Saturday, 4 July 2015

Oxwich Marsh 03/07/15: a new species for the site and another good catch

Due to a poor (windy) forecast for the weekend, it was decided to try ringing on Friday.  This is not ideal, as due to work commitments only a few are typically able to attend and as such, it is only possible to put up a limited number of nets.  However, it is infinitely better than not getting a session in at all!

A total of 260 feet of net was erected, all running through scrub.  The number of finches using the scrub appeared very high, hence the concentration on that area.

The catch of 140 birds was made up of the following:

Species New Re-trapped      Total
Great Spotted Woodpecker 1 3 4
Wren 3 0 3
Dunnock 1 3 4
Robin 3 4 7
Blackbird 5 3 8
Song Thrush 2 0 2
Reed Warbler 1 0 1
Blackcap 2 0 2
Chiffchaff 7 0 7
Blue Tit 7 7 14
Great Tit 13 9 22
Nuthatch 1 0 1
Chaffinch 8 2 10
Greenfinch 15 3 18
Goldfinch 22 4 26
Siskin 4 4 8
Reed Bunting 1 2 3
Total: 94 44 140

The highlights were two more new song thrushes (we had already beaten the total for 2014), a good little haul of fledgling chiffchaffs, and, predictably, a good catch of finches.  The only unexpected bird was a nuthatch, however.  This was the first capture of the species at the site since ringing recommenced in early 2013.  Prior to this, ringing at Oxwich between 2001 and 2010 inclusive had returned only one nuthatch.  The nearest mature deciduous woodland habitat is approximately 300m to the west, and it is possible that birds don't tend to find the feeders in the marsh.

Adult nuthatches can be sexed on the depth of the red colouring of the flanks and under tail coverts, with males (which also typically have longer wings than females) being strongly rufous in these areas and females more buff-brown.  Adults have a summer complete moult and fledged birds a partial post juvenile moult of body feathers and coverts.  Our bird was a juvenile, and showed fresh flight feathers but pin feathers on the body.  It had a wing length of 86mm and a weight of 23.4g.  Svensson suggest that on the basis of wing length it is either a small male (wing 85-91mm) or a relatively large female (81-87mm).

A picture of the nuthatch, taken by Keith Vaughton, is below.



At this stage of the season it is interesting to note that we are currently considerably down on the total number of blackcaps and chiffchaffs trapped by the same date in 2014, and that we are also down on greenfinches.  Goldfinches and chaffinches are considerably up on last year's totals, however.

Highland cattle are used to break up the sward on the marsh, and prevent it becoming too rank and succeeding to bramble patches and willow carr.   We put nets in places that the cattle can't get to, as you really don't want to catch one of these:


Thanks to yesterday's team of Cedwyn Davies, Keith Vaughton and Heather Coats, particularly to Keith for organising things in my absence. 

Owain Gabb
04/07/15


2 comments:

  1. What a contrast to my French STOCcapture (CES) site. I use 280 ft of netting for six hours from dawn and catch 20 - 30 on a good morning. Standard fare is Blackbird, Blackcap, Black Redstart and (not-black) Serin.

    There are compensations, as catches in the past ten years have included Subalpine, Melodious and Bonelli's W's, Cirl Bunting, S-t Treecreeper, and Dipper. Oh yes, and a couple of Nuthatch !

    John Morgan

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  2. Well at least it sounds like you get some quality John! Hoping to see the juveniles flooding through over the next few weeks, particularly warblers.
    All the best
    Owain

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