of sightings by local people strongly suggest that the population is now extremely small, thus it is placed in the band 50-249 mature individuals, assumed to equate to c. 70-380 individuals in total.

Trend justification: No new data are available on population trends, but the species is suspected to have undergone a very rapid decline over the past three generations (estimated at 20 years), based on the low number of recent records, and owing to the partially synergistic effects of forest degradation by cyclones and invasive tree species, as well as accidental mortality from hunting and direct loss of habitat through agricultural expansion. Consensus among reliable hunters corroborate this downward trend (Serra et al. 2016, Serra et al. 2017). This assessment of the rate of decline may be conservative given the perceived change in abundance since the 1990s and the potential impacts of Severe Tropical Cyclone Evan in December 2012 (R. Stirnemann in litt. 2012). It is suspected that a very rapid decline will take place over the next three generations if conservation actions are not increased, owing to the expected impacts of intermittent powerful cyclones and the inherent consequences of the species's extremely small population size.


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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Samoa Aleipata Marine Protected Area
Samoa Apia Catchments
Samoa Central Savaii Rainforest
Samoa Eastern Upolu Craters
Samoa O Le Pupu-Pu'e National Park
Samoa Uafato-Tiavea Forest

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland major resident
Altitude 0 - 1600 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Small-holder farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation
Biological resource use Hunting & trapping terrestrial animals - Unintentional effects (species is not the target) Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species mortality
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Whole (>90%) Unknown Unknown
Stresses
Indirect ecosystem effects, Ecosystem degradation
Climate change & severe weather Storms & flooding Timing Scope Severity Impact
Past, Likely to Return Majority (50-90%) Rapid Declines Past Impact
Stresses
Indirect ecosystem effects, Ecosystem degradation, Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Felis catus Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Rattus exulans Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Rattus rattus Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Reduced reproductive success, Species mortality

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - Non-trivial Recent

Recommended citation
BirdLife International (2019) Species factsheet: Didunculus strigirostris. Downloaded from http://www.birdlife.org on 15/12/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 15/12/2019.