Sunday, 8 February 2015

Oxwich Marsh 7 February 2015: a nice pecker

The start of 2015 has been pretty woeful in terms of ringing at Oxwich.  The weather has often been too windy to allow ringing, and when we have had opportunities, northerly winds and open skies have resulted in cold, bright days which have made the nets very visible.  In addition, the perception has been that bird numbers on the marsh have been lower than in 2014.
With this in mind, I decided to review data for the first five weeks of both 2014 and 2015, to see if there was any evidence to support this.

The results are presented in the table below:

Species 01 Jan to 7 Feb 2014 01 Jan - 07 Feb 2015
  New Re-trapped Total New Re-trapped Total
Green Woodpecker 0 0 0 1 0 1
Great Spotted Woodpecker 0 1 1 0 0 0
Wren 0 1 1 0 1 1
Dunnock 0 2 2 1 8 9
Robin 0 3 3 1 8 9
Chiffchaff 0 0 0 2 0 2
Goldcrest 1 1 2 0 2 2
Blue Tit 28 33 61 17 35 52
Great Tit 2 1 3 0 9 9
Chaffinch 8 1 9 19 3 22
Goldfinch 0 0 0 16 9 25
Greenfinch 5 0 5 5 1 6
Siskin 0 0 0 1 0 1
Bullfinch 0 0 0 1 3 4
Reed Bunting 14 6 20 3 1 4
Total: 58 49 107 68 79 147

The breakdown shows that, in fact, we have trapped more birds in 2015 than we had by the equivalent stage of 2014 (which was even more weather affected).  However, what it does not show is that in 2014 we had only got two sessions in by now, while in 2015 we have completed five.  This suggests that there are indeed fewer birds in the marsh so far in 2015, although between year differences in weather on the days that ringing was possible may well have influenced results.
The main differences in the composition of the catch between years have been in terms of goldfinch and reed bunting.  During the first 5 weeks of 2014, no goldfinches were trapped (despite a total of 443 new birds being subsequently captured during the calendar year), while 25 individuals have been captured already in 2015.  Secondly, the number of reed bunting captured has been lower in 2015 than in 2014.  This appears to reflect numbers on the marsh: only a few birds are generally seen / heard during ringing visits, but may also be due to the lack of ground feeding this year (seed including millet was put out in 2014).  Ground feeding has stopped due to evidence of trichomoniasis in the local greenfinch population (and for economic reasons!).  The capture rates of other species appear relatively similar / proportionate, although it would appear that there are less blue tits using the feeders than in 2014 at present.
The main reason why five weeks of inactivity in blogging terms has come to an end, however, is that we have caught our first notable bird of 2015, a green woodpecker.  A picture of the bird, taken by Charlie Sargent, is below:
The bird was a male.  The malar stripe (the stripe below and extending back from the bill) is red, bordered by black below and behind (whereas in a female the stripe is entirely black).  Ageing is slightly less straightforward, particularly if you don't trap the species regularly.  However, the tertials lacked extensive barring, and the colour of the primary coverts, which had distinctive yellowish-green leading edges, together with a number of other supporting features, indicated this was not a bird that had fledged in 2014 (i.e. it was an adult, the specific age of which was unknown).
A beautiful bird.  The first caught on the marsh since Gower Ringing Group started trapping on the site in early 2013 (despite the fact that they are commonly heard and seen), and fairly notable in Welsh terms (only 4 were trapped in Wales in 2013 - 2014 data for Wales are not available on line yet).
Many thanks to Heather Coats, Charlie Sargent, Keith Vaughton, Wayne Morris, Darren Hicks, Emma Cole, Phil Mead and Hannah Meinertzhagen for company and assistance yesterday.
Owain Gabb

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