Western Marsh Harrier

(Circus aeruginosus)


The western marsh harrier (Circus aeruginosus), also known as Eurasian marsh harrier, is a large bird of prey and the largest harrier in Europe, but slightly smaller than the Asian eastern marsh harrier (Circus spilonotus). This is a migratory species, except for several populations around the Mediterranean and in the Middle East, and it breeds in temperate Eurasia and winters in southern Europe, Africa or the Indian subcontinent. It reaches a length of 43-54 cm (17-21 in) and has a wingspan of 115-145 cm (45-57 in).


Males and females of western marsh harrier look different. The female has a dark chocolate brown plumage all over, except for the head, where the nape, throat and top of the head is conspicuously cream-colored. Females are also larger than males. The male has a more reddish-brown plumage, with pale to yellowish streaks on the head, neck, chest, and belly. Backside and upper parts of wings are darker brown. The secondary wing feathers and most of the primaries are grey, with black wingtips. The pattern of brown-grey-black on the wings is clear to see on the male in flight.

Diet & habitat

Western marsh harrier is a species most often connected to wetland habitats, especially habitats with plenty of reeds. It can also be found in open grassland and farmland, as long as it is close to wetlands. It is an opportunist feeder, and its diet consists of everything small of enough to catch and kill, from small mammals, birds, amphibians and reptiles to various invertebrates.  


Breeding season varies from mid-March to early May. In contrast to many birds of prey, this is not a strict monogamous breeder. Males can pair with up three females. A pair usually last for one breeding season, although some pairs may last for several breeding seasons. Nests are usually built on the ground concealed in reedbeds, and consist of sticks, reeds and grasses. Between three and eight eggs are laid and incubated for 31-38 days. The chicks fledge between 30-40 days.


The western marsh harrier is a widespread species, but it has declined in many areas of its range. Destruction of habitat, pesticides and persecution has been the main culprits for its decline. It is now a protected species in many countries, and in some countries, such as the United Kingdom and Ireland, it has recovered from extinction. One of the main threats today is the hunting of migratory birds in areas around the Mediterranean. Due to its protection and recovery many places, it is currently listed as least concern on the IUCN Red List.

Similar species

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