Saturday, 5 April 2014

Oxwich Marsh 4 April 2014

A poor forecast for the weekend meant some last minute arrangements were made to try a Friday session.  The wind was a light south-westerly, and overhead cloud resulted in conditions that were not far from ideal.  As has been typical of recent sessions, the first couple of rounds were fairly quiet, and the numbers of birds trapped per round gradually increased over the course of the morning.

A total of 38 birds were captured in 160 feet of net.  The nets were up by 06:45 and were taken down just after 11:00.  The species trapped, and the ratio of new to re-trapped birds (previously ringed individuals) can be seen in the table below.

Species
New
Re-traps
Total
Wren
0
1
1
Dunnock
0
2
2
Cetti's Warbler
1
0
1
Blue Tit
1
5
6
Great Tit
1
7
8
Greenfinch
2
0
2
Goldfinch
7
1
8
Siskin
1
0
1
Bullfinch
1
1
2
Reed Bunting
3
4
7
Total:
17
21
38

The highlights of the morning were the first new Cetti's warbler of the year, a siskin, a couple of bullfinch (including the first newly ringed bird of the year), and three new reed bunting (as this took the annual total to 60 new birds).

The first impression of the Cetti's warbler in the net was that it was a small bird, almost certainly a female.  It had balled itself up like a wren, and the clear supercilium and small size made it look very like that species on approach.  In terms of wing length and weight the two species can be relatively similar: the Cetti's warbler had a wing length of 55mm and a weight of 11.0g, while a retrap second calendar year wren, caught during the same session, had a wing of 52mm and a weight of 10.5g. 




Female Cetti's warbler




Female bullfinch

A breakdown of species during the year to date is below.
 
Species New Re-traps / Controls Total
Great Spotted Woodpecker 0 2 2
Wren 1 4 5
Dunnock 3 9 12
Robin 1 6 7
Stonechat 2 0 2
Cetti's Warbler 1 1 2
Chiffchaff 3 0 3
Goldcrest 2 1 3
Blue Tit 63 91 154
Great Tit 12 32 44
Chaffinch 28 2 30
Greenfinch 106 11 117
Goldfinch 127 16 143
Siskin 10 1 11
Bullfinch 3 2 5
Reed Bunting 60 26 86
Total: 422 204 626
 
Many thanks to Heather Coats, Keith Vaughton and Jessica Whitehead for coming along on Friday.  It will be interesting to see if this is the last session where finches are trapped in any numbers.
 
Owain Gabb
05/04/14

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