18th January 2010 - Woods and Wings

Chesworth Farm this morning produced 42 new birds as always dominated by Blue and Great Tits but the first bird of the day interestingly followed suit of the last bird in my garden - a fatty and muscly Robin. After missing every time on the last three visits we finally caught a Woodpigeon (below) and very nearly a second, but it got away just as Jake reached it - sounds familiar!
Probably the best birds of the morning were two Redwing of very different weights one of 62g and the other 53g (below). Other captures included the 2007 Reed Bunting that was recaught last week although had gained 1.6g in that time.
The most interesting bird was a very unusual adult female Greenfinch (below). This bird had symmetrical amounts of orange colouring on second primary, second primary covert, outermost lesser covert, belly, vent and dusting over ear coverts and around eyes. This plumage is thought to be due to extra development of carotene in the feathers due to the particulars of its diet. It is interesting that the colouring on the wing follows the moult pattern of the second primary on both wings which seems to indicate that the bird had been eating this diet whilst growing this feather, but not before or after. An interesting paper on this occurrence in Greenfinches in Brockham, Surrey in the late 1960s can be seen here http://tinyurl.com/yz4cz25.
Birds ringed:
Robin - 2
Blue Tit - 22
Chaffinch - 6
Great Tit - 6
Greenfinch - 3
Redwing - 2
Woodpigeon - 1