In life, you must make choices. You can’t succeed at everything. For example, Tiger Woods is an excellent golfer, but a terrible husband. Shaquille O’Neal? Great at basketball, but acting? Not so much. (Bo Jackson could be the exception.)

Penguins realized this about 70 million years ago, when they gave up flying for diving and swimming. Now, a study in the Proceedings of the National Academy of Sciences explains why.

Researchers from the University of Manitoba studied murres, a type of auk—a family of birds that is similar to penguins but not at all related. Apparently, this species didn’t get the message about excelling at one skill. The murres both fly and swim. But research shows the dual skills come at a very high cost.

The scientists measured the energy usage of the birds. According to National Geographic News Watch,

They injected the birds with stable isotopes of oxygen and hydrogen to serve as tracers to mark the physical costs of their activities.

The team found that when flying, the murres’ sustained the highest metabolic rates ever measured for any animal. (Previously, the bar-headed goose held the record, but they are the world’s high-altitude flying champions.) In fact, the energy costs of the murres were 33% higher than the biologists expected after doing biomechanical modeling of the bird. The birds are sufficient swimmers, but researchers found that the birds’ energy costs while swimming were higher than penguins, who are specialists in the sea.

Lead-author Kyle Elliott remarks in both Nature News and ScienceNOW that the murres are at “the edge of what a bird can do.” And the team suggests that such high flight costs may have led aquatic birds, like penguins, to develop their wings for  propelled diving in response to foraging opportunities at increasing depths, behavioral adaptations that led, finally, to flightlessness.

In short, good flippers don’t fly well. But they’re great for swimming and diving. Fine choice, penguins.

Image: Ken FUNAKOSHI/Flickr

Thanks to Ryan Wyatt for reporting from the American Astronomical Society meeting this week—such exciting news from the conference. If you missed any of his tweets or posts, take a look back by scrolling through the timeline on the top right of this screen.

The big news breaking today is Eodromaeus murphi, a small pet- or pint-sized dinosaur that lived about 230 million years ago. Though it weighed only 10-15 pounds, this predator was fast and ferocious and possibly an early ancestor of Tyrannosaurus rex. Science Friday has a great video on the discovery and reconstruction of the tiny beast.

In addition to global warming, some penguins faced more bad news this week. French scientists reporting in Nature found that banding king penguins can actually harm the birds. In the 10-year study, the authors found that wing bands slow the penguins down, causing the penguins to arrive later to breeding grounds, because it takes them longer to forage for food. From Ed Yong in Discover:

As a result, the banded latecomers were less likely to breed successfully, or even to try to mate at all. Slowed by their bands, would-be parents had to make longer foraging trips to find enough food for their chicks. Overall, they reared 39% fewer young than the unhindered birds.

But all penguins and bands are not created equal, according to one of the world’s leading penguin experts, Dee Boersma, of the University of Washington. She told both Yong and NPR that while the study may be true of those bands and those penguins, it is not universal. The Academy’s own penguin expert, Pam Schaller, agrees. She told us via email that

Banding studies have shown that that flipper banding appears to affect some species of penguins and not other species. The results of the king penguin study cannot be directly applied to the African penguin (the species of penguins we care for).

Based on a 2009 study published regarding “The Effect of Flipper banding on the breeding success of African penguins Spheniscus demersus at Boulders Beach, South Africa” in the publication Ostrich, “There were no significant differences in breeding success between…banded and unbanded (African) penguins.”

Banding birds allows researchers to study trends in penguin populations, evaluate rehabilitation success, breeding success, growth rates and sexual maturity. These statistics are vital to understand and protect penguins.

Finally, there were many reports this week on the one-year anniversary of the massive earthquake in Haiti. Among the bad news were stories of lack of engineers (NPR) and health services (Scientific American) and the fact that in places like Haiti, “Corruption Kills”—a comment in Nature about the fact that “83% of all deaths from building collapse in earthquakes over the past 30 years occurred in countries that are anomalously corrupt.”

But, there was also good news—new technologies that emerged from the disaster as well as six frogs, previously thought to be extinct.

What bad and good science news did you uncover this week? Share with us!

Image by Todd Marshall