Whales kept in captivity are able to shape their "melon" into at least five different forms.

The beluga whale displays its heart on its forehead, or more appropriately, its sleeve.

Utilizing their highly mobile "melon," a squishy deposit of fat on the forehead that aids in directing sound waves for echolocation, researchers have produced a visual encyclopedia of the various expressions that belugas (Delphinapterus leucas) in captivity seem to make.

To create an impressive fleshy top hat, belugas skillfully lift their melon vertically, squish it down until it flattens against their skull, stretch it forward until it juts over their lips like a cap's bill, and then shake it with such force that it jiggles like Jell-O, all through the use of their muscles and connective tissue.

According to Justin Richard, an expert in animal behavior from the University of Rhode Island in Kingston, if that doesn't scream "pay attention to me," he's unsure what would. He continued, It was like seeing a peacock spread its feathers.

Richard worked closely with the enigmatic belugas at the Mystic Aquarium in Connecticut for ten years as a trainer before pursuing a career in science. Even as a trainer, Richard claimed to have understood the significance of the forms. However, no one had been able to piece together enough observations to make sense of it, he said.

Richard and his colleagues carefully observed the interactions between four beluga whales at the Mystic Aquarium over the course of a year, from 2014 to 2015. The scientists named the five unique melon forms the belugas make—flat, lift, press, push, and shake—after analyzing the video. The team reported in Animal Cognition on March 2 that, during social interactions, the belugas displayed an average of about two behaviors per minute.