Spring would not be spring without bird songs.
Francis M. Chapman、
鸟、比喻、道理 (Birds are used in metaphor, analogy, figure of speech )
a bird in the hand is worth two in the bush (saying 谚)一鸟在手, 胜于二鸟在林（最好满足于现有的, 以免因贪心而失去一切）
A bird in the hand is a certainty, but a bird in the bush may sing.
Bret Harte
the early bird catches the worm (saying 谚) the person who arrives, gets up, etc first will be successful 早起的鸟才能捉到虫; 捷足先登.
Did you ever see an unhappy horse? Did you ever see bird that had the blues? One reason why birds and horses are not unhappy is because they are not trying to impress other birds and horses.
Dale Carnegie
Use those talents you have. You will make it. You will give joy to the world. Take this tip from nature: The woods would be a very silent place if no birds sang except those who sang best.
Bernard Meltzer
Intelligence without ambition is a bird without wings.
C. Archie Danielson