Chiffs that don’t chaff?
Sweeoo vs tuuit chiffchaffs
If, like us, you do a lot of birding by ear then you may have noticed that last autumn there was a passage of Common Chiffchaffs, a considerable number of which were using different calls from the typical “tuuit” call that we are all used to.
This was documented by a number of observers in Spain, including myself one day in October, when I heard what I thought must be a Yellow-browed Warbler. I hastily pulled out my phone and activated the Merlin app and it gave me “Common Chiffchaff”!
“What? No!” I said to myself, and tried again, with the same result. Merlin was telling me again that that “sweeoo” call I was hearing was from a Common Chiffchaff. The truth is that when I set eyes on what I thought must be the bird making the call it looked just like a Common Chiffchaff.
So … Merlin 1 Steve 0
Obviously I was not the only observer to be taken in, as later this was published as something particular to that autumn, and quite widespread. The most likely explanation was that there was a larger than normal passage of juvenile birds which had not yet acquired the use of the typical “tuuit” call.
So, there you go. Be careful out there!