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.
Though they once nearly disappeared from the lower 48 states, today wolves have returned to the Great Lakes, northern Rockies and Southwestern United States. Wolves play a key role in keeping ecosystems healthy. They help keep deer and elk populations in check, which can benefit many other plant and animal species. The carcasses of their prey also help to redistribute nutrients and provide food for other wildlife species, like grizzly bears and scavengers.