Alain Hubert counts penguins as a hobby. His day job is collecting climate data as a summer resident at the Princess Elisabeth Antarctica research station. For someone needing a penguin fix, he is in the right place. More than a million emperor penguins inhabit the rugged Antarctic coastline. And when satellite images revealed a previously unknown colony near the research center, the Belgian adventurer knew he had to find them and bring back a count.

The satellite images, from a 2009 research project conducted by the British Antarctic Survey and reported in Global Ecology and Biogeography, did not discern individual penguins. Instead they showed large patches of reddish brown guano clearly visible against the white surroundings, evidence of where a penguin colony had spent the winter huddled on the frozen coast.

When researchers decoded the satellite images, they found ten new emperor penguin colonies in 2008 and four more in 2009. Hubert studied the results and saw on the map that one colony was located not far from his research facility. That was all the incentive he needed to start searching in his spare time around the Ragnhild coast.

It was challenging terrain. "There were crevices everywhere and many places where we couldn't take our Ski-Doo," said Hubert, an experienced mountaineer who leads expeditions while working at the station, established in 2009 by the International Polar Foundation. For parts of three years he looked for the colony.

View Images Adult penguins take a break on the ice. Since adults spend much of the summer months hunting in the sea, the colony is mostly populated by the young. PHOTOGRAPH COURTESY OF INTERNATIONAL POLAR FOUNDATION

Finally, on a December night in 2012, the Antarctic summer sun above the horizon, Hubert and a team of fellow explorers found what they were looking for.

"We were walking on the edge of the shore, standing above the black ocean, when we came across these cliffs that stood 40 meters [131 feet] high," he said. In a rift by the cliffs' side, he saw a huge gathering of baby penguins.

In a few hours of walking the ice, Hubert counted 3,000 newborns with their distinctive gray down. (Adult penguins jump in and out of the ocean and are too difficult to count.) He multiplied that number by three for a rough estimate of 9,000 penguins, including parents and bachelors.

The Ragnhild colony turned out to be some 170 miles (274 kilometers) from the research station, a 12- to 16-hour journey by Ski-Doo. With photos and research notes in hand, the adventurers made their way back and soon reported their findings to the British Antarctic Survey.

Penguins From Space

View Images MAGGIE SMITH, NG STAFF. SOURCES: SIERRARIOS; WRI; WWF

Satellites and Ground Truth

Hubert's old-fashioned method of counting contrasts with the computer-aided survey from space. "We tell the computers how to differentiate between the guano [reddish brown pixels] and the penguins [black pixels]," said Michelle LaRue, researcher and author of the first satellite penguin census in 2012. This study used images from the 2009 satellite study to estimate the number of emperor penguins in Antarctica, a first for researchers. From the photos, she estimated that there are a total of 595,000 emperor penguins in 44 different Antarctic colonies.

Though the numbers generated from satellite images are imprecise, they remain the most efficient and reliable tool for locating and sizing penguin colonies. Yet nothing beats ground truth. A year after his first visit, Hubert again found himself in the vicinity of the Ragnhild colony. Because of moving ice, the ship that delivered supplies to the research station had to dock farther than usual from the usual drop-off point. Unpacking the ship, Hubert realized that he was less than 80 miles (129 kilometers) from the penguin colony. He felt compelled to visit again.

View Images By the end of January, these baby penguins will molt their gray down and grow waterproof feathers. PHOTOGRAPH COURTESY OF INTERNATIONAL POLAR FOUNDATION

Facing only a four-hour journey to Ragnhild this time, he and field guide Christophe Berclaz left on Ski-Doos. "Since the ice is continuously moving, the first and second trips were completely different," said Hubert, "but once you learned the entrance rift to the colony, you can move much quicker."

Cloud and fog cleared as Hubert and Berclaz arrived in Ragnhild. "It was a scene you could transpose onto a beach somewhere," joked Hubert. Below the cliffs the baby penguins were huddled in loose groups, standing in the reflection of the sun from the water. Hubert and Berclaz spent nearly ten hours counting the juvenile penguins. The good weather enabled them to count more penguins than they did on their first journey.

By the end of the day, they had estimated there were 15,000 penguins at Ragnhild, a leap of 6,000 from the previous count and a similar figure to that of the satellite-derived figures from LaRue's census in 2012.

"This groundwork is encouraging for researchers," said LaRue about Hubert's visits. "It may tell us that Ragnhild is a relatively stable colony."

The fact that the human count was close to the satellite count suggests that satellites are reliable tools for census taking. What ground visits provide that satellite research doesn't are valuable, up-close observations and descriptions. But making good counts isn't the only thing that drives Hubert's trips to the colony. He returned, he said, to satisfy himself that the population of emperor penguins at Ragnhild wasn't shrinking.

View Images Emperor penguins are the largest of all penguins. They can grow up to 45 inches (114 centimeters) tall and weigh up to 88 pounds (40 kilograms). PHOTOGRAPH COURTESY OF INTERNATIONAL POLAR FOUNDATION

Future Monitoring

As a polar explorer and climate researcher, Hubert is concerned that melting sea ice could make it harder for penguins to find food sources, ultimately reducing emperor penguin populations in the coming decades. "We're all working together to answer questions about the state of the food chain in Antarctica, such as krill, the birds, etc. But it's so difficult to monitor in this huge territory," said Hubert. "Antarctica is twice as big as the whole United States."

View Images Emperor penguins slide and waddle to the icy shoreline, ready to plunge into the freezing sea. PHOTOGRAPH COURTESY OF INTERNATIONAL POLAR FOUNDATION

When Hubert walked the grounds of the colony, he spotted only a few dead baby chicks, a sign that the population had made it through the winter successfully. But he won't know until next year on his anticipated return if the adult penguins found enough food under the sea ice to survive the molting season. (Learn more about the penguin molting season.) Already a few scientists have requested to join him later in 2014 to conduct studies.

After counting the penguins, Hubert headed back to the research center. It had been another worthwhile visit. He left the colony in high spirits, hoping that he would see the Ragnhild penguins again. He jumped back on the Ski-Doo, covered his face from the brisk winds, and drove back across the jagged ice rift, following the seemingly endless white snow line on the horizon.