Sunday, 9 August 2015

Oxwich Marsh early August: an influx of migrants

Friday and Saturday were both calm and mainly sunny at Oxwich.

On the Friday we put up 240 feet of net and on the Saturday 620 feet.  However the catches were similar in number (104 and 107), suggesting that the unsettled weather over the previous few days had seen bird numbers in the reedbed build before a lot moved out on Friday night.  Evidence of turnover of warbler was provided by the fact that we had no retraps from the previous day (albeit we did recapture a lot of tits).

The combined catch was as follows:

Species New Re-trapped Total
Great Spotted Woodpecker 0 4 4
Wren 9 1 10
Dunnock 0 3 3
Robin 1 5 6
Stonechat 1 0 1
Blackbird 1 0 1
Cetti's Warbler 2 0 2
Grasshopper Warbler 1 0 1
Sedge Warbler 15 1 16
Reed Warbler 15 0 15
Whitethroat 2 0 2
Garden Warbler 4 0 4
Blackcap 23 0 23
Chiffchaff 3 0 3
Willow Warbler 18 0 18
Long-tailed Tit 1 0 1
Blue Tit 12 24 36
Great Tit 4 11 15
Greenfinch 29 7 36
Goldfinch 7 0 7
Siskin 0 1 1
Reed Bunting 4 2 6
Total: 152 59 211

Of particular interest were:
  • Our first stonechat of the year, a juvenile.  A family party was around the fen meadow nets;
  • Two new Cetti's warblers, one of which was in entirely juvenile plumage and cannot long have left the nest;
  • Further proof, following reeling over a prolongued period and catching a male grasshopper warbler twice in four weeks a and a female bird in breeding condition, that breeding has taken place on the marsh.  A young grasshopper warbler that had just begun its post juvenile moult was captured;
  • A trickle of garden warblers.  This is a scarce autumn passage species in Gower.  It would be nice to go close to the 2014 total of 21 unique birds;
  • Evidence of migration, with some sedge warblers and willow warblers in particular showing reasonable fat stores (up to 5 with reference to the BWG system).
  • A recaptured reed bunting initially ringed by Barry Stewart in July 2008, and therefore in excess of 8 years of age.    

A solid start to the most interesting period of the year.

Thanks to Keith Vaughton, Heather Coats, Daren Hicks, Emma Cole and Wayne Morris for company and assistance over the sessions.

Photographs taken by Keith and I are below

Owain Gabb
09/08/2015

Juvenile stonechat (KV)


Young sedge warbler

Reed warbler (also a young bird)


Garden warbler (KV): we caught three juveniles and an adult.  Ageing is challenging.  If there is no brood patch apparent it is based on (often) subtle differences in feather wear



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