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seal pup

NSF Polar Program

U.S. Antarctic Program


The National Zoo's Antarctica Expedition is sponsored by the National Science Foundation's Office of Polar Programs.

All photographs depicting Weddell seals were taken under NMFS Permit No. 763-1485-00 issued under the authority of the Marine Mammal Protection Act.

 

 

 

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The View From My Window
November 25, 2007

Fluffy snow has fallen during the night and covered the camp in a clean white blanket. Unfortunately, it is now so warm (relatively speaking) that the snow on the roof melts and drips, leading to rude awakenings in the early hours of the morning. Outside, the landscape is serene and beautiful, the sky washed with delicate hues of blue and white and silver and in the distance the mountains and valleys of the Royal Society Range, beckoning like some frozen Shangri-La.

The weather was not always so benign. Not long ago, a fierce storm hit the camp. The prevailing winds here at Hutton Cliffs are from the south to southeast and we set up our camp in a rough horseshoe pattern—lab hut, kitchen hut, girls’ hut, and rack tent, where the boys sleep—to provide some shelter in this very windy place. Alas, the storm mocked our designs by blowing from the northeast for a change.

Lying in bed, I could feel the hut shudder and tremble as gust after gust hit the walls. Before Olav went to bed that night, he measured wind speeds of 50 miles per hour. The storm blew the power cord out of the generator, dumped snow on our doorsteps and stole the flag we use to indicate whether the outhouse is occupied or empty. The wind tears the heat from our bodies and our shelters faster than it can be replaced, and this is no time to be outside. Sometime during the night, the heater in the rack tent quietly expires, and everything freezes. What would this place be like in winter?

The previous day had been clear and calm, and had brought visitors and a wonderful treat. Michael Lang, Dive Officer for both the Smithsonian Institution and National Science Foundation's Office of Polar Programs, and Rob Robbins, Scientific Diving Coordinator at McMurdo Station, came to dive in our colony. Snail-like, the divers dragged along behind them their own shelter, a bright red spherical hut called a tomato. A hole was drilled through the thick multi-year ice and the divers descended into the deep blue ocean below. So close to a colony, the seals were there, watching the divers.

Michael and Rob have an underwater camera and bring back treasure from The Deep: images of multicolored invertebrates clinging to the volcanic rocks of the ocean floor, next to pale delicate growths of anchor ice. But best of all are the seals. Animals that are comically obese and condemned to crawl on the surface of the Earth now move with serene grace, effortlessly and supremely in their element. As they glide through the water, their bodies form beautiful arabesque shapes against a sky made of ice. If I was prone to puns, I might call them “sealhouettes.”

Enter the pup. He flounders, he drifts, and he labors mightily to gain any depth, fat and buoyant, as he is, a small furry cork. Unlike the smooth, spare strokes of his elders, his flippers seem to go in every which way at once, to no great effect. But soon, the pup will learn, and slide through the water effortlessly and gracefully like all his kin.

The fat that makes it hard for pups to dive protects them against the merciless cold of their home. As soon as the pup is born onto the ice, wet and shivering, it is a race against time. Mothers and pups are constantly together during the first week of life, and pups nurse as much as they can. The marvelously rich milk of the Weddell seal nourishes the pups and allows them to grow a thick layer of blubber, fat deposited under the skin that acts like an insulating blanket against the cold.

Weddell seal pup growth

As they grow toward maturity, seal pups literally gain pounds every day (see the chart above), becoming sleek and fat and streamlined, and shedding the rag-doll appearance of early infancy together with their woolly neonatal fur. The rate of growth in young Weddell seals is once again amazing. Just like last year, all the animals we are studying are increasing in mass and are well on their way to becoming sleek hunters of the deep.

Regina Eisert
Smithsonian Antarctic Ice Camp