Data Zone
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. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
| Critically Endangered | Endangered | Vulnerable |
|---|---|---|
| - | C2a(ii) | C2a(i,ii) |
| Year | Category | Criteria |
|---|---|---|
| 2016 | Endangered | C2a(ii) |
| 2012 | Endangered | C2a(ii) |
| 2008 | Endangered | C2a(ii) |
| 2006 | Endangered | |
| 2004 | Endangered | |
| 2000 | Vulnerable | |
| 1996 | Vulnerable | |
| 1994 | Vulnerable | |
| 1988 | Threatened |
| Migratory status | not a migrant | Forest dependency | Low |
| Land mass type |
Land-mass type - shelf island |
Average mass | - |
| Estimate | Data quality | |
|---|---|---|
| Extent of Occurrence breeding/resident (km2) | 660,000 | medium |
| Extent of Occurrence non-breeding (km2) | 766,000 | medium |
| Number of locations | 11-100 | - |
| Severely Fragmented | - |
| Value | Data quality | Derivation | Year of estimate | |
|---|---|---|---|---|
| No. of mature individuals | 1000 | medium | estimated | 2007 |
| 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) | - | - | - | |
| Decline (10 years/3 generation past and future) | - | - | - | |
| Number of subpopulations | 1 | - | - | - |
| Percentage in largest subpopulation | 100 | - | - | - |
| Generation length (yrs) | 10.5 | - | - | - |
Population justification: Survey data from 2003 and 2004 combined with past literature suggests that there are no more than 1,500 individuals, roughly equivalent to 1,000 mature individuals.
Trend justification: This species's population is suspected to be decreasing in line with levels of egg-collection and hunting, cutting of nesting-trees, conversion of remaining wetlands to rice-paddies, and siltation of wetlands as a result of watershed deforestation. The likely rate of population decline, however, has not been estimated.
| Country/Territory | Occurrence status | Presence | Resident | Breeding | Non-breeding | Passage |
|---|---|---|---|---|---|---|
| Comoros | V | Extant | ||||
| Madagascar | N | Extant | Yes | |||
| Mayotte (to France) | V | Extant |
| Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
|---|---|---|---|
| Artificial/Terrestrial | Arable Land | suitable | resident |
| Forest | Subtropical/Tropical Mangrove Vegetation Above High Tide Level | suitable | resident |
| Marine Coastal/Supratidal | Coastal Brackish/Saline Lagoons/Marine Lakes | major | resident |
| Marine Intertidal | Mud Flats and Salt Flats | major | resident |
| Marine Neritic | Coral Reef | major | resident |
| Marine Neritic | Estuaries | major | resident |
| Wetlands (inland) | Permanent Freshwater Lakes (over 8ha) | major | resident |
| Wetlands (inland) | Permanent Freshwater Marshes/Pools (under 8ha) | major | resident |
| Wetlands (inland) | Permanent Rivers/Streams/Creeks (includes waterfalls) | major | resident |
| Altitude | 0 - 1500 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 | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
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| Biological resource use | Fishing & harvesting aquatic resources - Unintentional effects: (subsistence/small scale) [harvest] | Timing | Scope | Severity | Impact | ||||
| Future | Minority (<50%) | Slow, Significant Declines | Low Impact: 3 | ||||||
|
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| 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 | ||||||
|
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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 | Habitat shifting & alteration | Timing | Scope | Severity | Impact | ||||
| Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
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| Human intrusions & disturbance | Work & other activities | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
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| Pollution | Agricultural & forestry effluents - Soil erosion, sedimentation | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
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Recommended citation
BirdLife International (2023) Species factsheet: Ardea humbloti. Downloaded from
http://www.birdlife.org on 22/03/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 22/03/2023.
