'Penguin Cam' Reveals Penguins Hunting Underwater
You can now see what the world looks like to a penguin as it hunts underwater.
Cameras temporarily taped to little penguins in Australia provide a rare look at how they hunt underwater, revealing what they like to eat.
Analysis of the footage, outlined in the journal PLOS ONE, also yielded a surprising find: although the little penguins (Eudyptula minor) often hunt together in groups, this behavior did not offer much extra nutritional benefit to them. In fact, they enjoyed better meals when foraging on their own.
"This study showed little penguins gained no benefit in capturing prey when from hunting in groups, suggesting individuals may forage in groups to improve detection of prey or avoid predation but, once they find prey, it is every penguin for themselves," lead author Grace Sutton of Deakin University said in a press release.
The study was conducted at two breeding little penguin colonies located in southeastern Australia: London Bridge and Gabo Island.
Sutton and colleagues Andrew Hoskins and John Arnould got the footage by taping "penguin cams" to the bodies of the small flightless birds. The cameras were very lightweight and small, so as not to impede the penguins' movements. The cameras were also simply taped to the birds' bodies, and were then removed after a single foraging trip per penguin.
Many of the penguins, as Sutton indicated, hunted in groups. She and her colleagues suspect that fear may drive this behavior. The penguins themselves don't want to be eaten by predators, so it is a bit safer for them to be in a group.
In addition to more eyes, ears and other senses detecting predators, all of these senses could also improve finding prey, which might save an individual's energy.
The authors could see no signs that the penguins were coordinating their moves to improve prey capture, as some other marine species, like whales and dolphins, are known to do.
However disorganized their hunting groups were, the little penguins predictably went after large schools of fish when behaving in this manner. Their favorites appeared to be anchovies and a fish called "sandy sprat," or white pilchard.
The little penguins also enjoyed munching on small shrimp-like crustaceans called krill.
The penguins were additionally spotted eating a lot of jellyfish, which has not been reported much before. The researchers suspect that the jellyfish's "rapid deterioration means that they may often be overlooked in diet studies." In other words, there is not much to digest, so once a jellyfish is eaten, there is little evidence of the unfortunate victim left behind.
The researchers continued, "In the present study, individuals were observed to consume both whole small jellyfish and the inner portions of larger jellyfish, which are the most nutritious components."
Other than that, jellyfish are like the junk food of the sea, at least for penguins, the scientists indicate.
They explained, "While jellyfish are relatively easy to capture due to their slow mobility, they are generally of low nutritional content."
Jellyfish might also be tasty to the little penguins, but the palate of most animals, even widely studied ones like dogs and cats, largely remains a mystery. Nevertheless, the latest study provides a clue: Sutton and her team determined that 28 percent of all observed consumed prey items were jellyfish.
In future, the researchers hope to learn more about little penguin social dynamics, such if individuals preferentially choose whom to associate with when hunting, and for how long they might do so. The answers to such questions could shed light on the optimal ways that many group-living predatory species, not just these penguins, maximize their energy conservation and fitness.
This is a video still of a little penguin hunting fish.
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!
Once waterbound, penguins are fantastic swimmers that can zoom through the ocean at some 15 to 20 miles per hour.
There are 18 species of penguin, ranging in size and even color.
Sometimes they're blue.
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.
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.
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.
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.
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.
Should this gang on the ferry ride decide to go for a swim, they could stay underwater for about 15 to 20 minutes and go as deep as nearly 300 feet (91 meters).