Deer, forming the family Cervidae, shed their antlers annually after the mating season. The rut, as the mating season of deer species is known, varies depending on the climate of their habitats. Male deer use the antlers during mating season to display, challenge and fight other males for dominance.
With the exception of reindeer, only males of the species grow antlers. Elevation of a deer's testosterone levels prompt the growth of the velvet-covered bone. The velvet is a vascular tissue that is eventually worn away, leaving a dead bone structure. The members of the Cervidae family include white-tailed deer, mule deer, elk, moose, red deer, reindeer, fallow deer, roe deer, pudu and chital.