November 21, 1996

Emperor Penguin Returning to the Ice Surface After a Dive. Viewed from the observation tube.

Another glorious day! After a rather prolonged start to the morning, Don and Jim returned to McMurdo. Tom, Dan, Rob, Mike and I headed out to the Penguin Ranch. Enroute, we stopped by Tent Island to tag Weddell seal pups and see if we could find a crabeater seal which had been seen on the ice. Sure enough, the crabeater we there, in the lee of the island, lying next to a Weddell mother and nursing pup--a casual encounter. Mike and Tom tagged one newborn pup, which could not have been more than a few days old; it had a downy lanugo coat and its umbilical cords was still attached and bright red. We also counted three dead pups and a starvling that could barely hold its head up. The mortality rate of Weddell seals is very high--in some colonies nearly 50%.

It was a clear day and we could see the Penguin Ranch 3 miles distant--two orange specks on the horizon. Since the earth is, in fact, slightly oval, rather than a perfect sphere, one's sense of distance is skewed. Add to this the relative absence of air pollution and space and distance seem protracted and hard to judge. We spread out on snowmachines and negotiated the sea ice and sastrugi fields.

Gerry Kooyman was back from Cape Washington and he had joined Jeff Graham and Anaika Dayton. He laughed as I showed up with a posse of sealheads. Gerry is a research physiologist with the University of California at San Diego and the Scripps Institution of Oceanography Center for Marine Biotechnology and Biomedicine. The title of his current research project is, "Physiology and Energetics of the Aptenodytes." Their work this austral summer involves looking at several dimensions of emperor penguins, notably the physiology of diving, the developmental aspects of diving in chicks, ways in which to examine foraging success and to conduct a census of chicks in the major colonies in the western Ross Sea.

The Penguin Ranch is one of two sites being used by the "penguin cowboys," as they are called. It is here that Gerry and his group, which includes his son, Carsten and Robert van Dam, in addition to Jeff and Anaika, are studying aspects of diving physiology. Emperor penguins can dive to a depth of about 1,800 feet--a record in the world of birds. What they are trying to understand is what happens to penguin metabolism, heart rate and physiology in the process of diving, and how can this be described developmentally as chicks grow up.

The Penguin Ranch is a study area with 20 captive birds--the capture was easy, as they had wandered into camp. A corral was built and two diving holes bored into the ice. In addition, an observation tube was mounted at the periphery of the corral. This tube is a light blue steel pipe, fitted with ladder rungs, which extends some 30 feet into and below the ice--which measures about 6 feet in thickness. At the base there is a small, windowed chamber, bulbous in shape in which two people can be accommodated (two small people, I might add). The "ob tube" is anchored by a tripod of leg extensions on the surface--to prevent a slip to the sea floor, some 6,000 feet below. What the researchers are doing is allowing the birds to dive at will to feed in an area that is isolated in McMurdo Sound. They plugged all other holes within a 1-2 kilometre radius, so the penguins would have to use the holes that were provided. As they deplete the fish at shallower depths, they will dive deeper to new layers of the Ross Sea for food. Gerry and his group will be mounting Time/Depth Recorders and transducers to measure heartrates among the sample group.

The corral.

"The Penguin Ranch"

Upon our arrival, Gerry, Jeff and Anaika had opened up the ice holes and the penguins, after nearly ten days of hesitation, jumped in en masse. The sealheads took turns descending into the tube for photos. I stayed in one of the huts, learning how to help with observations, as the time of day and duration of each dive was recorded in a notebook--generally for about 12 hours per day. As the diving gets on track, they plan to monitor every dive for 24 hour periods. The fish hut/kitchen has a wide window, which faces the colony and a hole in the kitchen, where seals surface for air. As Tom Gelatt wrote in the guest book,"Penguins in the yard. Seals in the kitchen. God, I love science!"

We all spent the day watching the penguins dive, watching Weddell seals surface and the interaction between them. As a group, we took turns down the ob tube well into the evening. The sealheads returned to their camp at Big Razorback and Jeff and Anaika made for McMurdo and a shower--it had been at least a week. Gerry and I spent the evening talking, watching and listening. The breadth of his experience in marine reserach is remarkable, and I enjoyed hearing of his adventures in oceans around the world.

As night came, the wind picked up and it was obvious that very little recording would get done. However, ever optimistic, I planned on getting up every hour or so to listen and see what he penguins were up to. I slept in the fish hut on a couch with the trap door open. My alarm was a Weddell seal who regularly came up for air--two feet from my face in the hut. Yo, fish breath! I did not sleep much, but the penguins did and the wind howled all night...

Emperor penguins diving.