Mike Harris describes himself as one of those "sad people" who, having worked an entire career on a cause, continue even after retirement. Since leaving full-time research and teaching, Harris devotes two months a year to working on the Isle of May, a small and desolate nature reserve off the coast of Scotland, as a research fellow with the Centre for Hydrology and Ecology, monitoring one of Britain's puffin colonies—the largest in the North Sea. Puffins appear on land only a few months a year, just long enough to rear their young, which means the photogenic birds spend most of their 30-year life span entirely at sea, diving into the water, using their wings to propel them far below the surface, to feed on small fish and plankton. "Puffins are a bit like penguins," says Harris. "People have a sort of death wish on them. You only have to have half a dozen wash up dead on a beach, and [people] go into mourning." Because conservationists have cried wolf in the past, Harris is cautious about making public proclamations of threats to the birds. "It takes quite a big jolt before I'm prepared to say there is something the matter."
The big jolt came during this year's breeding season. A survey showed a 30 percent reduction in the number of nesting pairs on the island. Returning adults also weighed less than in the past, which suggests they are having problems finding food in the winter. Across the cold, choppy sea, the Norwegian Institute for Nature Research reported a 10 percent decline. Although these numbers don't spell the imminent demise of the North Sea puffins, scientists are particularly worried because until recently the puffin was considered a conservation success story. Local environmental disasters, like oil spills, tend not to kill large numbers all at once because the birds don't congregate on the high seas during winter months. "If you have lost a lot of puffins, it means that something big has happened over a substantial area," says Harris.
The puffin isn't the only bird at risk. Bird populations across Europe have been declining steeply in recent years. A 2007 report published jointly by several conservation groups warned that nearly half the continent's most common birds, such as the partridge and turtledove, are in trouble. The nightingale, a source of inspiration in English poetry from Milton to Keats, has experienced a 63 percent decline since 1980, when the study began. The little bustard, a pheasantlike bird that inhabits dry grasslands across southern Europe, has become regionally extinct in 11 countries, including Germany and Poland. The 2008 Red List of Threatened Species, published by the International Union for Conservation of Nature, has had several new entries, including the Dartford warbler, named after a town in the English county of Kent. Although the bird has only recently recovered in Britain from a severe winter 45 years ago, it has gone from a status of "least concern" to "near threatened" throughout Europe and the rest of the world.
The reason for the decline in birds is a mystery. Intensive fishing and agriculture are likely among the causes. For example, bird populations in Eastern Europe flourished after the fall of the Iron Curtain, as food production waned and farmland was abandoned. The surge in agricultural investment in nations such as Poland as a result of accession to the European Union has birds declining just like their counterparts in the West. Out at sea, large-scale fisheries have decimated the once plentiful species that gulls and other seabirds rely on, causing populations to decline.
Climate change is another factor. Scientists can't be sure, but rising ocean temperatures may be altering the makeup of plankton in the sea, with drastic consequences for the food chain. For migratory birds that winter south of the Sahara, abnormal weather only multiplies the many difficulties they face on the long flights back and forth. Increasingly milder winters and hotter summers might mean that spring arrivals of birds no longer coincide with the appearance of seeds, berries and vegetation that are essential for the journey. A poignant example is the whitethroat, a small songbird common throughout Europe. Its population crashed in the late 1960s when a drought decimated the African Sahel—but what affected the bird was a single species of shrub that failed to bloom. Ornithologists admit they know very little about what happens to birds once they cross south of the Mediterranean.
The recent reversal in the puffin's fortunes after decades of successful conservation efforts comes as a disappointment. In the 1970s, the British North Sea population was only 29,000, less than a quarter of the current population, and there were only a handful of birds on the Isle of May. Britons considered puffins fodder for the table, or sometimes shot them purely for sport. For purposes of Lent, Christians used to consider the bird a type of fish. Effective habitat protection and conservation measures, however, brought the puffin back. The Isle of May was transformed into a nature reserve, allowing the birds to nest peacefully; their numbers on the island peaked in 2003 at 69,000—more than 10 percent of the entire British and Irish populations combined. The puffin has risen to superstar status among a constellation of beloved birds. When British celebrity chef Gordon Ramsay, in a recent episode of his television series "The F Word," hunted and feasted on the adorable birds, eating a puffin heart raw, a public outcry erupted.
The recent decline in puffins could be a symptom of changes in the ocean's ecosystem. Rising water temperatures may have an effect not only on the quantity of food available but also on its nutritional value. Ecologists have observed that puffins are turning from their traditional diet of sand eels to less optimal sources that contain fewer calories and less beneficial oils. "I'm not worried about the future of the puffin," says Harris. "It's not going to become extinct in the next 20 years. But I am interested in what's causing this mortality as an indicator of something going wrong with the sea. It's only these charismatic species that get people to stop and look." A celebrity species can make or break a conservation effort. The puffin will have to be awfully cute to pull it off.