Rangifer tarandus is the only species of deer in which both sexes have antlers. Mature bulls can carry enormous and complex antlers, whereas cows and young animals generally have smaller and simpler ones. Males compete for access to females during the fall rut, which occurs in October and early November. Two males will lock each other's antlers together and try to push each other away. Dominant males can collect as many as 15-20 females to mate with. Males stop feeding during this time and lose much of their body reserves. Mature bulls usually shed their antlers shortly after the rut whereas cows can keep theirs until spring. Visit WWW.STOCKSHOT.NL for highres version or broadcast video footage.