Donkey, By Jill Bough

The latest addition to Reaktion's animal series – surely one of the most successful publishing ventures of recent years – reveals the donkey, "generally considered beneath notice", to be a creature of the utmost fascination.

Capable of carrying two-thirds its own body weight, it was the first pack animal to be domesticated. Upwards of 40 million still serve humanity. Only the camel has a lower water requirement and better control of temperature.

Ironically, this placid animal proved invaluable in warfare and is still serving in Afghanistan. However, Bough goes too far in asserting "semantic associations between the animal and human buttocks".

The American "ass" from "arse" is merely a homonym of "ass" meaning undomesticated donkey.