Topi are an antelope species that are often seen around wildebeest herds and migrate with them. When it comes to crossing rivers, notwithstanding the danger of lurking crocodiles, unlike the wildebeest, they do not dawdle. When pressed they have been known to reach speeds in excess of 50 mph, although they typically travel at a jog. They are one of the fastest antelopes in Africa. They are also social animals that are often seen around other species.