The slow, waddling penguin, isn't particularly a challenge to observe when on land. But all bets are off once the sleek birds make it to water, where they swim like little feathered rockets. So to get an up-close peek at these birds under the sea, scientists suited them up with cameras, Gemma Conroy reports for ScienceAlert.
Researchers recorded the birds to better understand the meanings behind their various calls. When on land, penguins make all sorts of grunts and squeals to communicate within their colonies, writes George Dvorsky at Gizmodo. They use their “language” to guard territory, attract mates and locate their chicks. In the water, however, Gentoo penguins make a strange buzzing sound while searching for dinner. While researchers believed these noises were likely some sort of communication, they couldn’t figure out just what the penguins were conveying to one another.
That’s why Won Young Lee from the Korea Polar Research Institute and his team attached 'penguincams' to the heads of 26 Gentoos near King George Island in Antarctica. They monitored what happened over the course of two breeding seasons.
Getting a little GoPro-style camera on the 3-foot-tall, 35-pound birds is not as easy at it seems. “It was very sensitive work to place the camera on the penguins,” Lee tells Dvorsky. “This work usually took about eight to ten minutes. Strictly speaking, we did not strap the cameras. We used a waterproof tape (Tesa tape) and put the cameras on the feathers in the back.”
In all, they collected 598 offshore penguin calls as well as images of how the penguins behaved after making the calls. They published their results in the journal Scientific Reports.
What the researchers found after analyzing the videos is that almost fifty percent of the time, the hunting penguins group up within one minute of the call. After that the birds conducted shorter foraging dives and often moved to a new hunting spot. While the researchers didn’t come up any definite reason for the calls, the do have some guesses.
“The calls can help them form a group,” Lee tells Dvorsky. “In a group, a penguin is more likely to find prey. Because Gentoo penguins in our study [are] dependent on Antarctic krill, which are normally found in large patches, it’s beneficial to be in a group to detect these krill patches.”
As Sarah Gibbens at National Geographic reports, it’s unlikely that the calls were warnings that predators are near since the vocalizations are made in the open ocean, while the penguins' most common predators, like leopard seals, tend to stick by the shoreline.
The calls are largely still something of a mystery. Even though the birds form large groups like dolphins and whales, the calls do not seem to transfer info between individuals and do not seem as sophisticated as mammalian calls. “We do not know why these penguins produce calls or how they recognize these calls in the open ocean,” Lee tells Conroy. “We suspect that there are other mechanisms involved in vocal communication.”
Whatever the reason for the calls, Lee’s penguin videos themselves were worth the effort. The footage shows the penguins bobbing in the water and flying through the ocean, gorging on delicious little fish.
This is not the first time researchers have strapped cameras to penguins. A study based on penguin cams released last year revealed the penguins targeted jellyfish with large gonads while hunting. There's no doubt that future camera missions will continue to help unlock the secret lives of these flightless tuxedo-clad birds.