The skeleton of a pigeon weighs just one twentieth of the weight of its whole body. This is to help it fly.

For the same reason as airlines fuss about luggage allowances, birds have evolved to ensure that as many savings as possible are made on weight. To be able to fly they have to work within weight limits so they have a very lightweight skeleton. Their bones are not as solid as ours; they are hollow with a network of struts to reinforce them. The skull is light so that it does not weigh the bird down in the air. Birds do not have any unnecessary bones or teeth.

But birds have to be strong too so that they can fly for long distances. They have small compact bodies and most of the weight is in the centre. The strong breastbone balances the pull of the flapping wings. The long neck is flexible helping the bird to reach food and preen its feathers.

Pigeons eat both wild and cultivated plants. They have one unique feature, which is a pointed beak which they can use like a straw when drinking.