Montagu's Harrier

Circus pygargus (Linnaeus, 1758) MO MONHA 2630
Family: Accipitriformes > Accipitridae

Montagu's Harrier, Graham Catley

Arguably our rarest breeding diurnal bird of prey, Montagu's Harrier is an exclusively summer visitor and one associated with drier habitats than our other breeding harrier species.

Britain is on the north-west fringe of the Montagu's Harrier's European breeding range, holding just a very small number of breeding pairs annually. This wider distribution suggests that we should be able to support more pairs, implying that lack of suitable habitat or other factors may be limiting.

While there are some areas within Britain that have held pairs over many years – for example the open arable farmland of Wiltshire and neighbouring counties – atlas data suggest a more fluent pattern of settlement.

Select a topic for more facts and statistics about the Montagu's Harrier

  • Breeding
  • Winter


Montagu's Harrier identification is often difficult. The following article may help when identifying Montagu's Harrier.

related video

Identifying grey harriers

Harriers are stunning, lithe and elegant birds of prey. Two species of grey harrier are regularly found in the UK, Hen and Montagu's - the males are relatively easy to separate, but the females and young birds can be more tricky.


Listen to example recordings of the main vocalisations of Montagu's Harrier, provided by xeno-canto contributors.

Flight call


Develop your bird ID skills with our training courses

Our interactive online courses are a great way to develop your bird identification skills, whether you're new to the hobby or a competent birder looking to hone your abilities.

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Status and Trends

Population size and trends and patterns of distribution based on BTO surveys and atlases with data collected by BTO volunteers.


This species can be found on the following statutory and conservation listings and schedules.



The Montagu's Harrier is an extremely rare breeding species in the UK and the population has decreased strongly over the 25 years to 2019; in 2019 only two pairs were present and only one pair bred (Eaton et al. 2021). Breeding numbers have previously fluctuated: After having peaked at around 30 pairs in the mid-1950s they decreased and there were no pairs in 1974, before numbers improved again to a maximum of 13 pairs in the late 2000s (Balmer et al. 2013).


During Bird Atlas 2007–11

Montagu's Harrier breeding distribution 2008-11
Britain and Ireland Breeding Distribution 2008-2011.
More from the Atlas Mapstore.

Occupied 10-km squares in UK

European Distribution Map

European Breeding Bird Atlas 2



Montagu's Harrier is an increasingly rare summer visitor, arriving from April onwards.

Weekly occurence of Montagu's Harrier from BirdTrack
Weekly occurrence patterns (shaded cells) and reporting rates (vertical bars) based on BirdTrack data. Reporting rates give the likelihood of encountering the species each week.


Information about movement and migration based on online bird portals (e.g. BirdTrack), Ringing schemes and tracking studies.

An overview of year-round movements for the whole of Europe can be seen on the EuroBirdPortal viewer.


View a summary of recoveries in the Online Ringing Report.

Foreign locations of birds ringed or recovered in Britain & Ireland

Foreign locations of Montagu's Harrier ringed or recovered in Britain & Ireland
Encountered in: Winter (Nov-Feb); Spring (Mar-Apr); Summer (May-Jul); Autumn (Aug-Oct)


Lifecycle and body size information about Montagu's Harrier, including statistics on nesting, eggs and lifespan based on BTO ringing and nest recording data.



View number ringed each year in the Online Ringing Report


Feather measurements and photos on featherbase


For information in another language (where available) click on a linked name

Welsh: Boda Montagu
Catalan: arpella cendrosa
Czech: moták lužní
Danish: Hedehøg
Dutch: Grauwe Kiekendief
Estonian: soo-loorkull
Finnish: niittysuohaukka
French: Busard cendré
German: Wiesenweihe
Hungarian: hamvas rétihéja
Icelandic: Gráheiðir
Irish: Cromán Liath
Italian: Albanella minore
Latvian: plavu lija
Lithuanian: pievine linge
Norwegian: Enghauk
Polish: blotniak lakowy
Portuguese: águia-caçadeira
Slovak: kana popolavá
Slovenian: mocvirski lunj
Spanish: Aguilucho cenizo
Swedish: ängshök
Folkname: Ash-coloured Falcon


Interpretation and scientific publications about Montagu's Harrier from BTO scientists.


Causes of change

Pesticides and a drought in the Sahel which began in 1968 may have driven the declines in the late 1950s and 1960s (Clarke 1996). Numbers have never recovered fully and, with Montagu's Harriers often nesting in agricultural crops, local action and monitoring can be important to support and protect nests and young (Clarke 1996, Balmer et al. 2013).


Peer-reviewed papers
Juvenile Greater Spotted Eagle in the nest

Long-term effects of rewilding on species composition: 22 years of raptor monitoring in the Chernobyl Exclusion Zone

2022 | Dombrovski, V.C., Zhurauliou, D.V. & Ashton-Butt, A.Restoration Ecology

Over 2,000 km² of Belarus previously given over to intensive agriculture and dense settlements was affected by the 1986 reactor meltdown at the Chernobyl Nuclear Plant in Ukraine.

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