I'm not an expert on this group of corvids, but I believe that this is a White-necked Raven (Corvus albicollis) based on the placement of the white patch on the base of the back of the neck. Also, this is the most common species of exotic raven in captivity in the U.S. The Thick-billed Raven is very similar and closely related, but its bill is even a little bit thicker (if that's possible) and it has a white patch of feathers on the back of the head even with the eye rather than the back of the base of the neck.