North American populations of Atlantic puffins – rotund seabirds with black-and-white plumage and rainbow-colored beaks – may be in trouble, according to a recent report, with altered conditions as a result of climate change possibly to blame.

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In the past – particularly in the nineteenth century – puffins were imperiled across large swaths of their Atlantic range by overhunting for their meat and eggs. Since then, they have mostly rebounded, although the birds are still hunted food in some locales, and in Iceland – where there are reckoned to be several million of the birds - there have been calls for the hunt to be suspended because of renewed concerns over its sustainability. Elsewhere, on some islands puffins may be at risk from introduced animals such as rats; conversely, in the North Sea, the population is sufficiently robust that it appears to have withstood the deaths of over 3,500 birds in fierce storms earlier this year.

But, on the western side of the Atlantic, scientists are troubled by the fact that, according to the Associated Press:

The survival rates of fledglings on Maine’s two largest puffin colonies plunged last summer, and puffins are in declining health at the largest puffin colony in the Gulf, on a Canadian island about 10 miles off eastern Maine. Dozens of emaciated birds were found washed ashore in Massachusetts and Bermuda this past winter, likely victims of starvation … On Seal Island [in Maine], a national wildlife refuge 20 miles offshore that’s home to about 1,000 puffins, only 31 percent of the laid eggs produced fledglings, down from the five-year average of 77 percent. Similar numbers were experienced at Matinicus Rock, a nearby island with more than 800 birds.

The AP’s Clarke Canfield reports that instead of feeding their chicks herring, the puffin parents were attempting to feed them butterfish, which were too big for the chicks to swallow. Butterfish is a more southerly species of fish that has become more abundant in the Gulf of Maine as waters have warmed, or perhaps more accessible to seabirds because it has moved higher up in the water column; according to Steve Kress of the National Audubon Society’s seabird restoration program, exceptionally warm water temperatures in the Gulf of Maine last year may have prompted an earlier-than-usual phytoplankton bloom, resulting in an early-season boost in numbers of butterfish.

It remains to be seen whether this is a harbinger of future years, or whether, if such changes are a sign of the ‘new normal’ in the Gulf region, puffins will be able to adapt. Some, however – seeing precipitous declines in some other area seabird colonies – are concerned that starving puffins may be a symptom of a broader problem.

As Rebecca Holberton, a puffin expert at the University of Maine, told Canfield, the seabirds “are our marine canary in the coal mine, if you will.”

Photograph of Atlantic puffins on Machias Seal Island by Thomas O’Neill, via Wikimedia Commons