What can happen when an unfamiliar gray wolf enters another pack’s territory?

When an unfamiliar gray wolf enters another pack’s territory, the outcome is often hostile. Because wolf packs vigorously defend their territory against neighboring packs, intruders are frequently killed by the resident members.1

However, this is not a universal rule; in some circumstances, an intruding wolf may be accepted into the pack. These territorial boundaries are maintained through vocalizations, such as howling, and scent marking with urine and feces, which serve as clear warnings to outsiders to avoid intrusion.1