Not the game—real angry birds. You may not always notice angry birds, but they are all around you. Birds mob other (usually larger, threatening) birds, flying at them and even hitting them. Imagine if mice got together to run headfirst into cats…
(Actually, I know some cats that might be scared of those mice. You might call them scaredy-cats… Don’t hurt yourself laughing at my witticisms.)
Birds also fight others of their own species. Physical fights are pretty rare: birds usually try to work their fights out using “words not fists”—or rather, song not violence. Birds will usually start with songs and calls, then escalate to threatening postures and movement, and only if none of that resolves the issue will they fight. Recently, I watched a Snowy Egret face what I think must have been an intruder on his territory. First he called. When the intruder didn’t leave, he raised the crest on his head high and flew at the intruder, chasing him away.
Compare the silhouette of the intruder:
with that of the threatening bird:
Birds frequently use communication to avoid dangerous physical fights. In this case, the communication worked: the egrets didn’t have to fight.
But birds do fight. In Central Park one winter I watched a pair of male House Sparrows tackle each other in mid-air, fall to the ground, and roll around in a tangle of clutching feet and fluttering wings. About a dozen other sparrows gathered to watch, as if it were a sport.
Ornithologists encounter a lot of angry birds. Stick your hand in a House Wren’s nestbox to count the eggs, and enjoy the furious chattering she will direct at you, bouncing around inside a bush, practically bursting with indignation. Some juncos will start scolding you when you’re still a few meters from the nest, which can be a great way to locate their nests! Birds get even angrier when you catch them—although it depends on the bird. Sparrows and thrushes seem to be fairly zen about being handled, while chickadees will peck at you like crazy.
That’s a funny thing about being an ornithologist: I do this work because I love birds, but the work makes a lot of birds really, really hate me.