We are experiencing huge losses from ravens, as well. Unfortunately, we didn't notice until we had already lost a few dozen chicks (we had a batch of 100 & they run around so much, I don't regularly count them). I saw ravens out by our Salatin-style tractors & figured, like others have claimed, that they were simply capitalizing on another predator's work pulling chickens out from under the tractors.
However, one morning, my husband happened to check before leaving for work & saw the ravens going around the tractor pulling out the 2"x4" blocks we'd placed around the tractor in the dips of the pasture. The ravens were reaching under the edges in the back of the tractor where the metal is, and pulling out whatever body parts were near enough to grab.
They pull off feathers, toes... whatever they can reach. If they can get a good enough grip on something, they'll grab hold & drag the whole pullet/cockerel out from under the tractor and eat it. They're even taking 13 week old birds at this point. One morning, all they were able to get was a few feathers, so they flew into our chicken coop, took 6-10 eggs and smashed them on the floor outside the coop in the middle of the barn. They didn't even eat them. Just made a mess to show they were upset. They're smart & usually fly away before we can get close enough to do anything about them. Obviously, we have some holes to plug up where they are entering the coop/barn and run, but the tractors I'm a little bit stumped! We ordered a dead raven decoy, but couldn't get one to ship earlier than the end of July. They've eaten 80 birds so far up to 13 weeks old.
I understand the skepticism of some here, because I thought for sure it had to have been ravens working with a 4-legged predator of some sort at first, but since they were caught in the act all by themselves I know it's just ravens.
We're working on getting our pasture completely fenced so we can possibly get a some livestock guardians out there. All this just to say, yes, ravens can & do kill - they are not merely scavengers piggybacking on other predators, they are ravenous opportunists and smart enough to figure out ways to hunt & kill.
