A cave crawl reveals life in the darkest of places
When Matt Adam Williams surveyed Manx shearwaters in Scotland, it was easier to hear them than to see them.
There are no better chaperones than bottlenose dolphins. Five flanked us on our boat trip out to the island of Lunga, the largest of the Treshnish Isles off the west coast of Scotland. Now that’s what I call arriving in style!
I had come to survey Manx shearwaters for a week with the Treshnish Isles Auk Ringing Group, which has been visiting this Site of Special Scientific Interest and Special Protection Area since the 1970s.
‘Manxies’ are amazing low-gliding, stiffwinged seabirds that breed on a few UK offshore islands, and understanding how they’re doing is critical in order to conserve them. The migratory species is nocturnal and burrow-dwelling, making it hard to survey.
The only way to count the birds is to play a recording of their call down each burrow and listen for a response. Day by day, we worked our way around the island, clambering up and down the steep, rocky cliffs to stick our heads and arms down hundreds of burrows, with MP3 speakers playing the bird call.
Despite hearing hundreds of Manxies calling back to us, by our penultimate day I still hadn’t seen one. Near the top of the island, I spotted a small cave in the rock face – though we were a long way from the water, I belly-crawled in to check it out. It was so dark, I couldn’t see a thing and had to use my phone as a torch. But there it was – a Manx shearwater sitting at the back of the cave.
I gathered my senses and played the recording. The bird didn’t call back, but it walked right up to the end of the cave-burrow to take a closer look. Underwhelmed by my visit, it shuffled back to the far end of its burrow, settled down and tucked its beak beneath its body to readjust an egg it was incubating. What an amazing sight to behold. I soon moved back out of the cave, soaking wet and coated in guano, but very happy.
Six weeks later, I returned to the islands for more surveying. Finding the cave among the overgrown bracken was a challenge but, when I did, I was delighted to discover that the egg had been replaced by a huge, grey, fluffy chick. I hoped it would prove emblematic of the health of this population of Manxies, which our surveys revealed were occupying more burrows than in 2000.
S I spotted a small cave in the rock face and bellycrawled in to check it out.