In early November, a male Adélie clambers atop a female to mate. Females are often identifiable during this period by the muddy footprints left on their backs by their mates.

An Adélie attempts to nest in the snow. Increasing snowfall, particularly in spring, has made nesting more difficult for Adélies in the Palmer Station area.

On Torgersen Island, Adélies return from foraging at sea, waddling along a trail formed by elephant seals in the snow.

Looking south from the Marr Ice Piedmont around sunset. On clear days, peaks more than 100 miles away can be seen through the dust-free Antarctic atmosphere.

Looking west from the Marr Ice Piedmont at sunset.

Another view to the west at sunset, which occurred around 10 pm in November.

The tracks of a tobogganing Adélie penguin in the Marr Ice Piedmont.

From atop the Marr glacier, sea ice can be seen stretching to the horizon.

A NASA satellite photograph shows why Bill Fraser’s birding team was confined to station for most of November because of sea ice. The Antarctic Peninsula runs across the bottom of the picture. Anvers Island is in the center of the picture, in bright white, and along its southern and western shores, in milky white, can be seen a massive raft of sea ice..

Looking from Arthur Harbor toward Torgersen Island, where two small colonies of Adélies nest on the snow.

Clouds above the Marr Ice Piedmont reflected in the waters of Arthur Harbor on one of the many uncommonly still days that spring.

Cormorant Island, looking east toward the peninsular range.

Mt. William, as seen from Cormorant Island.

A close-up of a section of the peninsular range, with sea ice in the middle distance. Due to rapidly rising temperatures, sea ice now covers the waters off the western Antarctic Peninsula three months less a year than 30 years ago. That loss of sea ice is believed to be a major reason for the decline of Adélie penguins, as the Adélies use the ice as a feeding platform in winter. But during the 2005-2006 summer season at Palmer Station, prevailing winds from the southwest kept the sea ice packed tightly against Anvers Island in November.

Looking east from atop the Marr Ice Piedmont, with Mt. William, at left, and the peaks of the peninsular mountain range in the distance. In the middle distance is the etched surface of the Southern Ocean, covered in ice.

On Cormorant Island, Jen Blum, left, and Peter Horne walk among the Adélie colonies, counting penguins. They wear snowshoes in the deep spring snow. Mt. William is in the background.

In Colony 23 on Torgersen Island, Adélies endure a spring snowstorm. The colony had shrunk to the point that – like numerous other Adélie colonies around Palmer Station – it went extinct during the 2005-2006 reproductive season.

Adélies, top, try unsuccessfully to move their eggs out of the melt ponds. Snowfall is increasing along the western Antarctic Peninsula as sea ice melts, exposing more open ocean and leading to greater evaporation and precipitation.

In the evening light, Adélies build nests and incubate eggs in a small colony on Torgersen Island. In the background are the towering, glaciated mountains that form the spine of the Antarctic Peninsula.

Incubating Adélies lie down in a small colony on Torgersen Island. In spring, the pebbly Adélie colonies surrounded by snow are a common sight.

In the foreground, Adélies sit on cup-shaped nests to incubate their eggs as a male Adélie, flippers outspread, carries a pebble in his beak to build his nest.

When Adélies mate, they tap their bills together in a long, quivering touch and join their genitalia in what is known as a “cloacal kiss.”

On Cormorant Island, a small and rapidly shrinking Adélie colony occupies higher ground to avoid nesting in snow. In the center of the colony, foreground, an Adélie incubates its eggs standing up. In the background, clouds tugging at its summit, is 5,249-foot Mt. William.

Torgersen Island, looking south on a still November day. At left, male Adélies, heads pointed skyward, try to attract mates using the so-called “ecstatic display.”

On Torgersen Island, one of five penguin islands within a few miles of Palmer Station, an elephant seal rests between two small penguin colonies.

A female elephant seal and her pup on Torgersen Island. Elephant seals, sub-Antarctic marine mammals, have become increasingly common around Palmer Station as the region warms.

On Torgersen Island, Adélies attempt to incubate eggs in a pond created by snowmelt. Increased snow and snowmelt during nesting season have decreased the reproductive success of Adélie penguins in the Palmer region and is one of several reasons why Adélie populations there are crashing.

Addled Adélie eggs are visible in the snowmelt pond. Even though their eggs are underwater, the penguins still try in vain to incubate them.