Do Crows hold funerals? Nah, not really, but they're up to something when one among the murder is murdered, and scientists are fascinated by their behavior around fallen comrades.
Calling to each other, gathering around, and paying special attention to a fallen comrade is common among the highly intelligent corvids, a group of birds that includes crows, jays, magpies, and ravens, says Kaeli Swift, a Ph.D student in environmental science at the University of Washington. (See "Are Crows Smarter Than Children?")
But it doesn't necessarily mean the birds are mourning for their lost buddy. Rather, they're likely trying to find out if there's a threat where the death occurred, so they can avoid it in the future.
One study involved using masks to see if crows would avoid humans who handled dead crows (and thereby implicated themselves in the investigation.) They did. On the other hand, if crows are smart enough to investigate murders, maybe they're smart enough to take one look at that mask and think: "OK, that is definitely a murderer."