Sunday, 4 May 2014

Oxwich Marsh 3 May 2014: reaching 1000 in style

Despite a gusty south-easterly wind, the net rides in the scrub were relatively sheltered, although the nets in the reedbed were moving a little too much to suggest we would catch much in there. In addition to 180 feet of net in the reeds and 160 feet in the scrub, we also put a 60 foot net across a compound used by Natural Resources Wales for the storage of machinery and materials.

The wind caused some early pessimism about the size of the catch, but in the event it was probably one of the best days in the last year.  In total 65 birds were processed, with the highlights being the first wood warbler for the site, evidence of breeding siskin, and a spring grasshopper warbler (captures of grasshopper warbler in 2013 were limited to passage birds in the autumn).

Species New Re-trapped Total
Great Spotted Woodpecker 0 2 2
Wren 1 2 3
Dunnock 0 2 2
Robin 0 1 1
Blackbird 1 0 1
Grasshopper Warbler 1 0 1
Sedge Warbler 2 0 2
Blackcap 2 0 2
Wood Warbler 1 0 1
Willow Warbler 1 1 2
Coal Tit 1 0 1
Blue Tit 2 2 4
Great Tit 0 3 3
Chaffinch 3 0 3
Greenfinch 12 7 19
Goldfinch 0 2 2
Siskin 9 7 16
Total: 36 29 65

Wood warbler (Charlie Sargent)

The wood warbler had a wing length of 77mm, substantially longer than willow warbler (60-70mm) and chiffchaff (53-68mm).  In the net its size was instantly apparent, with the clean white underparts, lemon yellow throat and colouration of the upper parts confirming identification.  It was not in breeding condition, so could not be sexed.  However a brief snatch of early morning song suggests the bird was a male.


 
 


The grasshopper warbler was caught in the compound: a really odd place to catch it.  The only reedbed warblers trapped were two sedge warbler.  Reed warblers are present at low density in the marsh, but seemed more intent on securing territories than moving around.


Siskin (left) may breed on Gower (at Whiteford or in other large areas of coniferous or mixed woodland), although whether there are previous records of this is unknown at this stage.  It is great to be able to confirm they have bred at Oxwich this year.  As we have been scoring the brood patches of female siskins over the past month or so, it should have been no surprise that we captured juveniles on this visit.  The brood patches of the adult females trapped during this session were no longer thickened / engorged, and we trapped 4 juveniles over the course of the morning.



Other notable captures were a great tit now in excess of 5 years of age, a coal tit, which is only the second trapped since March 2013, and a willow warbler (DEL468) which was first trapped at the site in July 2013, and has been recaptured on two recent visits.  Amazing to think such a small bird has spent part of the intervening period in sub-Saharan Africa.  Finch numbers remain good.  The continued steady stream of greenfinches continues, and the number of chaffinches is rising incrementally.  Goldfinch numbers have now dropped off: a few are present around the marsh, but these are almost exclusively ringed birds.


We have now passed 1000 birds processed on the site in 2014, which is good given it is only early May.  The next target is beating the 29 species processed in 2013.  However, with 25 already, we are well on track.

Species New Re-trapped Total
Kingfisher 1 0 1
Great Spotted Woodpecker 1 6 7
Wren 5 11 16
Dunnock 5 16 21
Robin 1 8 9
Stonechat 2 0 2
Blackbird 1 0 1
Cetti's Warbler 2 3 5
Grasshopper Warbler 1 0 1
Sedge Warbler 4 0 4
Reed Warbler 3 2 5
Blackcap 8 0 8
Wood Warbler 1 0 1
Chiffchaff 7 0 7
Willow Warbler 7 2 9
Goldcrest 2 1 3
Coal Tit 2 0 2
Blue Tit 69 100 169
Great Tit 15 59 74
Chaffinch 51 9 60
Greenfinch 151 28 179
Goldfinch 179 36 215
Siskin 52 36 88
Bullfinch 3 2 5
Reed Bunting 71 38 109
Total: 644 357 1001

An excellent session.  Thanks to Charlie Sargent, Heather Coats and Julian Trevino-Villarreal for their help and company this morning.

Owain Gabb
04/05/2014


1 comment:

  1. An unringed wood warbler was singing in a small stand of birch in the dunes at Oxwich (SS505873), 7:30am, 28 May 2014.

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