A massive silverback gorilla hurls itself at a mirror left in the middle of the Gabon jungle, perhaps judging his own reflection to be a challenging opponent. Meanwhile elsewhere, chimpanzees stretch, scratch and groom themselves in front of another mirrored glass, lining up around it in an orderly fashion as if waiting for a performance to start. The drastic variation in these reactions tells biologists a lot about how well certain animals are able to recognise their own reflection, an important marker in judging a species’ self-awareness. First utilised in 1969, the ‘mirror test’ is usually conducted on captive animals, so the opportunity to observe wildlife interacting with a reflective surface offers a rare glimpse at previously unstudied behaviour.
French photographer Xavier Hubert Brierre began installing mirrors in the rainforest in 2012, hiding nearby and filming the animals that came in for a closer look. It wasn’t just primates that stopped to examine the strange, familiar-looking creatures that seemed to lurk just beyond the glass. Leopards, elephants and even birds were filmed checking themselves out. Some didn’t seem to connect the movement of the reflections with their own actions, while others repeatedly stroked their fur or moved their arms around, watching as their doubles did the same.
Some animals were so enthusiastic that they smeared grease, mud and blood all over the glass, requiring Brierre and his wife to repeatedly clean the surface to encourage continued interaction. For all of the excitement the mirror incited, only a few animals seemed to realise that they were looking at themselves. This isn’t too terribly surprising, considering that even human babies don’t recognise their own reflections until they’re about 18 months old.
In a classic mirror test, subjects are marked with an odour-free dye on an area of their body that they can’t see without assistance, and then are placed in front of a mirror. If they notice the dye and attempt to remove it, it’s believed that they can distinguish between themselves and others. But not all animals are groomers, displaying concern about the state of their bodies, and results can differ between individuals of the same species. In a 2006 mirror test on elephants in Thailand, just one subject passed, but the other two still displayed some self-aware behaviour, like making repetitive movements while watching their reflections.
Perhaps unsurprisingly given their intelligence, chimpanzees seem the most responsive, with groups hanging out in front of their own reflection for hours. When the mirror was removed they lurked in the spot where it had been, pacing and seemed almost celebratory when it was replaced—leaving one to wonder exactly what mischief these clever relatives of ours would get up to if they were ever given camera-phones and selfie sticks instead.