Harriers are typically slim, long-winged birds of prey that can often be seen flying low over wetlands and grasslands hunting, recognisable by the way their wings are held in a shallow, uplifted “V” while they fly.
Many birds of prey are known for their excellent eyesight, harriers, however, have evolved to rely on their hearing.
Taxonomically, they belong to the genus Circus in the Accipitridae family.
Western Marsh Harrier (Circus aeruginosus)
The Western Marsh Harrier is commonly seen in wetlands particularly where you can find common reed. They are considered to be less social than other harriers.
Residents in parts of Galicia, they typically nest in reedbeds and arable fields and can be seen hunting in the usual way of harriers, gliding low over open ground in search of their prey. They feed on small mammals and birds as well as reptiles, frogs and insects.
According to the IUCN they have a stable population, meaning they have been classified as least concern.
Hen Harrier (Circus cyaneus)
Like most harriers, Hen Harriers typically inhabit open ground, such as marshes and moorland, where they can frequently be seen flying low hunting for prey; their diet consists primarily of small mammals.
They are a resident in some parts of Galicia, however over the years there have been numerous reports of population decline in the region due to habitat loss.
In the UK, they are one of the rarest birds of prey and in 2026 the government published the results of a brood management trial to reduce illegal killings.
Despite a declining population, their numbers aren’t believed to be falling sufficiently to lose their IUCN least concern status. But that doesn’t necessarily reflect, or can even mask, threats to local populations where the loss of an apex predator can have knock on effects on the wider ecosystem.
Montagu’s Harrier (Circus pygargus)
Montagu’s Harriers are long distant migratory birds breeding in parts of Western Europe, including Galicia, and Eurasia, then wintering in Africa or India. They are often found nesting on agricultural land making them particularly vulnerable during harvests.
Their diet is usually made up of small rodents and birds, reptiles and insects.
In 2023 they were voted as bird of the year by the Spanish Society of Ornithology. While their population is declining in Galicia and in general, they are still classified with an IUCN status least concern.