The big jolt came during this year’s breeding season. A survey showed a 30 per cent 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 also reported a 10 per cent 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—its population shot up from 29,000 in the entire North Sea in the 1970s to 69,000 in the Isle of May in 2003. Because they don’t congregate on the high seas during winter months, local environmental disasters, like oil spills, tend not to kill large numbers all at once. “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 has experienced a 63 per cent decline since 1980. The little bustard, a pheasantlike bird that inhabits dry grasslands across southern Europe, has become regionally extinct in 11 European countries. 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.

The reason for the decline in birds is a mystery. Intensive fishing and agriculture are likely among the causes. Large-scale fisheries have overfished the once plentiful species that gulls and other seabirds rely on, causing populations to decline.
Climate change is another factor. 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.

The recent decline in puffins could be a symptom of big 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 already observed that puffins are having to turn 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 sea. It’s only these charismatic species that get people to stop and look.”
_CHRISTOPHER WERTH, Newsweek