Hen Harrier

The hen harrier (Circus cyaneus) is a rare bird of prey in Scotland, known for its dramatic "sky-dancing" mating displays and its status as one of the UK's most persecuted raptors. While once widespread, they are now primarily found in the uplands and islands of Scotland, which holds roughly 77% of the UK and Isle of Man breeding population. 

Life History and Behavior

• Appearance: Sexual dimorphism is strong. Males are pale grey with black wingtips ("grey ghosts"), while females and juveniles are brown with a striped tail and white rump ("ringtails").

• Diet: They are raptors that feed mainly on small birds (meadow pipits) and small mammals, particularly field voles, but they can be opportunistic.

• Breeding: They nest on the ground, usually in heather moorland or young conifer plantations. They are known for their spectacular, acrobatic, and sometimes noisy "sky-dancing" courtship displays.

• Polygyny: In some areas, particularly Orkney, males may mate with multiple females, with one male feeding up to six broods.

• Food Pass: To protect the nest, the male often passes food to the female in mid-air.

• Longevity: While individuals can live over 16 years, many rarely live beyond 8 years, with high mortality in their first year. 

Occurrence and Distribution in Scotland

• Population: The Scottish population has seen mixed trends; a 2023 survey estimated around 529 territorial pairs. However, this is a significant decline from the 2004 peak, as they are considered highly endangered.

• Key Locations: The strongest populations are found in the Western Highlands, Hebrides, and Orkney.

• Seasonal Movement: During the breeding season (April–August), they are found on upland moors. In winter, they move to lower ground, including coastal marshes, farmland, and river valleys.

• Habitat Shift: While preferring heather moorland, they have adapted to using young, pre-thicket forestry plantations. 

Threats and Conservation

• Illegal Persecution: The primary factor limiting the recovery of the hen harrier is illegal killing, trapping, and destruction of nests, which often occurs on grouse moors.

• Conflict with Game Management: Because hen harriers may prey on young red grouse, they are often perceived as a threat to managed grouse shooting.

• Persecution Hotspots: The 2021 RSPB Bird Crime Report highlights a "startlingly clear connection" between raptor persecution and land managed for gamebird shooting.

• Conservation Efforts: Organizations like the RSPB and NatureScotare involved in monitoring and protection, including the use of satellite tagging, nest cameras, and the "Heads Up for Harriers" project.

• New Legislation: The Scottish Government has passed the Wildlife Management and Muirburn (Scotland) Bill to introduce licensing for grouse shooting and to enhance habitat protection.