pics © Marijn van Oss & Jorrit Vlot sound © Thijs Fijen
Earlier I wrote about Siberian Chiffchaffs with common Chiffchaff calls (here). That bird (mostly) looked like a Siberian Chiffchaff, and after analyses it indeed showed Siberian mtDNA - but in the field didn't utter the characteristic
No, it called like a Common Chiffchaff!
Now the following bird, observed on Vlieland on 25 October by Thijs Fijen and his mates Marijn van Oss and Jorrit Vlot, could very well be a similarly confusing - but highly interesting - bird.
This was a field observation so no DNA was obtained, but even though the bird is half hidden, and it's pretty dark, the pics absolutely give a tristis feel. These guys are are keen on identifying difficult birds, and based on plumage it sure looked like a bonafide tristis to them.
But here are the calls the bird uttered:
(if sound app doesn't work, use this link)
Not even remotely close to a Siberian. So yet another intriguing bird!
In the mean time our DNA work on chiffchaffs continues. At the momente we're collecting our final feather samples. We now have over 800, from several countries. Peter de Knijff and myself hope to publish the Dutch mtDNA data in 2019. A full gene analyses of all tristis (to see if we get birds with mixed genes; the bird with the 'wrong' call will be super interesting to test) will take a bit longer.
Thanks for the pics and sound recording, Thijs, Marijn & Jorrit!