Chiffchaff? ID verification, Poland (1 Viewer)

[JayFeatherPL]

North-eastern Poland, today, morning, my garden.
Is it Chiffchaff (pp) despite its pale legs?

 

[THE_FERN]

Probably, and despite the pronounced supercilium. The wing looks very blunt (short primary projection) which is good for chiffchaff. Brightening images like these (taken against the light) helps...

 

[JayFeatherPL]

Probably, and despite the pronounced supercilium. The wing looks very blunt (short primary projection) which is good for chiffchaff. Brightening images like these (taken against the light) helps...

Does it? When comparing Chiffchaff and Willow Warbler...Anyways, thanks for help

 

[Jane Turner]

Despite the short primary projection, the bill shape and face pattern both look better for WW. I'd be deferring to call and behaviour on this in the field - was it tail dipping? Can't see a 6th pp emargination (which would have nailed it in terms of proving Chiff, but I wouldn't read too much into not being able to. Every year I get Phylloscs I can't pigeonhole, despite catching them - eg this is a WW with a few anomolies inc a shortish primary projection.

 

[THE_FERN]

Despite the short primary projection, the bill shape and face pattern both look better for WW. I'd be deferring to call and behaviour on this in the field - was it tail dipping? Can't see a 6th pp emargination (which would have nailed it in terms of proving Chiff, but I wouldn't read too much into not being able to. Every year I get Phylloscs I can't pigeonhole, despite catching them - eg this is a WW with a few anomolies inc a shortish primary projection.View attachment 1641481

Entirely agree with your comments but would just note that your captive bird seems to have a longer "thinner" wing than the op. I'd like to think I'd id it as we in the field...

 

[JayFeatherPL]

Despite the short primary projection, the bill shape and face pattern both look better for WW. I'd be deferring to call and behaviour on this in the field - was it tail dipping? Can't see a 6th pp emargination (which would have nailed it in terms of proving Chiff, but I wouldn't read too much into not being able to. Every year I get Phylloscs I can't pigeonhole, despite catching them - eg this is a WW with a few anomolies inc a shortish primary projection.

Thanks. I can't remember its behaviour...However, I've got two questions:
1. What are the differences between Chiffchaff's and WW's bill? Haven't heard of this feature in any guide.
2. How can you see the emarginations? Where do you look at? Personally, I can't see any emarginations on any photo (despite knowing the definition).

 

[Jane Turner]

I will do this in two posts. First, the emarginations. You can often see the edge of a feather vanish suddenly. The leading edge on Phyllosc primary feathers is often paler, making the sudden disappearance easier to see. WW usually has brighter edges, but chiffchaff usually has sharper emarginations.

Here is a long-winged chiffchaff with 4 emarginations, but the inner one is very subtle:


And here that short-winged Willow Warbler (both birds from the last few days) - 3 emarginations and you can see that the 6th primary counting from the outside (I put a blue blob on it) has a bright clear edge that is parallel to the shaft.



On your bird I can only see two certain emaginations - I think I can see a third, but I can't see either a 4th or a clear unemarginated leading edge hence it doesn't help.

 

[Jane Turner]

Now for the bills. Chiff bills tend to have a more even, finer tip - the upper mandible has less of a curve to it - this is a plate from Subalpine birding's paper on Iberian Chiffs - these are common Chiffs though




Willow warbler have a less straight upper mandible and the top of it is usually a little curved over the lower one - ie is less symmetrical

 

[Frank van Drogen]

Definitely higher level IDing!!!

Thanks for sharing

 

[JayFeatherPL]

Thank you very much!

 

[Stonefaction]

Something else I've noticed with Willow Warblers and Chiffchaffs that is a bit tricky to put into words accurately (but I will try and hopefully it makes some sort of sense) is the shape of the curvature of the top of the head. Chiffchaff seems to (mostly) have a more evenly rounded curve to the top of the head, with the highest point (usually) above the eye. Willow Warbler seems to (often) have a flatter top of the head profile, and when it appears more rounded the highest point is behind the eye/closer to the back of the head. Even looking at the photos posted above by Jane it obviously isn't always helpful but it does seem to provide an extra supporting clue towards an ID in most cases.

 

[Jane Turner]

Yes re the more angular head shape! Its not
the thread for it - really - but there is a risk (perhaps not in Poland) of treating all birds as either WW or CC - which is how non-singing Iberian Chiffs are missed. I gave that short-winged WW the 3rd degree but despite the shortish pp, retained juv feathers which WW really shouldn't have and a long for a WW short for a CC 2nd primary - but it had WW head and bill shape, didn't have a white throat and had brown tones in the mantle.

 

[JayFeatherPL]

I gave that short-winged WW the 3rd degree

What's 3rd degree?

 

[Richard Dale]

What's 3rd degree?

An English turn of phrase used to mean subjecting something to an intensive interrogation or investigation. In this case Jane is implying that she examined the WW very closely in case the bird was an Iberian chiffchaff.

 

[JayFeatherPL]

An English turn of phrase used to mean subjecting something to an intensive interrogation or investigation. In this case Jane is implying that she examined the WW very closely in case the bird was an Iberian chiffchaff.

Ah, I see. Thanks.