Went for a walk and saw something...kinda weird. I was out at the stream, watching the usual suspects cavort around the water's edge. A pheobe was doing an odd little dive-and-swoop manuever--it would perch on a log in the water, then hop off, swoop down, splashing the water at the bottom of the dive, then return to its perch. Then it would shake the water off its feathers, perch for a minute, and retreat.
I was engaged by this behavior, when I started hearing the yammering of angry crows. This is usually a good sign that they're making life miserable for some poor predator, and I looked up.
More crows than I've ever seen, a huge flock of what looked like hundreds, but was probably forty or fifty individuals, were swirling through the air downstream. They were making the mobbing call, they were doing the mobbing swoops, but they weren't harrassing a predator.
They were mobbing each other. In little knots of two and three and four, they would break off, mob one crow, and then half the time, the crow who'd done the swoop would end up a little ahead of the mobbed crow, who would then swoop and mob the one that had been attacking it. They were playing a kind of hostile leapfrog. It wasn't just one crow getting abused--they kept breaking off into knots and attacking each other, then merging back into the main group. Occasionally the whole flock would turn and fly overhead to a new chunk of woods, whereupon they would begin hassling each other again.
Their constant alarm calls were making the other birds edgy. The air was full of calls, much more so than I usually hear during the late afternoon, as blue jays and chickadees and nuthatches and flickers tried to make themselves heard over the absolute cacaphony of the crows. There were even honks from the Canadian geese downstream.
This went on for a good half hour. By the time I left, the crows were settling into a few trees, include more crows than I've ever seen in a single pine tree, flailing and charging at each other, still shrieking at the top of their lungs. Occasionally they would all take off from the tree, swirl around dogfighting, and then land again, in very close proximity, snapping at each other around the trunk and hulking along the branches.
As I was walking away, the calls were becoming almost eerily synchronized, like a colosseum crowd shouting for blood.
My only guess--and it's not much of one--is that the lake supports two seperate flocks of crows, adn they were having a territorial dispute of some sort--one that's happened often enough that they weren't actually trying to kill each other, but which required posturing and snapping on both sides.
I'm a nature buff as we all know, and I'm glad that I saw it--it was fascinating--but after a good half hour of listening to angry crows, bits of my hindbrain were starting to get edgy. The sheer hostility of the sounds--even assuming that a lot of it was kind of corvide ritual rather than actual bloodbath--was unsettling. (We're having that oppressive pre-thunderstorm air at the moment, so that probably didn't help, mind you.)