Barred Warbler Sylvia nisoria at Hengistbury Head - 15th September 2008

On a typical early autumnal morning, a last minute decision to put up an extra 40-foot mist net certainly paid dividends. We were trapping the last remnants of the 'acro' warblers in the Hengistbury Head Centre (HHC) reedbed, but a good number of Chiffchaff were also being trapped nearby. So the signs were good that a rarity might turn-up - and it certainly did!

At 8.00am, on about the second or third net-round a largish, sylvia warbler was seen caught in the aforementioned mist net. I had not trapped a single Garden Warbler all summer so my first thoughts that this was what I had caught, owing to the stocky nature of the bird and its largish bill. However, the pale edges to its coverts quickly put that idea out of my head, so thoughts turned to what it could be. I got the bird quickly into a bird bag and proceeded to clear the rest of the net, mostly Chiffchaff, and finished the net round. Whilst walking back to my car I thought of Barred Warbler as the only viable possibility.

Back at my car, I checked over the bird and first of all measured the wing - 86mm. So that definitely ruled out an aberrant Garden Warbler. Checking my reference books, the pale edges to the coverts and other biometrics led to the conclusion it could only be a Barred Warbler - only the third ever to be trapped within the CHOG recording area and the first seen since 2003.

The two photos below show the main identifying features of the Barred Warbler. The upper photo clearly shows the pale edges to the tertials and greater coverts, while the lower photo shows the dark spotted under-tail coverts.

Barred Warbler Kevin Sayer

Barred Warbler Alan Hayden

Ageing and Biometrics

The bird was aged as a first-winter (Euring Age Code 3) due to eye colour (iris very dark - adult bird would have a dull yellow or bright orange-yellow iris), lack of barring on the breast and narrow and abraded central tail feather.

The wing was measured as 86mm, the tail was 68mm, the bird weighed 28.8g and the fat deposits were scored as 5 (out of 8).

After processing the bird was immediately released into bushes surrounding the HHC, but was not subsequently seen.

References

Identification Guide to European Passerines, Lars Svensson, 4th Edition 1992

Kevin Sayer