bird in the bosom

a little bird told me

I received the information from a source which I am not prepared to disclose.

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.

flip the bird

To make a rude or obscene gesture (at somebody); particularly, to extend the middle finger.

ghetto bird

A police helicopter, specifically in the context of patrolling or searching impoverished, high-crime urban areas (the ghetto).

go the way of the dodo bird

Alternative form of go the way of the dodo.

nourish a viper in one's bosom

To do acts of kindness that will be met with ingratitude and will cause one harm in the end.