Friday, 18 October 2013

One for the nerds

Great sunny weather today caused me to go searching for the Bearded Tits (skjeggmeis) at Fornebu to get even better pictures. Well that was a waste of time as two hours of waiting produced no Beardies and as my attempts to photograph chiffchaffs proved the bright low autumn sun may allow a lower ISO but was extremely challenging otherwise.

I met Jan Erik Haugen when I arrived at Fornebu and he had heard a bird he believed was the tristis Chiffchaff (gransanger) and a quick check of a recording I had on my phone confirmed this was the sound. We both went over to the reedbed at Koksa where after a short wait we heard the bird briefly. It called a couple of times in a typical tristis manner (monosyballic “peep”) and after a short wait a chiffchaff popped out of the reeds and showed in a tree.
This is the type of call I heard:

This bird looked the part and when I played the call of tristis it immediately reacted by looking at me and flying closer, but did not call. I was quite happy with this being a (the) tristis although wanted better (portrait) pictures. We lost the bird after it dropped down into the reedbed and it was around half-an-hour later and 100m away that we again heard a chiffchaff but this was not the classic tristis sound, nor was it the classic “huit” of a normal western chiffchaff. It was somewhere between the two and corresponds with what are often reported as “eastern Chiffchaff” (I don't believe there is agreement as to the exact identity of these birds but presumably an intergrade between western Chiffchaffs and tristis).

This recording from xeno-canto has a similar call to the second bird:

This bird also popped up out of the reeds (although again I never actually saw it calling) and on restricted views looked the same as the previous bird although I did not get to really grill it.

I did get pictures of both birds and whilst not entirely conclusive they do support that there were two different individuals although it would have been nice to see and/or hear both at the same time to irrefuteably confirm that there were two individuals present.Based on the fact that I heard two different calls and that the photos back up that there were two different birds then it looks like there was both a tristis and an "eastern" Chiffchaff in the same area.

Bird (sighting) 1, which popped up after briefly hearing a tristis call and which also flew towards me when I played the call of tristis. A pale bird with shades of grey and brown.
no yellow or green colours visible. Also note the very weak bill which is given as a tristis character
the best profile picture I managed. The suggestion of a wing bar is a good tristis sign as is the distinct black allula.

here the light was against me but note the contrasting wing with darker flight feathers and suggestion of a pale wing bar
Bird 2. This individual called like an "eastern" Chiffchaff and not like a classic tristis. The crown looks to be more olive than in Bird 1, the bill stronger and there is a yellow wash below the wing on the right side of the bird (which is present in other pictures and seemingly not an effect of the light). This yellow wash counts against tristis and is not present in the pictures of Bird 1.
I never got any pictures of this bird in profile but

there is a yellow wash under the wing here which is not visible on bird 1

We also surprised a male crossbill sp from a small pine tree which flew low over us calling. It was all over very quickly and there was no trumpet call and I only saw the underside of the wings but I am 90% sure it was Two-barred. The call had me first thinking of redpoll and the red colouration seemed far more scarlet like than on a Common Crossbill but it all happened to briefly to be sure. Something to search for again.

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