The local Malagasy people in Madagascar gave the Sifaka its name because of the unique sound it lets out that sounds like "shif-auk". Sifakas are lemurs. And while they too spend most of their time in trees; they actually remain upright while leaping through the jungle. They jump from tree to tree by using their hind legs like humans do. In fact, they can leap distances of 30 feet. But they can move quickly on the ground too, using a two-legged sideways hop.