Antlers grow on the heads of many deer. Antlers are made of bone and have branches. Every year they shed their antlers, so they lose them. Female reindeer also have antlers. In the case of red deer, fallow deer, and moose, only the males have antlers.
The male deer want to impress each other with their antlers, i.e. show who is the more powerful. They also fight each other with their antlers, mostly without injuring themselves. The weaker male must then disappear. The stronger male is allowed to stay and breed with the females. That’s why one speaks of the “top dog” in a figurative sense: that’s someone who doesn’t tolerate anyone else next to them.
Young deer do not yet have antlers, nor are they ready to give birth. Adult deer lose their antlers after mating. His blood supply is cut off. It then dies and regrows. This can start immediately or in a few weeks. In any case, it has to be done quickly, because in less than a year the male deer will need their antlers again to compete for the best females.
Antlers should not be confused with horns. Horns only have a cone made of bone on the inside and consist of the material “horn” on the outside, i.e. dead skin. In addition, horns have no branches. They are straight or a little rounder. Horns stay on for life, as they do on cows, goats, sheep, and many other animals.