The Ankole cattle are distributed from Lake Mobutu to Lake Tanganyika in eastern Africa. The original animals were thought to have been brought to northern Uganda by Hamitic tribes sometime between the 13th and 15th centuries. The Ankole's susceptiblity to the tsetse fly forced the tribes and their cattle further south. The Hima or Bahima tribe settled on the shores of Lake Victoria in Uganda, Kenya and Tanzani. The Watusi or Tutsi tribe continued to Rwanda and Burundi with their cattle, some of which have spread to the lake districts of Zaire. Selection in all the tribes is based on horn size.