Studying the Earth’s Ultimate Survivors
The Emperor penguins, rising from the depths, levitate into the blue glow of an air hole in the ice.
No single creature more embodies the popular image of Antarctica than these droll birds dressed by nature for every formal occasion. Yet remarkably little is known about their behavior and biology.
The Emperors’ captivating underwater behavior while foraging in what may be the planet’s last unspoiled sea is a wonder normally denied to naturalists. The water in which they gambol is cold enough to quickly kill an unprotected human. An 8-foot-thick crust of ice hides the birds’ activities from the surface.
But in a cramped glass observation chamber suspended a dozen feet beneath the sea ice that girdles Antarctica, a wiry field biologist from La Jolla named Gerald Kooyman has opened a unique window into one of the planet’s most inaccessible habitats.
No sooner does the first Emperor crawl out of the water onto the surface of the ice than an observer crouched below in the chamber can see the streamlined silver shadows of half a dozen other penguins swim into view. One sports a small computerized depth gauge on its rump. Another has a catheter tucked under its left wing.
The underwater song of a lovesick seal--an eerie aria of trills, glissandos and percussive clicks--drifts across the sluggish currents and resonates in the chamber.
Kooyman, a University of California research professor at the Scripps Institution of Oceanography, is seeking to understand how penguins thrive under conditions that are lethal to most life forms.
The underwater chamber, like the use of special depth gauges and catheters that measure the diving bird’s changing blood chemistry, are techniques the 60-year-old naturalist has improvised in a life devoted to the study of what may be the world’s most unusual bird.
The Emperors of Antarctica dive deeper and longer than any other bird into Earth’s coldest waters. No other animal breaks so many of the rules that govern life in Antarctica, an icebound vastness larger than North America.
In a manner that makes them seem neither fish nor fowl, the sleek, flightless Emperors are equally at home in two of Earth’s most inhospitable environments.
No other bird dives deeper than the Emperor, as much as 1,500 feet for as long as 18 minutes. They also thrive on the surface under conditions that would doom almost any other animal--from temperatures that drop to 100 degrees below zero to winds that top 200 mph.
“The biology of this is still very much a foreign frontier,” Kooyman says.
As he talks, he struggles to keep his balance in a wind blowing with enough bluster to flatten the tents pitched on the ice. Nearby, the penguins huddle together comfortably.
Last Pristine Ocean
The penguins’ well-being is so closely linked to the ice they inhabit that their numbers rise and fall depending on the condition and extent of the sea ice each year. That may make the birds especially sensitive barometers of global warming and climate change, researchers say.
Until recently, most researchers thought that penguins of all kinds were safe from human disturbances or environmental changes. Now some researchers are worried about a disturbing decline among the penguins of Antarctica.
In the past four years, the numbers of several species in other parts of the continent have plummeted. No one knows whether the decline is caused by a succession of unusually warm winters, a drop in the population of the shrimp-like crustaceans on which they feed, or stress caused by the growing influx of tourists visiting crowded nesting colonies.
The Ross Sea, where Kooyman conducts his research, may be their last undisturbed haven.
There are 30 Emperor colonies on the continent, home to a quarter-million birds. Seven are around the Ross Sea, where Kooyman has counted about 70,000 Emperor breeding pairs. Only one of the seven colonies was known at the turn of the century. Most were discovered in the 1960s. The newest--which was home to 8,000 Emperor chicks last year--was discovered by Kooyman in 1993. It took him five years to find it.
“The Ross Sea is a pristine ocean and, as far as I know, it is the only pristine ocean in existence,” Kooyman says. “It is the only one where there has been no commercial exploitation and no severe environmental problems.”
In the short run, Kooyman and his colleagues are eager to simply understand the animals themselves. But they also hope that what they can learn about how penguins survive without oxygen for extended periods might one day lead to medical applications for humans.
“We have a remarkable opportunity here that we have nowhere else.”
Antarctic Laboratory
To understand the Emperors, Kooyman has made all of Antarctica his laboratory.
Working under the auspices of the National Science Foundation, he has been coming here for so many years that a mountain peak is named after him, so many years that his hair is now the color of snow.
Kooyman first traveled to the bottom of the world in 1961. After dropping out of graduate school at UC Berkeley, he signed on as a field assistant with a Stanford University group bound for the Antarctic. That is when the unusual diving physiology of two species found only there captured his attention--Weddell seals and the Emperor penguins. He went back to school, made them his graduate thesis, and secured funding from the National Science Foundation.
He has spent about one-third of every year since in the field--if not studying penguins in the Antarctic, then tagging bluefin whales off Monterey or tracking seals in Siberia. Now his sons, Tory and Carsten, work as field assistants in Antarctica.
Kooyman has followed the Emperors on skis across the sea ice in the bright noon of the Antarctic summer, watched from an aircraft as thousands of them incubated their eggs under the full moon of winter midnight, and trailed them in protective scuba gear through the water under the ice.
He weighs them, tags them and records their heart rates. To monitor them as they migrate across the barren ice, he enlists the tracking abilities of satellites in deep space.
Using sensors he invented, he follows them to the limits of their diving ability.
This past November, Kooyman pitched his orange-and-yellow tents on the sea ice not far from Inaccessible Island, a rocky outcrop ringed by dramatic cliffs, about four miles from Cape Royds--site of a major penguin colony. He was so close to the sea edge that visitors could find his camp by looking for the distinctive “water sky” that forms where the low clouds are darkened by the reflection of the open water lapping at the edge of the ice.
His camp--dubbed the “penguin ranch”--is 16 miles from McMurdo Station, the main U.S. base in the Antarctic. The observation chamber, weighted by a ton of lead to keep it from bobbing to the surface, is lowered through a hole drilled in the ice, then anchored. The water freezes it in place. Observers squeeze themselves down a narrow 15-foot tube roughly the width of a sewer pipe to reach the glass sphere, where crouched in the dankness, they can film the behavior of the diving birds or take notes.
Kooyman’s infrequent visitors must follow a route from McMurdo across the sea ice marked only by red and green flags. In a diesel-powered “Sprite” snow tractor, the journey takes about two hours.
The Emperors spend their lives on this vacillating margin of ice between the coast and the open sea. This margin grows in March at a rate of 22 square miles a minute until it is twice the size of the United States; then in October, the sea ice shrinks twice as fast as it formed until it barely rims the continent.
Most specimens of Antarctica’s wildlife can fit neatly on a microscope’s stage--fugitive lichens that live inside rocks and microbes that somehow survive in temperatures cold enough to sterilize almost the entire continent. There are exotic mites and wingless flies.
But nothing much larger than a pinhead lives year-round on the continent itself.
Even the Emperors rarely, if ever, venture off the sea ice into the interior. Sea birds are the most common animals in Antarctica but all except the Emperors must build their nests and breed on ice-free open land or a beach. Emperors are the only birds who have adapted to survive in such bitter cold and the only seabird anywhere to reproduce in winter.
Although their survival depends on the sea, the Emperors never set foot in water until they are almost adults, when they waddle unprompted to the edge of the ice and learn to swim by hurling themselves into the ocean.
Then, in a remarkable biochemical transformation, they acquire almost overnight the unique oxygen metabolism and blood chemistry of a deep-diving aquatic animal. The oxygen storage capacity of an adult Emperor’s muscle tissue is about 12 times that of a chick.
That is one of the mysteries Kooyman is trying to unravel.
“When do these changes take place to make them true divers?” asks research assistant Lisa Starke. “Do the biochemical changes occur first or does diving stimulate them?”
Biochemical Mysteries
At every point in his work, Kooyman wrestles with one of the most fundamental problems in science--how to conduct controlled experiments with wild animals without allowing his presence to alter their behavior--and distort his results.
Normally, field biologists strive to be unobtrusive, keeping their distance from their subjects so they can investigate natural behavior.
But Kooyman is trying to understand the hidden biochemistry that makes the behavior possible.
“My main goal has been to understand how they respond to their environmental variables and to do so under as natural conditions as possible,” Kooyman says.
His only alternative would be to conduct the experiments in a more conventional laboratory. Indeed, aside from his own work, the only other scientific data on the physiology of such deep diving has been conducted with caged birds. Researchers simply held the animals underwater and measured the metabolic changes.
For Kooyman, those findings inevitably are distorted by the stress of confinement, the anxiety of prolonged contact with humans, and the animal’s panic at being forcibly submerged.
In his work, he juggles what seem to be irreconcilable goals--to impose scientific controls in a harsh environment that rejects constraints, to confine wild birds without restricting them unduly, to monitor their blood chemistry without hurting them, and for himself to survive under conditions that tax human endurance to the extreme.
“We try to have as little impact as possible, [which] limits the things we can do,” he said. Taking such pains slows the speed at which Kooyman can conduct his experiments, thereby slowing the accumulation of data.
In his blood chemistry study, he works with one Emperor at a time. It may take no more than a few seconds to collect the blood sample after a prolonged dive--and the birds may dive dozens of times in a day--but Kooyman is careful to take no more than two or three measurements a day, to ensure that the animal has sufficient time to recover its equilibrium.
Kooyman and Starke raised 15 abandoned Emperor chicks on the ice last year to study their development. They took blood samples from each chick only once, to minimize any stress. When the birds were old enough to swim, they released them.
It is slow work. He may only be able to conduct each experiment for a few weeks every year.
Often, the wind and snow are so severe, he can get no data at all.
“Most people who work with animals don’t work with them under these kinds of conditions,” he says. “They may not appreciate what we are trying to do here.”
Corral on the Ice
The Emperor penguins belly-flop out of the air hole and onto the ice by Kooyman’s camp. They toboggan away on their stomachs, slip-streaming through the strong wind as easily as they glide through the water. But a makeshift corral, fashioned from a red wooden snow fence, keeps them from escaping across the ice.
The fence--an incongruous sight on the world’s last open continent--allows Kooyman to isolate and confine a dozen Emperors without interfering with the diving behavior he studies so intently.
The penguins are penned only on the ice surface. They can dive back through the air hole to roam freely underwater whenever they want. In order to breathe, however, the penguins eventually must return to the air hole at Kooyman’s camp. No other is within range.
In the corral, the researchers can gently corner the bird outfitted with the catheter after a prolonged dive and sample its unique blood chemistry and oxygen metabolism.
“They do not like to be handled. We do not grab her or restrain her; we try to surround her so there is nowhere she can go,” Kooyman says. “We try to get it done within four minutes from the time she surfaces.”
Three Emperors are poised at the lip of the air hole, hyperventilating to charge themselves with extra oxygen. In a flash of white and silver, they vanish into the sea.
A fourth struts on stiff legs, then trumpets in the wind.
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Following the Emperor Penguin
National Science Foundation researchers working around the Ross Sea are trying to understand how penguins thrive in the Earth’s harshest habitat. The Ross Sea, home to seven of Antarctica’s 30 Emperor colonies, is the species’ last undisturbed haven.
Emperor penguin colonies
1. Cape Colbeck
2. Cape Crozler
3. Beaufort Island
4. Franklin Island
5. Cape Washington
6. Coulman Island
7. Cape Roget
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Penguin Facts
Penguins live in the southern half of the world, from the icy Antarctic to the shores of the Galapagos Islands and Africa.
There are 17 species of penguins. Early explorers thought the flightless birds were feathered fish.
Here are three types:
Adelie penguins, the best-known penguin species, live all around Antartica and as far north as New Zealand.
Chinstrap penguins, numbering about 7.49 million breeding pairs, live mainly on the Antarctic peninsula and on South Atlantic islands.
Rockhopper penguins, with their distinctive yellow crest, are found mainly on the islands of the South Atlantic and Indian oceans.
Penguins in Antarctica today are protected by treaty from any undue inteference by humans.
But for almost 300 years, penguins were killed for their meat, while penguin eggs were a regular menu item for many early Antarctic explorers.
