Size: 26-32 inches tall at the shoulder; 4 1/2-5 1/2 feet long; 60-80 pounds; about the size of a German shepherd dog.

Diet: Mostly large, hoofed animals such as deer and elk; also known to eat wild pigs, rabbits and ground squirrels.

Conservation status: Critically endangered. The Mexican gray wolf is the most endangered of all North American gray wolf subspecies.

At the Minnesota Zoo: Before Wednesday, the zoo had three of the animals. The zoo's Mexican gray wolves are part of a species survival plan, of which the goal is to breed and raise wolves for reintroduction into the wild.

Sources: Minnesota Zoo, Defenders of Wildlife, mexicanwolves.org