Tuesday, 13 May 2014

Oxwich Marsh 13 May 2014

As the weather at the weekend had been dominated by strong south-westerly winds, we had been unable to get a session in at Oxwich.  With the weather settling down, however, we managed to get in a quick visit to the marsh before the group turned its attention to more serious concerns i.e. catching up on the long-running Re-trapping Adults for Survival (RAS) project on pied flycatcher at Cwm Clydach and the two Constant Effort Sites (CES).

The weather while better than of late still wasn't ideal.  A light north-westerly wind picked up over the morning and, together with smaller numbers of birds visiting the feeders, is likely to have limited the catch.  Only 37 birds were trapped, and for the first time in 2014 re-captured birds outnumbered new birds ringed.  The breakdown was as follows:

Species New Re-trapped Total
Great Spotted Woodpecker 0 2 2
Dunnock 1 0 1
Robin 1 0 1
Blackbird 1 0 1
Blackcap 1 0 1
Chiffchaff 1 0 1
Willow Warbler 1 0 1
Blue Tit 1 2 3
Great Tit 0 2 2
Magpie 1 0 1
Greenfinch 3 4 7
Goldfinch 3 1 4
Siskin 4 6 10
Reed Bunting 0 2 2
Total: 18 19 37

Goldfinch
The pleasing aspects were the captures of single willow warbler, chiffchaff and blackcap, as these are all migrants (willow warbler being the only sub-Saharan migrant of the three), and the continued captures of small numbers of finches.  The total of newly captured greenfinch (154), goldfinch (182) and siskin (56) for the year to date all comfortably exceed expectations at the start of 2014.
 
Evidence of local breeding was confirmed in siskin during the last session.  No fledged greenfinches or goldfinches have been trapped to date however, although it is clear from the brood patches of the females that there is a good population of greenfinches breeding locally.  Evidence for locally breeding goldfinch is more scant, and the large flocks that we present in late winter and early spring disappeared a few weeks back.
 
For Charlie, the highlight was a magpie, as this was a new species for him.  A female bird was trapped in the NRW compound.  It showed a well developed brood patch (thickened / engorged), had a wing length of 183mm and a weight of 159.7g (for context a blue tit often weighs slightly in excess of 10g and an adult female blackbird caught during the session weighed 93.1g).  This was the second magpie caught at the site, following an unsexed bird in October 2013.
 
A photo of the magpie, taken by Charlie Sargent, is opposite.
 
Hopefully the weekend will bring more unexpected birds, but preferably in the form of long distance migrants .........

Thanks to Charlie, Cedwyn Davies and Keith Vaughton for coming along this morning, and for continuing the session after I had to go to work.
 
Owain Gabb.
13/05/2014

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