A beluga whale named Natasha stretched her neck, pirouetted, nodded, and shook her head in front of a two-way mirror at a New York aquarium. Her daughter Maris did much the same. Researchers watching hours of underwater video footage say both animals showed the behavioral hallmarks of mirror self-recognition, a cognitive ability that had never before been documented in beluga whales.
The findings were published in the journal PLOS One. According to a report by Ars Technica, the result would place belugas on a remarkably short list of species that have passed the mirror self-recognition test, or MSR test, with any degree of confidence.
That list currently includes humans, who typically develop the ability starting around age two, a handful of great apes including chimpanzees, bonobos, and orangutans, Asian elephants, bottlenose dolphins, probably magpies, possibly orcas, and a cleaner wrasse fish. Dogs, cats, and monkeys have been tested and failed. Many species long assumed to possess some form of self-awareness have not cleared the bar.
The test itself works like this: while the animal is not looking, researchers place a visible mark on a spot the animal can only see by looking at its own reflection. A mirror is then placed in front of the animal. If the animal touches or examines the marked spot while viewing its reflection, the conclusion is that the animal understands the figure in the mirror is itself, not another individual.
The logic behind treating this as a test of self-awareness goes back to psychologist Gordon Gallup, who invented the procedure in 1970. His argument was that using a mirror as a tool to inspect your own body requires a mental representation of yourself as a distinct entity. The test is straightforward to set up and simple to observe, which is part of why it has been used so widely. It is also part of why so few species pass it.
Natasha and Maris were observed displaying behaviors consistent with self-directed use of the mirror, including movements that appeared to be deliberate self-inspection. The study, published in PLOS One, documents these behaviors as meeting the recognized criteria for mirror self-recognition.
The result carries a caveat that researchers and observers have debated for years. The mirror test was designed with human and great ape cognition as the baseline. Some scientists have raised questions about whether the test reliably captures self-awareness in animals whose sensory worlds differ substantially from our own. Dolphins and belugas, for instance, rely heavily on echolocation and acoustic perception rather than vision. A test built around a reflected visual image may measure something other than what it claims to measure, or may undercount species that are self-aware in ways the test cannot detect.
Still, if the beluga result holds up under further scrutiny, it extends the known boundary of mirror self-recognition into another branch of the mammal family tree and adds new data to a long-running debate about where, and how, self-awareness evolved. The two whales at the center of the study, Natasha and her daughter Maris, remain at the aquarium where the footage was recorded.
