| The cheetah (acinonyx jubatus) is an unusual cat; the only one in its sub-family. They are the world's fastest land mammals, who can reach 70 mph for very short distances and can go from 0 to 45 mph in two seconds. About 30 inches high at the shoulder, they are very slim, have elongated hind legs, oversized lungs, and claws long enough that even when retracted they are still visible (unlike other felidae, who can completely retract their claws) -- all of these features help them attain speed and traction when they run.
Cheetahs can be solitary or travel in pairs, and sometimes families of nearly-grown cubs and their mothers are seen being social. They are day hunters, so their spotted coats provide camouflage, but once the chase starts, other animals can't help but see them. Many larger carnivores will try and scare a cheetah away from its kill.
Cheetahs used to range over Africa and the Middle East; now they are limited to small areas in sub-Saharan Africa and a very small number in the mountains of Iran, and those cheetahs remaining have a very limited gene pool due to some catastrophe about 10,000 years ago which killed off about 99% of cheetahs -- all those now in existence are descended from the survivors. Inbreeding has caused a lot of abnormal sperm and low sperm counts among male cheetahs, and as many as 70% of cheetah cubs die before adulthood because of predators. Also, the cheetah's habitats are being built over and their prey (usually herd animals) is being killed off, and they are hunted for their fur (especially the king cheetah variety, which has stripes or large blotches
instead of small spots, but is the same species). There may be as few as 10,000 left in the wild. | 
