Hooded Crows in North America

The American Birding Association says in 2011 a hooded crow got spotted on Staten Island. There were sightings as far afield as Chicago, Illinois, New Braunfels, Texas and the Salton Sea of California. Are these like captive crows that have escaped? What's their whole deal? Did they go get on spirit airlines and get redirected somewhere where they didn't want to go? We think either they were captive and got released or more likely they got lost and rode ships, like human ships.