Why did Dumbo have big ears

A. A recent study shows that Dumbo's wouldn't have used his big ears just to fly, they were also essential for losing the extra heat from his body that flying would have created and so stopped him from overheating. Researchers Polly Phillips and James Heath of the University of Illinois wanted to study how effective this method of cooling was. After creating a computer model to calculate heat loss in real elephants they decided to see how Dumbo would have fared.

It seems that if his ears had been any smaller he'd have suffered severe heat stress while flying. The study shows that his cooling system was so efficient that resting for too long would have brought hypothermia.

Q. How do real elephants cool themselves

A. The same way as Dumbo, via their ears. Elephant skin lacks sweat glands and so they rely on their ears to help cool them down. They transport body heat to the skins surface, where it can disperse, by pumping blood around their large ears. They have very large veins in their ears that become even bigger in warmer weather. When it is hot elephants flap their ears, sending the cool air over the enlarged veins. The cooled blood is then pumped around the rest of the animal's body.

Q. How did the scientists work out how much heat Dumbo produced

A. By calculating his likely weight and metabolic rate based on Dumbo's dimension extrapolated from Walt Disney drawings. They also calculated the surface area of his ears to determine how much heat could be lost via them.

Q. How did flying affect Dumbo's metabolic rate

A. The researchers believe it would have increased his metabolic rate by 10 times compared to resting, with a corresponding increase in body heat.

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by Lisa Cardy