Monts de Gueret Animal Park
The wolf pack howls on average for 85 seconds. It is usually started by a single wolf, after which other wolves may join in. The pack leader, the alpha wolf, usually uses a lower-pitched howl and howls more frequently than wolves standing on the lower rungs of the pack's hierarchy. Although some functions of the howling are still unknown by scientists, they believe that wolves may howl to scare off other wolf packs from their territory and to gather their own pack, as wolves possess perfect hearing and their howling can be heard for up to in the forest and in open space. Researchers have found a relationship between the number of times a wolf howls and the strength of their relationship with other pack members. According to Friederike Range, co-director of the University of Vienna's Wolf Science Center, "the strength of the relationship between wolves predicted how many times a wolf howled."
Wolves and moose on Isle Royale
Wolves on the island have, historically, been separated into three or four packs, with each pack usually having between three and eight members, including two or three pups. The number of wolves in a pack depends mainly on the amount of snow that fell in the previous winter. In winters with light snow, pups tend to leave the pack to find mates, so packs run at four or five members; in heavily snowy winters, the pups stay with the pack, which can reach ten to twelve members. If many members of a pack die, the pack dissolves and a new one forms within a year. One pack will dissolve about once every thirty years.