Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
Critically Endangered | Endangered | Vulnerable |
---|---|---|
- | C2a(i); D | C2a(i); D1 |
Year | Category | Criteria |
---|---|---|
2024 | Endangered | C2a(i); D |
2016 | Endangered | C2a(i) |
2012 | Endangered | B1ab(ii,iii,v);C2a(i) |
2008 | Endangered | B1a+b(ii,iii,v) |
2004 | Endangered | |
2000 | Endangered | |
1996 | Vulnerable | |
1994 | Vulnerable | |
1988 | Lower Risk/Least Concern |
Migratory status | not a migrant | Forest dependency | high |
Land-mass type | Average mass | - |
Estimate | Data quality | |
---|---|---|
Extent of Occurrence (breeding/resident) | 1,380 km2 | medium |
Area of Occupancy (breeding/resident) | 640 km2 | |
Severely fragmented? | no | - |
Estimate | Data quality | Derivation | Year of estimate | |
---|---|---|---|---|
Population size | 125-250 mature individuals | poor | estimated | 2022 |
Population trend | decreasing | poor | inferred | - |
Generation length | 4.89 years | - | - | - |
Number of subpopulations | 2 | - | - | - |
Percentage of mature individuals in largest subpopulation | 75% | - | - | - |
Population justification: This species is patchily distributed and difficult to find, seemingly absent from large tracts of suitable upland habitat (O'Brien and Masibalavu 2017, M. O'Brien in litt. 2022). It was found to be common but patchily distributed in Savai'i highland forests in 2005 (Pratt and Mittermeier 2016). The Rapid Biodiversity Assessment of Upland Savai'i, Samoa, conducted in 2012, detected small numbers at two sites on the island (Butler 2012). The ICCRIF study of 2014 found it at only one of five sites it surveyed (R. Stirnemann in litt. 2016), and during surveys of multiple sites in 2016 the species was recorded on point counts only at Aopo (O'Brien and Masibalavu 2017, M. O'Brien in litt. 2022). Based on point count data from 2016, there were crudely estimated to be 1 pair for every 16 to 22km2 overall, equating to c. 50 mature individuals on Savai'i (M. O'Brien in litt. 2022). However, although its call is far-reaching, the species' detectability is otherwise very low and this is likely to be an underestimate (though the subpopulation is not thought to exceed 250 mature individuals) (M. O'Brien in litt. 2022). As such, the population on Savai'i is tentatively placed in the band 100-200 mature individuals, with the global population placed at 125-250 mature individuals under the assumption that c.75% of the population occurs on Savai'i.
Trend justification: Although the species was considered common in preferred upland habitat on `Upolu and Savai'i in 1984 (Bellingham and Davis 1988), it has reportedly become rarer and appears to be absent from sites it was recorded at previously (e.g. Uafato) (M. O'Brien in litt. 2022). The species is mostly restricted to montane forest and declines are believed to be associated with habitat loss and degradation, as well as high rates of nest failure and predation (USFWS 2020). A decline in distribution in the 1990s it thought to have been driven by a series of cyclones (Lovegrove et al. 1992, Park et al. 1992), and surveys in 2005-2006 indicated that numbers were continuing to decline (MNRE 2006, USFWS 2020). Nest predation by Black rat Rattus rattus has been shown to impact reproductive success (Stirnemann et al. 2015a) and the species appears to have increased following rat control in Malololelei (M. O'Brien in litt. 2022). This threat acts parallel to that of habitat loss and fragmentation, with nests near plantations or on forest edge likely experiencing higher predation rates than those in interior forest (Stirnemann et al. 2015a). These threats are thought to be especially impactful for this species due to its slow life history traits. As the threats are ongoing, a continuing decline is inferred.
Country/Territory | Presence | Origin | Resident | Breeding visitor | Non-breeding visitor | Passage migrant |
---|---|---|---|---|---|---|
American Samoa | extinct | native | yes | |||
Samoa | extant | native | yes |
Country/Territory | IBA Name |
---|---|
Samoa | Apia Catchments |
Samoa | Central Savaii Rainforest |
Samoa | Eastern Upolu Craters |
Samoa | O Le Pupu-Pu'e National Park |
Samoa | Uafato-Tiavea Forest |
Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
---|---|---|---|
Artificial/Terrestrial | Plantations | suitable | resident |
Forest | Subtropical/Tropical Moist Lowland | major | resident |
Forest | Subtropical/Tropical Moist Montane | major | resident |
Shrubland | Subtropical/Tropical High Altitude | marginal | resident |
Altitude | 760 - 1800 m | Occasional altitudinal limits |
Threat (level 1) | Threat (level 2) | Impact and Stresses | |||||||
---|---|---|---|---|---|---|---|---|---|
Agriculture & aquaculture | Annual & perennial non-timber crops - Agro-industry farming | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
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Agriculture & aquaculture | Annual & perennial non-timber crops - Shifting agriculture | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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Agriculture & aquaculture | Annual & perennial non-timber crops - Small-holder farming | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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Biological resource use | Hunting & trapping terrestrial animals - Intentional use (species is the target) | Timing | Scope | Severity | Impact | ||||
Unknown | Minority (<50%) | Unknown | Unknown | ||||||
|
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Biological resource use | Logging & wood harvesting - Unintentional effects: (large scale) [harvest] | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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Biological resource use | Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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Climate change & severe weather | Storms & flooding | Timing | Scope | Severity | Impact | ||||
Past, Likely to Return | Majority (50-90%) | Rapid Declines | Past Impact | ||||||
|
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Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Bos taurus | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
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Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Felis catus | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
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Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Named species | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
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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 | ||||||
|
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Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Sus scrofa | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
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Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Unspecified species | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
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Residential & commercial development | Housing & urban areas | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
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Recommended citation
BirdLife International (2024) Species factsheet: Mao Gymnomyza samoensis. Downloaded from
https://datazone.birdlife.org/species/factsheet/mao-gymnomyza-samoensis on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/12/2024.