Short answers, pulled from the story.
Wapiti comes from a Shawnee and Cree word meaning "white rump", referring to the distinctive pale fur around the animal's tail region. The Cree written form is ᐙᐱᑎ or ᐚᐱᑎ. Elk may raise or fluff this rump patch to signal agitation or distress to other members of the herd.
Male elk generally weigh between 178 and 497 kg, with females between 171 and 292 kg. The largest subspecies is the Roosevelt elk (Cervus canadensis roosevelti), found west of the Cascade Range; males introduced to Alaska are estimated to weigh up to 600 kg.
Mitochondrial DNA studies beginning in 1998 provided the first evidence that elk and European red deer are distinct species. A larger study in 2004 examined hundreds of samples and confirmed elk as Cervus canadensis, separate from the red deer Cervus elaphus.
Chronic wasting disease is caused by a misfolded protein called a prion and affects brain tissue in elk. Infected animals show weight loss, behavioral changes, excessive salivation and urination, and eventually die. In 2002, South Korea banned the importation of elk antler velvet due to concerns that velvet from infected animals could expose humans to a prion disease.
The Greater Yellowstone Ecosystem elk herds, which can number as many as 40,000 individuals, undertake the longest elk migration in the continental United States, traveling as much as 168 miles between summer and winter ranges. The Teton herd of 9,000 to 13,000 elk winters on the National Elk Refuge.
The IUCN has named the elk one of the world's 100 worst invaders because of its impact in Argentina and New Zealand. In Argentina, introduced elk and red deer compete with the indigenous Chilean huemul. In New Zealand's Fiordland National Park, elk alter forest regeneration by consuming more palatable plant species, reshaping the ecosystem for other animals and plants that depend on those trees.