Atlantic puffins listed as endangered species in Europe

Puffins in some parts of the Atlantic are fighting a battle beyond their control.

European puffin populations werelisted as endangeredonthe International Union for the Conservation of Nature'sRed List of Threatened Species in October. The oceanic shiftscaused by climate change are cited as a key threat in the recentlisting.

• Watch Puffin Patrol on The Nature of Things

In Europe, many Atlantic puffinpopulations, especially those that breed inIceland and Norway, are in decline.

That's a striking contrast to the status of Atlantic puffins that breed in Newfoundland, where the seabirds seem to be doing just fine.

Why this drastic difference between Europe and Newfoundland?

The issue in Europe seems to be the puffins' supply of fish. Northeastern Atlantic waters have warmed, saysGreg Robertson, a research scientist with Environment Canada, whohas been trackingseabird populations for over 15 years off the Newfoundland coast.

For seabirds, "when you have pulses of warm water coming up, in general, bad things seem to happen,"Robertson says.

One of the puffin's favourite foods in European waters is the sand eel.

"If they are not there in sufficient numbers at the right time, these seabirds don't do well," says Robertson.

As the water warms, fish such as sand eels retreat to deeper waters or to areas farther away from the puffins' northern Europeanfeeding grounds, where they're hardfor the puffins to find.

In Europe, human overfishing of sand eels is thought to be another problem for puffins.

Around Newfoundland, the Labrador current carries cold water from Greenland and the Arctic towardthe Gulf of Maine, bringing capelin and other fish for the puffins to feed on.

"We don't get those warm water intrusions like they do in Europe and the eastern Pacific," says Robertson."From the seabird perspective, it seems to be a little more stable. They seem to be able to get what they need."

Troubles in Maine

The puffin outlookappears less favourable farther south.

In Maine, puffins were reintroduced in the 1970s following their absence for over a century. Their returnwas thanks to efforts led by Stephen Kress and the Audubon Society.

Now, in the Gulf of Maine, when it getstoo warm for fish like sandlance that these more southerly puffins normally eat, they're periodicallyforced to hunt warm water fish like butterfish. Those fishare too wide and bony for the gullets of their chicks, with sometimes tragic results the babies may starve or choke.

This climate change development signals "a new message from birds to people," Kress tells The Nature of Things.

As the climate continues to warm, puffin populations in Maine could declinelike those in Europe.

Meanwhile, not all European puffins are in decline.

Those that breed at Skomer Island,Wales, seem to be "doing quite well," says PhDstudent AnnetteFayet, who is studying that populationwith University of Oxford zoologistTim Guilford.

And in Europe, because wind and watercurrents move differently than they do off the east coast of North America,it's not necessarily the southern populations that are doing worse.

Iceland and Norway, both farthernorth thanWales, are home to 80 per centof Europe's puffin populations. Thosehave "declined markedly since the early2000s," according to theIUCNRed List of Threatened Species.

Puffin puzzles

After breeding in the thousands at their seabird condominiums the grassy slopes of coastal islets honeycombed with their burrows puffins take to the seas. Yet puffins that are next-door neighbours while raising their pufflings may spend the winter in vastly different places. That's the surprising picture emerging from Fayet's work.

She attached geolocators to puffins during the breeding season andretrievedthem the following summer to download their data. This lightweight technology marks a big improvement over previous efforts to find puffins in the winter, which required spotters insmall planes that crisscrossed the Atlantic, scouring the seas.

Each geolocator, weighing just a few grams, measures and logs light levels, allowing researchers to estimate, using mathematical models that take into account day length, the approximate latitude and longitude of its wearer.

"The average accuracy of these positions is about 200 kilometres, which is quite rough," says Fayet.

But the geolocators have helpedher to determine that some Welsh-breeding puffins go all the way to Newfoundland in winter. Others stay around the U.K., and many head to the Mediterranean.

"Some of these birds cover absolutely huge distances," says Fayet, "and that was quite surprising."

Knowing where the puffins spend the winter could help scientists figure out other reasons whysome populations thrive while others don't.

The work of Robertson, Kress, Fayet and others isexplored in Puffin Patrol, the latest episode of CBC's The Nature of Things, produced by CBC in partnership with Rock Yenta Productions.