Everyone’s favourite seabird

Richard Collins wonders if puffins are becoming extinct or just migrating north.

ACCORDING to a BBC report, there has been a sharp decline in the number of puffins nesting on the Farne Islands off Northumberland. There used to be up to 56,000 pairs nesting in this famous colony but now there are only 37,000. Ornithologists are worried; the usual suspects, global warming over-fishing and pollutants are in the dock but nobody can say, for certain, what is going on.

The puffin, sometimes called the ‘sea parrot’, is everyone’s favourite seabird; it even has a range of children’s books called after it. The cartoonist’s dream bird is a cross between a penguin and a chicken with a ridiculous multi-coloured bill and bright red legs. Its inquisitive disposition adds to the bird’s charm; puffins fly past humans who visit their colonies and stand around gazing at the intruders. They come ashore only to breed, spending the rest of the year at sea. The small wings act as fins underwater, making puffins poor flyers. However, they still manage to travel huge distances. In winter, rafts of puffins can be found from the fringes of the Arctic pack-ice to the Canary Islands and across the ocean to North America.

We’ve had puffin scares in the past. I remember one British expert telling a BirdWatch Ireland conference, during the 1970s, that the species would be extinct by the year 2000. There had been huge declines in puffin numbers at traditional haunts back then, but ornithologists failed to notice increases elsewhere. Puffin numbers had not declined; their populations had moved.

That an expert could make such a blunder may seem odd but puffins are very difficult to census. They nest deep in burrows on the steep grassy slopes of island cliffs, difficult places for ornithologists to approach. Nor are the comings and goings of birds at a colony a reliable guide to numbers. Both parents, one parent, or neither parent, may be home when a count is being attempted. Unpaired, widowed and immature birds will be loafing about, further complicating matters.

Even when it’s possible to access a burrow, how do you decide whether it’s occupied or not? The only reliable way to census a colony is to divide the area into 10 x 10 metre squares and probe all of the burrows in a few of the squares with wire hooks to discover whether a bird is present. A rough indication of the number of occupied nests is obtained with practice, from which the size of the colony as a whole can be estimated. The final tally may not be very accurate but, with the technique applied year-in year-out by the same people, significant changes in the fortunes of a colony soon become evident.

The Farne Islands population is monitored by experts from the National Trust and we can be sure the decline reported by them is real. The situation there looks ominous and it’s not the first crash to be recorded in recent years. In 1939, there were about 3,500 puffin nests on Lundy, a tiny island off the Devon coast. By 2001, there were only 10. An infestation of rats, which eat Puffin eggs, may have been a factor.

The Farne Islands problem, according to experts, is not the result of conditions at the colony. David Steel, head warden on the islands, is quoted as saying that the birds are breeding successfully but that fewer pairs are returning to nest. Puffins may be dying at sea during the winter but there is another possibility; are the birds deserting their southern haunts and moving northwards? Trigger fish, and other warm-water creatures are turning up off our coasts; perhaps our seas are becoming too warm for puffins?

Cold water holds more oxygen and supports more life than warm water. The largest puffin colonies are in the north, where the seas are cooler; about 10 million puffins breed in Iceland, five times as many as in Ireland and Britain combined. If sea temperatures continue to rise, Irish waters may soon resemble those of the Bay of Biscay. No puffins breed there.