Now here's the surprising part: Boersma's acquaintances are penguins. Since 1982, Boersma has been visiting Punta Tombo, a coastal area of Argentina that is a breeding ground for more than half a million Magellanic penguins. She has been studying all aspects of the penguins' lives: their mating, feeding, shelter selection, and other characteristics. "I've been interested in what sea birds can tell us about the environment," Boersma explains. "Humans are putting up more obstacles to their survival all the time."
Penguins are particularly desirable for study because they cannot fly (except through water) and are therefore easier to track than other sea birds. "We can hold them, measure them, and band them," says Boersma, who figures she has attached an identifying band on more than 45,000 penguins over the last 15 years. "Plus I find them really enjoyable to watch. Their lifestyle, in a lot of ways, is much like that of humans. They live in a raucous environment and have to get along together."
A priority to penguins is finding a desirable home. "They are really tenacious about holding their nest site," says Boersma, "and you can see why. If you are a male and don't have a nest site, you are not going to attract a female." Boersma has studied males who have moved from one nest site to another more desirable site with more cover, and "sure enough, more females stop to visit them" at their new nest. If they move to a nest with less cover, fewer females visit.
Although Boersma has learned much about penguin breeding habits, it's been harder to study their foraging and migration. There have been clues about the penguins' annual migration to Brazil-- more than 2,000 nautical miles--since some of the banded penguins have been found dead along the migration route, but the details of the journey have been sketchy. Even less has been known about where the penguins go to feed. Now the details of life at sea are coming into focus, thanks to special satellite tags--miniature radio transmitters that beam up data to an orbiting satellite--that Boersma has been attaching to about 50 birds each year. The tags allow her to track the birds' progress from a distance.
The satellite data have already revealed that some penguins swim up to 300 miles from their nesting area to find food while their mates sit in the nests on their eggs. Such a foraging journey can take nearly three weeks, leaving the penguins' newborn chicks at risk of starving before the parent returns. This is particularly worrisome since the number of Magellanic penguin chicks surviving to adulthood has declined in recent years.
Boersma suspects that changes in the marine environment--including fishing, oil pollution, and climate change--may be factors in the steady decline in penguin numbers over the past dozen years. "When there's an oil spill, penguins end up taking it in the shorts," Boersma explains. "That's it for them. After an oil spill in 1991, my students and I walked more than 150 miles of beach in Patagonia and estimated that over 17,000 penguins had died from that one spill."
Climate change and overfishing can mean less available food for the penguins, which can also be devastating for younger penguins. "Penguins aren't very adept when they first start to hunt fish," explains Boersma. "It's important to have lots of food around so mistakes can be made."
As Boersma has been learning more about where penguins forage and migrate, she has been sharing her data with local officials, environmental organizations, and fisherman in Argentina in an effort to reduce conflicts between people and penguins. "At the heart of the problem is a conflict between humans as stewards of the world's resources and as insatiable consumers," she says.
How the conflict will be resolved, and at what cost to penguins, remains unclear. But Boersma remains "cautiously optimistic" about the future of Magellanic penguins.
"I think penguins are fairly resilient," she explains. "And people like penguins. Popularity with people remains a key for penguin survival because some human restraint will be required to balance penguins' needs with human wants. We are often willing to give up something when we care about the animals affected. As long as people like penguins, I'll remain optimistic."