Saturday, 11 August 2018

Oxwich Marsh Bird Ringing: late July and early August

As is usual at Oxwich (a coastal reed bed with fringing scrub) in late July and early August, the numbers of birds captured has varied widely between sessions. A total of 431 birds have been captured over four visits, albeit almost 200 of these were on 4 August.

The breakdown is as follows:

Species Name
Ringed
Recaptured
Total
Blackbird
9
1
10
Blackcap
30
2
32
Blue Tit
23
9
32
Cetti's Warbler
2
1
3
Chaffinch
1
0
1
Chiffchaff
3
0
3
Dunnock
5
13
18
Garden Warbler
9
0
9
Goldfinch
3
1
4
Grasshopper Warbler
1
1
2
Great Spotted Woodpecker
0
3
3
Great Tit
7
24
31
Greenfinch
8
0
8
Reed Bunting
2
9
11
Reed Warbler
66
14
80
Robin
0
2
2
Sedge Warbler
76
5
81
Siskin
1
5
6
Song Thrush
2
0
2
Stonechat
1
0
1
Swallow
1
0
1
Tree Pipit
5
0
5
Whitethroat
13
0
13
Willow Tit
1
0
1
Willow Warbler
61
0
61
Wren
9
2
11
Grand Total
339
92
431

Highlights have been:
  • A willow tit (only the second to be captured at the site since 2013) on 27 July
  • Our first garden warblers of the year (3) on 27 July. At the time of writing we have captured nine.
  • Sixty-one willow warblers, including a day total of 46 on 4 August
  • Seventy-six sedge warblers, including a day total of 58 on 4 August
  • Our first stonechat of the year, a recently-fledged juvenile
  • Our earliest tree pipits (by one day) to date; three on 9 August with two more on 11 August.
The willow tit was a young bird in post juvenile moult. The principal features in identification (i.e. separation from marsh tit) were the unmarked upper mandible, the lack of contrast between the white cheeks and the neck sides, the difference in length between the longest and shortest tail feather, and a relatively clear pale panel in the wing (for a young bird). 

Willow tit is a notable record for south / west Gower; the remnant local population is confined to the northern edge of the recording area, so this represents an indication that a local breeding population persists in the Peninsula.

Garden warbler is a scarce breeder and under recorded passage migrant in Gower. They typically first appear each year in the last few days of July, and are captured throughout August before becoming scarce in early September. The willow and sedge warblers have clearly included birds preparing to migrate, with some carrying significant fat. The tree pipits to date have all been fledged birds of the year.

Among the recaptured birds during the period have been a reed warbler and a reed bunting ringed in 2013. We have also been notified that one of our young reed warblers was recaptured at the Teifi Marshes recently (ringed 14 July and recovered at Teifi on 1 August). This is a north north-westerly movement of 67 km. Initial dispersal further away from the wintering grounds is not atypical of young reed warblers.

Thanks to all who have attended recent ringing sessions: Heather Coats, Keith Vaughton, Wayne Morris, Edward O'Connor, Richard Dann, Joanne Conway, Alex McCubbin, Martin Thomas, Martin Georgiev, Val Wilson, Sarah Davies, Amy Schwartz, Sophie de Grissac, Dionne Jenkins and Kathryn Dunnett.

Owain Gabb
11/09/2018

Willow tit (Richard Dann)

Whitethroat (Alex McCubbin)

Tree pipit (Amy Schwartz)
Tree pipit (Richard Dann)

Tree pipit (Richard Dann)

Common lizard (Richard Dann)

Sunday, 22 July 2018

Oxwich Marsh 21 July 2018: Autumn Migration begins

A third consecutive catch of over 200 birds. As in the previous two weeks we predominantly captured common resident species, supplemented by good numbers of sedge and reed warbler and occasional other long distance migrants.

Species Name
New
Recaptured
Total
Blackbird
1
5
6
Blackcap
6

6
Blue Tit
11
17
28
Bullfinch

2
2
Cetti's Warbler
2

2
Chaffinch
11
3
14
Chiffchaff
1

1
Dunnock
5
15
20
Goldfinch
4
1
5
Great Spotted Woodpecker
1
10
11
Great Tit
17
43
60
Greenfinch
2

2
Reed Bunting
3
6
9
Reed Warbler
23
18
41
Robin
1
11
12
Sand Martin
1

1
Sedge Warbler
15
7
22
Siskin
6
9
15
Song Thrush

1
1
Swallow
1

1
Whitethroat
1

1
Willow Warbler
4
1
5
Wren
1

1
Grand Total
117
149
266

The highlights were:
  • Our first sand martin of 2018. Captured leaving a reed bed roost just after dawn (along with a swallow). 
  • The first indications of return migration of the year. Adult reed and sedge warblers were captured with fat scores of four (BWG system).
  • A control reed warbler - details awaited, and a number of recaptures of reed warblers ringed in 2015 and 2016.
  • Our 28th newly ringed great spotted woodpecker of the year.
  • A dunnock ringed in March 2014, which had been recaptured in 2015, but not since.
The table below provides a breakdown of newly ringed birds between 1 Jan and 21 July 2018, and the the same period in 2017.

Species Name
2018
2017
Diff
Blackbird
28
18
10
Blackcap
25
13
12
Blue Tit
138
60
78
Brambling
21
0
21
Bullfinch
11
8
3
Cetti's Warbler
5
9
-4
Chaffinch
130
54
76
Chiffchaff
12
26
-14
Coal Tit
2
2
0
Dunnock
43
22
21
Goldcrest
5
4
1
Goldfinch
159
218
-59
Grasshopper Warbler
4
4
0
Great Spotted Woodpecker
28
12
16
Great Tit
154
48
106
Greenfinch
28
40
-12
Jack Snipe
5
6
-1
Lesser Redpoll
1
0
1
Lesser Whitethroat
1
0
1
Long-tailed Tit
3
6
-3
Marsh Tit
3
0
3
Nuthatch
1
0
1
Reed Bunting
48
23
25
Reed Warbler
94
49
45
Robin
34
31
3
Sand Martin
1
0
1
Sedge Warbler
49
29
20
Siskin
175
128
47
Snipe
27
22
5
Song Thrush
7
3
4
Stonechat
0
1
-1
Swallow
8
0
8
Treecreeper
3
2
1
Whitethroat
7
8
-1
Willow Warbler
19
16
3
Wren
21
11
10
Yellowhammer
0
1
-1
Grand Total
1300
874
426

Being over 400 (ringed) birds up on 2017 in mid-July is notable (we have also recaptured over 500 more birds than during the equivalent period of 2017), but a bit of bad weather in August or September (when catches are consistently large) will soon put us back in line with previous years. However, the autumn proper begins at the marsh at the end of the month (usually signalled by the first garden warbler of the year). It will be fascinating to see whether the larger catches are sustained.

Thanks to Heather Coats, Keith Vaughton, Wayne Morris, Val Wilson, Jo Conway, Alex McCubbin, Martin Thomas, Martin Georgiev and Dionne Jenkins for company and assistance. It was a tribute to the quality of the team we had out that it didn't feel a particularly busy morning.

Owain Gabb
22/07/2018

Sand martin (Carly Green)