I can tell each one in a minute by their calls. We had more Fish Crows where I lived only 2 miles from here. We are surrounded by ponds, rivers and numerous bodies of water including the Long Island Sound, The Hudson River, The Saw Mill River, The Bronx River and the Hutchinson River. It is exciting to see and hear the American Crow when they do come by and a real thrill to see the RAVEN. The ones I have seen were in pairs and took over the top peak of the Middle School.
I agree, I enjoy crows too and sometimes I scold them when they seem to be complaining or yelling too much. I moved and am in an apartment complex near a McDonald's etc. There were tons of crows but since the storms this past week, they seem to have moved on but the trees were filled with them. My binoculars are not strong enough to differentiate
Snakes and squirrels kill more baby birds or eat the eggs I assume. I have never actually seen a crow's nest but it in my old neighbourhood they loved the highest evergreen trees it seems.I can tell them by their call and when you see a pair of Raven's they are huge around us and rarely appear. Crows are always communicating with each other and I am pretty sure animals and other birds learn their calls generally as danger or hey party, there is lots for everybody here.