Sunday, 20 September 2015

Oxwich Marsh 19 September 2015: an unexpected skylark

A very light breeze that swung from the north to the south-west over the course of the morning, and relatively open skies resulted in a very pleasant morning on the marsh.

We erected a total of 700 feet of net, including a triangle of 40 foot nets for catching pipits, a line of 400 feet of net along a bund through the marsh, and a few other nets in scrubby reedbed edge habitats.  The hope was to catch some late autumn reedbed warblers, some chats and reed buntings, as well as meadow pipits and maybe a late tree pipit.

We managed to achieve most of what we set out to.  The catch of 69 birds was as follows:

Species
New
Re-trapped
Total
Kingfisher
1
0
1
Skylark
1
0
1
Meadow Pipit
15
0
15
Wren
5
1
6
Dunnock
2
1
3
Robin
1
0
1
Stonechat
4
0
4
Reed Warbler
2
2
4
Blackcap
5
0
5
Chiffchaff
6
0
6
Goldcrest
2
0
2
Blue Tit
5
4
9
Great Tit
1
0
1
Reed Bunting
10
1
11
Total:
60
9
69

The highlights were a kingfisher (the third of the year to date [seven were trapped in 2014]), a reasonable haul of 15 meadow pipits (which allowed us to start to get our collective eye in with regard to ageing them), an excellent haul of four stonechats (all first winters), a couple of reed warblers and eleven reed buntings (of which ten were newly ringed).  The most unexpected bird of the day was a skylark however.  While we had caught two birds in 2014, this was in a net configuration set for pipits on a day in late autumn when overhead passage of skylarks was occurring. Catching a bird on a narrow strip of enclosed open ground between two stands of reed was a real surprise, and it took a few seconds and a couple of double takes before we absorbed it.

We missed out on a fly over tree pipit and a whinchat.  The latter, a very well marked bird, spent some time in the vicinity of the nets, and we delayed closing in the hope that it might find its way in.  


Kingfisher (1st winter)

Stonechat (1st winter)
Skylark

The kingfisher was aged as a first winter based on the brown colouration of the feet and tarsus and the grey hue to the breast feathers.  It was considered likely to be a juvenile male (due to the blue / blue-green as opposed to green / green-blue colour of the crown, lower-back and rump) - albeit the subjectivity associated with this meant it was not formally recorded as such.

The stonechats were all first winter birds.  In all the greater coverts had been completely moulted, and one had also moulted the alula feathers.  However clear contrast was noted with the primary covers (and the alula feathers in those birds that had not moulted them), and they generally showed a fair amount of wear in the tips of the primaries.  Tail feather shape and the colour of the inside of the upper mandible were also examined.

The skylark was not aged.  Both adult and juvenile birds undergo a complete moult between July and late autumn and are therefore indistinguishable.  Based on biometric data provided by Svensson (1992) the bird was likely to be a male.

It will be interesting to see if we have now seen our last reed and sedge warblers of the year.  In 2014 the last reed warbler was captured on 27 September and the last sedge warbler on 1 October (after a gap of three weeks from the penultimate capture).

Thanks to yesterday's team of Heather Coats, Cedwyn Davies, Dan Rouse, Darren Hicks, Wayne Morris, Val Wilson and Mike Shewring for company and assistance.

Owain Gabb
20/09/2015

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