Encounters with the skydancer

By Fiona McAuliffe

Before moving to Edinburgh to begin my PhD I worked as an ecological consultant in the southwest of Ireland. One of my main projects was to undertake winter and breeding season vantage point surveys of a windfarm. Vantage point surveys involve selecting points from which you can have a clear view over your observation area. These are stationary surveys and are usually carried out in fine weather with good visibility. I had a total of five vantage points from which I could observe the windfarm, and each survey lasted 6 hours, split into 3-hour blocks (provided the Irish weather complied!). I have a keen interest in raptor ecology and conservation, and my target species for these surveys was the Hen harrier (Circus cyaneus).

A male hen harrier gracefully flying over a field. Footage by Fiona McAuliffe.

The Hen harrier is a medium-sized ground-nesting bird of prey that breeds between April and July in upland areas. They spend winter at communal roost sites distributed throughout a broader range, including low-lying agricultural areas, blanket bog,s and coastal reedbeds. Hen harriers traditionally breed in open moorland, but will also use recently established, open canopy conifer plantations for hunting and nesting. However, once the canopies of these plantations close over, they offer little value in terms of biodiversity.

Mature male and female Hen harriers differ in both size and colour. Females are brown with a white rump and white tail bars and are much larger than the males, which are grey and white with black-tipped wings. Juveniles of both sexes are similarly coloured to adult females until they begin to moult into their adult plumage at the end of their first year, hence they are often referred to collectively as 'ringtails'.

A ringtail hen harrier. Photo by Phoebe Owen.

I’ll never forget the first time I saw a Hen harrier during my surveys. It was early in the morning and a thick fog lay across the land. I was walking along an old track that crossed the bog to locate my vantage points for future surveys. Suddenly, out of the fog, the grey ghost of a male Hen harrier appeared no more than 100m away from me. It glided slowly across the track in front of me and I watched as it disappeared beyond a patch of scrub. Whilst that wasn’t the first time I had seen a Hen harrier in my life, it was certainly one of the most special.

During later surveys, I had another memorable encounter with a Hen harrier. During the breeding season, Hen harriers perform one of the most beautiful spectacles seen in our uplands- the sky dance. Males perform the sky dance to impress females and attract them to their territory. They rapidly climb into the sky, before twisting to fall back towards earth and finally swooping to turn skyward again. Once seen, it is not a sight that is easily forgotten. However, it is a sight that is becoming increasingly rare across UK and Irish uplands.

Hen harriers are a species of conservation concern and are protected by The Wildlife and Countryside Act 1981 and listed on Annex I of the EU Birds Directive. The main pressures and threats facing Hen harriers are plantation forestry, predation, loss of habitat, disturbance from recreation, and infrastructure development. However, in the UK Hen harriers face an additional threat from persecution associated with grouse moors. There are an estimated 545 pairs in Britain and 108-157 pairs were recorded during the last national survey in Ireland during 2015.

However, there is hope for our upland skydancers. Projects such as drain blocking to protect peatlands and appropriate grazing to maintain moorlands and semi-natural grasslands are helping to restore balance to these upland ecosystems. By protecting these habitats, small mammals and birds like the Meadow pipit thrive and these, in turn, provide an important food source for Hen harriers. Hen harriers can be viewed as an indicator species, as in areas where they thrive we know that upland ecosystems are intact and functioning, providing us as a society with valuable ecosystem services such as biodiversity, flood prevention, and carbon sequestration, essential in the fight against climate change. For that reason, the Hen harrier represents so much more than just a beautiful bird of prey to me.

This piece was written by our Treasurer, Fiona McAuliffe (pronouns she/her), who is a PhD student at Edinburgh.

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