‘Talking’ Orca Learns To Mimic Human Speech
We know that parrots, corvids and other birds can mimic human speech, but now you can add a mammal to that list: A captive orca has been taught to mimic human words by blowing air through her blowhole
Parrots, corvids and a variety of other birds aren’t the only animals that can mimic human speech. According to a study published today, an orca, Orcinus orca, has been trained to mimic human speech (ref). The female orca, named Wikie, was captive-born at Marineland in Antibes, France, where she still lives. Wikie has been recorded repeating the words, ‘hello’ and ‘bye bye’, counting up to three, and she even has been recorded saying ‘Amy’, the name of her trainer.
“Although the ability to copy sounds from conspecifics is wide-spread in birds”, the authors write in their paper, “it is strikingly rare in mammals, and among primates it is uniquely human.”
Wikie’s abilities don’t stop there: she also twitters like a bird, squawks like a parrot, and blows raspberries — lots of raspberries, actually — which she is quite skilled at producing and seems especially fond of.
Wikie’s accomplishment is remarkable because whales create sounds by producing bursts of air that pass through their nasal passages — somewhat like a human blowing his nose — whilst humans rely on the larynx, or “voice box”, and a number of other physical structures, like the tongue and lips, to speak.
More remarkable, Wikie produced airborne sounds, whilst partially submerged in water with her blowhole exposed to the air, despite water being the medium typically used by orcas for acoustic communication.
Cetaceans — whales and dolphins — are one of the few mammal groups that are capable of learning and then producing specific sounds. Humpback whales and their eerie songs are a particularly famous example of this. But it’s unclear where this ability originates: Orca calls are not wholly inherited genetically. The evidence indicates that orca calls are also influenced by their environment. For example, orcas have been heard imitating the sounds produced by orcas from different groups (or “pods”), the barks of sea lions, and the whistles of bottlenose dolphins.
Further, scientists have long known that whales have recognizably different accents. For example, families of several wild cetacean species, including orcas, share their own special sounds that are substantially different “dialects” from the calls and clicks produced by other family groups of the same species, and they use these sounds to communicate and coordinate underwater over long distances. In bottlenose dolphins, some whistles may even be names for particular individuals.
Thus, the most widely accepted explanation is an orca’s vocal repertoire is the result of social learning, particularly imitation of other members of its pod. This study suggests that these differences are learned when young whales imitate adults in their family groups, similar to how human children learn to speak by copying those around them. But this idea has not been formally tested, until now: This is the first time an orca has been trained to repeat novel sounds from another orca, and even human speech sounds given by a human, using a controlled series of experiments.
To train Wikie to repeat sounds, she first was taught a signal to “copy” a particular behavior, then she was asked to “copy” 11 different sounds. Five of these novel sounds where produced by another orca, named Moana, who was trained to produce novel sounds that Wikie didn’t know until the test, and the other six sounds were human words given by her trainer. Some of the sounds that Moana taught Wikie were a wolf howl, an elephant call, a creaking door — and a “soft” and “hard” raspberry. After learning to produce these new sounds, often on her first try, Wikie was recorded and six human judges who didn’t know which sound was the copy, were asked to determine whether her sounds matched the original.
Wikie was judged capable of matching both Moana’s sounds and human speech, and waveform and spectrogram analyses showed that three of Wikie’s words were a “high quality match” to the originals.
These findings are also interesting because Wikie was 14 years old — an adult — when she learned to imitate these sounds. (Wikie is now 16 years old.)
“It means that killer whales [another name for orcas] have evolved the ability to control sound production and qualify as open-ended vocal learners as other cetaceans, like belugas and bottlenose dolphins”, said lead author of the study, comparative psychologist, José Zamorano-Abramson, who was a postdoc at Universidad Católica de Chile whilst this work was done. Open-ended learners are species that can learn new sounds throughout their lives. (This is in contrast to closed-ended learners; species that can only learn new sounds within a short time frame, typically as juveniles.)
“Our results lend experimental support to the hypothesis that the dialects observed in natural populations of this species can be socially learned by imitation,” explained Dr. Zamorano-Abramson in email.
Captive whales of other species have also learned to imitate human voices, as demonstrated by “NOC”, a wild-born beluga whale, Delphinapterus leucas, who lived for 30 years at the National Marine Mammal Foundation in San Diego until his death in 1999 (ref). This whale spontaneously learned to imitate human speech so convincingly that human divers responded to his vocal requests to get out of his tank before they realized that it was NOC who was doing the talking.
This raises the question: why would an orca imitate human voices? I think this has something in common with many birds, and is a product of these animals’ natural history and high level of social intelligence. Like many birds, whales use sounds to communicate over long distances with others in their family groups, and like parrots, they may give each other individual names. Thus, sound is a way to maintain family groups, or to communicate with one particular individual, so it stands to reason that they use specific sounds to identify and communicate with members of their family groups when they cannot see them. This would explain why NOC learned to mimic human speech on his own rather than through any formal training: he was learning to produce his social group’s sounds.
“It could mean that cultural differences like dialects can drive the evolution of the species, as we see between ecologically divergent killer whale populations that have resulted in sufficient reproductive isolation despite sympatry to lead to incipient speciation,” added Dr. Abramson in email.
“For example killer whales that produce very different dialects don’t interbreed despite their living in the same geographic area, and this culturally driven social isolation may give rise to genetic isolation and incipient speciation [where] different groups or populations of the same species might end up splitting into different subspecies.”
This effect of dialects also is seen amongst some songbird species.
The ability to communicate using specific sounds that have been learnt from others in one’s social group is fascinating because humans are the only primates with this ability, suggesting this trait arose some time after humans separated from the other Great Apes approximately 5 million years ago.
Does Wikie understand what these words mean, as at least some parrots do (ref)? This study was designed to determine whether whales can actually mimic human voices and other novel sounds, so there is no evidence at this time that Wikie attaches any specific meaning to specific sounds, although she clearly uses these new sounds to get what she wants.
“Wikie loves inventing new games with the trainers to get their attention around the pool, like splashing trainers for fun or sticking out her tongue to trainers,” Dr. Zamorano-Abramson wrote in email.
“After the imitation experiment, she used all the vocals to get the trainers’ attention, so we ended up with an orca making all these crazy sounds all day.”
José Zamorano-Abramson, Victoria Hernádez-Lloreda, Lino García, Fernando Colmenares, Francisco Aboitiz and Josep Call (2017). Imitation of novel conspecific and human speech sounds in the killer whale (Orcinus orca), Proceedings of the Royal Society of London B: Biological Sciences, 20172171 | doi:10.1098/rspb.2017.2171
Irene M. Pepperberg (2010). Vocal learning in Grey parrots: A brief review of perception, production, and cross-species comparisons, Brain & Language, 115(1):81–91 | doi:10.1016/j.bandl.2009.11.002
Sam Ridgway, Donald Carder, Michelle Jeffries, and Mark Todd (2012). Spontaneous human speech mimicry by a cetacean, Current Biology, 22(20):R860–R861 | doi:10.1016/j.cub.2012.08.044