We are all fascinated by the intellectual abilities of animals; with the blatant use of personification in
advertising:
movies/stories:
and teaching:
one could rightfully think that deep-down, we all wished our beloved creatures could do the things we see them accomplish in cartoons and storybooks. I’m no different; in fact, whenever I read Bob O’Hara ’s posts or comments, in my head, I imagine The Beast moving his lips and doing most of the talking. So it is easy to understand that when science actually does present us with some evidence that animals are indeed like us (at least cognitively), we get excited. Sometimes I wonder if our excitement goes a little far…
Mirror self-recognition (MSR) as a test for “knowing oneself” was introduced in 1970 by Gordon Gallup when he revealed that chimpanzees can recognize a colored spot placed on a part of their body, only visible with the help of a mirror, is in fact NOT on another animal, but on the monkey looking into the mirror. Many animals have been tested, but only 4 great apes, bottlenose dolphins and Asian elephants have passed this test. Besides humans, of course.
MSR is the gold standard test of self-identity in science and a new member has entered the club. In the most recent issue of PLoS Biology, researchers from Germany present evidence that magpies also recognize themselves in a mirror.
Essentially, the researchers placed a sticker on the black throat feathers of the birds, which caused them to subsequently scratch at the mark until it was gone. This did not happen in the absence of a mirror. Nor did it occur if a black mark was placed on the black feathers (the best “sham” mark used in a MSR test to date, by far.) Thus, there was no choice but to conclude that since the corvids only scratched the non-visible mark with the assistance of the mirror, they in fact understood that they were looking at themselves.
We knew that magpies (and their close cousins, scrub jays, crows, etc…) are smart, with many an outdoorsman providing an anecdote describing how one of these birds successfully opened a zipped pack or saddlebag. But these data shed some new light on the avian world in general, with one of its members possessing the recognition skills of primates.
However, let’s take a closer look at the raw data. Only one of the birds (“Gerti”) was a real pro. Another (“Goldie”) had a decent showing in one trial, but the performance of the other subjects didn’t even come close. So in chimpanzees, while 75% of adult individuals exhibit MSR (ref), we now have 1 (maybe 2) magpies doing this. This is hardly the basis for a broad general conclusion that a corvid species exhibits a sense of self.
For me, the best that we can say about any of this is that there are individual animals out there that seem to be special. Koko the gorilla immediately comes to mind. As does this brilliant beast:
These animals should fascinate us because they are special. But why are so many not that interested in what makes those particular few so special. Why did Gertie the magpie exhibit a strong sense of self while Harvey wouldn’t even enter the compartment with the mirror? Using the surprising gifts of a select few animals to create generalizations about a species’ intelligence seems a bit cavalier to me.
So while I am fascinated with Gertie’s gifts, and excited that it was reproducibly reported, I think that I’ll hold off on bringing the corvids into the pavilion of consciousness just yet.
Prior, H., Schwarz, A., & Güntürkün, O. (2008). Mirror-Induced Behavior in the Magpie (Pica pica): Evidence of Self-Recognition PLoS Biology, 6 (8) DOI: 10.1371/journal.pbio.0060202
Last updated:
Wednesday, 27 Aug
2008 - 04:01 UTC
Very nice blog post, Noah!
I did learn the word “magpie” also. The findings were all over German tv lately, also because magpies or other birds, I forgot, perform amazing intelligence using tools.
What also struck me is: the interpretation which part of the bird`s brain does many of the tricks seems to have changed. It seems to be diffrent and bigger than so far assumed.
Yours friendly
Hans
I was thinking of posting something about Güntürkün’s fantastic work as well. Maybe a good approach would be to look at the percentage of individual animals in a species who can do MSR? My own concept of self is so confused (try to put it in words!) that I have no problems assuming a somewhat continuous measure of “self”. Species in which the concept is closer to ours will have more individuals with MSR, species in which their concept is further away, will have fewer individuals.
I found it very entertaining to have the notion confirmed in the paper that apparently all animals which do MSR do the Marx Brother’s mirror scene to make sure :-)
A nice summary of the work, Noah. Saves me reading the whole thing myself.
I guess that our concept of self is heavily shaped by the type of society we live in. This means that we tend to set up tests for self recognition for other species that would be easily understandable in the context of someone who developed in a human society context, but perhaps not so sensible in a magpie society.
The reproducability was also a problem for tool use in New Caledonian crows I was told today, although this suggests otherwise.
Aw, Nuts, Noah. I agree that a lot of the problems with this kind of study relate to low sample size. However, I don’t think that there is much doubt that corvids are self-aware and have a ‘theory of mind’ — see the work of Nicky Clayton on Florida Scrub-Jays.
Gerti Marx and related blog post.
Hans – The paper does make an interesting point that considering the vast differences in the structure of the avian brain vs. that of a primate, the potential “theory of mind” in the corvids must have an independent neural substrate and correlate, suggesting that being self-aware has independently evolved at least twice.
Mike – It is of course a good point. We actually have no idea what is going on in the minds of any human let alone a bird. We only have reproducibility to hang our hat on, allowing us to generalize about a population even if it doesn’t reflect many of the individual members. So, indeed, the absence of evidence (in this case, the lack of interaction or recognition of the image in the mirror by poorly-responding magpies) is not necessarily evidence of absence (in this case, meaning self-awareness).
Perhaps Harvey was extremely self-conscious and refused to look at himself because he did not want to be reminded of his funny-looking throat feathers…
Magpies are great, although they unfortunately seem to be incapable of winning any trophies.
[EDITOR’S NOTE: The reference at the beginning of Henry’s comment refers to this post and this comment.]
It’s nice that we do seem to have two independently-evolved systems – this will make discovering how they work easier and more interesting, and perhaps cheaper and freer if we can investigate things in crows we thought needed dolphins or apes for. It also tends to suggest that alien life forms (if any) might well share some of our mental features, so long as it’s not too important that we and magpies started from the same joint ancestor. (On bird brains, Koch says birds have brain cells one third the volume of mammals’, so we might have to re-think our indices of cranial comparison.)
When you put a black patch on a magpie that it can’t see, it’s important to remember that even humans can detect three types of pitch black on their plumage (matt on the head and neck, and two shades of iridescence) and besides, the bird might even see something beyond our spectrum!
With land species, the ability to understand a mirror migt have some evolutionary involvement with water, but dolphins presumably don’t see mirror images of themselves since the surface of the water above them won’t(?) reflect back at the right angle, though they might see others reflected. (They might see themselves very fleetingly when jumping, and their ancestors presumably saw reflections, but before they’d gained the dolphins’ mental abilities.)
I can’t agree with: “We actually have no idea what is going on in the minds of any human let alone a bird.” ! “No idea” is going a bit far!
Dear Björn,
you wrote:“My own concept of self is so confused (try to put it in words!) that I have no problems assuming a somewhat continuous measure of “self”.”
Not sure if I get you right. Anyway, those birds do not seem to have much problems about self like humans possibly or apparently have.
Self basically means to be inside that body! And MSR thus means to recognize that that awareness that is in that body is seeing the mirror image of that body in the mirror.
Self thus is defined simply via the body and the inside of the body residing awareness.
Maybe we should learn from those birds not to make so much fuss about what kind of self we have… ;-)
Yours friendly
Hans