13 June, 2013
A priority for me this week was providing a couple of pages’ worth of content for a forthcoming guidebook for the Brough of Birsay, a tidal island just off the Orkney mainland. This is a must-see site for its archaeology and stunning natural beauty.
The archaeological remains here are of a 9th-century Norse settlement overlying an earlier Pictish one. The settlement is on a south-east-facing slope – it’s sheltered to some extent from the harsh wind and waves of the Atlantic by the sea cliffs beyond the settlement. Life here is very much on the edge and this is reflected in the plants and animals. They have to be able to withstand a difficult conditions.
Sea pink, a pink flowered plant that grows in tufts near the sea shore, is adapted to life on the edge. Growing on sand, pebbles or rock and constantly battered by salt-laden wind, it is not best placed to get fresh water. It has therefore developed tap roots that can go down many feet in search of moisture. It has thin, grass-like leaves to reduce moisture loss and its dense tufts retain water like a sponge.
Older readers may recall this plant as a design found on some of the pre-decimalisation coins known as ‘Threepenny bits’. They were worth 3d, a quarter of a shilling, or one and a quarter new pence. The image of the plant may have had something to do with the alternative name of the plant, ‘thrift’. If you still have one of these coins you are certainly thrifty as there were not many made and they are quite valuable!
Birsay is also home to two rare bumble bees – the rare great yellow and the moss carder. The second of these has a striking bright orange upper body and yellowish lower body, and is so called because the queen builds its nest at ground level, covering the nest with moss and other plant debris.
Both bees are only found in the north of Scotland. They have largely been eradicated from Britain by intensive farming practices; however, these windswept heathlands cannot be cultivated and are a protected habitat for them.
They can often be seen feeding on bird’s-foot trefoil. This beautiful plant, with its tiny, clover-like yellow flowers, is to be seen growing among the ruins of the Viking settlement. Many people know this flower as ‘bacon and eggs’ – an allusion to the vibrant red and yellow/orange colour of the flowers when they begin to open
Visitors at this time of year will also be able to see the iconic puffins which breed in burrows along the cliff tops. There are also many other cliff-dwelling seabirds.
Other animals to look out for are harbour seals and common seals, as well as other sea mammals like dolphins, minke and killer whales. These would of course have been an important part of the diet of the residents of the Brough, especially the seabird eggs which would have been a gastronomic treat after the depredations of the winter diet.