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.
Predator and Prey. What the wolf lacks in size, power and weapons it makes up for with collaboration and intelligence. Smaller and less powerful than mountain lions, for example, wolves work together to take down prey much larger than an individual wolf; prey that may otherwise elude them. While individual wolves have been able to subdue large prey animals, their advantage is in collaborating with their pack. Wolves are opportunists. They test their prey, sensing any weakness or vulnerability through visual cues and even through hearing and scent. Contrary to ambush predators that rely on the element of surprise and a short and intense burst of energy to secure their prey, wolves are endurance or coursing predators.