Whether or not they did that doesn't matter, because at best that would just prove that crows can or can't distinguish one particular mask of a certain type from another mask of the same type. This would have absolutely no effect on the experiment's conclusion that crows rely on facial features to recognize individuals, therefore it is irrelevant to the experiment, therefore no one cares.

Also, no offense intended, but "I'm an amateur programmer" is just one step above "I stayed at a Holiday Inn last night."

Der, stars.

So if they reacted to one mask and not to another that looks exactly the same, that would have no impact on the theory that crows react to facial features? Because it seems like it would to me.

And I mentioned the programming thing because I wanted to give perspective to my question; I'm asking because it would seem natural to me to eliminate as many variables as possible, and it's possible that crows could, let's say, go by smell and mark the mask somehow. But yet, I secretly knew someone here would take that as posturing.

If you had two masks that rolled off the same factory line and seemed to look identical, and the experiment showed that the crows responded to one mask but not the other, that would just be bizarre. It could mean that the crows can differentiate the masks by smell, or it could means that the crows are differentiating them by sight; but in no case would that one additional piece of evidence, either by itself or in conjunction with the other evidence presented here, give you any substantive basis on which to accept or reject their conclusion. That's what I meant when I said it was irrelevant to the experiment.

As for the crows using smell and not sight to identify the mask, we can probably rule out that hypothesis: because when the masks were rotated to be upside-down, the crows could be observed flying upside-down in response. It's hard to see how that would benefit their sense of smell, but it makes sense in terms of what we know about the neurology of vision and in particular face perception (in mammals, anyway - I know little about avian vision, to be honest).

If I wanted to raise an objection to this experiment, it would be that it might not have been blinded correctly, since it would be easy for any experimental observer to notice the Dick Cheney and caveman masks. (Honestly, blinding an experiment like this seems like a BITCH.)

Typos, drunk, natch.

The smell thing is just an example I constructed off the top of my head; I wasn't actually proposing that it could be true. Is it really standard practice for scientists to dismiss the relevance of variables because there's no reason they can see for it to impact the findings? That seems absurd to me.

The researcher probably was not paying attention to the alignment of the stars that day.

Let me try a different tack. Assume crows CAN tell "identical" masks apart: What conclusion can you possibly draw from that? By itself, that fact doesn't tell you if the crows are distinguishing the masks on the basis of smell or some small variation in color; either assumption could explain the result. The purpose of a scientific experiment is to generate a result which is impossible according to one of two competing hypotheses; but the test you propose, regardless of its outcome, is compatible with both hypotheses that were tested in this experiment. Therefore this test would not be useful.

For contrast, compare the test where they reversed the mask: it generated a new response from the crows that was ONLY sensible if you assume that the crows are using vision to recognize the mask, since vision is the only sense that would be affected by the crow's behavior. Therefore that test DID yield useful information which allowed the researcher to exclude certain hypotheses.

If my answer STILL doesn't make sense, please consult the first chapter of any decent, college-level introductory science textbook. Every single one of them starts with a discussion of exactly this topic.

Terminology Nazi! Or if you would prefer, terminazi.

Redlof beat me to it.

Would you call this the Nazi paradox?

crow racist