Granddad’s Camera
Marsh harrier, as it appears in the game

No.041 · Birds · Uncommon

Marsh harrier

Circus aeruginosus

The biggest of the British harriers glides low over the reeds with wings held in a shallow V, quartering for prey. Males sky-dance in spring.

When to look

All year, mostly at dawn, day and dusk.

Time of day

Best time
Day, all year; best March–June for sky-dancing and food passes over the reeds.
Where in the game
the Norfolk Broads (reedbed, fen and grazing marsh)
Size
Length 48–55 cm (Wildlife Trusts)
Wingspan
About 1.2 m (Wildlife Trusts)
Weight
About 600 g (BTO mean 602 g)
Lifespan
Oldest ringed bird 13 years 3 months (BTO); breeding birds average around 6 years
Population
About 590 pairs (BTO, 2016); RSPB now says around 700 pairs
Status
Amber (Birds of Conservation Concern 5, 2021)

Diet

Small waterbirds, young coots and moorhens, small mammals, frogs and eggs

Habitat

Reedbeds for nesting; hunts over reed, fen, grazing marsh and farmland

Breeding

Nests on the ground in reed; clutch 4–5 eggs, incubation 31–38 days; young fledge after 35–40 days.

Field signs

  • Long, low glides over reeds with wings raised in a shallow V and wobbling side to side
  • Males are brown above and chestnut beneath with grey, black-tipped wings; females are chocolate brown with a creamy or golden crown and throat
  • A mobbing flock of lapwings or gulls rising from the marsh

Did you know?

  • Marsh harriers were driven extinct in Britain by persecution in the 19th century, and were down to a single pair in Suffolk in 1971 (RSPB, BTO).
  • In spring the male sky-dances, tumbling towards the ground before swooping back up (RSPB).
  • Food passes: the male drops prey from the air and the female flips over to catch it beneath him.

Moments worth waiting for

  • Sky-dance March to May, day and dawn
    A male climbs high, folds and tumbles towards the reeds before swooping up again.
  • Food pass May to July, day
    The male carries prey over the nest; the female rises, rolls and takes it mid-air.

Photo tip

Park at a viewing spot with the sun behind you and follow a bird along the reedbed edge; use continuous autofocus with a 400–600 mm lens and 1/2000 s for in-flight shots.

Be a good naturalist

Marsh harriers are Schedule 1 birds. Never approach nests, keep to public paths and hides, and never flush a bird to make it fly.

The law

Schedule 1 of the Wildlife and Countryside Act 1981: illegal to intentionally or recklessly disturb at or near the nest.

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