The Puffins Keep Their Secrets
These small seabirds delight human visitors to rocky islands in north seas, yet remain biological mysteries
The lore of the Atlantic puffin, a species that ranks among everyone's favorite seabirds, includes an enduring story about how parent birds starve their single nearly grown chicks until hunger motivates the youngsters to leave the security of clifftop burrows and, in the dark of night, leap to the pounding sea.
A famous Welsh birdman, Ronald Lockley, discovered this behavior in the 1930s while studying puffins on the island of Skokholm off Wales. When matchsticks that he lodged at entrances to puffin burrows were not knocked down by adults delivering fish, Lockley concluded that the "pufflings" were deserted about a week before fledging. For the next 40 years, the fast of the puffin chick was repeated as gospel in scientific and popular writings.
Then, in 1976, Lockley's poignant image of the puffin chick sitting bereft at the burrow mouth night and day, uttering plaintive cries but "too timid to venture out," was shattered like a hatched egg. It's the other way around, declared Scottish seabird expert Mike Harris: The young puffin deserts its parents. Harris weighed chicks on the Isle of May every two hours and determined they were fed regularly before their great adventure. The clincher: After the young made their nocturnal exit, adult puffins would arrive the next morning with bills full of fish and stand around the empty nests in apparent astonishment.
However, a newer study from the Barents Sea, conducted by Russian scientist I.P. Tatarinkova, suggests that both Lock-ley and Harris are right-or wrong. Some puffin chicks, on some colonies, in some years, apparently do endure a pre-fledging fast. For some reason.
Confusion about one of the most important events in the puffin year illustrates how well the Atlantic puffin and its three peers in the North Pacific-the horned puffin, tufted puffin and misnamed rhinoceros auklet keep their secrets. Indeed, puffin life history is like a huge jigsaw puzzle with dozens of pieces missing. That's not surprising since puffins spend nearly eight months-roughly mid-August to midApril-at sea. What they do out there, even where they go in winter, remains a scientific mystery.
The difficulties of puffin research are compounded because, during the relatively few weeks that they repair to remote breeding colonies, puffins keep out of sight much of the time, either underwater or underground. Nesting puffins, says Harris, "do not take kindly to too much detailed attention."
Still, even a picture full of holes offers us a glimpse at the dynamic lives of these dumpy denizens of cold northern waters, especially their lifeline to the fecund little fish that they gather by the millions in their improbable bills.
Oh, those puffin bills! Their neon hues, which fade after the breeding season, have a single purpose: to send messages during spring's courtship es capades. Think of the beak, which is flattened like a leaf, as a semaphore flag announcing, "Let's mate." But for some species the beak is not enough. The tufted puffin supplements its massive red jaws with a pair of wild yellow tufts that droop over its neck. During mating season, the rhinoceros auklet, the only nocturnal puffin, grows a preposterous rhinolike horn at the base of its bill. A horned puffin in search of a mate takes on a devilish look appropriate to the activity, sporting "horns," really only fleshy spikes, above each eye.
Puffins are members of the auk family, a kaleidoscope of northern seabirds that serve as ecological counterparts of the Antarctic's penguins. The penguins, of course, have lost the power of aerial flight (as did the extinct great auk). But both penguins and auks are marvelous underwater fliers, using their stubby wings as powerful paddles to exploit the rich marine smorgasbord. This is a textbook example of convergent evolution, two unrelated groups of birds with biologically similar lifestyles at opposite ends of the globe.
Penguins and puffins share another trait: They cram together by the tens and hundreds of thousands on islands inaccessible to land predators. How many puffins are there in the world? Harris hazards a "reckless speculation" of 15 million Atlantic puffins. Ten million nest around Iceland where, he adds, most colonies have never seen an ornithologist. North America's share of the Atlantic puffin bounty is modest, some 338,000 pairs at 52 colonies, according to David Nettleship of the Canadian Wildlife Service's Seabird Research Unit. Three islands within sight of each other in Newfoundland's Witless Bay account for 200,000 pairs. In the Gulf of Maine, southern limit of the breeding range, only two colonies survived the relentless commercial egging and shooting that decimated puffin numbers from Maine to Labrador in the nineteenth century: 900 pairs occupy Machias Seal Island, and 125 pairs nest on Matinicus Rock.
In a much-publicized attempt to reestablish puffin colonies on other Maine islets in the 1980s, the National Audubon Society and Canadian Wildlife Service cooperated in a transplant of chicks from Newfoundland. Researchers raised 2,000 nestlings by hand in the hope that the birds would return five years later to breed. "Our goal with the Puffin Project was to establish a self-sustaining colony of puffins, and we've done that not once but twice," says Steven Kress, the ornithologist who conceived the project. "I consider that a success."
But not everyone agrees. Nettleship, a partner in the effort, calls the Puffin Project "an abysmal failure." The experiment was far too costly, he says, especially in the loss of young birds that perished in their first winter at sea. "I wouldn't do it again."
Pacific puffmologists estimate that the northern Pacific holds 3.5 million tufted puffins and 1.2 million horned puffins. The birds' world is centered on the Aleutian Islands and the Alaska Peninsula. Rhinoceros auklets may number a million, the majority breeding from Southeast Alaska to Puget Sound.
Buldir Island, far out in the Aleutian chain, is a citadel for both tufted and horned puffins. There Duff Wehle, as a University of Alaska graduate student, launched a landmark study of the birds' breeding biology in 1975. In spring, a day or two after a few scouts appear, Wehle says, a puffin flotilla arrives en masse in nearshore waters.
A week or more passes before the first birds venture ashore, but courtship begins in earnest on the sea. The displaying male puffin jerks his head up and down, opening and closing his bill as if he were "tossing and catching a pea in mid-air." During copulation, the male flails his wings as the female sinks beneath the water until only her head shows. Now and then, Wehle says, excited spectators form a head-jerking entourage behind the female being courted, effectively dampening the ardor of her suitor. He watched one frustrated puffin try to mount the float of a bull kelp.
Spring cleaning is the first order of business when the mating game wanes and puffins venture ashore. Atlantic puffins, rhinoceros auklets and tufted puffins typically nest in burrows on turf-covered clifftops and sea slopes. Rhinos also breed on forested islands, where well-worn trails lead to burrows beneath spruce and hemlock. Horned puffins are the exception. Instead of nesting in turf, they favor talus slopes and boulder-strewn beaches. Several pairs will use one door that leads to a labyrinth of nest chambers.
Sometimes nocturnal storm petrels, murrelets and even rhinoceros auklets may move in with the diurnal tufteds, laying eggs in separate alcoves. With different working hours, the neighbors never meet.
Puffin burrows are used year after year, and re-excavation is usually necessary after months of rain, snow and ice have done their worst. Puffins use their triangular bills both as chisels and pliers to loosen chunks of soil along the tops and sides of burrows, while sharp claws deepen the floors. "The power of the feet and legs is impressive, with dirt being thrown more than 3 feet from the entrance," Wehle says. One burrowing puffin kicked out a rock more than twice its weight.
Atlantic puffins have been known to dig themselves out of house and home. "It seems to be a habit of puffins to colonize a turfy island, work it to ruin, and, perforce, depart for new territory," Ronald Lockley wrote. One colony in Wales held 200,000 puffins in 1894; by 1940, after relentless winds swept away most of the island's shallow, burrow-riddled layer of peat, only two dozen pair hung on.
Puffins lay a single egg once their nursery is renovated. The journey from embryo to independence is a long one for the puffin chick: six weeks to hatching, six weeks or longer to fledging. Food shortages will prolong the nestling period, after which the young puffin may be too weak to survive on its own at sea. "The young grow better and fledge at higher weights when fed on oil-rich fish," Harris stresses. The parents bring the most nourishing food available, but what's, available sometimes is not adequate. Wehle observed that when natural fluctuations made high-energy capelin and sand eels scarce near Buldir Island, tufted and horned puffins had to prey upon less nutritious squid. The breeding season was a total failure.
Parent birds feed growing puffins several times a day, each meal consisting of fish of the same species and size. Foraging adults, diving as deep as 200 feet, apparently exploit a school of fish until they collect a full load, which can be a dozen or more fish totaling half a pound. "The record," Harris says, "is held by a puffin which had 61 sand eels and a rockling clamped in its beak." Fish are caught one at a time and held between the tongue and spines on the upper palate. Harris dismisses as untrue the "nice story" that a puffin's catch is arranged neatly, heads and tails alternating on each side of the bill.
Puffin chicks depart for the sea undercover of night, out of sight of predators-and scientists. That may explain the confusion over whether fledglings can fly. Wehle believed that fledging tufted and horned puffins were flightless and fluttered from the clifftops. Nettleship,
however, says Atlantic puffin fledglings may fly several miles before alighting. "They need fully developed wings to catch their prey underwater," he says.
Puffins have a short list of natural enemies. Arctic foxes and gulls steal eggs and young, and so do ravens that dig through the thin topsoil over the nest chamber. Bald eagles and snowy owls carry off adult puffins. The impact of predation is usually negligible, but a small colony of rhinoceros auklets off Washington's Olympic Peninsula suffered heavy losses when peregrine falcons took up residence on the island.
Squadrons of herring gulls patrol Atlantic puffin colonies, hijacking bill-loads of fish destined for the chicks. Puffins, however, have devised an effective strategy against piracy. After fishing, they circle above the colony until the sky is full of puffins carrying fish. A synchronized landing swamps the gulls, greatly reducing an individual puffin's risk of being robbed.
Puffins, unfortunately, have no way to counter the looting of their fish by humans. "The breeding regime of puffins in the north west Atlantic has evolved over the past 10,000 years around the predictable arrival in inshore waters of shoals of capelin," says David Nettleship. But an international fishing fleet mining the Grand Banks, after obliterating the cod resource, turned to this 6-inch smelt, which feeds not only puffins and other seabirds but seals, whales, salmon and halibut. Now the capelin population also has crashed. Nettleship says that no other fish in cold Newfoundland waters can fill the capelin's niche. "We have depleted one of the world's richest fisheries to the point where few fish remain. It doesn't bode well for the specialist species."
Les Line, former editor of Audubon magazine, spent a summer living with puffins on Machias Seal Island off Maine.