The Mocking Birds (Florida State Bird) put the Blue Jsys to shame in the aggressiveness department.
They regularly go after the crows, chasing and circling them like fighters going after a lumbering bomber.
I'm pretty sure I lost one of my cats to an eagle about 7 years ago. During a particularly cold winter a pair of eagles came south into my neighborhood.
I had an aging 17 year old cat who was wasting away from hyperthyroid and I was close to putting down disappeared while the eagles were around. She had a pure white coat so no camouflage.
A few days after she disappeared I was sitting on my front step watching my cats eating their dinner when the male eagle flew over my yard no more than 25 feet in the air. He circled.
I chased the cats in the house and came back out to see what he was up to. He landed in the street about 50 yards form my house. I walked toward him and got to about 15 feet away before he took off and soared right over my head.
His wingspan had to be over 6 feet.
Killing a Bald Eagle (National Bird) is a federal offense, nut I would have killed him in a heartbeat for preying on my family if I had gotten the chance.
We had mocking birds in Los Angeles growing up. The cat my family had when I was born was a great hunter. He would go near mocking bird nests and invite them to dive bomb him, then spin around and catch them out of the air just before they hit him. Later we had a neurotic cat who was a terrible hunter. She was just tortured by the mocking birds and had no idea why.
Currently we have a 21 year old cat. He's kept his weight up (around 10 pounds) so he's not great eagle bait, but he also doesn't go out for long anymore either. We have coyotes around here, so I'm careful when he wants to go out at night. A friend of our neighbor had her small dog taken by a coyote while she was walking it and that was only a mile or so from here. I haven't seen any coyotes in the front yard, but they do come up in our backyard. Last year a bunch of them had a bit howl up right outside our back door. I almost jumped out of my skin. There were at least 10 of them.
The eagles around here are more interested in fish than land critters. They have plenty of fish between the Columbia River and several smaller rivers flowing into it.
I learned about the coloring change when we moved here. We saw a number of eagles around that were brown and my SO initially thought they were a different species, but we learned they were just young bald eagles. They turn color about the time they fully mature at 2-3 years of age.
Growing up in the Whittier hills with a whole string of outdoor cats (we would lose them to coyotes on a fairly regular basis), mockingbirds were pests. They would dive-bomb our cats while we were standing a foot away. A couple of our cats were decent hunters and could occasionally catch a mockingbird as s/he pulled out of the dive, but most tried to run and hide.
Coyotes have pretty much overrun most of Southern California in the past 15 years, even heavily populated areas. I nearly ran one over in the middle of the day on a residential street in San Marino. Tired of trash strewn all over the yard, my brother-in-law nailed one with an arrow in Whittier on a recent night; my sister made him clean up the blood (which trailed to a neighbors front yard) before anyone noticed. They couldn't find the body and it hasn't deterred any other coyotes.