I wrote about birds and mirrors a while ago, and not much has changed scientifically since then. Most bird species tested have interpreted their own reflections as other individuals, responding either with aggression or courtship. Female pigeons who view their own reflections ovulate, apparently interpreting their reflections as suitable mates. Among birds, only magpies, so far, have been demonstrated to understand that the mirror reflects their own image, although pigeons can be trained to use spatial information from mirrors correctly in the real world.
So why bring this up again? Recently I saw a Yellow-rumped Warbler interacting with its reflection in a car side mirror, and took a video with my phone. Here it is (apologies for the lack of zoom):
At the time I took the video, I didn’t think much of it beyond general amusement. But rewatching it, I began to have some questions.
Since several people have contacted me to defend junco intelligence after the mirror post yesterday, I thought I might talk a bit more about birds and mirrors.
Very, very few species understand mirrors, and an enormous majority of them behave as if the mirrored images are real, as the junco did. The list of birds that do not recognize themselves in the mirror is long: Budgerigar; House Sparrow; Kea; Black-capped Chickadee; Zebra Finch; Cedar Waxwing; Glaucous-winged Gull; Blue Grouse; Peach-faced Lovebird; reviewed in (1). In 1964, Edith Andrews kept an injured junco in a cage with a mirror and observed that it was quieted by the mirror, liked to perch next to it, and “appeared to be smitten with its own image” (2).
The other day I saw a junco perched on the ledge of the front side window of a parked car. As I watched, he flew at the side-view mirror, a full head-on charge. When that didn’t seem to work, he sat back on his perch on the window, looked at the mirror, and charged again. And again. When some people passing by scared him up into a tree, he waited until they were gone, and then he flew back down and resumed his attack. He was really determined to win this fight against Mr. Uppity Mirror Junco.
I’m hoping this was a fluke. No one wants to think that their study species is dumb.