Plate 111 of the Birds of America by John James Audubon, depicting the pileated woodpecker. Adults are 40 to 49 cm (16 to 19 in) long, span 66 to 75 cm (26 to 30 in) across the wings and weigh 250 to 400 g (8.8 to 14.1 oz), with an average weight of 300 g (11 oz).
How Wolves Help. Wolves play a very important role in the ecosystems in which they live. Since 1995, when wolves were reintroduced to the American West, research has shown that in many places they have helped revitalize and restore ecosystems. They improve habitat and increase populations of countless species from birds of prey to pronghorn, and even trout.
Wolves are very social animals. They live and hunt together in groups called packs. A wolf pack is really just another name for a family of wolves. A pack is usually made up of an adult male and female wolf and their offspring of various ages. Pack sizes range from three to twenty wolves. A wolf pack has a definite social structure and rules of conduct.