Data Zone
Taxonomic source(s)
Christidis, L. and Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. CSIRO Publishing, Collingwood, Australia.
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 |
|---|---|---|
| - | - | - |
| Year | Category | Criteria |
|---|---|---|
| 2022 | Least Concern | |
| 2016 | Near Threatened | D2 |
| 2013 | Near Threatened | D2 |
| 2012 | Near Threatened | D2 |
| 2008 | Vulnerable | D2 |
| 2004 | Vulnerable | |
| 2000 | Vulnerable | |
| 1996 | Vulnerable | |
| 1994 | Vulnerable | |
| 1988 | Lower Risk/Least Concern |
| Migratory status | not a migrant | Forest dependency | Low |
| Land mass type | Average mass | 8 g |
| Estimate | Data quality | |
|---|---|---|
| Extent of Occurrence breeding/resident (km2) | 72 | medium |
| Extent of Occurrence breeding/resident (km2) | 72 | good |
| Number of locations | - | |
| Severely Fragmented | - |
| Value | Data quality | Derivation | Year of estimate | |
|---|---|---|---|---|
| No. of mature individuals | 3800-8000, 5000 | poor | estimated | 2020 |
| Population trend | Unknown | medium | not applicable | - |
| 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) | - | - | - | |
| Number of subpopulations | 1 | - | - | - |
| Percentage in largest subpopulation | 100 | - | - | - |
Population justification: Inside Norfolk Island National Park, 3,830 (95% CI 2,650-5,540) mature individuals were estimated in 2009 (Dutson 2013), followed by a higher estimate of 6,305 (95% CI 5,166-8,583) in October 2019. Following Nance et al. (2021), the population size of the whole island is therefore set to 3,800-8,000 mature individuals, with a best estimate of c.5,000.
Trend justification: Historically, c.1600 pairs were estimated to persist in 1988 and 1997 (Robinson 1988, 1997). A larger estimate was made in 2009, when 3,830 (95% CI 2,650-5,540) were thought to exist in the national park (Dutson 2013), while an even more recent estimate (6,305; 95% CI 5,166-8,583) from 2019 suggests the population may have increased further (Nance et al. 2021). However, each of these estimates was born from differences in survey technique, such that direct and robust comparisons are not possible. Nonetheless, a decline is considered very unlikely, and the species is probably increasing in abundance (Nance et al. 2021).
| Country/Territory | Occurrence status | Presence | Resident | Breeding | Non-breeding | Passage |
|---|---|---|---|---|---|---|
| Norfolk Island (to Australia) | N | Extant | Yes |
| Country/Territory | IBA Name |
|---|---|
| Norfolk Island (to Australia) | Norfolk Island |
| Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
|---|---|---|---|
| Artificial/Terrestrial | Pastureland | suitable | resident |
| Artificial/Terrestrial | Rural Gardens | suitable | resident |
| Forest | Subtropical/Tropical Moist Lowland | major | resident |
| Shrubland | Subtropical/Tropical Moist | major | resident |
| Altitude | 0 - 320 m | Occasional altitudinal limits |
| Threat (level 1) | Threat (level 2) | Impact and Stresses | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Agriculture & aquaculture | Annual & perennial non-timber crops - Small-holder farming | Timing | Scope | Severity | Impact | ||||
| Past, Unlikely to Return | Majority (50-90%) | Negligible declines | Past Impact | ||||||
|
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| Agriculture & aquaculture | Livestock farming & ranching - Small-holder grazing, ranching or farming | Timing | Scope | Severity | Impact | ||||
| Past, Unlikely to Return | Majority (50-90%) | Negligible declines | Past Impact | ||||||
|
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| Biological resource use | Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] | Timing | Scope | Severity | Impact | ||||
| Past, Unlikely to Return | Majority (50-90%) | Negligible declines | Past Impact | ||||||
|
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| Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Felis catus | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | No decline | Low Impact: 4 | ||||||
|
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| Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Rattus exulans | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | No decline | Low Impact: 4 | ||||||
|
|||||||||
| Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Rattus rattus | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | No decline | Low Impact: 4 | ||||||
|
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| Invasive and other problematic species, genes & diseases | Invasive non-native/alien species/diseases - Unspecified species | Timing | Scope | Severity | Impact | ||||
| Future | Whole (>90%) | Unknown | Unknown | ||||||
|
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Recommended citation
BirdLife International (2023) Species factsheet: Gerygone modesta. Downloaded from
http://www.birdlife.org on 25/03/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 25/03/2023.
