Species	Ringed	Recaptured	Total
Sand Martin	1	0	1
Swallow	107	1	108
House Martin	1	0	1
Wren	3	0	3
Robin	1	2	3
Song Thrush	1	1	2
Grasshopper Warbler	1	0	1
Sedge Warbler	13	4	17
Reed Warbler	18	8	26
Whitethroat	4	0	4
Blackcap	4	1	5
Chiffchaff	6	0	6
Willow Warbler	7	3	10
Blue Tit	0	1	1
Chaffinch	1	0	1
Greenfinch	1	0	1
Siskin	1	0	1
Reed Bunting	5	4	9
Total:	175	25	200

Swallows have been roosting in the marsh for some time (a roost began to build in mid-July), but this was the first time we have managed to get an evening session in. The catch was a slightly under par 105 birds, with singles of both sand martin (after dusk) and house martin (before dusk), and a few other odds and sods, including two willow warblers and single sedge and reed warblers.

The swallows were mainly juveniles. Only four adults were noted among them. We caught a few birds prior to dusk, which were released following processing, and over-nighted the remainder in purpose made boxes. The house martin was a bonus. It is only the third we have caught since February 2013.

The highlights of Saturday’s catch were the eleventh grasshopper warbler of the year, steady numbers of reed and sedge warbler, a few whitethroat and siskin number 150 of the year (a record for the site by some distance). Some overhead movement of siskin was noted, which may indicate dispersal following breeding.

We also noted a reed bunting that resulted in some discussion with regard to sexing.

Back of reed bunting showing white neck collar

Brood patch of reed bunting (the feathers have been gently blown to reveal the brood patch in this photo)

The reasons for this may be clear from the photos above. Photos 1 and 2 might suggest a male: the bird is scruffy as in main moult, but has a predominantly black head (albeit with some brown flecking) and a marked white collar. The third photo is of its brood patch. This was very well defined and wrinkled, suggesting recent engorgement (a female characteristic). The bird also had a short wing (74 mm), which also suggests a female. We tend to handle over 150 reed buntings a year at Oxwich, but don’t often see a bird showing such a confusing set of features. However on the basis of the brood patch we concluded it could only be a female. Any comments with regard to experience of similar birds would be useful (thanks to Jerry Lewis for some very useful notes via email).

Thanks to all who attended one or more of the two sessions: Heather Coats, Keith Vaughton, Cedwyn Davies, Emma Cole, Val Wilson and Lynn Watts.

Owain Gabb

09/08/2016