Thursday 6 October 2016

Blyth's Reed Warbler - Berry Head

Today I decided to visit Berry Head where a Blyth's Reed Warbler has been frequenting the quarry since Mike Langman first found the bird on the 4th October. It was surprisingly sheltered in the quarry and the bird was regularly on view, giving its presence away by its regular "tek" call. The bird varied in appearance vastly dependent on lighting conditions. Below are some photos and notes that hopefully help with the id process on what is always a tricky bird to identify in the field. Thanks Mike for a superb Devon find!

Useful references: 
Blyth's Reed Warbler: Problems & Pitfalls
Blyth's Reed Warbler Nanzial - 1st for Cornwall Sep 2015
Blyth's Reed Warbler records at Portland Bird Observatory


Amazing how different the colouration of the bird looks in different light - Here in darker light and below....

 More in the open and in brighter light. The bird seemed to show a grey shawl around the neck at times. Also uniform coloured tertials.
Reed and Marsh should be far more contrasting.

Showing a slight "banana posture" and the bronze wing panel

Pale legged and pale throated from certain angles and an all yellow lower mandible lacking any dark tip that BRW is often meant to show

Skulking! The supercilium appeared deceptively striking behind the eye at times

Again in the open briefly!

This photo shows the emargination on the 3rd and 4th primary feathers, P3 and P4. Emargination is the narrowing of the 
outer web of the feather towards the tip of the wing. On Eurasian Reed & Marsh Warblers this emargination should normally only be 
present on P3. The photo also shows P2 as being distinctly shorter than P3 whereas on Eurasian Reed and Marsh Warblers 
these should be almost the same length. 
NOTE: P1 is greatly reduced or vestigial in most passerines, so the primary count begins at P2 on this photo.

Berry Head looking towards the quarry


2 comments:

  1. Chris - thanks for comments - very great photos, and well done in taking the time to show and explain the complexities of the wing formula, there are a lot of birders that can learn a thing or two from your blog. It's amazing how things have moved on with bird id, it wasn't that long ago a Blyth's Reed in the field would not even have been considered by the old BBRC now its a local rarity and the the quality of photographs mean we can see and prove tiny details like the emarginated primaries. If the camera isn't already , it is fast becoming an essential part of a birders kit. I videoed the bird too, not for the poor footage I obtained but to capture the call which the camera did very well.
    Your blog was so good I think I'll copy itall and send it to the DBRC to assess - As you're on the committee I expect it to fly through... Its gone today so your visit was perfectly timed.
    Cheers
    Mike

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  2. Many thanks Mike - I will maybe put a link on the Devon Birds website if you think it useful. As you say, Blyth's Reed Warbler was historically a no go bird unless trapped! Agree cameras are now essential these days. Anyway, thanks again for finding it in the first place! - I resisted it for 2 days hoping to find something this end as I can clearly see Berry Head, but it never quite works like that! Glad I ventured over as a great bird to learn from and always worth seeing. Sorry I missed you.

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