Observations during the breeding season do not suggest that greenfinch breeds in or adjacent to Oxwich Marsh. In previous years, ringing has been concentrated between the spring and early autumn, when birds are not likely to be using the area. In 2013, the establishment of a feeding station, and the extension of ringing into the winter, has resulted in flocks of greenfinches moving in.
Greenfinches can be sexed throughout the year, based on between-sex differences in the extent (and depth of colour) of the yellow in the primaries and on the tail feathers. They can also be aged based on moult limits in the wing (juveniles may retain one or more old greater coverts and alula feathers and always retain their primary coverts). In males ageing birds can be fairly straightforward, but in some females colour contrasts are subtle. One complication in ageing birds is that birds of both sexes can replace all or part of their tail during post juvenile moult, so only retained tail feathers are useful in ageing.
No goldcrest or long-tailed tit flocks were seen during the morning, but overhead flocks of siskin and smaller numbers of redpoll were moving. The number of teal on the marsh had also increased, and snipe were noted throughout the session.
Many thanks to Charlie Sargeant and Heather Coats for coming along on Sunday.
Happy New Year.
Owain Gabb 01/01/2014