Mystery on How Penguins Stay Ice-Free Solved
Christopher Michel, Wikimedia Commons
Antarctic penguin jumping out of the water while others stand by.
Penguins! Unlike the dodo, this flightless bird has figured out how to make a go of it, capturing our hearts into the bargain. With winter well underway, and a historic blizzard pummeling the east coast as we speak, what better time to chill with some pictures of penguins? Enjoy these amazing creatures!Found: Africa's Oldest Penguins
Once waterbound, penguins are fantastic swimmers that can zoom through the ocean at some 15 to 20 miles per hour.Penguin Huddles Move Like Waves
There are 18 species of penguin, ranging in size and even color.Penguin Head-Cam Captures Underwater Hunt
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Some penguins receive checkups from tiny robot penguins. This remote-controlled fake penguin's job is to read radio tags placed by researchers on actual penguins.Undercover Penguin Reduces Wildlife Stress
A penguin couple holds hands, or flippers. Penguin couples are monogamous during mating time.
It can vary a bit by species, but wild penguins can live from 15 to 20 years or so.New Penguin Flu Found in Antarctica
Emperor penguin siblings take in the scenery. The Emperor is the largest species of penguin. When these two grow up they'll weigh around 75 pounds and stand about 3 feet 7 inches tall.
Emperor penguin chicks will begin to fledge once they hit about half their adult size.Babies Abound at Penguin Colony Found by Poop
This nest has a mouth to feed. Penguins eat krill, fish, squid and other types of marine life they can fetch while underwater.
This African penguin, found on the continent's southwestern coast, is also called a jackass penguin, although it won't answer to that name.Humans Visit Huge Penguin Colony for First Time
Penguins are quite nearsighted when on dry land. It's underwater where their vision really steps it up. There, they can really hone in on the colors of the ocean such as blue or violet. Such eyesight helps them avoid being eaten by killer whales or leopard seals, their chief predators of the deep.
King penguins, that is. They're the second-largest penguins, after the Emperors.
Penguins do enjoy a crowd. The Southern hemisphere wins the penguin population census. It's tempting to think penguins mostly hang out in Antarctica, but they're actually all over the lower half of the planet, and further north than you might guess. From islands in the South Pacific, to Australia, New Zealand, South America and South Africa, you can find penguins making a living. There are even three species that call places as far north as the Galapagos Islands home.
The temperature in Antarctica can nosedive to -135.8 degrees Fahrenheit, and yet penguins there manage not to ice over due to a combination of attributes that make them “superhydrophobic,” according to new research.
Now that the super water repelling powers of these sturdy flightless birds have been determined, the techniques could be used in future to improve the design of airplane wings, flaps and rudders, which can collect ice and cause planes to crash.
Researcher Pirouz Kavehpour, a professor in the Department of Mechanical and Aerospace Engineering at UCLA, first got interested in penguin feathers while watching a nature documentary.
“I noticed the penguins were coming out of very cold water, and sitting in very cold temperatures, and it was curious that no ice formed on their feathers,” said Kavehpour, who presented his later research findings at the annual meeting of the American Physical Society’s Division of Fluid Dynamics, which is being held this week in Boston.
For the study, he, penguin expert Judy St. Leger, and other researchers used scanning electron microscopy to analyze penguin feathers donated by San Diego SeaWorld.
The scientists discovered that the feathers had tiny pores that trap air and make the surface incredibly water repellent. They also noticed that the penguins apply an oil, which is produced by a gland near the base of their tail, to their feathers. This one-two punch makes the feathers superhydrophobic.
When water meets such a surface, the droplets bead up and can roll off or be shaken away by the penguins. The droplets on the feathers also take on a spherical shape that delays ice formation. That is because heat has a hard time flowing out of the water droplet if it does not make much contact with the surface.
“Heat flow could be compared to traffic,” Kavehpour explained in a press release. “If you have a freeway that turns into a tiny, two-lane road, the traffic will back up. Similarly, heat does not flow well from the large cross-section of the middle of the drop to the small cross-section where the drop makes contact with the feather.”
When the researchers compared the Antarctic penguin feathers with those from penguins hailing from warmer, more northerly climates, they found that the latter lack the small pores. The penguins from warmer regions even use a different type of preen oil that is not as water-repellant.
As for how the findings could be applied to airplane design, perhaps planes in future will be outfitted with similar superhydrophic pitted surfaces and lubricants to prevent ice formation. Currently, chemical de-icers are applied, but the process can be expensive, time consuming, polluting and flawed. Compare that to the ease of penguins, whose feathers naturally keep the iconic black and white birds from becoming living popsicles.
Kavehpour concluded, “It’s a little ironic that a bird that doesn’t fly could one day help airplane fly more safely.”