AOU are not treating Hen Harrier and Northern Harrier as two separate species so it is very odd that the BOURC and the BOU are going out on their own. The Northern Harrier was formerly called the “marsh hawk.” It is a subspecies of the Hen Harrier of Eurasia, although the juvenal plumages, in particular, are quite different. In the breeding season hen harriers are found on the upland heather moorlands of Wales, Northern England, N Ireland and Scotland (as well as the Isle of Man). British Birds 104 • April 2011 • 192–201 195 Taxonomy of Hen and Northern Harriers 80. BTO bird identification videos are supported by Natureguides Each gray-and-white male may mate with several females, which are larger and brown. The northern harrier has been split from the hen harrier by some taxonomists based on genetic analysis. I can see another rewrite on the ID books. Circus cyaneus is a medium-sized bird of prey that is widely distributed across the Northern Hemisphere. 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. Up close it has an owlish face that helps it hear mice and voles beneath the vegetation. 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. "_____ Hen harrier definition is - a slender, long-tailed, Eurasian hawk (Circus cyaneus) inhabiting open and marshy regions that is largely pale gray above and white below in the adult male and brown above and buff with dark streaks below in the female and young male. Photo Luke Delve A male Hen Harrier – a grey ghost – elegantly flying back and forth just above the vegetation over a misty moorland is a sight that once seen is never forgotten. 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. The two subspecies Hen Harrier C. c. cyaneus and Northern Harrier C. c. hudsonius occupy the Old and the New Worlds respectively. The hen harrier (Circus cyaneus) is a bird of prey.The genus name Circus is derived from Ancient Greek kirkos, meaning 'circle', referring to a bird of prey named for its circling flight.The specific cyaneus is Latin, meaning "dark-blue".. Female Hen harrier. Each gray-and-white male may mate with several females, which are larger and brown. Swamp Harrier (Circus approximans) + African Marsh-harrier (Circus ranivorus) Reunion Marsh-harrier (Circus maillardi) Madagascar Marsh-harrier (Circus macrosceles) Long-winged Harrier (Circus buffoni) Spotted Harrier (Circus assimilis) Black Harrier (Circus maurus) Hen Harrier (Circus cyaneus) Northern Harrier (Circus hudsonius) They are migratory and winter as far south as northern South America, but some stay as far north as northern Canada. There are two currently recognized forms, the Palearctic form C. c. cyaneus (Hen Harrier), and the Nearctic form C. c. hudsonius (Northern Harrier). Thank You Hen Harrier Ireland. Male mostly uniformly greyishis Harriers are very distinctive hawks, long-winged and long-tailed, usually seen quartering low over the ground in open country. Up close it has an owlish face that helps it hear mice and voles beneath the vegetation. The hen harrier, recently renamed as the northern harrier, is most at home in open moorland, where it quarters low over the ground in search of small birds and mammals. It breeds in North America and its closest relative is the Cinereous Harrier (C. cinereus).