Sunday, 22 November 2015

Oxwich Marsh 22 November 2015: the onset of winter

A light northerly breeze at the marsh swung to the west over the morning.  Apart from a half hour period of persistent light to moderate rain, the weather was very pleasant, and the light wind allowed us to put nets across both the open marsh and in the scrub around the feeders.  We initially tried tape luring for redwing and 'crests,' but only the latter proved particularly productive, with small numbers of goldcrest and two chiffchaffs captured.

The totals were as follows:

Species
New
Re-captured
Total
Snipe
1
0
1
Wren
1
3
4
Dunnock
0
7
7
Robin
0
2
2
Blackbird
1
1
2
Redwing
1
0
1
Cetti's Warbler
0
1
1
Chiffchaff
2
0
2
Goldcrest
9
1
10
Long-tailed Tit
2
7
9
Coal Tit
1
1
2
Blue Tit
30
33
63
Great Tit
0
2
2
Chaffinch
17
1
18
Greenfinch
14
2
16
Goldfinch
19
3
22
Total:
98
64
162

The tendency of snipe to use the edges of the net rides results in an occasional bird being incidentally captured (we will have dedicated snipe rides deeper in the marsh when the water levels are lower later in the winter), and this was the case today.  We didn't have a lot of time to study plumage detail, as the rain came in as it reached the processing table, and we closed the nets.

Otherwise, the features of the catch were a fairly exceptional 63 blue tits, controls of goldcrest and long-tailed tit (birds ringed at another site and recaptured at the marsh), a couple of chiffchaffs (one of which was carrying considerable fat) and moderate catches of common finch species.  A single redwing took the year total to 99.

The photograph below shows three dunnocks, all of which were trapped during the same net round:

Dunnocks (Emma Cole)
The uppermost bird was aged as a 1st winter, with the others not specifically aged. The greyish-olive iris of first winter dunnocks typically 'reddens' over the winter, to the more typical adult iris colour of reddish-brown. By November, some first winter birds cannot be accurately aged based on the iris alone, and conspicuous moult limits in the wing that might otherwise help determination are rare.  As a result, may birds cannot be specifically aged, at least by us, with confidence.

During data entry, the age of all three birds was confirmed, as they had all been originally ringed as recently fledged juveniles.  The uppermost bird and one of the others were fledglings from 2015 (so the bird specifically aged as a first winter on eye colour was indeed a first winter), with the third bird being from the 2014 cohort.  

Thanks to today's team of Charlie Sargent, Emma Cole, Suze Lewis, Heather Coats, Val Wilson and Wayne Morris for company and assistance.

Owain Gabb
22/11/2015

Friday, 20 November 2015

Oxwich Marsh 31 October 2015 & early November at Overton: a new species for the group

After a few weeks where personnel have been limited by holidays and other commitments, we had a good turn out for a session on 31 October.  Since this time activity has been fairly limited due to weather, although Cedwyn has managed a couple of trips to Overton.  Our combined efforts are summarised below.

Oxwich
The weather conditions were fairly good at Oxwich on 31 October, with a moderate south-easterly wind that gradually lessened over the course of the morning.  We nevertheless limited our netting to a couple of 60 foot nets on a raised bund (where we have been successful of late catching redwings), a few forty foot nets on the edge of some wet rush-dominated meadow (which caught more dor beetles than birds), and nets through some damp scrub and around the feeding station.

The results were as follows:

Species
New
Re-trapped
Total
Great Spotted Woodpecker
1
0
1
Wren
3
1
4
Robin
0
1
1
Blackbird
0
2
2
Redwing
11
0
11
Chiffchaff
3
0
3
Goldcrest
12
0
12
Coal Tit
0
1
1
Blue Tit
17
24
41
Great Tit
1
10
11
Nuthatch
0
1
1
Chaffinch
4
5
9
Greenfinch
18
13
31
Goldfinch
14
7
21
Total:
84
65
149

The number of redwings trapped at Oxwich was undoubtedly influenced by the high wind speed. Large scale movement of redwing was noted over the morning.

A new great spotted woodpecker was unusual for the time of year, and the other features of the catch were the three chiffchaff (all of which were very obvious collybitas), the continued good number of goldcrests and a reasonable haul of the usual finches.

Overton
Overton Mere is an area of rocky shore with a pebble storm beach (and usually extensive areas of strandline wrack) which typically holds good numbers of pied wagtails, rock and meadow pipits at high tide (when they become concentrated on the upper shore).

Following a few sessions with very little success, recent efforts have been more positive and nine rock pipits have now been captured.  The intention is to repeat the exercise at intervals over the winter.  If we have sufficient success, it may be feasible to run a Re-trapping Adults for Survival (RAS) project or work with Swansea University on a research project involving colour-ringed birds.

Some pictures are below:

Rock pipits (Darren Hicks)

Rock pipit (Darren Hicks)

Rock pipit (Emma Cole)

Rock pipit (Emma Cole)

Thanks to all who have made it to recent sessions: Paul Aubrey, Darren Hicks, Valerie Wilson, Heather Coats, Keith Vaughton, Charlie Sargent, Suze Lewis and Emma Cole.

Owain Gabb & Cedwyn Davies
20/11/2015