Metronome Bird?

I heard a bird that sounded a constant beat like a metronome crotchet = c100 pitched around the E above middle C in Corsica many years ago, and have heard it again (probably not the same bird!) last week in Portugal. I am a composer and want to write a piece of music called "The Metronome Bird" I didn't see it so it remained elusive for the whole of my holiday. There were also different pitches and intervals but the main thing is that the beeping was constant and it usually did this early in the morning. Can anyone identify the bird please?

Pammy