Buru babirusa teeth are strong enough to crack any kind of nuts. Babirusas lack the rostral bone in their nose, which is a tool used by other wild pigs for digging. Therefore, they prefer feeding on roots in soft muddy or sandy soils. Cannibalism was reported among babirusas, feeding on the young of their own species or other mammals. North Sulawesi babirusas form groups with up to a dozen of individuals, especially when raising their young. Older males might live individually. The north Sulawesi babirusa reach sexual maturity when they are 5–10 months old. Their estrous cycle is 28–42 days, and the
Wild horse cranial and metacarpal differences, indicates the presence of only two subspecies in postglacial times, the tarpan and Przewalski's horse. At present, the domesticated and wild horses are considered a single species, with the valid scientific name for the horse species being "Equus ferus." The wild tarpan subspecies is "E. f. ferus", Przewalski's horse is "E. f. przewalskii", and the domesticated horse is "E. f. caballus". The rules for the scientific naming of animal species are determined in the International Code of Zoological Nomenclature, which stipulates that the oldest available valid scientific name is used to name the species. Previously, when