A small population exists in Mexico. Of the 48 contiguous states only Minnesota currently has a wolf population large enough to maintain itself. Government plans to reintroduce wolves into what was once their native habitat have met with opposition, particularly from ranchers and hunters, who fear the wolves' killing of livestock and game. The basic social unit of wolf populations is the pack, which usually consists of a mature male and female plus offspring one or more years of age. Pack size can reach 36, but usually 2 to 8 individuals are present.
Members form strong social bonds that promote internal cohesion.
Order is maintained by a dominance hierarchy. The pack leader, usually a male, is referred to by behaviorists as the alpha male. When two wolves meet, each shows its relationship to the other by indicating dominance or submission through facial expression and posture. Additional modes of wolf communication are howling and other vocalizations and scent marking. Scent marking involves deposition of urine or feces on conspicuous objects along travel routes, usually by dominant wolves.