Saturday, 16 September 2017

Oxwich Marsh 16 September 2017: the changing of the guard

A light northerly breeze and open skies was a welcome change to the unsettled, and often very wet weather that had dogged us during the ringing course (see previous post) and in the preceding week.

The day had an autumnal feeling, both in terms of the cool weather and in terms of the birds captured. The breakdown was as follows:

Species
Ringed
Recaptured
Total
Meadow Pipit
29
0
29
Grey Wagtail
4
0
4
Pied/White Wagtail
1
0
1
Wren
2
1
3
Dunnock
0
1
1
Robin
3
0
3
Stonechat
3
0
3
Cetti's Warbler
4
1
5
Sedge Warbler
1
0
1
Reed Warbler
2
1
3
Whitethroat
1
0
1
Garden Warbler
1
0
1
Blackcap
9
0
9
Chiffchaff
11
0
11
Willow Warbler
1
0
1
Goldcrest
2
0
2
Blue Tit
2
1
3
Great Tit
3
0
3
Treecreeper
1
0
1
Reed Bunting
5
1
6
Total:
85
6
91

The highlights of the catch were:

  • Four grey wagtails. The birds responded to a tape. All were first winters, as was clear from the large number of unmoulted greater coverts and tertials they had each retained. We had only captured a single grey wagtail on the marsh previously, but had not tried tape luring overflying birds before.
  • A reasonable day total of 29 meadow pipits. These were almost exclusively first winter birds. Clear moult limits in the median and greater coverts were noted, with some moulting one or more tertials and others very few wing feathers at all. The only adult bird captured showed uniform olive-tinged wings and buff edges to all coverts.
  • Three stonechats. The hay in the ringing field has been cut very late this year. Until last week the chats were scattered around the field, foraging from stems of bracken and fringing vegetation. They now have fewer options, and are more frequently using ruderal vegetation on the edge of the marsh, allowing us to capture them more easily.
  • A few long distance migrants. A slightly sandy-coloured whitethroat and a reed warbler, both of which were carrying a good amount of fat, reasonably late willow and garden warblers, and a couple of lingering young reed and sedge warblers with very limited fat deposits.
  • A good catch of Cetti's warblers. This species very rarely carries fat, but in the mid to late Autumn we tend to see some birds with reasonable deposits. This probably indicates dispersal into the marsh. The recaptured bird was an adult coming towards the end of main moult. All of the other birds that could be aged (fault bars on the tails were useful), were first winters.

The clear out of long distance migrants, overhead movements of meadow pipits, steady catches of chiffchaff and blackcap, and the arrival of the first crests and treecreepers into the marsh signal the changing of the seasonal guard from early to mid autumn. We will soon be thinking about migrant thrushes and yellow-browed warblers.

A first in the nets today was a hornet. Only slightly more welcome than a bat!

Thanks to Heather Coats, Wayne Morris, Valerie Wilson, Stephen Vickers, Kirsty Franklin and Jo Conway for company and assistance this morning.

Owain Gabb
16/09/2017

Grey wagtails (Wayne Morris)

Hornet (extracted with care!)

Meadow pipit

Stonechat (male) (Stephen Vickers / Kirsty Franklin)

Treecreeper (Stephen Vickers / Kirsty Franklin)

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