That’s wonderful, and interesting observation with aerial predators.With roos, I don't get low hawk fly-bys buzzing the coop and foraging area. That degree of boldness from hawks ended when I got my first roo and they stayed much higher up. Unfortunately when he passed away (nothing to do with predators) the hawks started buzzing the coop area again. With his sons grown up, the hawks stopped again. While not a total guarantee, I do feel my roos have lowered the aerial threat level. Obviously this will not be the same in all situations.
Also watched my original roo keep a fox from testing the enclosure or trying to dig. I do think the enclosure would have held up just fine, but his striking at the fox kept it from being able to get in close to have a try. His sons also put a stop to an annoying cat that kept coming through every so often and harassing the flock in their enclosure.
My current roos have herded the flock away from snakes on a number of different occasions. Snakes aren't something that comes up much in the topic of predators, but they can still be a problem. This morning they got the hens away from an aggressive one that was giving me problems (got a whole different thread on that). After the main flock was moved away, one of my roos went running around very obviously looking for his chicks even though they only go outside for about half an hour each day; he checked the empty chick tractor over and over again.
One of my roos bites when he's frustrated/confused about what's going on, but he's getting better about it. He puts a lot of effort into keeping the flock together when foraging and follows voice commands for a few things so I will take the occasional nip in exchange for that. He has also stopped a vision-challenged hen I have from doing a runner into the forest when she's been spooked by things.
My gang relies more upon the Blue Jays, Crows, and Ravens for aerial predators, and also foxes - a crow was pitching a hissy fit, and I thought it was being silly. But it kept circling and buzzing a spot in my paddock, then I saw the Fox. My Roo saw it the same
time also, he called the alert and everyone bolted for the barn.
I encourage the Crows and Blue Jay esp to hang around. And I notice the Roo listens to them and will check to see what they are going on about.