American elk are among the most vocal members of the deer family. Cows bark alarm signals, calves bleat and squeal, and bulls bugle. Bugling marks the beginning of the fall rutting or breeding season and advertises the bull's fitness to cows and rival bulls. During the rut, cows form small groups controlled by a dominant bull. For the remainder of the year, cows, yearlings, and calves form herds of 25 or more animals, while bulls form smaller bachelor herds. Living in a herd provides protection from predators, including bears, mountain lions, wolves, and coyotes. American elk are also called wapiti, a Native American word referring to their characteristic light-colored rump. Once found throughout North America, large populations of elk are now found only in the western parts of the United States and Canada. In the early 1900s, a trap and transfer program reestablished elk in Pennsylvania. The growing herd, now numbering over 1300, currently lives in the north-central counties.