III: IN WHICH GEORGE FIRST ENCOUNTERS THE
MYSTERY OF THE LITTLE BLACK BIRD
Cooper Island, June 6, 12:30 in the morning. The sky
is full of slanting rain and freezing fog, the air
temperature can't seem to reach 30 and the wind
continues to blow out of the northeast with such numbing
regularity that we've begun using it for support; if it
stopped in an instant, we'd both pitch face-forward into
the snow. Standing at the edge of the frozen Arctic Ocean,
George lifts a high-powered telephoto scope up to his
right eye and begins to scan the skies, wondering when
his birds will leave their winter habitat on the sea ice and
make their annual trip to Cooper Island to breed. George's
scope is black and cylindrical and strapped with silver
duct tape to the butt of an old wooden rifle. To brace the
rifle stock against his shoulder and peer through the
chunky, mortarlike scope, he must squint and lean back,
bending slightly at the knees. Beneath his hat, his hoods
and his thick fleece face mask, he looks like a nearsighted
bugler, blowing reveille into a gale.
With no sign of the birds just yet and weather conditions
such as they are, we appear to have two choices: walk or
freeze. We choose to walk, while George begins to tell the
story of how a heap of Navy trash -- some of it stamped
with the words please do not destroy, these boxes are
reusable -- came to be used by several hundred black
guillemots and one lone scientist whose narrow,
ornithological study eventually led him onto the trail of
worldwide climate change.
Except for the fact that the dead walrus by our campsite
had not yet decomposed, Cooper looked much the same
when George first came upon it in the summer of 1972.
Back then, five years after oil was discovered at Prudhoe
Bay, environmentalists were on alert for the possibility of
tanker spills, and George, 26 and already an ardent
ornithologist, was hired by the Smithsonian Institution to
go up and down the northern Alaskan coast to identify
any vulnerable seabird habitats. Traveling the coastline on
a Coast Guard icebreaker, he was dropped off one day on
Cooper. Remarkably, the sun was out, catching the
surface of all the Navy debris, and as he walked along,
marveling at this strangely picturesque collection of
scattered wood and rusted metal, two black guillemots,
startled by the crunch of gravel, suddenly flew out from
beneath an ammo box. Since guillemots don't normally
breed in this part of the Arctic -- they are cavity nesters
whose natural habitats, rocky cliffs and headlands, do not
exist for more than 500 miles -- it was, in George's words,
''definitely a hit.'' He looked around and found eight more
pairs breeding in the boxes, at which point, he says, ''I
almost wet my pants.'' Before he left that day, he flipped
over a piece of wood, creating a new nest site, and when
he returned to Cooper three weeks later, he looked under
the planks and found eggs.
George couldn't get enough money to return to Cooper for
three more years, but in 1975, when funds for another
assessment project became available, he asked to be sent
back. When he arrived, he found 18 pairs of guillemots
breeding in the boxes, and hoping to grow the colony,
George began creating -- and naming -- new nest sites in
earnest: Freshman Housing, the Condos, Married Student
Housing. . . . ''Not only were there these odd places,'' he
says, ''but you could create odd places and have them
breed there.'' To a degree that was unusual even in the
field of ornithology, George became obsessed, and over
the next 10 years, he came out to Cooper each summer --
creating nest sites, banding the birds and, because
guillemots are a long-lived species displaying fidelity to
both their mates and their nest sites, coming to know
them as individuals. One bird, nicknamed WOGy because
of its white-orange-gray leg band, has returned to her
same nest site on Cooper for more than 20 years. ''It was
like a suburban street in the 1950's,'' George says. ''I
knew who lived in every house.'' By 1978, there were 70
guillemots on Cooper Island, and by 1981 the population
was up to 220. By 1990, almost 600 birds were scrambling
around the drums and ammo boxes, looking for places to
breed.
Back then, George was thinking no more about global
warming than any well-informed person with an interest
in the natural world. Sharing the island with the birds
and the bears, he had other things on his mind, and if he
did pause to consider the Arctic climate, he assumed that
it was static. Because he always got out to Cooper after
the snow had melted and the birds had already occupied
their nest sites, he also assumed that his seabirds timed
their arrival on Cooper Island to the summer solstice,
their reproductive schedule cued by the lengthening days.
In 1984, however, he happened to come out to Cooper
earlier than usual, when the nest boxes were still covered
by snow, and seeing that, he began to wonder if the birds'
breeding habits were prompted not by the lengthening
photo period, as he'd originally thought, but by access to
their nest cavities -- like clockwork, the first egg in the
colony always showed up exactly 14 days after the birds
occupied their nests.
Scientific paradigms don't shift overnight, however, and
more than 10 years of grinding, repetitive fieldwork would
pass before George came to understand exactly what that
meant. In 1995, in response to Vice President Al Gore's
task force on climate change, a call went out for data sets:
did anyone have information that would shed light on
regional climate change? George acquired National
Weather Service data on when the snow melted at Barrow
and plotted the dates on a graph. Then he looked at his
own data on when the first egg showed up on Cooper
Island and plotted those dates as well. The correlation
leapt off the page: from 1975 to 1995, snow was melting in
northern Alaska, on average, five days earlier each decade.
Over those same 20 years, the date his guillemots laid
their eggs was occurring, on average, five days earlier each
decade. In fact, since guillemots require at least an 80-day
snow-free summer in which to copulate, ovulate, hatch
and fledge their chicks -- and there were rarely 80
snow-free days in northern Alaska until the 1960's -- they
wouldn't even be this far north were it not for warmer
temperatures. Expanding their range, playing with the
edge of a changing climate, his guillemots, he realized,
were tracking the region's snow melt on an annual basis.
And an earlier date of snow melt was, in effect, an
indication that the seasons were in flux; that in a mere 20
years, the brief Arctic summer was now arriving 10 days
earlier; and perhaps most important, that climate change
was having a biological effect, leaving a fingerprint on a
species living in a seemingly remote, pristine environment
thousands of miles away from the industrial hand of man.
And over the past few years, George has come to believe
that the warmer Arctic climate is changing not only his
birds' breeding habits but also the species in a far more
profound way. Traditionally, the birds come back to
Cooper Island over three successive nights, trying to
gauge the degree of snow melt from the air, and there are
dangers at every turn. If George's birds arrive on the
island when it is still covered by snow, they can't take
refuge in their dark, protected nest cavities and, with
black feathers set off against the white snow, they run a
high risk of predation; one summer a snowy owl showed
up during the birds' mass arrival and swiped a guillemot
out of the flock, eating it offshore and nicely
demonstrating why getting to the island too early poses
such a danger. If, on the other hand, the guillemots arrive
too late, they risk losing their longtime mates, which is
what happened one summer when one of George's favorite
birds, Black-White-Black, returned to Cooper two days
late only to find its mate, White-Red-White, otherwise
engaged. Major battles ensued as Black-White-Black tried
to fight his way back into his longtime nest. ''It was
something to watch,'' George recalls. ''There was blood on
top of the nest site and guillemot footprints in the blood!''
Caught between the perils of early and late arrival,
knowing that their survival and reproductive success
depends on perfect timing, the guillemots of Cooper
Island have had to develop a highly sophisticated method
for gauging snow melt. Those that can do it have
persisted; those that can't have not. In effect, the warming
of the North American Arctic has already precipitated
natural selection for birds that can assess climate change
in a highly sensitive way.
Just what a hormonally crazed, falcon-fearing guillemot
actually looks like became visible to me on our very first
night on the island, when George suddenly looked up at
the sky at 2 a.m. and said with considerable excitement,
''I think I hear guillemots!'' I heard or saw not a thing.
Again, George looked and listened: ''Yup, they're
definitely up there somewhere.'' And a moment later, I
had my first sighting: 12 black birds in a tight flock, flying
skittishly over the island at 500 feet, their rapid wing
beats making a faint, wobbly Doppler sound like the hum
of a dozen tiny windmills. Keeping in tight, antipredator
formation, determined not to descend into owl or falcon
range, they swooped over the snow-covered island,
assessing the degree of snow melt on their nest sites and,
evidently displeased with what they saw, disappeared as
quickly as they'd arrived, dispersing like dust motes into
the flat gray sky.
On the following night, with low fog engulfing the island,
just one bird showed up, checked out the dismal
conditions and flew back out to sea. But tonight, as we
walk back to camp after touring the island in the steady
rain, eight of them are back, flying lower and less
nervously than they were two nights before. Directly above
their nest sites, they set their wings and come
dive-bombing toward the ground, but pull out of the dive
at a hundred feet, caught between their hormonal urge to
breed and their terror of landing so conspicuously on the
white snow. Then, out of nowhere comes a second flock,
merging with the first, flying with agitation, a few
individual birds dropping from the flock with a stronger
urge to land, but joining the safety of the group once
again. Suddenly, their numbers have grown to 20, flying
in tight concentric circles at 50 feet -- around and around,
dipping, rising, surveying the ground still half-covered in
snow. I take my eyes away to write some notes, and when
I look up again there are 40, groups merging and
breaking apart, darting like schools of minnows, keeling
from black wing to white underwing, visible to invisible
against the slate gray sky. For half an hour, we watch the
complex choreography. And at 12:52 a.m., one bird
breaks from the group and heads toward ground. ''This
guy's going to land!'' George cries out. ''This guy's going to
land!'' Feet splayed, wings pulled back, the first guillemot
of the season arrives on Cooper with a great fluttering
fanfare of wings. George looks through his scope and,
recognizing the bird, lets out a hoot. ''That's a chick that
fledged here -- a Cooper product, back in the 'hood!''
After three nights alone on the island, George is delighted
that his birds are back. But he's also mindful of the grim
chronology: when he began his study almost 30 years ago,
snow persisted on Cooper, preventing his birds from
gaining access to their nests until the last week of June.
Over those same 30 years, despite natural year-to-year
variability, the birds have arrived, on average, five days
earlier each decade. ''The great thing about guillemots is
that they're birds, they're nonpolitical, they have no
choice but to react,'' he says. ''Every weather station in
the Arctic should have a bunch of guillemots nearby so
that if skeptics doubt the weather data, you can point to
the date the first egg gets laid in the colony.'' Tonight, it is
June 6. The birds are back three days earlier than they
were the year before.
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