When we were in Madeira recently, not too far from Portugal, we spent a lovely afternoon walking through the town and ended up in a streetside park which contained an open air market. Walking around, we could hear this very loud bird call and kept stopping to stare into the trees to try to locate this elusive bird. The only things we could see were pigeons but the bird calls continued.
After a fruitless search we sat on a bench with an ice cream. We were joined by a young woman and, on hearing the call again, I asked her what kind of bird it was. She replied, 'It's the man with the stall selling wooden bird callers.' Cheep, cheep!
We felt such fools :-)