Western marsh harrier
Circus aeruginosus
Peter T. Rühr · Dedoplistskaro, Kakheti Georgia field photo
Key facts in one look
- Size
- 48–56 cm, wingspan 1.15–1.3 m
- Diet
- Small birds and mammals, frogs
- Status in Georgia
- Resident, passage migrant and winter visitor
- Recorded regions
- Kvemo Kartli, Mtskheta-Mtianeti, Adjara, Samtskhe-Javakheti and others
- Habitat
- Reedy marshes, lake shores
- Family
- Accipitridae
- Protection
- Globally LC (2021)
The western marsh harrier (Circus aeruginosus) is the largest and bulkiest of the European harriers: it is 48–56 cm long, with a wingspan of 1.15–1.3 m; males weigh 400–650 g and females 550–800 g. The male is mostly reddish-brown, grey on the wings and tail, with black wingtips. The female is almost entirely chocolate-brown, with a pale, yellowish crown, throat and shoulders. It is harmless to people. The 2024 Georgian checklist lists it as a year-round resident, passage migrant and winter visitor. Records come from eight regions, most of them from Kvemo Kartli. Almost all winter records come from there too. Globally its risk of extinction is low (LC, 2021), and its numbers are stable.
Identification
Western marsh harrier: how to identify it
A large, bulky harrier with fairly broad wings. In flight the male is three-coloured: a brown body and forewing, a grey rear wing and tail, and black wingtips. The female is chocolate-brown with a pale, yellowish head and throat. It flies low over marshes and fields with its wings raised in a V.
It is 48–56 cm long, with a wingspan of 1.15–1.3 m. Males weigh 400–650 g and females 550–800 g. It is larger and bulkier than other European harriers. Its legs, eyes and the base of the bill are yellow, and the bill is black.
The male is mostly reddish-brown with pale yellowish streaks, especially on the breast. The head and shoulders are pale greyish-yellow. The tail and rear wing feathers are pure grey, and the wingtips are black. The female is almost entirely chocolate-brown, with a pale, yellowish crown, throat and shoulders, and dark around the eye. Juveniles resemble the female but have less yellow. Rarely, almost entirely dark birds occur.
A dark female can be mistaken for Milvus migrans, but that species has a forked tail and lacks the pale yellowish head. Buteo buteo has shorter wings and soars in circles on flat wings. The marsh harrier flies low and slowly, holding its wings in a V.
Colour
Swatches are illustrative. Do not identify a species by colour alone.
Often confused with
It is a bird of marshes: it lives in large freshwater or brackish marshes with dense vegetation, especially reedbeds. It also hunts over fields and grassland next to marshes. It is found mainly in lowlands, up to 2,000 m in Asia. It breeds from Europe and northwest Africa to Central Asia and the northern Middle East. In Georgia most records come from Kvemo Kartli, from Gardabani Municipality and Kumisi Lake. It is common in Mtskheta-Mtianeti, at Bazaleti Lake and in Mtskheta Municipality, in Adjara, near Batumi, Sakhalvasho and Kobuleti, in Samtskhe-Javakheti, at the plateau lakes around Ninotsminda and Akhalkalaki, in Shida Kartli, at Nadarbazevi Lake, and in Tbilisi, including Lisi Lake. It has been recorded in Abkhazia, at Inkiti and Skurcha lakes, and in Kakheti, around Dedoplistskaro and Sagarejo. Samegrelo-Zemo Svaneti, Guria and Imereti have only single records.
It eats many kinds of prey. It hunts in typical harrier fashion: it glides low and slowly over marshes and flat open ground, its wings held in a V and its legs often dangling. It mostly catches small birds, while in some regions mammals such as voles, rabbits and rats matter more. It also eats insects, reptiles and frogs.
It is mainly a migrant, although birds in western Europe, North Africa and southern Asia are resident. Migrants leave their breeding grounds in September and October, winter from southern Europe to tropical Africa and the Middle East, and return in March and April. The 2024 Georgian checklist lists it as a year-round resident, passage migrant and winter visitor. In Georgia there are records in every month, most in April and September, on migration. Winter records come almost only from Kvemo Kartli. It usually lives alone, though hundreds of birds sometimes gather at night roosts. Breeding starts between mid-March and early May. A male often pairs with two, sometimes three females. The nest is built on the ground, usually in a reedbed, from sticks, reeds and grass, sometimes in an arable field. It lays 3–8 white eggs. Incubation lasts 31–38 days, and the young fledge after 30–40 days.
Globally the western marsh harrier's risk of extinction is rated low (LC, 2021). A 2021 estimate puts the number of mature birds at 600,000–1,100,000, and numbers are stable. In the 19th and 20th centuries it declined in many areas because of persecution, habitat destruction and pesticides. The main threats are the drainage of wetlands, shooting, pesticide pollution and lead poisoning from eating waterbirds wounded by lead shot. It increasingly breeds and hunts on farmland, so intensive farming reduces its prey. The species is listed in Appendix II of CITES and of the Bonn Convention. The 2024 Georgian checklist also rates its risk in Georgia as low (LC).
Roman Vrbíček · sssuresh · Peter T. Rühr · Donsky · Arnold Wijker · hasenzahn · Anton Chechulin · Giorgi Natsvlishvili · Anastasiia Pashkovskaia
Related guides
Continue with related pages
Yes. The 2024 Georgian checklist lists it as a year-round resident, passage migrant and winter visitor. There are observations in every month of the year.
Most often in Kvemo Kartli, at the marshes of Gardabani and Kumisi, and at Bazaleti and Nadarbazevi lakes. In September many pass through Adjara, around Batumi.
The male is three-coloured: brown, grey and black. The female is almost entirely chocolate-brown, with a pale, yellowish head, throat and shoulders.
Yes, some birds spend the winter here. Almost all winter records come from Kvemo Kartli.
It is 48–56 cm long, with a wingspan of 1.15–1.3 m. Males weigh 400–650 g and females 550–800 g.
Mainly small birds and mammals, as well as frogs, reptiles and insects.
The western marsh harrier is harmless to people. Globally its risk of extinction is low and its numbers are stable. The 2024 Georgian checklist also rates it LC in Georgia.
References
What this profile is based on
Species profiles are compiled from peer-reviewed literature and established biodiversity databases, and are reviewed as new taxonomic and conservation data become available.
Prepared by the Reptiles.ge editorial team from the sources listed here.
