Sunday 27 October 2013

Autumn restart

With summer well and truly over, blackbirds have finished their post breeding moult and are becoming more obvious in the study site. This time of year is a good for spotting first year males - they will have brown outer wings, unlike adults which are a uniform black. 

http://blx1.bto.org/birdtrack
At this time of the year our resident blackbirds are also joined by birds from mainland Europe. These visitors are the same race (T. m. merula) as our resident birds. There is often great debate over whether male blackbirds with dark bills and eye rings are migrants from the continent or not. All first year male blackbirds will have these characteristics so they can not be relied on to determine the origins of these birds. However, at this time of year we do catch bird that differ in general size and feel different in the hand than "normal" and these could be migrant birds.
A winter visitor form the continent or a bird born locally late in the season? This
particular individual was noticeably smaller than would be expected compared to
birds we usually catch.
An easy to spot winter arrival whose numbers will be on the up in the next few weeks is the redwing. The BTO is looking for volunteers for its Winter Thrushes Survey which aims to map the distribution and work out the habitat needs of visiting fieldfares, redwings, mistle and song thrush and blackbirds. Were conducting the survey during our regular walks of the study site, although at the last visit we only recorded one redwing! We will keep you posted on our results but why not take part the survey yourself?