Serenading female birds

WHAT makes a bird sing? Male birds do most of the singing, though some females are noted for their tunes. (The female mockingbird is one songster.) In general, birds sing for two reasons. One is to send out the message that they are ready to mate.

The other reason is to stake out an area that is their own. Hormones trigger the desire to make melodies.

Spring to mid-summer is the time when you can hear the most singing of birds. The songs are only a few seconds long, but the birds will repeat them over and over.

They can sing from 1,500 to 3,000 songs in one day! How fast does the earth rotate? At the equator, the earth spins about 1,609 kilometres per hour. It spins more slowly towards the poles. The earth's spin on its axis creates day and night, but the tilt of the earth and its trip around the sun, creates the seasons.