Gentoo penguins in the Antarctic spend much of their lives swimming, making it hard for researchers to study their aquatic behavior. To learn more about how these birds communicate offshore, scientists from the Korean Polar Research Institute (KOPRI) attached tiny video cameras to the seabirds and observed them foraging for food in the ocean. The resulting footage suggests that the birds use their vocalizations to stay together in packs while hunting, National Geographic reports.

KOPRI scientists—who recently published their findings in the journal Scientific Reports—monitored 26 penguins over the course of two breeding seasons. Camera microphones captured nearly 600 penguin call events, and the birds' behavior was recorded on video.

Gentoo penguins have multiple types of calls, including food sharing calls, alarm calls, calls to maintain group coherence, and calls signifying “hostile interactions.” After watching the camera footage, scientists noticed that the birds also use certain offshore calls to assemble penguins into packs. This may increase their odds of snaring prey.

“The calls can help them form a group,” Won Young Lee, the study’s lead scientist, told Gizmodo. “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.”

Meanwhile, footage also showed that Gentoo penguins took shorter or shallower dives, and swam to other areas after making calls. This implies that their vocalizations might serve a variety of functions.

In the future, KOPRI researchers hope to use cameras to learn why Gentoo penguins make vocal calls during foraging trips. Until then, you can watch one of their videos below.

[h/t National Geographic]