Corvids – Ravens And Crows. Raven or Crow..the more you know, the better. While neither is permitted in the U.S. as a pet, without a special permit, they are ubiquitous and scavengers, with distinctive calls and differences. Ravens are much larger, and much more likely to do acrobatic flying maneuvers. Check out this Audubon article for more details. In the meantime, ask yourself whether you are a good steward of the planet for our flying friends.