Photo by p_adermark.

New in PLoS Biology: European Magpies can recognize their own reflection in a mirror. Self-recognition in a mirror is used as a test of self-awareness in non-human animals, so this suggests that magpies, and maybe other birds, are conscious of themselves as separate from other members of their species.

To see if a magpie knew that a reflection in a mirror was an image of itself, the study’s authors glued a colored paper spot to the feathers below a magpie’s “chin”, then allowed the bird to see itself in a mirror. The magpie would have no way of seeing the spot except in the mirror, so if it reacted to the mirror image by trying to remove the mark from itself, it can be said to have recognized its own reflection. (And, presumably, thought something like “What the heck is this on my chin?”)

The supplementary materials for the paper include a number of videos of the test in action: here’s a magpie reaching for the mark with its foot [.wmv file], and here’s one using its beak [.wmv file]. Black spots, which wouldn’t be visible against the birds’ black chin-feathers, served as a control.

This is the first time that a non-mammal has been shown to be self-aware, and (in this one regard, anyway) it means magpies are smarter than monkeys. (Great apes recognize themselves in mirror tests; monkeys don’t.) It’s also more evidence that what we think of as consciousness, that nebulous quality that separates humans from the rest of the animal kingdom, isn’t as clear-cut as we used to think. Human intelligence most likely evolved by the incremental assembly of different mental skills – including self-awareness, but also tool use and language – that we see in other smart animals.

Reference

Helmut Prior, Ariane Schwarz, Onur Güntürkün, Frans de Waal (2008). Mirror-Induced Behavior in the Magpie (Pica pica): Evidence of Self-Recognition PLoS Biology, 6 (8) DOI: 10.1371/journal.pbio.0060202