sometimes you can't help but approach science in a posture of wonder:

Did you know that crows recognize human faces? To prove this, she writes, a researcher at the University of Washington conducted an experiment. Volunteers who had captured and banded crows (something crows resent) while wearing caveman masks were cawed at and dive-bombed whenever they re-entered crow precincts.  When the same volunteers walked through the crow zone with their faces hidden by Dick Cheney masks, “the crows left them entirely alone.”

i would like to think that the scientists chose caveman and cheney masks out of a kind of magical-realist whimsy. but no doubt there were rigorous scientific standards that could only be upheld with these particular apparati. the proof does not appear entirely decisive, however: maybe crows don't like fake beards. or lowering brows. maybe crows recognize dick cheney as a carrion feeder like themselves. maybe the crows were in a better mood later on. or maybe masks are not, after all, human faces. other than that and a thousand other little problems, however, the research is rigorous and the results decisive.