Hi John. For crows, no. But watch your local bylaws re: discharging a firearm.
As for squirrels, if you mean red squirrels or Douglas squirrels you are NOT allowed to hunt them, they fall under the category of "furbearers" of which you are only allowed to hunt wolf, coyote, bobcat, lynx, bears, cougar and skunks and racoons, as well as some species of rabbit and hare, for all of which you will need to have hunting license (except for skunks and racoons, but that may have changed). Squirrels, foxes, martens, weasels, fishers, mink, beaver, muskrat, etc. can only be trapped for which you would need a trapping license.
Pick up a copy of the BC Hunting regulation synopsis and give it a carefull reading, more people should.
Cheers,
Ian