When I was just about to leave the area I heard a very strange Chiffchaff singing. Soon I understood that there is something to do with the tristis-type Chiffchaff in this song I'm just hearing. I checked the song of tristis from my tape and it was almost like that. This bird was singing all the other notes of the song like tristis except in the end of phrase it always said a couple of times a note 'chiff'. This 'chiff' was exactly like it is in the song of abietinus, not like nearly disyllabic note that can be found in the typical tristis-song. Probably a pure tristis is not allowed to have this abietinus-like note 'chiff' in his song? Or does anybody know that for sure? Hence, I consider this bird as a 'mixed singer' that is most likely coming from the overlap zone of breeding ranges of races abietinus and tristis.
I don't know how reliable is to identify tristis by the song. Probably the song is a good and rather reliable criterion as it should be always very distinct if the bird is singing like we know they do in the breeding range. I think the call is much more complicated. It should be also very distinct but after I heard many tristis-like calls in Eilat this spring I'm not very convinced anymore. Many times I had a Chiffchaff calling like tristis in a Helgoland-trap but when I got those birds in my hand the plumage looked always like a typical abietinus, nothing like tristis. Anyway, tristis-like call probably tells us that the bird is coming from somewhere near the range of tristis but maybe also some very eastern abietinus can have a call like this. I think I have seen an article about that matter somewhere but can't remember where. Many birds in Eilat with plumages like abietinus might support this theory.
The bird I heard was so interesting that I wanted to catch it to see it in hand but he wasn't interested of the tape so I saw it only with scope. The plumage seemed ok for tristis but I didn't see the bird so well that I could say it. Anyway, it was an interesting bird that would have been good to see in hand. Now I only have this poor documentary photo. There is only one accepted record of singing tristis in Finland.
Chiffchaff (Phylloscopus collybita) probably of type 'fulvescens'
(or what ever the name for those birds of overlap zone is)
