Crows are territorial and they recognise people. So if you visit the same location for a while and you are nice to the crows there (I always talk to them), maybe bring them something to eat, they will remember you and become less skittish. The crows that know me often come within MFD of my 300/4. I haven't shot them in ages, but here's an oldie of a crow that became a real pal. I was sitting in the grass and he was literally at arm's length. Taken around dawn.
I love the corvids - this is enchanting. Love the details in the feathers and the advice how to make friends.