Different research have been done to know why bird sings? To reach in a conclusion, try to discover the answer of the question "why human speaks?" Simple answer is for communication. Every animal have specific language for communication. Another analogy may consider. Suppose a parson who is some distance from you and you are trying to make attention of him. In order to do this you utter loudly "Hello". Animals sound loudly in order to send the sound far distance from it. Only then sound will be loud if some body to whom you are trying to send signal is places distance from you. Most of the birds are found to sing loudly, Because they want to send signal to whom is far distance from it. Whatever, scientists have found to major cause of birds singing. One cause is defining its own territory and another is get attention of mates. Their also have certain cause. To get relaxation bird sings. In this case most common is chorus song.
Very interesting things is that most of the male birds sings to attract female birds and female bird identify male birds quality on the basis of its singing. Researchers have found these male bird can sings well that have abundance of food in the area where it is living. Usually female birds chooses these male birds as a mate who can sings well. A good song gives message to female bird that in this area there have an abundance of food.
In animal world bacteria to human, even may be in alien life most common phenomenon is colonisation. Another research shows that birds sings also to territories the area. By singing birds defines that a specific area is only for it or its group. Birds singing is also a keep out message for some birds that controls unnecessary entrance into an area by other bird. Scientists recorded sing of male House Wren in an area. Technically they removed all of the male House Wren from this area. For a few days they displayed the recorded song of Male House Wren with loudspeaker.
They found that the male House Wren of the neighbouring area's male House Wren shows less tendency to enter in this area.
Some times few birds are found to sing chorus. It is exactly for relaxation, just as same children goes to field for playing. Playing is an entertainment of children. As same chorus song of bird is just one kind of entertainment of bird.
Singing birds
Singing birds are found in all over the world. Few birds are very familiar with their song. Red eyed Vireo sings more than 2000 songs in a day. Another kinds of birds are found that it spends more than 70% of time a day with singing that "Dickcissels". Brown Threshers are such types of bird that can sing 2000 different song.
