每年春季脱下毛衣换上T恤衫是不是很有意思?一些鸟儿也在春季换“衣服”。它们脱换羽毛。换毛意味着脱去旧的羽毛,长出新的羽毛。新羽毛从鸟的皮肤里长出来,替换已磨损的旧羽毛。生活在环境恶劣的沙漠和草原的鸟通常一年换毛两次,分别在春季和秋季。它们的羽毛比其他鸟的羽毛磨损快。其他大多数鸟主 Isn’t it interesting to take off your sweater every spring and put on a T-shirt? Some birds are also changing clothes in the spring. They remove feathers. Hair replacement means removing old feathers and growing new feathers. The new feather grows from the bird’s skin and replaces worn old feathers. Birds that live in harsh deserts and grasslands usually have twice a year of hair exchange, in spring and autumn, respectively. Their feathers wear faster than other birds’ feathers. Most other bird owners