EN
Grauer's Swamp-warbler Bradypterus graueri



Taxonomy

Taxonomic note

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.
Dowsett, R. J.; Forbes-Watson, A. D. 1993. Checklist of birds of the Afrotropical and Malagasy regions. Tauraco Press, Li
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- B2ab(ii,iii,iv,v) B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v)

Red List history
Year Category Criteria
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
Species attributes

Migratory status not a migrant Forest dependency Does not normally occur in forest
Land mass type Land-mass type - continent
Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 53,300 medium
Extent of Occurrence breeding/resident (km2) 250 good
Number of locations 11-100 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 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 - - -
Largest subpopulations - - -
Generation length (yrs) 3.5 - - -

Population justification: The density at Kamiranzovu Swamp, Nyungwe, is about 13 birds per ha based on surveys of singing birds; the swamp is c.25km2, resulting in an estimate of 33,000 birds at this site alone (A. Plumptre in litt. 2007). Therefore the total population is conservatively estimated to be somewhere in the range 20,000-49,000 individuals.

Trend justification: The population is suspected to be in decline owing to the drainage of marshes for agriculture and the cutting and burning of marsh vegetation. The likely rate of decline has not been estimated.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Burundi N Extant Yes
Congo, The Democratic Republic of the N Extant Yes
Rwanda N Extant Yes
Uganda N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Burundi Kibira National Park
Congo, The Democratic Republic of the Forests west of Lake Edward
Congo, The Democratic Republic of the Kahuzi-Biega National Park
Congo, The Democratic Republic of the Virunga National Park
Rwanda Nyungwe National Park
Rwanda Rugezi Marsh
Rwanda Volcans National Park
Uganda Bwindi Impenetrable National Park
Uganda Echuya Forest Reserve
Uganda Mgahinga Gorilla National Park

Habitats & altitude
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

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Livestock farming & ranching Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Gathering terrestrial plants Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Whole (>90%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation
Energy production & mining Mining & quarrying Timing Scope Severity Impact
Past, Unlikely to Return Minority (<50%) Negligible declines Past Impact
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2019) Species factsheet: Bradypterus graueri. Downloaded from http://www.birdlife.org on 15/02/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 15/02/2019.