Data Zone
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 |
|---|---|---|
| - | - | A3c+4c |
| Year | Category | Criteria |
|---|---|---|
| 2021 | Vulnerable | A3c+4c |
| 2016 | Endangered | B2ab(ii,iii,iv,v) |
| 2012 | Endangered | B2ab(ii,iii,iv,v) |
| 2008 | Endangered | B2a+b(ii,iii,iv,v) |
| 2004 | Endangered | |
| 2000 | Endangered | |
| 1996 | Vulnerable | |
| 1994 | Vulnerable | |
| 1988 | Threatened |
| Migratory status | not a migrant | Forest dependency | does not normally occur in forest |
| Land-mass type |
continent |
Average mass | - |
| Estimate | Data quality | |
|---|---|---|
| Extent of Occurrence (breeding/resident) | 53,300 km2 | medium |
| Area of Occupancy (breeding/resident) | 19,800 km2 | good |
| Number of locations | 11-100 | - |
| Severely fragmented? | no | - |
| Estimate | Data quality | Derivation | Year of estimate | |
|---|---|---|---|---|
| Population size | 12000-30000 mature individuals | medium | inferred | 2007 |
| Population trend | decreasing | medium | inferred | 2018-2028 |
| Rate of change over the future 10 years/3 generations (longer of the two periods) | 30-49% | - | - | - |
| Rate of change over the past & future 10 years/3 generations (longer of the two periods) | 30-49% | - | - | - |
| Generation length | 2.7 years | - | - | - |
Population justification: The density at Kamiranzovu Swamp, Nyungwe, is about 13 birds per ha based on surveys of singing birds; the swamp covers an area of c.25 km2, resulting in an estimate of 33,000 birds at this site alone (A. Plumptre in litt. 2007). Therefore the total population is conservatively inferred to be in the range 20,000-49,000 individuals, roughly equating to 12,000-30,000 mature individuals.
Trend justification: The population is inferred to be in decline owing to the drainage of marshes for agriculture and hydropower, encroachment for mining, and brickmaking (Kahindo et al. 2017). Ayebare et al. (2018) identified this species as being highly at risk of range loss due to climate change, with a suspected decline rate of 40% over three generations.
| Country/Territory | Presence | Origin | Resident | Breeding visitor | Non-breeding visitor | Passage migrant |
|---|---|---|---|---|---|---|
| Burundi | extant | native | yes | |||
| Congo, The Democratic Republic of the | extant | native | yes | |||
| Rwanda | extant | native | yes | |||
| Uganda | extant | native | yes |
| Country/Territory | IBA Name |
|---|---|
| Burundi | Kibira National Park |
| Congo, The Democratic Republic of the | Virunga National Park |
| Congo, The Democratic Republic of the | Forests west of Lake Edward |
| Congo, The Democratic Republic of the | Kahuzi-Biega National Park |
| Rwanda | Rugezi Marsh |
| Rwanda | Volcans National Park |
| Rwanda | Nyungwe National Park |
| Uganda | Mgahinga Gorilla National Park |
| Uganda | Echuya Forest Reserve |
| Uganda | Bwindi Impenetrable National Park |
| Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
|---|---|---|---|
| Wetlands (inland) | Permanent Freshwater Lakes (over 8ha) | major | resident |
| Wetlands (inland) | Permanent Freshwater Marshes/Pools (under 8ha) | major | resident |
| Altitude | 1950 - 2600 m | Occasional altitudinal limits | (max) 2750 m |
| Threat (level 1) | Threat (level 2) | Impact and Stresses | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Agriculture & aquaculture | Annual & perennial non-timber crops - Small-holder farming | Timing | Scope | Severity | Impact | ||||
| Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
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| Agriculture & aquaculture | Livestock farming & ranching - Small-holder grazing, ranching or farming | Timing | Scope | Severity | Impact | ||||
| Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
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| Biological resource use | Gathering terrestrial plants - Unintentional effects (species is not the target) | 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 | ||||
| Future | Whole (>90%) | Slow, Significant Declines | Low Impact: 5 | ||||||
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| Energy production & mining | Mining & quarrying | Timing | Scope | Severity | Impact | ||||
| Ongoing | Minority (<50%) | Negligible declines | Low Impact: 4 | ||||||
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Recommended citation
BirdLife International (2023) Species factsheet: Bradypterus graueri. Downloaded from
http://datazone.birdlife.org/species/factsheet/grauers-swamp-warbler-bradypterus-graueri on 29/11/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from
http://datazone.birdlife.org on 29/11/2023.
