Cold (21 page)

“You told me to tell you right away,” he says. “But I’m not that cold.”

We ski on.

In 1911, Robert Falcon Scott was in Antarctica, waiting for summer so that he could start what would prove to be his fatal
walk to the South Pole. Scott sent Apsley Cherry-Garrard, Edward “Bill” Wilson, and Birdie Bowers to Cape Crozier in July,
the height of the Antarctic winter. Their mission: to bring back eggs from an emperor penguin colony. “They are extraordinarily
like children,” Cherry-Garrard later wrote, “these little people of the Antarctic world, either like children, or like old
men, full of their own importance and late for dinner, in their black tail-coats and white shirt-fronts — and rather portly
withal.” The men hauled a sled sixty miles in the dark at temperatures of seventy below. Their tent blew away in a storm,
and for a time the men lay in a snowdrift singing hymns and waiting to die. But in the end, they survived. They observed the
birds at the nesting colony. Cherry-Garrard felt compelled to mention the tenacity these birds showed in caring for their
eggs and young. “Now we found that these birds were so anxious to sit on something,” he wrote, “that some of those which had
no eggs were sitting on ice! Several times Bill and Birdie picked up eggs to find them lumps of ice, rounded and about the
right size, dirty and hard.”

The men carried three eggs back to Scott’s base, and the eggs now sit in London’s Natural History Museum. Emperor penguins
may look ridiculous, standing in the cold, mistakenly sitting on rounded blocks of ice, but Cherry-Garrard and his companions
must have looked more ridiculous still, pulling their sled through the dark, resting in frozen sleeping bags, very quickly
reaching a point at which they wished for the comfort of their own deaths. The penguins, meanwhile — without bags, without
parkas, without kerosene or a stove to burn it in — maintained a body temperature of ninety-nine degrees. They did this despite
the fact that emperor penguins go without feeding for as much as four months during the winter. They stand with their feet
tipped up so that only their heels touch the cold ice. A heat-exchange system in their nostrils, a variation of the rete mirabile
seen in the blubber of a whale, captures eighty percent of the heat that would otherwise be lost with each exhalation. As
many as six thousand of them huddle through the winter in single groups, conserving heat, each bird leaning slightly forward,
maintaining pressure on the one in front of it, creating in the end a circulating mass of penguins so that no one animal is
stuck on the outside long enough to freeze. Eventually, under the care of the males, chicks hatch. A penguin chick is naked,
unfeathered from the neck down, so it spends its first days standing on its father’s feet, tucked into a brood pouch at the
base of the father’s rather portly belly. Although a sixty-mile hike almost killed Cherry-Garrard and his companions, and
likely would have killed almost any other humans who had attempted it with the equipment available to these men, the penguins
stand around incubating eggs and raising their young without feeding for months on end before marching fifty or sixty miles
back to the sea, where they will end their four-month fast by plunging into ice-cold water and chasing down crustaceans and
fish.

Nearly two hundred thousand emperor penguins live in Antarctica. They are, arguably, the most remarkable of the winter-active
birds, but they are hardly the only winter-active birds. Redpolls, ravens, chickadees, ptarmigans, and a host of others prefer
the risks of cold to the risks of migration. Of birds that overwinter in the cold, only the poorwill is known to enter into
a state of long-term hibernation. The others have various tricks to survive the cold. The ptarmigan, best described as a snow
chicken, a near cousin of the prairie grouse, has feathers that cover its feet and toes. In winter, when it has to digest
fibrous twigs and bark, its gut lengthens. It hunkers down in the snow, only to flush out suddenly, flying low, landing not
too far away, white feathers disappearing into white background. It goes beyond hunkering, knowing how to avoid wind by tunneling
into snow, forming a cave near the top of a curving passage that traps its body heat. It hides out with the lemmings and voles
and bugs beneath the snow, but unlike these subniveans, it uses its tunnels intermittently. It comes out to feed or, like
the raven, to take a snow bath, throwing snow into the air and rubbing it across its body.

A naturalist writing in 1900 described insulation found in a cross-bill’s nest, saying that the nest was lined with “long
black tendrils resembling horse hair.” Another, writing nine years later, described the insulation as “wool and moss” and
“rabbit fur.”

Other birds shiver through the winter. Shivering, though, requires calories. A chickadee’s feeding rate increases twentyfold
in winter. A crossbill needs to find a spruce seed every seven seconds. An emperor penguin might start the winter at eighty
pounds and end it at a lean fifty, emaciated under its feathers.

It is the feathers that allow all of these birds to remain active through the winter. Without feathers, none of them would
have a chance. Pennaceous feathers — feathers that can become quill pens — cover these birds. Feathery barbs extend from the
central shaft of pennaceous feathers, and along these barbs are microscopic barbules and tiny hooks called barbicels. The
barbicels lock one feather to the next, encasing it, superior to shingles covering a house. Dry beneath the pennaceous feathers,
down feathers — fluffy feathers with no barbules, the kind of soft, tiny feathers that are used to stuff jackets and expensive
sleeping bags — hold air and warmth. Even when the bird dives, the down, beneath the interlocking pennaceous feathers, remains
dry.

If the pennaceous feathers leak, the down becomes wet and useless. A bird with leaking pennaceous feathers cools quickly.
In oil spills, thousands of birds have found themselves swimming in crude. The oil makes their pennaceous feathers leak. They
try for a time to maintain body heat by shivering, first in their pectoral muscles, where the wings attach, and then later
in their leg muscles. Shivering burns stored calories. While they shiver, they preen, trying to scrape away the oil. When
the stored calories are gone and they can shiver no more, they die of hypothermia. Or is it starvation?

It has been said that feathers evolved first to protect birds from the cold, and later the birds realized or learned or somehow
found out that feathers, managed in just the right way, would allow the convenience of flight.

I
t is January fifth and twenty below at the edge of this frozen North Slope lake. I call it a lake, but really it is a flooded
gravel pit dug into an oxbow, a long-abandoned river channel, to provide gravel for the more than four hundred miles of roads
that crisscross the Alaskan oil fields. It is eleven in the morning, and what passes for dawn is upon us, which, at this latitude
and this time of year, means the sky is subtly lightening in the east. An almost full moon shines through ice fog, along with
the bright lights of industrial facilities in the distance and the headlights of an idling truck. The truck’s lights send
beams out onto the lake, bisecting wind-sculpted snow on top of ice and capturing tiny suspended crystals of ice fog. Everywhere,
the snow on the ground and the fog above it reflect the lights, snuffing out shadows and muffling any sense of contrast, the
end effect disorienting.

We are lucky. Yesterday it was forty below and the day before even colder, the temperature as brutal as a physical assault,
making one gasp for air but then forcing a stop mid-gasp as cold air batters warm lungs. The difference between forty below
and twenty below is striking. Today, at twenty below zero, it is cold enough only to ice up one’s eyelids and freeze the inside
of one’s nose.

We walk out onto the lake. The snow screeches under our boots, as if we are walking on Styrofoam while wearing Styrofoam boots.
It is so cold and dry that our boots kick up little clouds of snow that the breeze carries along the surface of the lake,
like dust clouds one might kick up on a desert sand flat. Fox tracks cover the lake, zigzagging from one side to the other,
looping around on themselves. There are rabid foxes in the area. Just a week ago, a fox ran repeatedly out onto a gravel road,
attacking anything that moved, including trucks. When the fox attacked a front-end loader, it lost, and its crushed carcass,
sent to a state laboratory, tested positive for rabies.

I am with a team of hydrologists. They want to understand how water chemistry changes through the year, and especially in
winter, when lakes are hidden by snow-covered ice. They want me to understand what they are doing and the difficulties they
face. They drag two sleds onto the lake. A woman carries shovels and a gasoline-powered drill, and another woman holds a tent
of the kind used by whiskey-sipping ice fishermen in Minnesota. The hydrologists shovel snow from the lake’s surface, pull-start
the drill motor, and bore down into the ice. Though the snow dampens it, the noise of the two-cycle engine fills the cold
air. In less than a minute, the drill cuts in a foot, two feet, three feet, and then water gushes up and spills out across
the surface of the ice, turning immediately to slush and within seconds forming clear ripples of new ice across the older
translucent ice of the lake’s surface. The hydrologists erect the tent over the hole. Inside, they light a small heater. The
heater’s immediate impact on the warmth of the tent is comparable to what one would expect from a birthday candle. It is so
cold in the tent that slush forms continuously in the hole. They scoop the slush from the top of the hole and lower an instrument
thirty feet into the water. They measure temperature, pH, conductivity, and dissolved oxygen. The heater glows in the corner
of the tent, but it is pathetically underpowered and effectively heatless, providing only a soft red glow and offering nothing
more than ambiance as one hydrologist reads off data and the other sits on a box taking notes.

It is oxygen that interests the team most. There are fish in this lake, grayling that swam in from the adjacent river during
high water. They overwinter in these deep lakes, these flooded gravel pits, where they find water that will not freeze solid
by spring. This lake will not freeze solid. In all likelihood, the ice will grow six feet thick — somewhat thicker than most
hydrologists are tall. Below the ice is fifty feet of liquid habitat. But the ice seals the surface. Whatever oxygen was in
this lake when it froze is all the oxygen these fish will share until spring. At the bottom of the lake, oxygen-hungry bacteria
work the sediments, decomposing anything that has fallen down from above. The bacteria compete with the fish for oxygen, sucking
it out of the depths.

“These lakes,” the hydrologist tells me, “provide water for industry.” The water in these gravel pit lakes is used for drilling
and for washing trucks. It is used for building temporary roads of ice that reach out across the tundra to winter construction
projects. It is even used for drinking and bathing. The fish are kind enough to give up millions of gallons each year, to
share it with the oil industry. The water level of this lake will drop five feet before spring, those five feet hauled away
ten thousand gallons at a time by big red tanker trucks. Even now, as we talk, a truck sucks water from the lake. The driver
sits in the cab, bored but warm, with a black hose running to a white pump house next to the lake and steamy exhaust from
the truck blowing sideways, out over the lake, toward our little tent with its glowing, insignificant heater and its scientists
armed with instruments and data sheets and thick gloves. Under all of this ice, the fish tread water, waiting for spring,
their chilled brains probably incapable of even wondering what that funny pumping sound is that they hear now and again as
these humans come and suck out five feet of swimming headroom.

Later, in the warmth of a dining hall, a man tells me that a worker has been attacked by a fox. It happened ten miles from
our gravel pit lake. The fox ran out of the darkness and bit the man in the leg. The man tried to shake it off, as one might
shake off a pit viper, but the fox hung on to the cuff of his snow pants. He kicked it. It lay in the snow as if dead but
later got up and staggered off into the Arctic winter. Its rabid teeth, slowed down by the worker’s snow pants and stopped
by his boots, never penetrated the man’s skin.