The gray wolf, canis lupus, first appeared about a million years ago in Eurasia and migrated to North America about 750,000 years ago. It is not clear how long dogs have been domesticated for but one estimate is about 10,000 years. Characteristically grey wolves have bushy tails and powerful jaws and teeth. Their bite is much stronger than that of a dog and they are more intelligent. An adult male grey wolf will typically weigh anywhere from 35 to 55 kilograms and be up to 2 metres long.
Female wolves are smaller.
Though 'grey' the wolves can range in colour from white in the arctic to black, brown and red. Wolves are very adaptable animals and tend to live in packs ranging from a monogamous pairing of two to a group of twenty but there can be solitary 'lone wolves'. These lone wolves are usually young adults looking for their own territories and mates. Wolves are very sociable and caring for other members of the pack. They have been known to bring food to injured members who are unable to get it for themselves.