Observatoire des droits humains (anglais seulement)

Why do giraffes have such long legs? Animal simulations reveal a surprising answer

(Version anglaise seulement)

par Roger S. Seymour, Professor Emeritus of Physiology, University of Adelaide
Edward Snelling, Faculty of Veterinary Science, University of Pretoria

If you’ve ever wondered why the giraffe has such a long neck, the answer seems clear: it lets them reach succulent leaves atop tall acacia trees in Africa.

Only giraffes have direct access to those leaves, while smaller mammals must compete with one another near the ground. This exclusive food source appears to allow the giraffe to breed throughout the year and to survive droughts better than shorter species.

But the long neck comes at a high cost. The giraffe’s heart must produce enough pressure to pump its blood a couple of metres up to its head. The blood pressure of…

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