What actually makes a cheetah fast (it isn't the top speed)

The cheetah is the fastest land animal. You knew that. The usual figure is 110 or 120 km/h, and it comes from timed runs of captive animals on straight tracks. In 2013 a team from the Royal Veterinary College in London published something better: data from wild cheetahs in Botswana, fitted with collars carrying GPS and motion sensors, during 367 real hunts over 17 months.

What the collars showed

The fastest run recorded was 93 km/h, a shade under 58 mph. Most hunts never got near that. The average chase was 173 metres long, and the cheetahs spent most of it well below top speed. What stood out in the data was not velocity but what the researchers called "grip and manoeuvrability": accelerations and decelerations almost double those measured in polo horses, lateral forces in turns of more than 13 metres per second squared, and the ability to drop from full sprint to a hard turn in a stride or two.

The cheetah's acceleration power, the team calculated, was about four times that of Usain Bolt in his world-record sprint. And hunts were won or lost at the end, in the final seconds of twisting after a gazelle that was turning for its life, not in the opening straight.

The engineering

Everything about a cheetah is built for this. The spine flexes and extends with each stride, adding length to the bound and acting like a spring. The shoulder blades are loosely attached, so the forelegs reach further. The claws do not fully retract, giving the grip of running spikes. A long, heavy tail swings out as a counterweight in turns. Enlarged nostrils, lungs and heart feed an engine that can only run flat out for about twenty seconds before it overheats; a chase longer than that is usually abandoned.

What that costs

A body tuned this far for speed is poor at everything else. Cheetahs are light, with small jaws and teeth; they cannot defend a kill against a lion, a leopard or a hyena clan, and they lose a significant share of their meals to them. They hunt by day to avoid the night-time predators, which means the heat. Cubs die at high rates. The cheetah is a specialist in a landscape that rewards generalists, which is a large part of why there are only around 7,000 left in the wild.

Where to see one run

You need open country and luck. The short-grass plains of the southern Serengeti and the Masai Mara are the classic places; so are the Kalahari and the central Kruger grasslands around Satara. If you see a cheetah sitting on a termite mound scanning the horizon, stay. It is not resting. It is choosing.