Family Hawks, Eagles (Accipitridae)

Least Concern

Western Marsh-harrier (Circus aeruginosus)


French: Busard des roseaux German: Rohrweihe Spanish: Aguilucho lagunero occidental
Other common names: Eurasian Marsh-harrier, Northern Marsh Harrier

Falco aeruginosus


, 1758,



Has been thought to form a species-group with C. spilonotus (presumably also spilothorax), C. approximans, C. ranivorus and C. maillardi (and presumably macrosceles), all of which have frequently been lumped within present species. Hybridizes with C. spilonotus#R. Two subspecies currently recognized.

Subspecies and Distribution
  • C. a. aeruginosus (Linnaeus, 1758) – Europe and Asia Minor E into C Asia, E to upper R Yenisey and Mongolia; winters in W & S Europe, Africa S of Sahara, Nile Valley, and in Middle East, Indian Subcontinent, Maldives#R and Sri Lanka.
  • C. a. harterti Zedlitz, 1914 – NW Africa from Morocco to Tunisia.
  • Descriptive notes

    43–54 cm; male 405–730 g, female 540–960 g; wingspan 115–145 cm. Plumage rather variable. Male generally brown above, particularly on back; underparts... read more


    Generally silent outside breeding season. Display call of male a far-carrying, shrill “whee-ah” or... read more


    Typically in extensive areas of dense marsh vegetation, especially reeds and reedmace, in aquatic... read more

    Food and feeding

    Great opportunist, lacks specialization; very wide range of prey, varying with local availability. Prefers small- or medium-sized birds,... read more


    Laying mainly in Apr–May, till Jun in N Europe. Generally monogamous, but males sometimes polygynous. Solitary or in small, loose... read more


    Mainly migratory in N & E Europe and C Asia; sedentary and dispersive in S portion of breeding... read more

    Status and conservation

    Not globally threatened (Least Concern). CITES II. Population trends varied in Europe throughout 20th century, but overall decline in numbers and range historically and... read more

    Recommended citation

    Orta, J., Boesman, P., Marks, J.S., Garcia, E.F.J. & Kirwan, G.M. (2020). Western Marsh-harrier (Circus aeruginosus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 19 February 2020).