SCIENCE
WHEN darkness falls, many people shut their doors, turn the TV on and chill out with a cup of tea or something stronger. For me, the cover of darkness is a time I enjoy being outdoors, because it brings out animals which aren't active during the day. And among these are certain birds.
Of the 11,000 or so species of birds, it is estimated that approximately 30 per cent are substantially nocturnal. That is quite a large proportion. But why would birds want to fly at night and, more importantly, how do they see in the dark?
For a start, we should be careful about categorising
