Sunday 22 July 2012

Titchfield Haven, Bird Ringing 22nd July 2012

With the weather set fair for a second day we decided to take full advantage and descended on Titchfield Haven for another ringing session this morning. The morning began in a similar pattern to the previous day, with the first birds captured being Grasshopper Warblers, and it was not long before we had captured 11, our first double figure haul of this species this year. Still much slower than last year, but we have now captured 18 birds, all of which have been juveniles. Eurasian Reed Warbler was once again the most common species, with 16 birds captured, but in contrast to the Groppers, the majority of these birds were adults.

Adult Reed Warbler Wing

Ageing reed warblers is a relatively straight forward process, since both adults and juveniles mainly have a complete moult on their wintering grounds. This means that the wing and feathers are usually extremely worn in adult birds in the autumn. Obviously the extent of wear is variable, but in the image above it is possible to clearly see the worn tips to the primaries, and bleaching of the feather tips where one primary overlays the other.

Juvenile Reed Warbler Wing
In a juvenile bird the primaries are very fresh, showing little or no wear, as can be seen above.  In addition to the worn plumage, adult birds also have a warm grey-brown or rufous-brown iris...

Adult Reed Warbler Eye
 ...whereas the juvenile iris is dark grey, as illustrated below.

Juvenile Reed Warbler Eye

The species captured was similar to that of the previous day, and included more Sedge Warblers, both adults and juveniles, four Chiffchaffs and four Blackcaps, and another adult Garden Warbler. Two juvenile Song Thrush, and a juvenile Reed Bunting made up the numbers. We ended the session having caught 57 birds of which 55 were new; finally it is looking like the autumn migration is getting going.

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