Wolves of northern North America and Eurasia vary in colour. A single pack may contain animals that are black, shades of grey-brown, and white. Wolves in the heavily forested areas of eastern North America are more uniform in colour. They are often a grizzled grey-brown, similar to some German shepherd dogs.
Male wolves can weigh between 20 to 70 kilograms while the female weighs in at 18 to 55 kilograms. In the wild their lifespan can be from 8 to 16 years.
