FACT #34

Ostrich is the largest bird in the world having the largest eyes in the whole animal kingdom that are even bigger than its brain. An ostrich's eyes are about 2 inches (5 centimetres) in diameter, i.e. almost of the size of a billiard ball. The ostrich needs large eyes to adapt to its terrestrial lifestyle. On sighting any danger, it doesn’t hide its head in the sand as is popularly believed. Thanks to the long neck and legs which make it stand up to the height of 9 ft., it enjoys an excellent view over the grassland and bush. Its large eyes with a high number of photoreceptor cells combined with the sheer size of the image from the lens help the ostrich to see phenomenal details of the predators even from great distances. So, if it sees something trying to sneak upon it then it will run away as fast as it can with its big, long powerful legs.

Well on a simple level an ostrich’s brain is as big as it needs to be. This sounds silly but in evolution it must have been more successful to have a bigger eye than a bigger brain, therefore all the ostriches which had slightly larger eyes (therefore better eyesight) must have been better at not being eaten, so could survive to pass on their genes to their babies. The size of a skull decides how large a brain can be, as you have to think of the skull being a rigid box surrounding the brain, so if you give up more space for a big eye in your skull then there is less space for the brain.