Matt Williams
Seabird surveys are not only vital for understanding how our birdlife is faring, they also reveal the health of our oceans
recalls his experiences of taking part in a Seabird Survey to understand how our birdlife is faring. Find out more:
There are few better ways to arrive in style than being chaperoned by dolphins. As our boat sped along on the calm, clear water, two of them leapt clean into the air. They were so close that if I had leaned out far enough I could almost have touched them.
The boat’s engine powered down as we approached the island. Arctic Terns were diving into the water with a magnificent splash. Puffins zoomed past, a multicoloured blur, on their way to gather sandeels. In the distance, the intimidating mass of Harp Rock loomed, plastered in black-and-white splodges – thousands upon thousands of seabirds.
We had arrived at Lunga, one of the Treshnish Isles. This small archipelago lies west of the Isle of Mull in the Inner Hebrides. The islands are a protected site because of their importance for wildlife. They are uninhabited by people, but Lunga is visited almost daily in the summer by boats that bring tourists across to visit for a few hours. We were going to be there for a bit longer, though.
This was just the start of a summer of seabird surveying. 2018 was the year of the decadal UK seabird census around our coasts. Seabirds are a bellwether of the health of our oceans.
Intensive fishing, climate change and other factors are affecting Puffins, Kittiwakes and many of our other most beloved seabird species. Some of their numbers have plummeted in recent years. But we only know that thanks to ongoing surveying efforts like these.
The week we spent camping on the Treshnish Isles in May was to survey one species in particular, the Manx Shearwater (or ‘Manxies’ as they’re known for short). Manxies are medium-sized seabirds that glide stiff-winged, low above the water. The coasts of Britain and Ireland are home to around 90% of the world population of Manxies. They spend their winter off the coast of South America. But they return to our coasts to breed.
Surveying Manxies is no mean feat. They’re nocturnal. And they live in burrows, many of which are on the steep rocky cliffs of the islands. The only way to survey effectively for them is to play recordings of their call down any possible burrow on the island and wait for a response. Later in July, we would return for two weeks to survey for a much smaller, but equally enigmatic, seabird, the Storm Petrel (or ‘Stormie’). Stormies, too, are nocturnal and live in nooks and crannies. They’re tiny brown seabirds, perhaps the size of a House Martin, with a white rump.
Abandoned cottages
These small birds are very cute and it’s extremely hard to imagine how they can survive out amid the crashing waves of the ocean. While the Manx Shearwater call is hard to describe (although I’ll never forget it, having heard it thousands of times) the Storm Petrel call can be accurately described as a ‘purr’. Our base was on Lunga – a derivation of the Norse word for Puffin. Up on the clifftop are a series of abandoned stone cottages that we use as a village. The larger cottage gets a temporary tarpaulin roof and we dot our tents among the other cottages for shelter. This was true wild camping – no running water, no electricity; one of the first jobs was digging a toilet trench.
It may have been remote and exposed, but I instantly felt at home. How could I not? Great Skuas frequently flew low overhead, checking us out. In the mornings, small family groups of Twite would come and bathe and drink in the
ON THE CLIFF A HUNDRED YARDS AWAY OR SO, A WHITE-TAILED EAGLE WAS PERCHED IN THE MIST
tiny pools of rainwater that collected in the tarpaulin that was the makeshift roof of our main shelter. They graced us by sharing their morning routines and activities with ours. I think we developed a sort of sense of solidarity with them. And a trip to the outdoor toilet often meant flushing the Corn Crake from among the long, damp vegetation.
As the days drew on, and we grew wearier, the incessant, infernal ‘crexing’ of the Corn Crake all night long among our tents came to be a bit of a pain. And if it wasn’t the Corn Crake keeping us awake at night, it was the singing of the seals. One morning, I unzipped my tent before anyone else was awake and rolled out of it onto the grass, bleary-eyed and with aching joints. On the cliff a hundred yards away or so, a White-tailed Eagle was perched in the mist. It was only a few moments before it took flight and rounded the corner, heading back towards the Isle of Mull.
Ringing with pain
Our main task for the trips was the surveying. To survey for Manx Shearwaters, we split into two groups and covered the whole of the island of Lunga. We based our approach on searching suitable habitat for burrows. The island is wild and unforgiving.
The cliffs are steep, leaving your knees and ankles ringing with pain at the end of the day; the soil is loose, and the Bluebells turn to a sheet of ice very quickly as you walk up and down over them. Three weeks of living and working here toughens you around the edges. It gives you a new respect for the animals that spend their lives in this environment.
Using a tape lure, we’d record whether or not the burrow brought a response. Of course, a negative response didn’t mean there was no shearwater home, it just meant it might be out at sea or may not have responded. Storm Petrels breed a few weeks later than the shearwaters.
Because petrels are smaller, they sleep and nest in almost any tiny hole. So, instead of seeking out burrows, we surveyed the whole island in two-by-two metre transects.
Much of the time, the most exciting thing to happen all day was the audible responses we got from shearwaters or petrels buried deep in a hole. One of the most memorable days in May began like any other. Over a fried breakfast and
coffee we did the ‘daily log’. We noted down the regular species and I was also able to mention one of the ‘island rarities’ I had spotted: a Woodpigeon. There were a few of these rarities throughout the summer – a Song Thrush, the odd Swift, a House Martin. After running through any non-bird sightings (usually a Rabbit or two, sometimes an Otter), Tim declared, as usual, ‘here endeth the log’. We gathered our gear, our notebooks and our MP3 speakers and headed out.
We were about halfway through our week of surveying and had reached some of the higher plateaus nearer the top of the island. While we seemed to be a long way from the water, there were plenty of shearwaters up here. In the cliff face, I spotted a huge cave. My inclination was to ignore it; it was way too big for a shearwater. But I decided to investigate anyway. The cave actually narrowed very dramatically and towards the back was a burrow. I played a recording and heard nothing. But I pulled my phone out of my pocket, turned on the torch and propped it up using a couple of stones.
There, sure enough, was an adult Manx Shearwater. It walked right to the end of the burrow to come and have a look at me. Then, satisfied that I wasn’t very interesting, waddled back. And, without a doubt, before settling back down, I saw it carefully tuck an egg beneath its belly.
Fluffy chick
If that wasn’t exciting enough, I returned to the same cave in July, six weeks later. Finding the cave was the first challenge. The Bluebells of May had been replaced by head-high Bracken. But, after a few false turns, I managed to find the cave. I repeated the same trick of using the torch on my phone and propping it up to cast some light. Instead of an adult Manx Shearwater, there was now a huge fluffy chick. Of all my experiences on the island, this one was the most special. To me it represented the reason we were there – to document the breeding season and success of these incredible, nocturnal burrowing seabirds.
The data from our surveys is still being processed. What we can say is that we counted more occupied Manx Shearwater burrows than were counted in the year 2000. I’d like to say a huge thank you to Turus Mara (the boat company which got us to, from and between the islands), the Hebridean Trust (which give us access to the islands) and to Scottish Natural Heritage (which covered some of the trip costs) and the Joint Nature Conservation Committee, which receive the data. The days spent surveying were long and tiring, particularly in May when we had a week of unbroken sunshine and 30°C temperatures. But the evenings were ours to do what we wanted with.
I WATCHED THE COMINGS AND GOINGS OF THE THOUSANDS OF GUILLEMOTS. THE CLIFFS REVERBERATED WITH THEIR CHATTERING
One of the most impressive features of Lunga is Harp Rock. This huge part of the island, so-called because of its shape, is where many of the Guillemots and Razorbills nest. That evening I went and sat there on my own, to process the day’s events. I watched the comings and goings of the thousands of Guillemots.
The cliffs reverberated with their chattering. Their strength in numbers was a decent defensive strategy against the attacks of various predators. In the distance, I spotted one. A tough, meanlooking silhouette of an Arctic Skua hawked casually back and forth behind the rock. It was waiting for an unaware Puffin or Kittiwake to take on.
I watched these deadly birds many a time. They looked as if they couldn’t possibly catch the seabirds darting in and out of the cliffs. But, when an Arctic Skua decides to go, all of a sudden it has several extra gears of acceleration to unleash, forcing its prey close to the water in an attempt to down it and drown it.
A spot of ‘furtling’
After dinner we decided to head to the ‘Puffin lawns’ for a spot of our communal sport of ‘furtling’ (or ’snagging’ as it’s also known). Ringing birds is an important scientific effort, but many seabird species can be difficult to catch. Furtling involves using a loop on the end of a fishing pole to catch the bird around the leg. It’s ideal for Puffins and Razorbills, although they aren’t too happy about the experience once you’ve got them in the hand. Our ringing completed, we settled into the bothie with a dram of whisky in our camping mugs and listened to the Snipe drumming overhead. As I walked back to my tent, the carpet of Bluebells beneath the moonlight (for the seasons are slower, more patient this far north) made the water, sky and air glow purple. The bloody Corn Crake began
‘crexing’ away somewhere in the Bracken. It was by the light of another full moon, upon our return in July, that we picked our way down to the boulder beach. We lay on our backs on the sharp, tough boulders, and settled in. We watched in silence as hundreds, perhaps thousands, of tiny Storm Petrels swirled only inches above our faces. I looked up at a starry sky, blotted out by the tiny whizzing bodies of the birds. Rarely do we experience moments in life that feel this magical. I felt hugely grateful that I live in a country whose shores are surrounded by seabirds.