I once witnessed a running battle between a peregrine falcon and a raven, nearly twice the falcon's size.
Just when you think you've seen all the odd things nature has to offer, along comes another unexpected phenomenon. And this happened just one week after I had witnessed an equally bizarre fight between two equally bizarre contenders, but that's another story.
I was hanging out on top of Frankenstein Cliff with a few other hikers, when we became aware of some commotion above the trees to the north. Before long, the commotion spilled out beyond the cliff-face to the west of us. A raven (Corvus corax principalis) and a male peregrine falcon (Falco peregrinus) were scuffling with each other.
We hikers had a spectacular view, as the battle raged through the empty air before us. The birds were just a few feet higher than the ledge, but several hundred feet above the forest below. As they fought, the two birds crossed from west to east, dropping from slightly above us right down to eye level. They scratched and pummeled each other with their feet, they pecked each other on the head, breast, and wings. Once in a while, one would cuff the other with its wing, but it was hard to tell whether that was an intentional blow, or just an attempt to stay airborne. Then, abruptly, they broke off and returned separately to the forest to the north, behind the cliff.
One of the observers said that it couldn't be a falcon because it was too small. Well, a peregrine falcon is not terribly large as hawks go, and is indeed considerably smaller than a raven.
Just as in the improbable hawk/woodpecker fight I had witnessed a week earlier, I had to wonder why these two birds were fighting.
Falcons feed on other birds, as well as small terrestrial animals, but a falcon would never see a raven, twice its own size, as prey, would it? And even if it were attempting to take a bird larger than itself (as they often kill ducks which outweigh themselves), it would arrange the hunt in such a way as to use its advantages. It would climb high above the intended victim, then stoop into a dive at blistering speed to kill the prey before it knew it was being hunted. Why would a falcon attack a larger bird at slow speed and at its own level? No, the falcon was not attempting to prey on the raven.
But why would a raven pick a fight with a falcon? Ravens often harass raptors, but only those that are larger and less agile than themselves, such as large owls, eagles, ospreys and other large hawks. Not smaller, more agile raptors like falcons. And the reason they harass raptors is to drive a threatening bird away from their territory, especially when they have nestlings.
Just as I had in the hawk/woodpecker fight, I concluded that this was a case of one bird raiding the nest of another, and the other bird defending its eggs or chicks.
A falcon, like any small hawk, will raid the nests of other birds. I can easily suppose that the smaller male falcon, desperate to feed its hatchlings, would be especially eager to take an easy meal of nestlings from an unattended raven's nest.
But ravens, too, are notorious nest raiders. They will take the unguarded eggs or chicks of any bird if they get half a chance.
So, just as in the hawk/woodpecker fight, I was not sure whether the raven was defending its chicks from the falcon, or the falcon was defending its eggs or chicks from the raven.
I'm not sure what, if anything, to infer from the absence of the female falcon. Was she remaining on the nest while the male drove the raven off? Or was her absence a clear indication that the male falcon was the raider here, and the female falcon was not even aware of the confrontation? I don't have enough information to make a good guess.
Less than a minute after they disappeared, the falcon and the raven were back, sparring in the sky to the east of Frankenstein Cliff, toward the main valley of Crawford Notch. They were more distant from each other now, circling for advantage. The falcon was somewhat higher than the raven, and trying to climb higher. The raven followed, using smaller circles so the falcon could never get out of his sight. A few times, the falcon swooped toward the raven, but he could never get a real speed advantage, and the raven always managed to dodge the falcon's charges, occasionally striking out with a claw as the falcon passed.
The battle dragged on, moving ever higher and ever farther south, until the combatants were nearly out of sight. I wasn't quite sure, but I thought I saw the raven break off and dive for the cover of forest near the braids of the Saco River just north of the village of Hart's Location. By this time, I couldn't see the falcon at all, but the straight dive of the raven indicated to me that the fight was over.
And to think that I saw it on Frankenstein Cliff!