Each wolf has distinctive voice, and pack members can recognize each other. A dog can exert up to 700 lbs. of jaw pressure. A wolf exerts 1700 lbs. Adult male wolves weigh up to 110 pounds, with females usually weighing 10 to 20 pounds less. They usually weigh 15 to 20 pounds more in the winter partially due to a heavier fur coat.
Wolves have a double layer of fur.
The woolly underlayer grows very thick in the fall and winter and allows wolves to easily survive temperatures well below zero. The outer layer of guard hairs repels snow and water, and keeps the insulating layer dry. During the spring, the thick underfur sheds so the wolf can survive the heat. Wolves are running machines, capable of sustaining a 35 mph run for up to 12 miles or a trot of 12 mph for 8 to 10 hours. Relocating these wolves and caring for them has been an expensive proposition.