Sunday, 10 November 2013

Oxwich Marsh 10 November 2013

A cool morning with a very light north-westerly wind and broken cloud provided good conditions for ringing at the marsh.  This was welcome, as it hadn't been possible to find a day in the last couple of weeks when conditions were right.
 
The catch comprised: great spotted woodpecker (1), chiffchaff (1), Cetti's warbler (1), goldcrest (3), robin (2), song thrush (1), wren (3), dunnock (2), great tit (4), blue tit (13) and long-tailed tit (1).  Despite having put millet down for the past couple of weeks, reed buntings were notable by their absence in the nets - but there is still a lot of food about at the moment and numbers have not built up.

All of the great tits and four of the blue tits were birds that had been previously ringed at the site (retraps).  One blue tit was approaching 4 years and 1 month since initial capture (as a first winter bird in October 2009). 
 
The ease with which great tits can be aged varies considerably between birds.  Some adults show broad 'battleship grey' fringes on the outer webs of the primary coverts (in first winter birds these feathers have a green or a grey green margin), while the most straightforward to age first winter birds typically have retained greenish-tipped alula feathers or even an old greater covert (these are retained far more regularly in blue tits).  However, many birds, particularly females, are not straightforward, and experience of variation is extremely useful if you are to age them accurately.  This great tit is a male, and was first ringed (as an adult) in Spring 2013.

 
The most notable species in the catch were the chiffchaff, the great spotted woodpecker and the Cetti's warbler.  The chiffchaff was carrying significant fat (this filled the tracheal pit and was convex [score 5]), so may still be preparing to migrate or may be a new arrival.  The Cetti's warbler was the tenth new bird of that species in 2013, while the woodpecker was the first at the site since December 2009 (they are regularly seen flying over).  It was a first winter female, and pictures are below.  Males show red on the nape, and the bird was aged on the basis of wing feather pattern and different generations of feathers in the wing.



Overhead there was a fair bit of movement during the course of the morning, with hundreds of woodpigeon streaming west during the first couple of hours of daylight, and smaller movements of siskin, redpoll, goldfinch and skylark.  Snipe were flushed from the reed bed during set up, and a nice male brambling was with goldfinches in nearby alders.
 
Thanks to Charlie Sargent and Heather Coats for company and a good session this morning.

Owain Gabb
10/11/13.

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