新托福阅读机经背景知识

　　BACKGROUND/DISCUSSION

　　Songbirds include those birds from the order Passeriformes, commonly calledpasserines. There are approximately 5,400 different species of passerines. Thesuborder Oscine includes those birds that we tend to think of as your typicalsongbird, those birds that have complex songs as adults. In the majority ofOscines, the male is the one with the complex singing ability, and there is muchdiversity among males of different species in the length and complexity of theirsongs.

　　Song needs to be developed, just like any other characteristic of songbirdbehavior. Singing the correct song for that species is not an instinctualprocess. The need to sing is instinctual, however what song to sing has beenfound to be learned. When and where young songbirds learn their songs has longbeen studied. Just as songbirds differ in their songs, they also differ in theirsong learning process, though some basic principles seem to be the same. Manyspecies learn their song only during the first few months, though a few canlearn songs their entire lives. Also differing between species is from who thesongs are learned, and how much of the songs are accurately imitated.

　　Some species may exactly copy the songs they are exposed to. On the otherhand, many will not exactly imitate the song or songs that they have beenexposed to. Instead they will take bits and pieces of it and invent their ownsong, though usually similar in construction to that which the species normallysings.