“Hello”, says a killer whale!

February 02, 2018 12:00 am | Updated 03:34 am IST

In a first, a recent study shows that orcascan make recognisable copies of human sounds

REPRESENTATIONAL PHOTO: REUTERS

REPRESENTATIONAL PHOTO: REUTERS

Have you ever wanted to talk to a killer whale? First, you should introduce yourself by saying “hello”. You might be surprised by what the whale says back.

In a paper published recently in Proceedings of the Royal Society B , scientists report that a 16-year-old orca named Wikie was able to copy a variety of new sounds on command. The study joins a growing body of research illustrating the deep importance of social learning for killer whales.

“We wanted to study vocal imitation because it’s a hallmark of human spoken language, which is in turn important for human cultural evolution,” said José Zamorano-Abramson, who led the study as a postdoctoral researcher at the Pontifical Catholic University of Chile. “We are interested in the possibility that other species also have cultural processes.”

In the wild, killer whales live in tight-knit, matriarchal pods with unique vocal traditions. For decades, scientists have suspected that orcas acquire these dialects through social learning rather than genetic inheritance. Observations of captive killer whales making new calls when moved to a different social setting, or even mimicking the whistles and clicks of dolphins and the barks of sea lions, suggested that might be the case.

This study takes it a step further, providing “gold-standard, controlled experimental evidence” that orcas can learn fresh sounds through imitation, said Luke Rendell, a cetacean and social learning researcher at the University of St. Andrews in Scotland who was not involved in the work.

The research was conducted at the Marineland Aquarium in Antibes, France. After the release of the documentary “Blackfish”, the keeping of killer whales in captivity has come under increasing scrutiny, and the park has faced criticism following deaths of some of its orcas. A French ban on breeding whales and dolphins in captivity has faced legal challenges.

Abramson agrees that new killer whales should not be captured, but noted that those already in captivity would not fare well in the wild. Engaging these animals in research hopefully yields insights that will help protect wild populations, he said.

For their study, Abramson and colleagues trained Wikie’s calf, Moana, to make five sounds outside of Wikie’s natural repertoire, including that of a creaking door, an elephant and a raspberry. Then they instructed Wikie to copy each vocalisation, either by listening to Moana directly or through speakers. Wikie attempted some breathy raspberries.

They also tested whether Wikie could emulate six human words or phrases, including “one two three,” “ah ah” and “Amy”.

The researchers first asked human listeners to judge whether Wikie’s calls matched the ones she was asked to parrot. Then they used an algorithm to evaluate her vocalisations, based on features such as tonality, rhythm and melody contour.

Both human and machine methods deemed Wikie successful at learning the novel sounds presented to her, including those uttered by humans.

“This is the first study to show that killer whales can make recognisable copies of human sounds,” Abramson said, which is unexpected because orcas have very different anatomical structures for vocalisation than us.

Heike Vester, director of Ocean Sounds, a nonprofit cetacean research organisation based in Germany, noted that this research was limited by its sample size of one. While it shows that a captive killer whale can produce novel sounds when trained, it doesn’t reveal how wild orcas use this ability.

Rendell said it is “somewhat ironic” that this study, performed on captive animals, adds to a growing case against keeping orcas captive.

The learning of culture, including vocal traditions, “is a key capability in the intertwining lives of killer whales”, he said, “and one that is critically harmed in captivity”, where animals are isolated and unable to develop the depth of emotions they would in the wild.

Wikie, who was born in captivity, has never acquired the culture she would need to rejoin her wild counterparts, Rendell added. Based on what she has shown she can learn in captivity, we can only imagine what she would have inherited in the wild.The New York Times

POINTS TO PONDER

  • ** Heike Vester, director of Ocean Sounds, a nonprofit cetacean research organisation based in Germany, noted that this research was limited by its sample size of one. While it shows that a captive killer whale can produce novel sounds when trained, it doesn’t reveal how wild orcas use this ability.

  • ** It is “somewhat ironic” that this study, performed on captive animals, adds to a growing case against keeping orcas captive, says Luke Rendell, a cetacean and social learning researcher at the University of St. Andrews in Scotland.

  • HOW WAS IT DONE?

    For the study, 16-year-old captive orca (or killer whale) named Wikie at Marineland Aquarium in Antibes, France, was trained to copy a variety of new sounds on command. Both human and machine methods deemed Wikie successful at learning the novel sounds presented to her, including those uttered by humans.

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