They heard the sudden twittering of a bird, but could not find the creature anywhere.
The city park was silent except for the twittering of birds, eager to find food.
You sink back to sleep, lulled by the sound of the lapping sea and the twittering birds.
A warbling, twittering song; call a twittering ' chi chi chi chi ' When to see it All year round.
Before emerging in the flight the bats utter a curious twittering sound.