Why do birds sing in the morning? It’s the triumphant shout: “We got through another night!”

Enid Bagnold (1889-1981) English writer

(Attributed)

Unsourced in this form.  In her 1969 autobiography she writes: "I hear it in the pillow; it intoxicates me. Why do they do it? I have never been taught about birds. Is it the triumph-shout - 'We have got through another night!' It may be."