I don't believe the coyotes would "wipe out" all of the cats. Maybe a few here and there, but until you have seen a feral cat defend itself, you would think the coyote would have the upper hand. We have a few feral cats out here and they are pretty good defensively. I was out in the feed yard one day a few years back trying to call in a big tom cat that kept killing off my grandpa's barn kittens. I got posted up on a double stack of round bales with a stack of square bales directly behind me, laid out in prone, and started with the rabbit distress. After about ten min I seen a coyote coming in to the call (this is only about 100 yards from our ranch house). I sat there and watched him come in to about 200 yards where he hung up. I started squeaking to bring him in closer (only had my .22) and when I was getting my range finder I noticed that big orange tom cat sitting on an old wire spool about 75 yards out. The coyote had spotted him to and since I had stopped calling he decided to take more interest in the cat. The cat jumped off the spool and started slinking in towards me with the coyote about 10 yards behind, the cat didn't know the coyote was there. They got about 50 yards away when the coyote made his move. The coyote rushed up behind the cat and tried grab it by the back of the neck but missed and rolled the cat. I figured the cat would get up and try to run, but it didn't. The big tom just laid there on its back! The coyote rushed over and was walking around the cat evaluating the situation, he decided to go straight in for the tom's belly... bad move. Quick as lightning the cat swatted the coyote a few times and it's claws got stuck in the coyote's eyelid. When the coyote backed off it carried the cat with it, so here's this coyote about 50 yards out, whining very loudly with a huge orange tom cat stuck to his face biting and scratching with his 3 free legs. I knew I was going to miss my chance so I shot the coyote and dropped him. The cat was still hooked to the yote when he fell over so I ended up shooting the cat also. Neat double huh? I do believe a coyote can kill a cat if they are hungry, but the coyote will also take a whipping in the process. Just my personal experience.