The average weight of a mature gray wolf is close to one hundred pounds. In exceptional cases they have been known to weigh one hundred and fifty pounds. They are, therefore, about twice the weight of the coyote, or prairie wolf, and considerably larger and heavier than the average collie. For the most part, those near the Arctic regions are larger than those in the southern United States. Seen in profile at a distance, the back line is comparatively straight. The ears rise just a trifle above this line; in front of the hips the back sags a trifle, while the tail is extended almost straight, with the point held slightly above the level of the back. With the coyote the ears are more prominent, the back more swayed, and the tail droops at a very sharp angle, with the point turned a little upward. Among Indians wolf pets are common. At an Alaskan Indian encampment I was once greeted by a number of romping Indian children who had several black-faced wolf puppies with faces painted vermilion and yellow. The puppies are born early in March. The number varies from six to twelve. For the first few weeks they are almost black, especially about the head. For a period after the young cease nursing the mother stays with them much of the time, while the father hunts and brings food to the entrance of the den or into it. At the age of a year the young wolf is still puppylike, and apparently he does not reach maturity until more than two years of age. Young wolves are sometimes seized by eagles or foxes; and all wolves are subject to attacks from parasites and disease. Old storybooks are full of tales of wolf ferocity. Wolves pursue the lone horseman, or even attack the occupants of a sleigh. A fiddler returning at night is forced to take refuge on top of a deserted building or in a treetop; or a mail carrier narrowly escapes with his life after losing his sack. All too frequently we still hear stories of wolves attacking a solitary traveller, but careful investigation of these stories shows them to be sheer fabrications. The howl of the wolf is deep, while that of the coyote is shrill and high-pitched. It appears that wolves have a language and a system of signalling. These consist of howls, snarls, and barks of varying length, with varying spaces or accents. Wolves prowl and howl mostly at night; but it is not uncommon for them to hunt or to wander in the daytime. The gray wolf is known also as the timber wolf. He may be gray, grayish yellow, or grayish black, occasionally reddish; and now and then he verges on cream colour. The colour varies greatly, even among the members of a single and perhaps related pack.