婉转，清丽，高亢，鸟儿在枝头欢唱。世界自然纪录片之父爱登堡老爵爷讲述鸟类鸣叫对于种群的意义。　　DavidAttenboroughchoosessevenofthemostremarkableanimalsongsfoundinnatureandexploresthesignificanceofthesesongsinthelivesoftheirspecies.