This week I at last went on a night trip to Mousa to see the Storm petrels at the broch.
Mousa is a tiny island just off Shetland (10 minutes’ boat ride away) which has the world’s most complete broch – a 2,000(ish)-year-old structure, some sort of fortified homestead. There are lots of these all over Scotland (which is, in fact, the only place you find them) and though all are fascinating, none of them has much remaining, other than a few feet of wall.
The broch at Mousa, however, stands 13 metres high, with its double walls still intact, a staircase going right up to the top between them, and chambers to explore at ground level. Even a day trip to Mousa is well worth it, to see this enigmatic and mysterious edifice, its blank face revealing nothing about what might have gone on inside.
One of the most exciting things about Mousa, though, is that it is home to more than 6,000 pairs of breeding Storm petrels. These amazing little birds – about the size of a House martin and similar in colouring – spend most of their lives out at sea, coming to land in the breeding season, to set up home in burrows and in rocky clefts and walls. At Mousa, they actually breed within the walls of the broch itself as well as in other walls and rocky areas all around the island.
Storm petrels have one egg only, and the adults take it in turn to incubate, with one sitting on the egg and the other going out to sea – sometimes hundreds of miles and for days at a time – to feed on plankton. Shift changes take place at night, to avoid predation by gulls and everybody’s favourite bird-to-hate, the bonxie, so this really is the only time to see them.
We had a beautiful, perfect evening for our trip. We watched the sun set spectacularly over St Ninian’s Isle before heading to Sandwick to get our boat out to the island, where a just-past-full moon rose. There are strict rules on visiting the island, to protect the birds: you have to stick together as a group, stick to the boardwalks, and absolutely no flash photography is allowed.
We stopped at the first wall, just before it got really dusky (it was about 11.20pm by now) as the birds on the nests began to start calling to their incoming mates. This is the other weird and wonderful thing about Storm petrels – the noise they make is, quite literally, indescribable. It has been tried – the most famous being the rather unromantic ‘fairies being sick’ – but the best I can do is to say it doesn’t sound like any kind of bird or animal, more like something electronic, a kind of white noise, with a bit of hiccuping and coughing at the end.
By the time we’d walked around to the broch itself, and all done a torch-and-simmer-dim-lit climb up the steep and narrow stairs and around the walkway at the top, it was midnight, the birds were calling in earnest and, at last, the travellers began to come home. They flit and flutter like bats, and, like bats, will come really close if you’re in their flightpath. Hundreds, if not thousands, of them started to appear, circling the broch before landing on the wall and disappearing into the nest. The changeovers happened so fast, that sometimes it looked like a bird just alighted on the wall and flew off again.
We stayed for half an hour more – some people lying on their backs on the ground, some sitting on rocks a few feet from the broch, some sitting inside the broch to listen to the calling birds in a kind of 2,000-year-old surround-sound system – but all too soon it was time to leave the Storm petrels in peace.
And as we drove away from Sandwick and began to head north at about 1.30am, the sun began to rise again.
Fairies being sick? I don’t think so, but there definitely was something magical about the experience.