We could do with some good news today.  I've just spoken with Mark Bolton, the RSPB's seabird ecologist, who is staying on Mousa undertaking a fascinating study on storm petrels (come back for news in future postings).  He told me that they've discovered their first storm petrel chicks of the year today!!  That's quite timely as our Date With Nature Assistant Stephanie Miles had written a blog entry following her and fellow DWN Assistant Blair's trip to Mousa at the weekend.  What with all the Puffincam drama, I hadn't got it posted. Enjoy!

"It was an overcast night, as Blair and I took the ferry over to Mousa, for a long anticipated experience of nocturnal storm petrels. Mousa is home to the largest colony in the UK, the birds nesting in gaps in the dry stone walls, boulder beaches and in the largest bird box in Britain, otherwise known as the prehistoric Mousa broch. This dry stone tower, that bulges in the middle as if from eating too much Christmas dinner, is as mysterious as its inhabitants, as archaeologists cannot decide exactly what it was used for. The sea was calm as we floated across it to the sound of waves and fiddle music, to land on the midnight isle.

A brief walk took us around the bay and down to the broch, while the Mousa Boat men told us all about the magical birds. At less than six-inches long, these tiny birds only return to their nests at night, after days away from their egg or chick, from foraging far out to sea, maybe even as far as the edge of the continental shelf. This means the remaining adult and egg or chick have to have survive without food for days on end and they do so by lowering their body temperatures, as a bear does to hibernate and this saves them the energy they need until their next feed. For the chick, this means awaiting the returning adult, which allows the other adult to go out to feed. This change-over always occurs under cover of darkness, to protect the vulnerable adults from predation. And this, was what we were here to witness.

Mousa Broch by day

At the broch, we saw our first glimpse of a storm petrel flitting bat-like across the top of the water surface in the bay. Then it was joined by another, and another. Going inside the broch and into its head-bumping alcoves, we listened out for the strange whirring-chirping noises, sounding like a cross between a wind-up toy and frog song, meaning the other storm petrels were waking up. These weird noises and night-time flights are thought to be where the myths about fairies came from and Mousa broch with its steep, uneven steps and windowless interior is certainly perfect setting for a gothic fairytale. We climbed up the steps, until we reached the very top and went out into the open air. There, a break in the cloud revealed a pearly moonlight shimmering upon the waters of the bay. As we took in the romantic scene, a storm petrel flew straight over my head and circled around, then another and another until there were dozens whirling around us. I felt something on my foot and on looking down, I saw the white rump and dark shape of a storm petrel shuffling across the flagstones, via Blair’s feet and into its hole half a metre away. We watched, entranced by these mesmerising creatures, for what seemed like seconds, but what was many, many minutes, trying to comprehend this privileged glimpse into their lives.

Storm petrel photo from www.rspb-images.com

On our way back down into the broch, the whirring-chirping chorus had reached its crescendo. Whilst, the birds spiralled down through the broch and to brush our upturned faces at the bottom, with one nearly landing on Blair’s outstretched hand. Outside, we leaned against the curved side of the bulging broch, for one last look up at the darting black shapes darkening the sky. As I remarked on their amazing aerobatic skills, we saw two collide in mid air with a dull thud, before carrying on their way, with no apparent ill-effects, except perhaps to my ego. Returning to the boat, we passed the boulder beach and a stone wall, both pulsating with the eerie calls of the storm petrels. As the air began to fill with the dampness that preceded the drizzle, it seemed as if the storm petrel were living up to their name, their calls summoning forth the night’s rain."

There's only a few more evening trips left this season, so make sure you book the Mousa Boat soon!