Marsh Harriers have always been part of the avifauna of the UK, but numbers dropped dramatically as the fens and wetlands in the east were drained for agriculture. As birds are three before breeding they spend their first two years ranging widely away from where they were hatched, and this may include leaving the country, through southern Europe and even as far as Africa (several wing-tagged birds have been recorded south of the Sahara). Birds may appear at winter harrier roosts with Hen Harriers. Most of them are associated with marshland and dense reedbeds. They are found almost worldwide, excluding only the Americas. Juveniles are brown with paler heads and breasts. They are sexually dimorphic in plumage, with adult females a handsome chocolate brown colour with cream heads and forewings whereas the males have a complex pattern of brown, russet and grey. This change of behaviour should offer opportunities for the recovering population. Take Merlin with you in the field! Marsh harrier by Nick Appleton 1/9 Marsh Harrier Circus aeruginosus This impressive bird of prey is the largest and broadest-winged of the harriers. They did maintain a toe-hold, with one nest annually at Minsmere until the use of pesticides was banned. Conservation status: AMBER (recovered from historical decline, but recent population and range declines). It is also known as the Eurasian marsh harrier. Adult males are predominantly pale gray with a dark-speckled head, blackish back with pale-edged feathers, and black wingtips. A resurgence was expected but numbers crashed once again and, by 1961, no Marsh Harriers bred in the UK. Status: Resident breeding bird. The Northern Harrier is distinctive from a long distance away: a slim, long-tailed hawk gliding low over a marsh or grassland, holding its wings in a V-shape and sporting a white patch at the base of its tail. During the breeding season, Marsh Harriers are typically seen in extensive reed beds but a few can be found in other open, well-vegetated habitats. Feeding: Marsh Harriers are catholic in their diet but prefer to take their prey from the ground. Marsh Harriers are not closely related to the other harrier species found in Britain, but form a group of species which occur across Asia, Indian Ocean islands and Australia. Marsh Harriers are not closely related to the other harrier species found in Britain, but form a group of species which occur across Asia, Indian Ocean islands and Australia. Females (670g) larger than males (540g). They will target small mammals, birds, insects, reptiles, frogs and even, on occasion, fish. Occasional birds, almost certainly originating from the continent, bred in Suffolk and Norfolk, with the core being at Minsmere reserve, but numbers increased in fits and starts up to the 1950s. Study of a number of birds of known age, however, has shown that plumage in Marsh Harriers is not straightforward, with some older birds having juvenile-type plumage, and some old females developing male-type plumage! Juveniles are brown with paler heads and breasts. Size: Average 52cm, wingspan 122cm. The largest of the harriers, the marsh harrier creates a distinctive V-shape in the air by holding its wings up. In winter, as birds range more widely, they may be encountered anywhere, but are still very rare outside of their core areas. Habitat and Distribution: Marsh Harriers are still very much birds of eastern England, centred on East Anglia and the eastern coast. They are medium-sized raptors and the largest and broadest-winged harriers. Males have a brown back, gingery belly, pale head and neck, and long, grey wings with black tips. It is likely that some adult individuals leave the country, whilst others show remarkable loyalty to their territorial areas. They are quite large birds, heavier and more sturdy than our other harriers, and have long wings often held in an upward ‘V’ shape, reminiscent of Buzzard or Black Kite which can cause confusion, especially when encountered away from their usual wetland habitats. Historically, British Marsh Harriers have always nested in reed beds, although in Europe they nest in rank vegetation and even in agricultural crops. Their tail is silvery-grey and their wings are bluey-grey with black primaries. The oldest known wild bird was 6½ years old (ringing recovery). The genus name Circus is derived from the Ancient Greek kirkos, referring to a bird of prey named for its circling flight (kirkos, "circle"), probably the hen harrier. The western marsh harrier (Circus aeruginosus) is a large harrier, a bird of prey from temperate and subtropical western Eurasia and adjacent Africa. Extremely similar to Western Marsh-Harrier, but range overlap is minimal. Juveniles tend to have a female-like plumage. Adult females are brown and streaky and lack the bold white rump patch of the similar female Hen Harrier. As with other harrier species, they can exchange food with their mates in mid-air. However, the low, inconspicuous quartering back and forth over the hunting site is characteristic. Lifespan: Average lifespan is 6 years, with an adult survival rate of 74% year on year. Females are chocolate-brown with a golden-yellow crown and throat. The population took a further hit in Victorian times as birds were targeted as predators by hunters, farmers and landowners and, at the same time, eggs were being collected or destroyed and habitat continued to be lost. Since recolonising, some British harriers are starting to show a wider breeding habitat, with records of crop-breeding and even moorland-breeding. Marsh harriers are the largest of the European harriers. Migrant and passage visitor. Nesting: Invariably, Marsh Harriers nest on the ground in long vegetation. It is common for males to support more than one female. Small populations also occur in a number of other places, most notably Lancashire and Dorset. Numbers once again began to climb and now, thankfully, these magnificent birds are an integral part of the fens, marshes and reedbeds of eastern England. Adult females are brown and streaky and lack the bold white rump patch of the similar female Hen Harrier. Adult males are predominantly pale gray with a dark-speckled head, blackish back with pale-edged feathers, and black wingtips. Extremely similar to Western Marsh-Harrier, but range overlap is minimal. First year survival is not known, but birds have a 15% chance of reaching their third year, when they will begin breeding. The specific aeruginosus is Latin for "rusty". Up close it has an owlish face that helps it hear mice and voles beneath the vegetation. This time it is believed that the population crash was caused by the use of organochlorine pesticides, especially in their Scandinavian heartland. A pair of Marsh Harriers, female left, male right. It is likely to be spotted flying low over reedbeds and grazing marshes, with the wings raised in the prominent and characteristic 'V' shape. Comprehensive life histories for all bird species and families. A common patroller above reedbeds, flying with wings raised in a shallow V-shape. Marsh harrier Scientific name: Circus aeruginosus Bird family: Kites, hawks and eagles UK conservation status: Amber Protected by The Wildlife and Countryside Act 1981 The marsh harriers are birds of prey of the harrier subfamily. Movements: It is almost certain that the recolonising birds originated from Europe, and for many years Marsh Harriers were regarded as migrants but, in fact, birds are more likely to remain all year. Photo: Andy Thompson. Adult males have chestnut underparts streaked with brown and a darker rump which is more robust than the other harriers. Free, global bird ID and field guide app powered by your sightings and media. On occasion one male may be paired with three females, although breeding success is often lower as the male is not able to provision all the nests and chicks sufficiently. By the late 1800s the species had become extinct in England and the last pair bred in Ireland in 1917.