The core members of a wolf pack are called the alpha male and alpha female, while other members of the pack are called subordinates. The second in command is referred to as the beta wolf. Research suggests there are male and female beta.
This hierarchy exists mainly in groups of wolves, or packs, in captivity. In the wild, a group of wolves normally consists of the alpha male and female, along with their pups from various years of mating. On occasion, a less closely related wolf may join the pack. Alpha wolves are aggressive and typically have higher levels of stress hormones than subordinates. The lowest ranking wolf in a pack is the omega.