“Go sit down on that rock,” Jean tells Kallin, “and let them approach you. You can’t approach them, but they are very curious, so they will come check you out.” We are adjacent to a penguin rookery at Cape Royds, an area of scientific interest (people can enter only with a permit to do research on the penguins). Kallin willingly obliges, and moments later, a pair of Adelie penguins waddles within 10 feet. They stop and cock their heads, pivoting to look at Kallin from different angles. She returns their curious stares, tilting her head in unison with the pair.
One penguin picks up a rock in its mouth and holds it there for a moment, moves it around, and places it back on the ground. Adelie penguins (Pygoscelis adeliae) use these rocks to build their nests, and they aggressively defend the nests as well as the rocks. Although Adelies live on the sea ice, they breed on land, and remain there from October or November until chicks fledge in March. During incubation of the eggs in December, one parent stays with the nest and chick while the other goes out to sea to look for food. The parent that is incubating the eggs does not eat until the other parent returns to watch the egg.
Finding no further excitement in the person sitting in front of them, they hop up onto a higher piece of ice which forms something of a penguin highway from the water (mostly frozen on this side of the point) to the rookery (a dry, rocky soil bed devoid of vegetation). About 1,200 penguins live in this rookery, although numbers vary over time –each year, about 85% of penguins return to the rookery. The rest –the weakest– succumb to predation by seals and whales; a few may disperse to a new colony to breed elsewhere.
Adelies are medium-sized penguins, standing 45-75 cm tall and weighing in at 4-6 kg, and males and females look the same and are the same size. They diverged from other closely related penguins about 19 million years ago. These penguins historically ate mostly fish, but with humans over-hunting seals (particularly the Antarctic Fur Seal) and baleen whales, there has become an over-abundance of krill, which have suddenly become the primary food of Adelie penguins (Emslie & Patterson 2007).
A few random notes about Adelie penguins: A rookery is a smelly place. Penguins are noisy, and almost constantly communicating by squawking, chirping and making other unusual noises. Adelies are some of the most social of all penguin species. They move by waddling, hopping up steps made of ice, swimming, and sliding on their bellies (apparently an efficient way to locomote on the ice). Adelie chicks are sometimes preyed upon by skuas, which live and nest within or close by the penguin rookery. Sometimes when penguins jump out of the water onto land, they are not graceful– they may bump their heads on the ice or land sideways and stumble before regaining their balance on their bellies or feet. They are white on the front and black on the back to disguise themselves from predators– viewed from below, they blend in with the bright sky, and from above looking down, they are camouflaged against the darkness of the ocean. These are charismatic animals!
Read more about Adelie penguins and research on their responses to environmental and climate change at http://penguinscience.com –an excellent resource!