Another beautiful day at Oxwich Marsh this morning. Due to the very low wind speed, and overhead movements of pipits, wagtails and Hirundines (barn swallow and house martin) we supplemented the usual nets in the reedbed and scrub with a triangle of nets in the open field (surrounding a tape lure).
The martins showed very little interest in the tape, but we did catch seven meadow pipits. Ageing meadow pipits (see pic opposite) is not straightforward if you don't catch them regularly, but before attempting this you firstly need to confirm the species. Apart from general plumage characteristics, they were separated from tree pipit on the basis of the length of the hind claw (which should be between 10mm and 13mm in length in meadow pipit and is shorter in tree pipit [7-9mm]). This was measured using calipers. Age was then determined based on a number of factors, particularly the colouration of the edging of the greater coverts, on the basis of different generations of feathers in the wing (adult wing feathers should be of one generation following post-breeding moult), and the shape and size of the dark 'teeth' on the median coverts. Juvenile flight feathers should also show more wear, which is a good supporting feature.
The photograph opposite shows the wing of a juvenile meadow pipit. It can be seen that one of the tertials has been retained (this has an abraded edge and a very white tip), but the others replaced. This bird also appeared to have moulted its two innermost greater coverts, which were fresh and edged yellow-brown, but not the remainder, which had far paler edges.
In total 51 birds of 14 species were trapped. The number of re-trapped birds (those already ringed at the site and recaptured today) is shown in parenthesis: meadow pipit 7 (0); reed warbler 9 (3); sedge warbler 6 (1); blackcap 4 (0); chiffchaff 5 (0); robin 1 (0); chaffinch 1 (0); blue tit 7 (2); wren 2 (2); dunnock 1 (0); song thrush 1 (0); bullfinch 5 (1); blackbird 1 (1); great tit 1 (1).
We are now pushing 500 new birds for the year at Oxwich Marsh, which has probably exceeded expectation. Thanks to Heather Coates, Barry Stewart and Cedwyn Davies for an enjoyable morning.
Owain Gabb 14/09/13.