JACKI LYDEN, host:
This is WEEKEND EDITION from NPR News. I'm Jacki Lyden.
A twitcher is British slang for a person who will travel long distances to spot as many hard-to-find birds as possible. Reporter Ari Daniel Shapiro became a twitcher this past summer in search of European storm petrels. These small dark birds spend the summer on the Shetland Islands - a spray of 100 or so islands north of Scotland.
One way to find the birds is to take a ferry to the small, unpopulated island of Mousa in the middle of a damp and chilly night, then stroll about in the mud for a few hours.
ARI DANIEL SHAPIRO: I made the short boat ride to Mousa last summer with a tour group numbering about 25, each of us hoping to spot storm petrels. We chugged through the near darkness. You could hardly tell the difference between the black sky and the inky water. And after about 15 minutes we landed. And we started walking along the sometimes stony, but mostly muddy path near the shorelines.
The coastline was dramatic with these massive fingers of rock that extended into the sea. The damp mist was so thick it tickled our faces. We walked with our guide - a jovial Shetlander in his 60s named Tom Jameson(ph). He sported a well-trimmed white goatee, and he moved with an easy familiarity across the island, wiping the fog from his eyeglasses from time to time. Jameson's been leading this tour in one form or another since 1971.
Mr. TOM JAMESON (Tour Guide): We used to do it one night in the summer. I used to get a friend of mine to help me, because we had a much smaller boat then. And it just started from early on.
SHAPIRO: These days Jameson runs the nighttime tour twice a week from late May to early July. He's come to rely on his wife and his two sons for help, because it's a full season. There's no shortage of people flocking from all over the world to do the tour and to walk this very same path. All of the sudden, Jameson came to a halt. Our walk had brought us to a beach covered in these smooth oval stones.
Mr. JAMESON: They're here right under our feet, just in here. They're actually just under the stones. The nests, that's where their nest sits. Don't go on the stones, though.
SHAPIRO: But this wasn't the place where Jameson said we'd find the largest number of petrels. That was up ahead. So we kept walking through the grass and sticky mud until we came to a braw(ph) - that's a fortified dwelling built 2,000 years ago by an ancient Celtic people. It looked like a stout stone tower as wide as a school bus and as tall as one, too. Jameson had gotten ahead of me and was already standing in the entrance of the braw, so I hurried to catch up with him.
Mr. JAMESON: (Unintelligible) again.
SHAPIRO: Yeah, maybe I'll check it out.
Mr. JAMESON: Yeah, yeah, come in.
SHAPIRO: Yeah, okay.
Mr. JAMESON: Yes, in you go. Now, you can hear the storm petrels in the braw here. And the storm petrels actually come in through the walls in between the stones in the crevices. There are actually nests just in the walls.
SHAPIRO: The braw is home for many of the storm petrels here. Their numbers on Mousa have doubled since the mid 1990s. That's good news, considering how vulnerable the birds are to climate change and to predation as well. It turned out the best place to hear the petrels was a small pile of rocks just outside the braw.
(Soundbite of birds)
SHAPIRO: They sounded like little, whirring pixies or tiny purring kittens.
Mr. JAMESON: It's like a tiny noise with a hiccup in the (unintelligible).
SHAPIRO: Do you like the noise?
Mr. JAMESON: It's a lovely noise, very soothing noise, I think.
SHAPIRO: Why are they making that noise?
Mr. JAMESON: Well, what they're doing is they're calling for their mate that's coming back from being out at sea fishing. They say they can be away as long as three days at a time before they come back to change over with the ones sitting in the nest.
SHAPIRO: And the ones sitting in the nest is warming the egg?
Mr. JAMESON: Yes, yes, sitting on the egg to hatch it, yes. Then the other one comes back and they change over and the other one goes fishing.
SHAPIRO: Back inside the braw, I climbed up the narrow staircase along the perimeter. The top opened to the sky and suddenly the island of Mousa was all around me. Tiny, dark shapes darted everywhere, circling and soaring before squeezing their way through the stones and into the black depths of the braw. The comforting purr of hundreds of storm petrels emanated quietly from inside.
A couple months later, these birds would begin their epic migrations southwards to the seas off South Africa, but on that summer night they nestled together, whirring away, scanning the airwaves for their mate and keeping the next generation warm.
For NPR News, I'm Ari Daniel Shapiro.