Cheetah in Maasai Mara National Reserve, Narok, Kenya (© Andy Rouse/naturepl.com)

High atop a termite mound in the Maasai Mara National Reserve—a protected savanna in southwestern Kenya—a cheetah scans the plains. Its sleek body can reach speeds of over 100 km/h, making it the fastest land mammal on Earth. Long legs and a flexible spine allow incredible acceleration, while its strong tail helps maintain balance during high-speed chases. With fewer than 7,100 individuals left in the wild, these are among Africa's most vulnerable big cats.