The large ears of the African savannah elephant serve above all as a biological radiator: they evacuate excess body heat thanks to a dense network of blood vessels located just under very thin skin, cooling the blood before it returns to circulate in the body.
A vascular air conditioning system
Each ear pinna can reach nearly 2 meters high in large males and represents a considerable heat exchange surface area compared to the mass of the animal, which can weigh more than 5 tonnes. The skin of the ears, only a few millimeters thick compared to several centimeters elsewhere on the body, reveals a mesh of veins and arteries that is easily visible. Warm blood from inside the body circulates in these superficial vessels and loses calories by simple conduction with the ambient air.
The flapping of the ears, often observed during the hottest hours of the day, accelerates this process by increasing air flow over the skin and promoting evaporation. This movement can lower the temperature of the blood by several degrees before it returns to supply the rest of the body, an essential mechanism for an animal lacking effective sweat glands and living in environments where temperatures regularly exceed 40°C.
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Why the African elephant has much larger ears than the Asian elephant
The African savannah elephant lives in habitats that are generally warmer and more open than the Asian elephant, which benefits from more forest cover and a more temperate climate in places. This stronger thermal pressure explains why its ears are significantly larger and differently shaped, in a flared triangle, compared to the smaller, rounded ears of its Asian cousin.
Beyond thermoregulation, the ears also play a role in visual communication: deployed widely, they amplify the impression of the animal's size during intimidation displays or confrontations, a signal that other elephants and potential predators instantly interpret.
