Dominant stags follow groups of hinds during the rut, from August into early winter. The stags may have as many as 20 hinds to keep from other, less attractive males. Only mature stags hold harems (groups of hinds), and breeding success peaks at about eight years of age. Stags two to four years old rarely hold harems and spend most of the rut on the periphery of larger harems, as do stags over 11 years old. Young and old stags that do acquire a harem hold it later in the breeding season than those stags in their prime. Harem-holding stags rarely feed and lose up to 20% of their body weight. Stags that enter the rut in poor condition are less likely to make it through to the peak conception period.