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LC
African Marsh-harrier Circus ranivorus

Justification
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Taxonomic source(s)
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.

Distribution and population
This species is resident in wetlands from South Africa north to Democratic Republic of Congo and southern Sudan. The extensive Okavango marshes (Botswana) are probably its stronghold (Harrison et al. 1997a).

Population justification
The species is reported to be still well represented at some wetland sites in both eastern and southern Africa, especially in Uganda, Botswana and Zambia (Ferguson-Lees et al. 2001). In South Africa, c.3,000-6,000 pairs remain, but populations are declining here (Barnes 2000), as is the case in some other parts of its peripheral range (Brown et al. 1982, Ginn et al. 1989). However, in some huge countries such as Zambia suitable habitat is extensive and the species is still locally common (F. Dowsett-Lemaire and R. J. Dowsett in litt. 2000). The population is preliminarily estimated to number between 10,000-100,000 individuals.

Trend justification
The population is declining owing to drainage and damming of wetland habitats, loss of habitat through over-grazing and human disturbance and , possibly, poisoning owing to over-use of pesticides.

Ecology
The species breeds in wetlands, foraging primarily over reeds and lake margins (Harrison et al. 1997a). Its diet consists largely of small mammals, particularly striped mouse Rhabdomys pumilio (Kemp and Dean 1988).

Threats
Drainage, burning and grazing of wetlands have probably led to general declines, although these have been partly mitigated by adaptation to new wetlands created by dams (Ginn et al. 1989) and sewage-works (Barnes 2000). The Okavango marshes are threatened by water abstraction (R. Simmons in litt. 1999), and there has been massive drainage of wetlands in KwaZulu-Natal (Begg 1986). Accumulation of chemical pollutants in eggs may be responsible for poor hatching success, although it does not appear to have an effect on adult reproductive output (de Kock and Simmons 1988, R. Simmons in litt. 1999).

References
Barnes, K. N. 2000. The Eskom Red Data Book of birds of South Africa, Lesotho and Swaziland. BirdLife South Africa, Johannesburg.

Begg, G. W. 1986. The wetlands of Natal (part 1): an overview of their extent, role and present status. Natal Town and Regional Planning Commission, Pietermaritzburg, South Africa.

Brown, L. H.; Urban, E. K.; Newman, K. 1982. The birds of Africa vol I. Academic Press, London.

de Kock, A. C.; Simmons, R. 1988. Chlorinated hydrocarbon residues in African Marsh Harrier eggs and concurrent reproductive trends. Ostrich 59: 180-181.

Ferguson-Lees, J.; Christie, D. A. 2001. Raptors of the world. Christopher Helm, London.

Ginn, P. J.; McIlleron, W. G.; Milstein, P. le S. 1989. The complete book of southern African birds. Struik Winchester, Cape Town.

Kemp, A.; Dean, R. 1988. Diet of African Marsh Harriers from pellets. Gabar 3: 54-55.

Further web sources of information
Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Butchart, S., Ekstrom, J., Harding, M. & Symes, A.

Recommended citation
BirdLife International (2014) Species factsheet: Circus ranivorus. Downloaded from http://www.birdlife.org on 21/11/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 21/11/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - African marsh harrier (Circus ranivorus) 0

Key facts
Current IUCN Red List category Least Concern
Family Accipitridae (Hawks, Eagles)
Species name author (Daudin, 1800)
Population size Unknown mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 4,390,000 km2
Country endemic? No
Links to further information
- Additional Information on this species
- Projected distributions under climate change