Oxwich Marsh: 7 May 2017 and the year to date – Gower Ornithological Society

Perfect conditions for the first few hours today, with a very light north-westerly wind that gradually strengthened and veered to the south. Net rounds returned a steady flow of birds.

The catch was as follows:

Species	Ringed	Recaptured	Total
Great Spotted Woodpecker	0	7	7
Wren	1	3	4
Dunnock	1	9	10
Robin	2	0	2
Blackbird	1	1	2
Song Thrush	0	1	1
Sedge Warbler	3	0	3
Reed Warbler	1	0	1
Whitethroat	2	0	2
Blackcap	1	1	2
Chiffchaff	0	2	2
Blue Tit	0	2	2
Great Tit	0	10	10
Chaffinch	1	2	3
Greenfinch	1	0	1
Goldfinch	0	2	2
Siskin	7	8	15
Reed Bunting	0	1	1
Total:	21	49	70

The features were:

A control (bird ringed at another site and recovered a Oxwich) chiffchaff on BTO Tring (as opposed to London) number. We will await the information with interest.
Six juvenile siskins (following the first juvenile bird being captured last week).
The first reed warbler and sedge warblers captured in 2017 (despite both being present on the marsh for over two weeks)
Seven different great spotted woodpeckers, leading to bloodied / scratched hands for all present.
Good between year survival data on great tit in particular.

With reference to the table below, it can be seen that the year to date has been a little quieter than the previous two years, despite high levels of effort. Totals of unique birds by species between 1 January and 7 May inclusive in each of 2015-2017 have been as follows:

Species	2017	2016	2015
Sparrowhawk	0	2	0
Water Rail	0	1	0
Jack Snipe	6	5	1
Snipe	22	6	2
Green Woodpecker	0	0	1
Great Spotted Woodpecker	11	4	4
Swallow	0	0	1
Wren	12	16	11
Dunnock	20	16	19
Robin	8	8	15
Blackbird	13	8	5
Song Thrush	5	3	1
Cetti’s Warbler	4	0	7
Grasshopper Warbler	1	2	1
Sedge Warbler	3	6	3
Reed Warbler	1	2	2
Whitethroat	4	1	1
Blackcap	7	5	14
Chiffchaff	13	11	7
Willow Warbler	2	5	2
Goldcrest	4	10	6
Long-tailed Tit	5	2	10
Coal Tit	2	4	0
Blue Tit	54	98	124
Great Tit	39	51	44
Treecreeper	0	1	1
Magpie	0	1	1
Chaffinch	39	88	99
Brambling	0	1	0
Greenfinch	28	40	104
Goldfinch	194	200	162
Siskin	85	123	15
Bullfinch	7	0	8
Lesser Redpoll	0	1	1
Yellowhammer	1	0	0
Reed Bunting	18	44	30
TOTAL	608	765	702

The main differences between 2017 and previous years are:

Higher captures of common snipe, reflecting better (drier) conditions in the trapping area and greater effort in 2017
Lower numbers of blue tits than in 2016, which in turn represented a considerable decline on 2015.
A decline in chaffinch numbers (which were relatively consistent in the previous two years) and a continued decline in greenfinch totals
Lower numbers of siskin than in 2016 (when we started capturing birds earlier), but far more than in 2015
Fewer reed buntings captured than in both of the two previous years.

Two years of poor productivity (fledging success) in blue tits is clearly reflected in the results from the year to date. There are simply less blue tits around to capture. This may also be the case for greenfinch and chaffinch, as trichomonosis has clearly affected the populations of both locally in recent years. For reed bunting the reasons for the lower numbers than in previous years are not apparent, while siskin seems to vary in terms of when birds start visiting feeders and the duration of capture between years. 2016 was the best year to date, but we are well up on 2015 when the annual total was just under 60 birds.

Thanks to Val Wilson and Natasha Dodds for company and assistance this morning, and to Keith Vaughton for running a session in the week.

Owain Gabb
07/05/2017.