a little bird told me

a little bit of bread and no cheese

Used to represent the song of the yellowhammer (Emberiza citrinella).

a little from column A, a little from column B

A combination of two factors or reasons.

a little of something goes a long way

Only a small amount of something is usually required to produce a great effect.

all told

With everything included, counted, or summed; in total.

bird in the bosom

A secret pledge that one makes for another.

bird of ill omen

A person who brings bad news.

bird of one's own brain

One's own idea or conception.

early bird

A person who wakes early or arrives early, typically before most others.