Marsh Harrier

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

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

UK Birds of Conservation Concern	Amber listed
Species of European Conservation Concern	Least Concern
IUCN Red List of Threatened Species (global)	Least Concern
Schedule 1 license required (to disturb)	Yes
Birds Directive Annex 1	No
Listed on the Annexes of	WCA(I,IV), Bern(III), Bonn(II), CITES(II)

Marsh Harriers became extinct in the UK in 1899 before recolonising from 1927 onwards; the population in the UK peaked at 15 nests in 1958 but then declined again and reached a low point of just one pair in 1971 (Underhill-Day 1998). It has since increased strongly with a mean of just over 400 breeding pairs reported to the RBBP over the five years 2015–2019 (Eaton et al. 2021). There has been a corresponding expansion in distribution with breeding birds now widely spread across Britain although its strongholds remain in the east of England (Balmer et al. 2013). It is now sufficiently widespread to enable short-term BBS trends to be calculated; these show a 36% increase over the most recent 10 year period for which results are available (2008–18) (Harris et al. 2020).

Breeding Marsh Harriers are concentrated in eastern England, but with small outlying populations in the north west and in Scotland, and have recently bred in Northern Ireland for the first time in over 100 years. In winter they are present in many coastal parts of southern and eastern England, and coastal Wales, plus some inland areas such as the Fens and Somerset Levels.

The breeding range of the Marsh Harrier has more than doubled since the early 1990s.

Marsh Harriers were formerly summer visitors but are now recorded consistently year-round.

View a summary of recoveries in the Online Ringing Report.

Foreign locations of birds ringed or recovered in Britain & Ireland

View number ringed each year in the Online Ringing Report

Maximum Age from Ringing	13 years 3 months 8 days (set in 2019)
Typical Lifespan	6 years with breeding typically at 3 year
Adult Survival	0.74
Juvenile Survival	0.151 (to age 3)

Feather measurements and photos on featherbase

Ring size	F (males) G (females)
Field Codes	2-letter: MR | 5-letter code: MARHA | Euring: 2600

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Causes of change

The restoration and re-creation of reedbed habitats for conservation of reedbed specialists is likely to have helped Marsh Harriers, although nesting in arable fields has also been important in the recent recovery (Underhill-Day 1998). Other factors which may also have contributed to the increases include the ban on organochlorine pesticide use and reduced persecution from humans (Underhill-Day 1998).