- short note, thinking out loud

- ssp. brevirositris or caucasicus proven on DNA in the Netherlands and Germany

- can these vagrants be identified in the field based on calls?


Figure 1. Mystery Chiffchaff, 22 February 2015, Lauwersmeer, Groningen, the Netherlands: is this a bird all the way from the Middle East or Transcaucasia? (Martijn Bot/ 


Who would have thought chiffchaffs from Turkey or Transcaucausia could end up in NW Europe? But they did! Molecular analysis proves no less than three birds either belonging to ssp. brevirostris or caucasicus have been sampled in the Netherlands and Germany. This web note gives a little background, and focuses on the vocal ID of these taxa. Because there might be Dutch field records, too!

Peter de Knijff already mentioned these three birds in his lecture on the Dutch Birding Day in 2018. During late 2015, two birds with brevirostris/ caucasicus mtDNA were sampled in the Netherlands and one in Germany. Whether these birds are from Turkey (brevirostris) or Georgia, Armenia or northwest Iran (caucasicus), they originate from a very unexpected corner!

A paper summarizing our 10 year genetic study on chiffchaffs is expected to be published this year. More details and photographs will be shared later.  


Interestingly, the German bird uttered a “sad” call, reminiscent of Siberian Chiffchaff (Jochen Dierschke in litt.). Unfortunately it was not recorded, but that surely does fit a bird from the south-east!  

A field sighting of a puzzling chiffchaff  on 21-28 February 2015 in Lauwersmeer, Groningen, the Netherlands came to mind. Due to its odd calls the bird was initially reported as a possible (but extremely unlikely) winter record of an Iberian!


It’s intriguing that former rarity committee member Rik Winters mentioned the similarity of the calls with brevirostris at the time (here). With birds from the south-east now being confirmed as vagrants, I wondered if this also sheds light on the ID of the Lauwersmeer bird. And, consequently; can these south-eastern vagrants be recognized in the field? This is what the Lauwersmeer bird sounded like: 

mystery chiffchaffDimitri Mulder
00:00 / 01:53

Dimitri Mulder, who found the bird, recorded these "down slurred" calls. With a descending pitch (somewhat Siskin-like), it's no wonder he thought of an unseasonal Iberian! 

mystery chiffchaffEllen de Bruin
00:00 / 00:07

Same bird, recorded a week later by Ellen de Bruin


Figure 2. Mystery Chiffchaff, 22 February 2015, Lauwersmeer, Groningen, the Netherlands: could this be a bird all the way from the Middle East or Transcaucasia? (Martijn Bot/ 

For starters, plumage of the mystery bird - especially the greenish hue, the yellow on the lores and brownish legs, does not a fit a Siberian Chiffchaff. Though the leg colour could fit, it doesn't seem to have the long primaries and long bill of a 'classic' Iberian either (though they tend to be variable). I don't know much about plumage features of south-eastern birds, but the calls might help. 

Slightly 'problematic' is that at the time of writing (February 2020) only calls outside the breeding season of the south-eastern taxa were available on xeno-canto. That's rather inconvenient for a call-analysis, since I do not want to mix things up with a possible migrant from elsewhere.


Fortunately José Luis Copete – who has been working on chiffchaffs for a long time – was kind enough to share some breeding season calls of Turkish birds. 

Common and Scandinavian Chiffchaffs are easily excluded, even by ear. I will therefore focus on Iberian, Siberian and Turkish/Caucasian (for now I'd say too little is known to separate these on call with certainty, but see conclusions/ questions). 

Iberian ChiffchaffJorge Letão
00:00 / 00:16

A very typical Iberian by Jorge Letão, Vila Real, Portugal, July 2018 (XC428200) - similar, but not identical! Note higher pitch. 

Siberian ChiffchaffAlbert Lustakhin
00:00 / 01:09

A very typical Siberian from the core-areas in Russia by Albert Lastukhin (XC336654). Note these calls are nearly "straight".

brevirostris callJosé Luis Copete
00:00 / 01:26

Breeding season brevirostris calls from José Luis Copete, May 2008, Osmaniye, Turkey. To the ear, this is more like it! 

brevirostris callJohan Buckens
00:00 / 00:10

brevirostris/caucasicus (outside breeding season) by Johan Buckens, March 2019, Antalya, Turkey. Hmmm, similar vibe but sounds different. 


Maybe the sonagrams shed some light on this. I blew them up to see more detail. 

Figure 3 (below). This is the Lauwersmeer bird.

Average duration per call 0,18 (n=5; +0,01/- 0,03). Range: 4,75-3,5 kHz (usually 3,75)

mystery chiff EdB Lauwersmeer.jpg

Figure 4 (below). I first compared the Lauwersmeer bird with Iberian. These calls are obviously shorter and they descent more steeply in pitch. Both calls end around the same frequency, but the start of the call is (also audibly!) higher in Iberian.

Average duration 0,14 (n=5 calls, 2 ind; - 0,02). Range: 5,5-3,5

ibericus Pt July 2018.jpg

Figure 5 (below). Siberian then. The duration is similar, but these call hardly drop in pitch, they are almost 'flat'.  
Average duration 0,18 (n=10 calls, 2 ind; +0,01/- 0,01). Range: 4,5-4 

Lakushtin tristis.jpg

Figure 6 (below). Now let's have a look at the brevirostris from Turkey from José. The range of the frequency  is almost exactly the same! It drops in pitch just like the Lauwersmeer bird does, from roughly 4,75 kHz to 3,5/3,75! The calls recorded by José are a bit shorter though in length though. 

Average duration 0,18 (n=10 calls, 2 ind.; +0,01/- 0,03). Range: 4,75-3,5 (usually 3,75


Copete brevirostris caucasicus.jpg

Figure 7 (below). This is the Lauwersmeer bird again, just for comparison. 

mystery chiff EdB Lauwersmeer.jpg

Figure 8 (below). What about the presumed brevirostris/ caucasicus calls from Johan then? Well, the range differs a bit, the shape perhaps, too (slighty), but the length in this bird is very comparable. 

(n=5; 1 individual):
Average duration 0,17 (n=5 calls, 1 ind. +0,01/- 0,02). Range: 4,5-3,1 (ending frequency variable: 3.1-3.5)

Buckens brevirostris caucasicus.jpg

Conclusions and questions
With Chiffchaffs from the south-east now being proven as vagrants to NW Europe (on DNA), the next question is: can we ID them in the field? Well, maybe we can! IMO the calls of the bird in Lauwersmeer in 2015 match those made in Turkey better than they match any other taxon. A perfect match was not found though, but with all individual variation within chiffchaffs in general this is might not be all that surprising. I'm actually convinced it's not an Iberian or a Siberian, so what other options are there? Sonagrams of birds from Armenia and Iran recorded by Alan Dean seem to be different, flatter, more Siberian-like  (bottom of page). Calls from both brevirostris (especially) and caucasicus in Clement et al. (1998, pdf; also depicted on Alan's website) look far more similar at first sight. I'd love to see more detailed ('stretched out/ blown-up) sonagrams of these calls. And the one 'uprising' call of caucasicus raises questions: could that be a migrant? Or are they really that variable?  A lot of questions still surround brevirostris and caucasicus. Can they be separated on plumage? Many more recordings of both taxa from the breeding grounds would be very usefull for a detailed analysis. Stuff we, as a birding community, will probably find out in the future. Birds like the one at Lauwersmeer can hopefully be identified with more certainty then. 


First of all José Luis Copete shared recordings of brevirostris from the breeding grounds. Martijn Bot, Ellen de Bruin and Dimitri Mulder (who found the bird) kindly gave permission to use there sound recordings and/or photographs of the Lauwersmeer bird. Without Peter de Knijff's DNA-analyses I would never have guessed chiffchaffs from the SE might reach NW Europe. 


Dean, A., 2017/2019. Southern forms of Chiffchaff Phylloscopus collybita: observations from Iran and Armenia, personal website. Hyperlink


Clement, P. & A.J. Helbig, 1998. Taxonomy and identification of chiffchaffs in the Western Palearctic. British Birds 91: 361-376 (pdf)


PS Some thoughts by Alan Dean
Alan Dean sent me some valuable thoughts, which he kindly allowed me to share:


I was very interested to read the fuller details about Chiffchaffs from the Netherlands and Germany confirmed as having mtDNA matching brevirostris/caucasicus. In particular, it confirms that SE races of Chiffchaff can reach NW Europe and therefore that a tristis-style call is not sufficient in itself to confirm Siberian Chiffchaff : a holistic approach remains necessary, embracing plumage and vocalisations. The call of caucasicus in particular is very similar to tristis.


The Lauwersmeer Chiffchaff is intriguing but also somewhat perplexing. It certainly does not look like Chiffchaffs I encountered in southern Armenia or Iran. Raković et al. (2019) inferred that the range of menzbieri was more extensive than hitherto established, and extended right across Iran and into southern Armenia. Given this is correct, then the birds which colleagues and I observed, photographed and sound-recorded in Iran would be menzbieri while those in Armenia would be in the region where the ranges of menzbieri and caucasicus converge. In terms of plumage, the Chiffchaffs we observed in both countries were characterised by rather white underparts. This is a feature of menzbieri, while Loskot noted this for caucasicus too. In their article on Chiffchaff races, Copete & Lopéz (2013) reported that photos of caucasicus supplied to them by Loskot did indeed exhibit distinctly white underparts. The photos of the Lauwersmeer Chiffchaff show quite extensive yellow (and olive) and hence do not look like caucasicus/menzbieri. I have no recent experience of brevirostris. Photos in Copete & Lopéz are variable but many were taken in June and could well be faded/bleached. ‘Photos 29 & 30’, taken in May and hence fresher, could well resemble the Lauwersmeer bird. Thus, on plumage brevirostris is a possibility – though this appearance is not that different from some collybita/abietinus.


So, what of the call of the Lauwersmeer Chiffchaff? Does it support brevirostris? I note that you favour sonograms with an extended time scale. While I can see that this might help evaluating the precise duration of calls, it also supresses the visual depiction of the extent of ‘inflection’ (rise and fall) of a call, so I think that a compromise is needed. Clearly, when comparing calls, all must be depicted on identically scaled axes. To my ear, the call of the Lauwersmeer bird immediately suggested a greater degree of ‘rise and fall’ than menzbieri or caucasicus. Indeed, it had a hint of one of the ‘alternative’ sweeoo calls of collybita/abietinus, though less sharply inflected and with a different timbre. I would suggest that such alternative calls need at least to be in the discussion somewhere.

To facilitate my own appreciation of the comparative characters of Chiffchaffs calls, I like to prepare a composite sound-file and thereby a composite sonogram - and that’s what I have done here. Attached are the results. The sound file has a single call from, successively, Lauwersmeer, Turkey (JLC’s recording of brevirostris), Armenia and Iran (the last two my own recordings). With the calls very much back-to-back, the Lauwersmeer call does have an audibly more-arched (almost disyllabic) sound to my ear and this is confirmed by the composite sonogram. Thus, while the frequency range of Lauwersmeer and brevirostris are similar, the structure of brevirostris call is much more on an even (if shallow) down-slope while the Lauwersmeer Chiffchaff’s call has a slight but perceptible arch. To me it sounds somewhere in-between a tristis-like call and one of the alternative ‘sweeoo’ calls of collybita/abietinus. Thus, for me, it is enigmatic and yet another instance where only genetic data could clarify which taxa might be involved. Chiffchaffs continue to intrigue and frustrate!

00:00 / 00:04

Figure 9. Sonagrams made by Alan Dean of the Lauwersmeer bird (D Mulder) compared with brevirostris from Turkey (J L Copete), caucasicus or menzbieri from Armenia (A Dean) and probable menzbieri from Iran (A Dean)   


Copete, J. L. & López, F. 2013. Identificación de subespecies en el mosquitero común, in  Rodríguez, N., García, J. & Copete, J. L.(eds). El mosquitero iberirico. Leon.

Raković, M., Neto, J.M., Lopes, R.J., Koblik, E.A., Fadeev, I.V., Lohman, Y.V., Aghayan, S.A., Boano, G., Pavia, M., Perlman, Y., Kiat, Y., Ben Dov, A., Collinson, J.M., Voelker, G., & Drovetski, S.V. 2019. Geographic patterns of mtDNA and Z-linked sequence variation in the Common Chiffchaff and the 'chiffchaff complex'. PLoS ONE 14(1): e0210268. (


Shipilina, D., Serbyn, M., Ivanitskii, V., Marova, I. &  Backstrom, N. 2017. Patterns of genetic, phenotypic, and acoustic variation across a chiffchaff (Phylloscopus collybita abietinus/tristis) hybrid zone. Ecology and Evolution 2017; 1–12.