Why are male birds usually more beautiful than female birds?

Why are male birds usually more beautiful than female birds? ( )the male are more beautiful than the female in the world male high school students are more likely than their female The birds are similar in appearance ,but the male ____ more Male lions are much bigger than female ones.Male lions are__ Now there are more than ______kinds of birds in our country. Are you male or female Birds the birds are singing beautiful songs for them. Listen!The birds are singing （beautiful）in the woods 英语翻译Why do birds suddenly appearEvery time you are nearJust male&female