increase evaporative cooling) causing dehydration and heat stroke.”
They conclude that “significant global climate change may contribute
to increased mortality and reproductive failure in Brünnich’s guille-
mots through increased mosquito activity. Insects pass through larval
stages more quickly at higher temperatures, becoming adults earlier;
this appears to be what we are seeing with the mosquitoes at Coats
Island.”
The experience of the Brünnich’s guillemots of Coats Island shows
how just one or two excessively warm years can be enough to prompt
slight changes that can prove devastating to small populations.
Elsewhere in the Arctic reaches of Nunavut, there is a similar story.
In 1996, biologist Frank Miller landed at his base camp on the
shore of remote Bathurst Island, far north of the treeline, in the bleak
regions of Canada’s High Arctic. For 8 years, he had been returning to
this place each summer to study the Peary caribou—a smaller cousin
of the familiar caribou and reindeer that inhabit much of the Arctic.
This year, however, proved different from others. Whereas before
he had been able to estimate the number of caribou in the region by
counting the animals he saw during helicopter flights over the area’s
ten islands, this time he hardly saw any live caribou at all. Instead,
seemingly everywhere, there were carcasses: hundreds of them, of
musk oxen as well as Peary caribou—most lying on the ground, but
some still standing, frozen into the sea ice. By the time he had finished
his count, he had been able to find only ninety-one Peary caribou and
ninety-seven musk oxen, from which he extrapolated that, in an area
covering 11,000 square miles, there were a mere 500 caribou and
about 430 musk oxen. This represented declines of 85 and 70 percent,
respectively, from the previous year’s figures.
Two years later, he and fellow biologist Anne Gunn provided an
even more sobering picture, when they could find only forty-three cari-
bou and seventeen musk oxen. What had happened, the biologists sur-
mised from the evidence before them, was that unusually warm tem-
peratures in the western Arctic had brought warm, moist air masses
from the south, resulting in the normally dry High Arctic receiving
unprecedented levels of snow, followed by unheard-of freezing rain.
Layers of alternately freezing and melting snow, and the freezing rain,
Alaska and the Western Arctic 103