It's so fun to learn from the birds!!!
I live in the country in northern central Texas and in the spring/summer have mockingbirds nesting in the rose bushes and trees around my house. The mockingbirds (when nesting) will chase the crows away from the yard/house area.
Then, when the crows are nesting in the pecan & oak trees out in the pastures, they will chase the hawks away. I've seen crows and mockingbirds join forces to harass and chase off the hawks that have come around. Boy they make a noisy fuss!!!
When my chickens were young they didn't understand the difference between the fussy mockingbirds, an upset crow and a hunting hawk, but through time my flock has come to know the difference and come to trust the mockingbirds and crows and listen to their warnings. Yes chickens can learn to understand crow and mockingbird language.
The crows around here seem to migrate in the fall. About 2 weeks ago they started to return, landing and marching about in my coastal hay fields. Every year I have been lucky enough to have them choose to nest in my area. I think the open hay fields, surrounded by the oak and pecan trees, gives them an environment they feel comfortable in. The crows do love pecans!!! I've seen them take a ripe pecan to a fence post, beat it on the top of the post, to break the shell and then pick the nut meat out and leave a pile of shells at the base of a favorite post. I've had neighbors tell me I needed to get rid of those crows....."they're eating up your pecans". I figure I've got enough pecans to share......my crows help me protect my flock.......so I'm happy to share my pecans with them.
The mockingbirds are excellent bug catchers!!! They will not visit a birdseed feeder, they're strictly insect eaters.......they can have all the grasshoppers and bugs they want!!!! A few years ago, as I was sitting on my backporch swing one evening, I saw a mockingbird, sitting on the fence between my house and my barn, become VERY upset!!! It was flying about 5 ft off the ground and fussing at something on the ground.......I went to see what the commotion was about and discovered a chicken snake heading towards my barn.
The mockingbirds and crows help me......so I help them. I believe in the barter system.