When bull reindeer shed their antlers in early to midwinter, the antlered female reindeer acquire the highest ranks in the feeding hierarchy, gaining access to the best forage areas. These cows are healthier than those without antlers. Calves whose mothers do not have antlers are more prone to disease and have a significantly higher mortality. Females in good nutritional condition, for example, during a mild winter with good winter range quality, may grow new antlers earlier as antler growth requires high intake.