The chaffinch has three calls: the song – we say izamzam – and another calling call. I'll start by trying the call of the haffinch that sings something like [whistles] It has another, completely different call [whistles] and yet another ‘calling' call [whistles]. It combines both. That's the call of the haffinch. It's hard to find a whistle for that, it doesn't exist or if it does I'm not aware of it. But for a lot of songbirds we don't know of any whistles. Trapping was done with birds rather than whistles. Whistles were mostly used for hunting – pluvieri, berwin are hunting whistles – since trappers would have birds and so wouldn't need whistles to trap.