RIR's are aggressive as well .
Chickens are at the bottom of the food chain . A rooster can sound the alarm but against most predators he will lose.
I added a Rhode Island Red to my flock of 15 hens and he is ever viligant. Recently I heard him making an unusual call. I looked outside and sure enough, a mid-sized hawk was swooping their favorite day roosting tree. Rex had gotten everyone safely under the coop and he was standing sentry outside of it. He’s huge too!