Saturday, 7 September 2013

Plenty of warblers, but no martins ...............

As the weather forecast had been poor right up until last night (when it changed completely), the ringing session at Oxwich Marsh this morning was far better than expected.  A light north-westerly wind wheeled gradually to the north and strengthened over the morning, but until around 10am the nets were relatively still, and the rain held off despite showers until dawn.

The decision to go to Oxwich was fully vindicated by the number of birds trapped.  In total 43 birds of 11 species were caught.  These were: reed warbler (20), sedge warbler (7), Cetti's warbler (2), chiffchaff (3), blackcap (1), whitethroat (1), blackbird (2), wren (3), blue tit (2), bullfinch (1) and robin (1).   

The catch was dominated by young of the year, with only one of the blue tits being more than 1 year old.  Many of the reed warblers had finished their post juvenile moult, and are likely to be feeding up prior to migration.  Only a few had significant fat deposits however. 

The young of some resident species, such as wren and bullfinch, in contrast, are less well progressed in terms of post-juvenile moult.  In fact, one juvenile bullfinch was still in entirely juvenile plumage, with a bare belly, and no sign of any replacement of body feathering.  It was good to catch two more Cetti's warblers: both were juveniles with fresh flight feathers but extensive moult of body feathers going on.

Attempts to catch some house martins (following several mixed flocks of swallows and martins across the site) were 'after the horse had bolted.'  By the time an additional net had been put up all hirundines seemed to have disappeared.  Visible migration was very limited overhead, with only meadow pipits and the odd pied and grey wagtail noted in addition to the swallows.

Thanks to Charlie Sargent, Keith Vaughton and Cedwyn Davies for a pleasant morning and a good session.

Owain Gabb 07/09/2013

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