The irony was too much: When Pope Francis and two children released two white "peace doves" at the Apostolic Palace in Vatican City on Sunday, the doves were immediately attacked by other birds, losing feathers and being driven away as a huge crowd watched.

Thus, tens of thousands of Tweets and Facebook posts were launched, some of which used words such as "demonic," "omen," and "apocalypse"—and inevitably, of course, referring to "angry birds." What really happened there?

View Images PHOTOGRAPH BY GREGORIO BORGIA, AP

Why did the crow and the gull attack the doves? Because the doves were white. Thousands of pigeons (relatives of doves) live in Rome, as in most cities. They range in color from grayish to brownish to blackish and everything in between. Many other species of birds live in Rome as well, but none are pure white. So if you're an aggressive, badass bird (as gulls and crows tend to be), what's going to draw your attention? The pure-white bird. What's going to be the target of your aggression? The pure-white bird. There's a reason that albino birds (and other animals born without any color pigment) generally don't live long in the wild: They're easily seen, they can't hide, and predators single them out for attack.

What are "peace doves"? Doves have been a symbol of peace for thousands of years, in part because of the biblical story of the ark, in which a dove brought an olive branch to Noah, showing that dry land was near and the terrible flood would soon be over. Christianity, especially, adopted the dove as a religious icon.

Are doves really peaceful? Not particularly. They have weak feet and small bills and mostly mind their own business, walking around eating seeds and the occasional tiny bug. But they're just as likely to fight each other over territory (with lots of wing-slapping) as any other species. I once saw a mourning dove chase a blue jay away from a bird feeder. No wimpy bird gets the best of a blue jay.

Why were these doves white? Because white symbolizes peace, purity, serenity, and other good stuff. But here's the thing: There are no pure-white doves in the natural world. The ones that were released were the result of hundreds of years of domestication and breeding, creating these freakishly white birds for use as pets, and for release at weddings and other ceremonies.

View Images PHOTOGRAPH BY GREGORIO BORGIA, AP

What were the birds that attacked the peace doves? One was a hooded crow, and the other was a yellow-legged gull. Both are very common birds in Europe. The former is related to the American crow, while the latter is related to the herring gull that's so familiar on seashores and at garbage dumps. The crow and the gull are both omnivorous, which means they eat anything from discarded French fries on a parking lot to nestlings stolen from other birds' nests and carrion on a roadside. And both are bold birds well adapted to surviving around people—like, say, in Rome.

View Images PHOTOGRAPH BY GREGORIO BORGIA, AP