Each year in late September through early October, populations of elk (Cervus elaphus) in the Rocky Mountain National Park begin their mating season. Dominant males defend their harems (which consist of groups of up to six females). Less dominant males must challenge the dominant males to win females.

This year, the elk mating season comes at a time when their numbers are soaring and park officials are proposing controversial methods of controlling elk numbers in the park. Among the proposed population control methods are culling, the administration of birth control drugs, and the reintroduction of wolves into the park (the elk's natural predator).

Find out more: Elk Mating Season Proceeds in the Rockies (NPR)

Photo © Ferenc Cegledi