The largest and most powerful harrier in the UK, regularly breeds on the Hawk and Owl Trust's Sculthorpe Moor Community Nature Reserve, Norfolk.
Adult males are three-toned with black wing tips, brown back and under body and grey head, tail and secondary wing feathers and coverts. Females are mainly brown, with a cream crown, chin and leading edges of the wings. Young birds are similar to females and young males become gradually paler with age up to 4 to 5 years.
Length: 48-56cm; wingspan: 115-130cm
Status in UK
360 breeding females, increasing; AMBER listed; resident and summer visitor
Population trends
Before the 19th century harrier species were not separated in the field, but marsh harriers probably bred in many English and Welsh counties and throughout Ireland. Drainage of its reedbed habitat must have reduced its numbers.
By the 1870s habitat loss and persecution had restricted this species to Northumberland and Norfolk. At this time it was extinct in Northern Ireland, though still present in small numbers in Eire. By the end of the century it had entirely disappeared from the UK.
Odd nests were recorded between 1911 and the mid-1920s and by the 1930s it was breeding every year in Norfolk and Suffolk; by the '40s there were five pairs and by the '60s 15 pairs. Its expansion was slowed by persistent pesticides, but continued once they were withdrawn. The population increase was helped by birds from continental Europe and a reduction in persecution.
Habitat and distribution
A bird of reedbeds and marshes, and has recently begun to colonise arable farmland.
The main population is in East Anglia and Lincolnshire, but it is now also established on the north Kent coast, the Somerset Levels and in Lancashire.
Breeding
The nest is on the ground in reedbeds and increasingly in maize crops. Courtship involves aerobatic displays by males often as early as February. Males are sometimes bigamous and will even pair up with a third late arriving female, though she is usually abandoned once the other nests hatch.
Feeding
Diet is varied depending on prey availability. Small mammals, birds and their nestlings are most common, while amphibians, reptiles, insects and carrion are also taken. When hunting they fly low and depend on surprising their prey.
