Once upon a time… three little chiffchaffs arising confusion and perplexity among the birding community.

 

 

Yeah… They look quite similar, and that’s the problem.

Back in 1996 there was virtually a single species of chiffchaff in mainland Europe. We had the widespread Common chiffchaff (Phylloscsopus collybita) in all Europe, and birds form the Iberian Peninsula were just considered as subspecies with a remarkably different song. Now it has been genetically proven that the Iberian chiffchaff (Phylloscopus ibericus) fully deserves its specific identity, and the status of the Siberian subscpecies Phylloscopus collybita tristis – commonly named Siberian chiffchaff – is still under discussion.

For these reasons – and because they are lovely creatures – chiffchaffs have drawn the birders’ attention to themselves. The songs and calls provided key features for their identification : in many cases it is still considered that the song or call are the only reliable diagnostic features.

So here’s our subject for today :

Sound identification of Common chiffchaff (Phylloscopus collybita collybita/abietinus), Iberian chiffchaff (Phylloscopus ibericus) and Siberian chiffchaff (Phylloscopus collybita tristis) : song and calls.

1. Song

The songs of these three taxa sound pretty much different, so that it should be quite easy to identify singing birds even if you’re a tone deaf.

1.1 Common chiffchaff

The song of the Common chiffchaff is usually quite long (>4s), and made up of only 4 simple elements. The order in which those elements are used can vary, but the single notes are always the same :

They are all  “reverse tick” (1,3) or “h” (2,4) shaped; i.e globally descending, but can vary in pitch and length of the “leg” (see number 4′ below in the odd song : higher-pitched and longer-legged than 4). The notes are globally high-pitched, with the longer leg going up to 7kHz or above. The “h” notes are very elongated : the slash (or first leg of the “h”) is very long in comparison to the second leg of the “h”, just as if the letter “h” was distorded vertically, thus looking more like a reverse tick than a “h”

Here’s a typical full song :

 

Note that even in odd songs, there are still 3 typical notes :

 

1.2 Iberian chiffchaff.

Iberian chiffchaffs have usually shorter songs, that have a better-defined structure (segments of identical notes). Some of these notes are very different from Common chiffchaff notes.

Generally speaking, while Common chiffchaff shows descending slashes with legs at the bottom, the legs can often be found starting at the top of an ascending slash in Iberian (see below). The notes are globally lower-pitched, with the slash rarely going over 6kHz. Thus the “h”  notes are actually more “h”-shaped in Iberian that in Common (elongated “h”, see above), since the first leg is lacking the 6-7kHz part.

And here a typical Iberian chiffchaff song :

Now a less obvious song :

1.3 Siberian chiffchaff

The song of Siberian Chiffchaff conveys an impression of fluidity. It is very different from the two other songs and way more melodious. The notes are less isolated from each other, and the melody goes upslurred and downslurred on and on. The frequencies don’t exceed 6kHz. In addition, it incorporates some downcurved notes that are unique for tristis.

Hence, it shouldn’t be difficult to identify a tristis song.

1.4 Mixed singers

Birds using both iberian and Common chiffchaff (or both collybita and tristis) notes in their songs occur within and outside the hybridization zone. Some birds are proven hybrids, some are unlikely to be hybrids. Hence, their identification should be considered as unsafe for now.

 

2. Calls

2.1 Common chiffchaff

The typical chiffchaff call is an ascending straigth “huit”, comprised between 2.5 and 5kHz, with a sometimes visible harmonic much higher pitched (up to 10kHz). It is interesting to note that the harmonic is slightly downcurved

Its repertory also includes a “sweeo” genlty downcurved single note, often with a slightly upcurved ending confering an almost bi-syllabicall impression. The “tseeo” call usually starts at lower frequencies (first leg) and ends at slightly higher frequencies (second leg). It is comprised between 2.5 and 6 kHz and can show a much higher harmonic too.

2.2 Iberian chiffchaff

Iberian chiffchaff produces a gently downcurved, descending call. The descending branch always go lower than the beginning of the ascending one (opposite for Common chiffchaff). The global range of frequencies is lower than on Common chiffchaff

2.3 Siberian chiffchaff

The call of the Siberian chiffchaff is a monotonous downcurved monosyllabic note around 4.5 kHz. The amplitude is very low, so that the frequency does not vary much. When zooming on the spectrogram, it often appears that the call is descending, but never as much as on Iberian. Beware of tseeo calls produced by young common Chiffchaff, even if they should never be as monotonous nor descending.

You can find out more about identification of Iberian and Common chiffchaffs here :

Research article about identification of vagrant Iberian chiffchaff

 

S.W