Jean Pennycook manages penguin education and outreach for the National Science Foundation, including a great website: www.penguinscience.com (check out the cool time-lapse video on the homepage). Hear what she had to say to say about her work during my visit to the Cape Royds rookery last week:
Adélie habitat has changed over time, especially in recent years. They build their nests on small stretches of land along parts of the Antarctic coast that are not ice-covered. The health and location of their colonies are directly related to the amount of sea ice (frozen seawater) nearby, as well as air and water temperatures and the presence of large marine predators, such as Minke whales, that compete for food. Adélies feed on krill and small fish in the ocean at the edge of the sea ice. If there is too much sea ice, the penguins have to walk too far to get food for their chicks, and the colony begins to decline.
In recent years, environmental changes have been occurring at a more rapid rate. A strong air pressure difference in the South Atlantic, warming air temperatures and the ozone 'hole' have changed the air and ocean circulations around Antarctica, and thus how heat is distributed in the Southern Ocean and the air above the Antarctic.
According to David Ainley, a marine biologist who has been studying Antarctic penguins for over 20 years, the Antarctic peninsula -- the area closest to South America -- now has less sea ice and warmer temperatures than it did in the 1960s, when he first started studying Adélie colonies. While less sea ice makes it easier for Adélies to get food, they are adapted to life in the cold and cannot survive well in warmer temperatures. So, populations there have been declining. On the contrary, the winds have broken up the sea ice in the more southern Ross Sea where temperatures are still cold, so populations there have been increasing. One exception is at the Cape Royds colony, where an iceberg grounded at the edge of the McMurdo Sound in 2000, locking the sea ice in the Sound and preventing penguins from being able to get to open water to feed -- an effect that lasted six seasons. Over the past two years, the colonies have again begun to grow.
Emperor penguins are even more attached to sea ice: they breed on it! Learn more about the effects of climate change on Antarctic penguins from Jean and David.
Here are some Adélie photos from Cape Royds colony, in addition to my favorite video that I took and a shot of four emperors hanging out near Pegasus ice field, the icy jet runway we landed on. I'll post a "best of" video from my trip to the Cape Royds rookery (nesting colony) in the next few days.
They're so cute!
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