A new twist in penguins’ already uncertain future

A new twist in penguins’ already uncertain future
P. Dee Boersma, a biologist at the University of Washington, has been watching the Magellanic penguins of Punta Tombo, in Argentina, for almost 30 years. For most of that time, their numbers have been declining: breeding pairs are down 22 percent there since 1987, she writes in BioScience. But the dwindling numbers do not just mean the birds are suffering, Dr. Boersma writes. Because penguins are “marine sentinels,” their decline is a blunt message that their marine environment is in trouble, chiefly from overfishing and pollution from offshore oil operations and shipping. Now, though, Dr. Boersma writes, they are also threatened by climate change, which is reducing sea ice and, as a result, the abundance of the marine creatures the birds eat. Magellanic penguins can swim almost 100 miles a day, she said in an e-mail message, but to get enough to eat now they must venture as much as 40 miles farther from their nests than they did a decade ago. Some of the food shortage is fishing-related, Dr. Boersma said, but some appears to be caused by climate change. As glaciers and sea ice retreat, she writes in her article, “even small variations can have major consequences for penguins.”

Dried fruits to carry on hikes, fresh ones for dieting
How does dried fruit compare with fresh fruit in nutritional value? How much should I eat? “There are pluses and minuses,” said Christina Stark, a nutritionist at Cornell University. “The main difference is that taking out the water concentrates both nutrients and calories.” This could be an advantage if you are hiking and want more calories that are easy to store and carry, she said. It could be a disadvantage if you are trying to lose weight. The heat used in drying fruit also decreases the amount of some of the heat-sensitive nutrients, like vitamin C. As for how much to eat, she said, the general recommendation is two cups of fresh fruit a day, the more variety the better. A half cup of dried fruit counts as a cup of fresh.

In sleep, we are birds of a feather
Did you sleep like a baby last night? You might think so, but actually you slept like a bird. Or rather, a bird slept like you. One bird, in particular — the zebra finch, which researchers say has a sleep structure very much like that of people and other mammals. Philip Steven Low of the Salk Institute for Biological Studies in San Diego, California, and colleagues report in The Proceedings of the National Academy of Sciences that electroencephalograms of the songbirds show they have episodes of rapid-eye-movement sleep and slow-wave sleep as well as transition stages and quick spikes, all reminiscent of mammalian sleep patterns. It’s the first time that this complete group of sleep characteristics has been found outside of mammals—a surprising finding, Dr. Low said, because birds lack a neocortex, the part of the mammalian brain thought necessary for such patterns.