@Cordelia
I live on the southwest side of Los Angeles very near the airport, LAX.
We have many crows flying and calling throughout the day. Usually 4-6, sometimes more. I have left raw peanuts (a pile of 20 perhaps) in the shell at the edge of my yard in the shade of a large cedar bush. I will call to them when they are over head and perched on the street lamp or in a neighbor’s tree. Sometimes I mimic their “caws”. Sometimes I use a turkey call that does a good job mimicking. And then sometimes I just talk to them. My wife is worried that the neighbors will think I’m strange.
‘They will ignore the nuts occasionally. But they are gone later when I come home. Squirrels get some also. Then I’ve had them rush in as a group , raucously vying to see who goes to the pile first. Sometimes they sidle up to the pile and are not sure if they want to partake. Then a more experienced or perhaps bolder individual will walk right up, grab a nut and fly to a perch to eat.
I like crows. They do seem to be warning each other at times. I’ve never seen why. We have opossums, raccoons, feral & domesticated cats, and probably coyotes. But I think theses creatures are almost strictly nocturnal. I assume the crows are sleeping at night. Aren’t they?