Dunnock singing - John BridgesWe've all heard the sound of birds singing, or the racket of seagulls or rooks squawking. If you listen carefully to birds singing you might know which bird is making which noise. But why do birds make the noises they do? What does it all mean? You can click on any of the blue links in this post to find out more and hear some bird song for yourself.

Look at me! Birds often sing to attract attention to themselves. They are either defending their territory or trying to attract a mate, or sometimes both at the same time. This kind of bird song is often the most beautiful to listen to. It's almost always the male that sings like this. When you hear the melodious song of the blackbird or the clear and repetitive song of a songthrush, it's because they are showing off to attract a female or defend their territory against other birds. One of the most famous bird songs of all is the song of the nightingale. These birds arrive in some southern parts of the UK around April. The males quickly find themselves a territory and then start singing loudly to warn off other males and to attract a female. Nightingales are one of the few birds that sing during the night as well as during the day. The males carry on singing day and night until they have found a mate. There are only a few female birds that sing, these include female robins which sing in the winter to establish their winter territories and female dunnocks.

Watch out! Birds also make alarm calls to alert other birds to danger. These calls can be the shrill alerts of blackbirds and redshanks, or quieter sounds, like the soft ticks and chacks you hear from the bushes, that let you know a wren, robin, song thrush or warbler has spotted you. These different shacks, ticks, tacks and clucks all sound quite similar and it is often very difficult to pin point where they are coming from. That's because when birds make alarm calls they throw their voices so that predators don't know where to look to find them.

Are you with me? If you see a flock of geese flying overhead, or a gang of tits moving through a wood in search of food, they will often be making some sounds. These aren't full songs, and they aren't alarm calls either. These are called contact calls, and they are ways that members of a flock keep in touch. They tend to be softer and easier to identify than alarm calls.