26 November, 2003
A windy day here at camp, with a weather report calling for even stronger winds and some snow later in the day. Definitely not a great forecast if you want to photograph and weigh seals, so it was time to come up with some alternative plans. Since I'd been hoping to visit one of the other research camps out on the ice, this seemed like a perfect opportunity. After calling ahead to find out what time might be best for our visit, we saddled up our snowmobiles and headed off for the Penguin Ranch.
Now, the Penguin Ranch is not your ordinary ranch. There are no cowboys and the only livestock they work with is a small group of Emperor Penguins. The head of ranch operations is Dr. Paul Ponganis, a research physiologist based out of the Scripps Institute of Oceanography, who is examining the diving physiology of the Emperor Penguin. These birds regularly dive to depths of up to 500 meters, spending 8 to 10 minutes at a time underwater. His group is measuring the effects of those dives on the oxygen content of the birds' blood. Another member of the ranch crew, Katsu Sato of Tokyo's National Institute of Polar Research, is testing new data recorders that can be attached to the penguins.
Emperor Penguins are difficult to study in the wild. The Penguin Ranch has developed techniques for studying them 'almost' in the wild-they have 13 to 14 penguins at any one time living in a corral at the ranch. This corral has a low fence, and is equipped with 2 dive holes through the ice. Since these are the only holes for many kilometers, the penguins will dive and return through the same hole, remaining within the corral between dives. The penguins can be caught, anesthetized, and equipped with sensors that monitor oxygen saturation levels in their blood stream and in the air sacs of their lungs while they are diving under the ice and retrieved from the penguins after their days dives are completed. In addition, some of the penguins have been equipped with Katsus's data recorders. These recorders have a small accelerometer that measures how fast they are going underwater, as well as sensors that can measure the speed, body angle, and the depth of the dive. The entire sensor package is less than 15 cm long and is light enough to be attached to the penguin's back.
Data collected during the dives has shown that the blood oxygen concentration in the birds can go from 20% down to 2% at the end of a diving sequence. This group is working to find out what the aerobic threshold might be for the penguins and how this might limit the length or depth of their dives. Katsu's work this season is focusing on perfecting the sensors. A few years ago he worked with the Weddell Seal project at Big Razorback, using sensors to determine diving depths and foraging behavior for some of those seals. Katsu worked with TEA Kolene Krysl while at Big Razorback-so you can learn more about his work there by accessing her journals from the archives. The sensors he is using on the penguins are miniature versions of those used on the seals. He pointed out one big difference between the way a seal dives and how a penguin dives-seals glide downward through the water column and use their flippers to propel themselves back up, while the penguins stroke on the downward trip and glide to the surface.
The logistics of creating a penguin corral are interesting. Once a hole is drilled through ice, it presents an open invitation for Weddell Seals. To prevent seals from coming up through the ice in the center of the corral, the researchers have drilled two additional holes through the ice in unique locations-under their lab and kitchen huts. Each of these huts has removable hatches in their floors that can be opened to expose the holes below. While we were talking with Dr. Ponganis in his lab, Wally the Seal surfaced every few minutes to exhale loudly and take a gulp of fresh air. Not everyone can say that they have a seal in their lab! At night the penguin's holes are 'corked' with a large, insulated circle of plywood to prevent them from escaping and to keep out unwanted seal visitors.
The best part of our visit to the Ranch was the chance to climb down into the famous 'Ob Tube'. This 20-footlong and 3-foot wide tube is set down through a hole in the ice near the penguin's corral. It's a pretty tight squeeze in your bunny boots and thick parka-definitely not a place for claustrophobics! One person at a time can climb down the narrow tube and sit on a bench in a small viewing chamber under the ice. This is as close as I'll ever get to diving under the ice. What an incredible treat to sit there under the ice watching Emperor Penguins drop through their hole and fly through the clear water in front of you. The ice above was translucent, with a beam of light shining down like a beacon through the hole. It was easy to see how seals under the ice use that light to find their holes to return to the surface.
Although we all felt like we could sit all day under the ice watching the penguins, we knew it was time to let Dr. Ponganis and his crew return to their work. It was time to leave the ranch and return to Big Razorback, so we saddled up the snowmobiles and rode off into the (non)sunset.
Climb into the tube
View a world under the ice
Look at that penguin!
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