Owls are certainly lovable. But bright? In many cultures they have been associated with wisdom, but they have a direct, often yellow-eyed glare that makes them look mindlessly gung-ho. As these two books show, however, owls are bright. In terms of problem-solving, they may lag behind crows and parrots, but the owl brain can do wonderful things.

To pinpoint sound, barn owls have space-specific neurons in their brains that perform advanced maths as they transmit information, all in far less than the blink of an eye. Furthermore, not content with computing incoming information, the barn owl’s brain also assesses its likely accuracy as more information becomes available. It does this in perfect conformity with a statistical method known as Bayesian inference. Barn owls evolved in the early Oligocene, rather more than twenty million years before Thomas Bayes had his light-bulb moment about reconciling variable probabilities. In short, throughout their history, barn owls have been carrying around in their heads miniaturised direction-finding equipment far more accurate and far faster than anything available in the most advanced missile.

Barn owls are not alone. Owls have relatively small brains, though not necessarily in proportion to their body size. (Most owls are smaller than they appear: profuse feathering bulks them out.) However, it has long been recognised that brain size is not the critical determinant of intelligence: it is