The elk, or wapiti (Cervus canadensis), is one of the largest species of deer in the world and one of the largest mammals in North America and eastern Asia. In the deer family (Cervidae), only the moose, Alces alces (called an “elk” in Europe), is larger, and Cervus unicolor (the sambar deer) can rival the C. canadensis elk in size. Elk range in forest and forest-edge habitat, feeding on grasses, plants, leaves, and bark. Although native to North America and eastern Asia, they have adapted well to countries where they have been introduced, including New Zealand, Australia and Argentina. Their great adaptability may threaten endemic species and ecosystems into which they have been introduced. Male elk have large antlers which are shed each year. Males engage in ritualized mating behaviors during the rut, including posturing, antler wrestling (sparring), and bugling, a loud series of vocalizations which establishes dominance over other males and attracts females.