The Orcadian Features - North Hill and Noup are alive with birds

The Birsay Moors is the RSPB’s largest reserve on the Orkney Mainland. Predominantly hill land, it extends from the Swannay loch southwards down across the Hillside road to Mid Tooin, close to the Lyde road, and from Burgar Hill, Evie, to Durkadale, Twatt. The RSPB own 1,500 hectares and lease a further 700 hectares, a total reserve area of 5,400 acres.

The Birsay Moors Reserve is an important area for hen harriers. Orkney is well known nationally for its hen harriers courtesy of the work initiated by Eddie Balfour in the 1940s.

Although Orkney’s hen harrier population has dropped considerably since its peak in 1978, even today this reserve holds as many as 14 nesting harriers, over two per cent of the British breeding population.

However, breeding productivity here continues to be low, a problem that recent research has linked to poor food supplies. The past couple of years have been more successful, thanks to a spell of experimental feeding and a couple of good summers. Perhaps less well known is the important winter roost at Durkadale, at which up to 25 hen harriers gather at dusk.

Viewed from the road it is quite an impressive sight, even though they can be very difficult to pick out against the heather in the failing light.

Populations

As well as hen harriers, other heather nesting birds of prey include the small, fast merlin, kestrels and short-eared owls.

The hill tops and blanket bog are home to nesting dunlin, golden plover and red-throated diver. There is a small, localised population of whimbrel as well as good numbers of their far commoner cousins, the curlews. Here you also find nesting arctic skua and bonxie (great skua). The hill lochans provide nest sites for red-throated divers.

The Burgar hill hide by the wind turbines is a great place to watch these magnificent birds, anytime from the start of their display in March, all the way through to the fledging of chicks in August.

The Burgar hill hide is a great place to watch the red-throated divers.

Perhaps surprising to many is the fact that there are also many duck breeding in the heather - wigeon, teal, mallard and even the occasional pintail. Gull colonies are also dotted about the reserve, mixed colonies of herring and lesser black-backs, loose colonies of great black-backs and several compact colonies of common gulls. The wetland at Whitemire has a noisy black-headed gull colony in most years.

Communities

Down into Durkadale, the jewel in the Birsay Moors’ crown, there are complex plant communities from sedge meadows and reed beds to willow scrub and raised bogs, home to high densities of birds like sedge warblers and reed buntings.

In winter the reed buntings are joined by twite as they feed on weed seeds amongst the crops around the Durkadale ruins. The surrounding wildflower-rich rough pastures support breeding redshank and lapwing.

Under the watchful eye of senior site manager, Keith Fairclough, the warden, Andy Knight, and assistant warden, Derren Fox, manage the Birsay Moors Reserve. Andy came to Orkney as the Mainland reserves warden five and a half years ago, from the Inner Hebrides where he worked at the Loch Gruinart Reserve on Islay, and before that the Isle of Tiree. Derren has been in Orkney since April, 2001, and he too has some West Coast background, having worked as a warden on the Uists and also having spent some time at Gruinart.

Andy brought with him a keen eye for active habitat management and was soon looking at ways to make the most of this huge reserve. Five years later the RSPB now have a 150 hectares grazing project established on “virgin” heath, a programme of muirburn has begun, 450 hectares of previously overgrazed heath is starting to revert to healthy moorland and a small area within Durkadale is being cultivated. All of this is intended to bring a greater diversity and some rejuvenation to the heathery sections of the hill. The large areas of blanket bog, which are too sensitive to allow active management, are simply left alone.

Management

Work on the reserve is determined by a five-year plan, last updated in 2000. This management plan is a public document that can be seen in the Kirkwall and Stromness libraries.

A reserve of this size requires a lot of maintenance. On the Birsay Moors, this mostly involves fencing, the greatest annual expense. All the “big” jobs (replacement fencing, cultivation etc) are contracted out locally. In addition, the RSPB have been gratefully helped by volunteers who have assisted with the removal of old fences.

Over 25 per cent of the reserve is grazed by sheep and/or cattle. This involves five separate areas let to neighbouring farmers, providing an extensive grazing system to promote heather regeneration, which in turn benefits breeding hen harriers and other key moorland species from plants and invertebrates to Orkney voles and the humble meadow pipit.

The largest let of 450 hectares, previously over grazed in terms of habitat quality, is now grazed by sheep at a level designed to enable heather recovery, signs of which are already evident after only three years.

Muirburn

Heather regeneration can benefit species such as red grouse.

Conversely, similar areas of habitat are considered under-utilised, and a variety of ways have been looked at to redress this: cattle or pony grazing, muirburn, mechanical and combinations of all three. Grazing trials started in 1999 at three 50 hectare study sites to the north of the Hillside Road. A very low grazing density was selected using cattle or ponies so that the heather is opened up to diversify the moor structure without changing the component vegetation species – more to do with the physical presence of cattle than what they actually eat; just by walking about, lying up, dunging.

This new diversity should suit birds like curlew, meadow pipit, skylark and red grouse, by improving their nesting habitats and the variety and availability of their food. In order to gauge the effects of the project, each grazed plot has been paired to an ungrazed (control) plot for future comparison of the “before and after” changes to bird populations and vegetation.

The muirburn project, which began last winter, has three large “burn plots” also linked with three control plots. This takes place on the extensive old peat cuttings in the Rusht area of the reserve. It is not simply a case of setting the hill alight - each plot involves many, separate small fires, not just one big one, and the result will be an intricate patchwork of variably aged heather.

Wet winter

The Orkney Business Ring carry out the actual muirburn contract and RSPB staff monitor the bird and mammal response. It is hoped that a quarter of each plot will be burnt over the next five years.

Despite last winter being so horrendously wet, some burning was achieved. Although well below target, nine separate fires burnt an area of 4.68 hectares. Staff are looking forward to a dry February and March this year!! Andy, Derren and a couple of volunteers monitor these and the grazing plots annually for breeding birds and voles.

An ecologist assessed the vegetation before the projects began and will return to assess the impact after five years.

Guided walks

The summer of 2002 was the first time that regular guided walks were introduced, and, as these proved so successful a more extensive programme is being planned for the coming season — look out for the posters later in the year. New display boards are also being produced this winter for the main parking areas. It is hoped that these will help the Orkney public to get the most out of Orkney’s RSPB reserves.