I'm hoping one of you amateur ornithologists out there can identify a bird -- I assume it's a bird and not a frog or similar -- which has been calling in the evening and after dark. The sound is quite a similar to the "churring" of a nightjar, but higher and softer; a continuous single note for approx 8 to 10 seconds at a time, a short pause then repeated. When I first noticed it a few days ago I thought it was a telephone ringing, then realised it was coming from the olive groves some distance away. It's quite a spooky sound and I can't find a match on the internet. All I'm sure of is that it's definitely not a skops owl. And it's not a phone! Any ideas?