Pronghorns are the fastest land mammals in the Americas. They have been recorded racing along at 72kph.
In late autumn, pronghorns gather into large herds of 1000 or more. They spend the winter in these herds and split into smaller single-sex groups when spring arrives. In October, older males compete for small territories, which they use to attract groups of females. Once females have entered the territories, the males will not allow other males near them.