Belugas Pass the Mirror Test. The Mirror Test Has a Problem.

A new study published in PLOS One reports that two beluga whales may have recognized their own reflections, using a mirror to investigate their own bodies. The findings are genuinely interesting. The mirror-related argument that follows the findings is arguably more so.

Researchers conducted the study with four captive female belugas housed at the New York Aquarium, observing behaviors they describe as "contingency testing" — unusual or repetitive movements designed to test whether the whale in the mirror was mimicking them. During their second session, two of the whales, Natasha and her daughter Maris, began approaching the mirror and exhibiting new behaviors: peering inside their own mouths, watching themselves do barrel rolls, flapping their pectoral fins, blowing bubbles and biting them.

Then comes the mark test, which is where it gets complicated. Natasha passed by orienting the marked area of her body toward the mirror. Maris did not pass any of the mark tests, though the range and novelty of her self-directed behaviors at the mirror led researchers to treat her case as inconclusive rather than negative.

The experiments took place roughly 25 years ago at the New York Aquarium and are only being published now because the video data wasn't fully analyzed at the time. A beluga has been waiting two decades to find out if she passed.

Here is the real wrinkle: neuroscientist Anil Seth of the University of Sussex has argued that the mirror test measures a specific type of bodily self-recognition rather than consciousness itself, and that the test is built around assumptions that fit some animals better than others. His broader critique is that the test was never as species-neutral as its designers believed.

Natasha's clearest mark-directed behavior was pressing the marked area behind her right ear against the mirror. Without arms, she couldn't point. It's the strongest data point in the study, but a softer kind of evidence than a chimp or an elephant typically delivers.

A cetacean echolocates her entire world in three dimensions; the fact that she engaged with a flat reflective surface at all is a remarkable finding.

Read the full story at Ars Technica, May 2026

Hot Take: Natasha pressed her ear against a mirror to investigate a mark she couldn't see any other way, which is exactly what a self-aware animal without arms would do, and the field's response was to spend two decades not analyzing the footage.