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Old Thursday 14th January 2010, 07:33   #13
citrinella
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Join Date: Sep 2004
Location: E.Lothian
Posts: 1,434
Quote:
Originally Posted by stonechat1 View Post
Im very astonished Mike that you even catch them at winter time!?
Remember our climate is much more temperate than yours. Lots of winter ringing goes on in Britain. It is a very important tool for informing conservation. We did give consideration as to whether we should ring at all on this occasion due to the amount and duration of lying snow, but decided that it was reasonable to proceed as the birds here are very well fed - I have been feeding 15kg/day at this site throughout the snowy weather. Temperatures have generally not been particularly cold here, -3 minimum commonly. We decided to proceed cautiously, monitoring bird welfare closely. We did decide in advance to reduce the amount of net erected, to ensure birds could be removed quickly, and to shorten the session, to minimize the time feeding was disrupted. Birds were able to, and did, continue feeding during the snow shower when we had the nets furled.

This is part of a long term study, so we were influenced by that. Information on bird condition in the current weather would be especially valuable to compare with sites which are not fed so well. In the event we were surprised at how good condition was overall. We had a handful of birds in very poor condition, but the majority were good, or even very good. As examples, while we had one male blackbird at 86g and one female fractionally under 90g, 11 were over 100g of which 3 were in the 120s (one being female) and one male managed over 146g. This last was a retrap from this site, ringed two years ago so perhaps not a migrant from the continent. General perception is that continental migrants tend to be larger birds. However we seem to have had a surge in blackbird numbers over the last couple of months, and sizes before the recent bad weather were not large.

Other species showed a similar generally good condition with only a few birds in total in markedly poor condition.

Weather has been milder this week, with a steady thaw, so we hope to carry on with our project.

Mike.
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