One of the most noticeable physical differences between a donkey and a horse is the sheer size of a donkey's ears. With ears so big that they sometimes flop to the side rather than pointing up, the donkey adapted to a different environment and lifestyle than the horse, who has small, pointed ears that balance with the size of his head.
Bigger for a Reason
A donkey's ears are significantly larger than a horse's, appearing out of proportion to the rest of his head. There are two main reasons for this, and both are adaptations to a donkey's environment. Horses live in tight herds and have a strong instinct to stay close together for safety. This means that it is not necessary for them to be able to communicate with each other over long distances. Donkeys on the other hand, spread out to graze, a habit developed as a result of living in desert areas with sparse plant growth. A donkey's large ears allow him to hear other members of his herd call from long distances. A horse's small ears are not a major part of his natural cooling system, but a donkey's long ears help to keep him cool in his natural desert environment as blood flows near the skin through large veins in his ears.
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