Stallions acquire females by abducting young mares from another family. This happens at the onset of a female's first estrus, when she is one to two years old. These young females adopt a very obvious and distinctive stance when they come into estrus, standing with their legs apart and their tail lifted. Competition is intense for females and a dozen or more stallions fight for possession of young mares, making it almost impossible for the harem male to withstand their challenge. Older females conceal estrus, and only adopt this stance when about to mate with the harem male. Females give birth in the vicinity of their family group, and foals can stand within 10 to 15 minutes and walk shortly afterwards. They can run within the hour.