Circus aeruginosus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Accipitriformes Accipitridae

Scientific Name: Circus aeruginosus
Species Authority: (Linnaeus, 1758)
Regional Assessments:
Common Name(s):
English Western Marsh-harrier, Western Marsh Harrier, Eurasian Marsh Harrier, Marsh Harrier, Western Marsh-Harrier
French Busard des roseaux
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.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2015
Date Assessed: 2015-10-01
Assessor(s): BirdLife International
Reviewer(s): Symes, A.
Facilitator/Compiler(s): Butchart, S., Ekstrom, J., Harding, M., Khwaja, N. & Ashpole, J
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). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over 10 years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in 10 years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Previously published Red List assessments:
2013 Least Concern (LC)
2012 Least Concern (LC)
2009 Least Concern (LC)
2008 Least Concern (LC)
2004 Least Concern (LC)
2000 Lower Risk/least concern (LR/lc)
1994 Lower Risk/least concern (LR/lc)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Countries occurrence:
Afghanistan; Albania; Angola (Angola); Armenia (Armenia); Austria; Azerbaijan; Bahrain; Bangladesh; Belarus; Belgium; Benin; Bosnia and Herzegovina; Bulgaria; Burkina Faso; Burundi; Cameroon; Cape Verde; Central African Republic; Chad; China; Congo, The Democratic Republic of the; Côte d'Ivoire; Croatia; Cyprus; Czech Republic; Denmark; Djibouti; Egypt; Eritrea; Estonia; Ethiopia; Finland; France; Gabon; Gambia; Georgia; Germany; Ghana; Gibraltar; Greece; Guinea; Guinea-Bissau; Hungary; India; Iran, Islamic Republic of; Iraq; Israel; Italy; Jordan; Kazakhstan; Kenya; Kuwait; Kyrgyzstan; Latvia; Lebanon; Liberia; Libya; Liechtenstein; Lithuania; Luxembourg; Macedonia, the former Yugoslav Republic of; Malawi; Maldives; Mali; Malta; Mauritania; Moldova; Mongolia; Montenegro; Morocco; Mozambique; Myanmar; Nepal; Netherlands; Niger; Nigeria; Norway; Oman; Pakistan; Palestinian Territory, Occupied; Poland; Portugal; Qatar; Romania; Russian Federation; Rwanda; Saudi Arabia; Senegal; Serbia (Serbia); Sierra Leone; Singapore; Slovakia; Slovenia; Somalia; South Africa; South Sudan; Spain (Canary Is.); Sri Lanka; Sudan; Sweden; Switzerland; Syrian Arab Republic; Tajikistan; Tanzania, United Republic of; Togo; Tunisia; Turkey; Turkmenistan; Uganda; Ukraine; United Arab Emirates; United Kingdom; Uzbekistan; Western Sahara; Yemen; Zambia; Zimbabwe
Regionally extinct:
Algeria; Andorra; Bhutan; Congo; Faroe Islands; Guadeloupe; Iceland; Indonesia; Malaysia; Mauritius; Seychelles; Thailand
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 13500000
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Upper elevation limit (metres): 3000
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: In Europe, the breeding population is estimated to number 99,300-184,000 breeding females, which equates to 199,000-367,000 mature individuals (BirdLife International 2015). Europe forms approximately 48% of the global range, so a very preliminary estimate of the global population size is 415,000-765,000 mature individuals, although further validation of this estimate is needed. It is placed in the band 500,000 to 999,999 mature individuals.

Trend Justification:  In Europe, the population size is estimated to be increasing (BirdLife International 2015).
Current Population Trend: Increasing
Additional data:
Number of mature individuals: 500000-999999 Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology:

Behaviour It is mainly migratory, with populations in Western Europe, North Africa and at the south of its range in Asia being generally resident (del Hoyo et al. 1994, Ferguson-Lees and Christie 2001). Migrant birds leave their breeding grounds in September and October, wintering from France south as far as sub-Saharan Africa, and east as far as the Middle East (del Hoyo et al. 1994). They begin their return journey in February and March, arriving in March and April (del Hoyo et al. 1994, Snow and Perrins 1998, Ferguson-Lees and Christie 2001). Migration is generally on a broad front, although there is some concentration at a few sites (Brown et al. 1982). Hundreds of birds occasionally gather at roosting sites, sometimes with other harriers such as C. pygargus, but otherwise they are usually solitary, associating only temporarily at especially rich feeding sites (del Hoyo et al. 1994, Snow and Perrins 1998, Ferguson-Lees and Christie 2001). They have a slightly greater tendency to be gregarious while on migration but the above still generally applies. Birds fly c. 10-30 m above the ground (Brown et al. 1982). Habitat The species inhabits extensive areas of dense marsh vegetation, in fresh or brackish water, generally in lowlands but up to 2,000 m in Asia and 3,000 m on its wintering grounds in Cameroon (del Hoyo et al. 1994). Diet It is a generalist predator taking a variety of prey types, with small birds generally preferred but mammals such as voles, rabbits and rats being more important in parts of its range (del Hoyo et al. 1994). Breeding site The nest is a pile of reeds built in dense marsh vegetation (del Hoyo et al. 1994). Management information The species requires extensive wetland in its breeding range (del Hoyo et al. 1994).

Systems: Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 8
Movement patterns: Full Migrant
Congregatory: Congregatory (and dispersive)

Threats [top]

Major Threat(s):

Major threats include wetland desiccation and drainage; persecution by shooting; pollution, especially from excessive pesticide use in and around wetlands (although widespread bans have reduced this threat somewhat), and poisoning by heavy metals, notably the consumption of lead-shot through feeding on contaminated waterbirds (del Hoyo et al. 1994, Ferguson-Lees and Christie 2001, Orta et al. 2014). The historical threat of hunting in southern Europe has mostly subsided, but illegal shooting is still rife locally, notably on Malta (Ferguson-Lees and Christie 2001). The species is also highly vulnerable to the effects of potential wind energy development (Strix 2012). In its West African range, the species is vulnerable to habitat degradation through wood harvesting and overgrazing as well as exposure to pesticides (Thiollay 2007).

Citation: BirdLife International. 2015. Circus aeruginosus. The IUCN Red List of Threatened Species 2015: e.T22695344A80169858. . Downloaded on 01 December 2015.
Disclaimer: To make use of this information, please check the <Terms of Use>.
Feedback: If you see any errors or have any questions or suggestions on what is shown on this page, please provide us with feedback so that we can correct or extend the information provided