Long-billed Dowitcher at RSPB Lodmoor in Weymouth - January 2012 - the sort of vagrant from the USA that can arrive in Dorset in exceptional weather conditions
When I started ‘birding’ it did not take long to understand that the weather was an important factor in determining what one might see at each part of the year; some birds fly south for the winter whilst others come to us for the winter months from much further north. We call this ‘migration’!
What took some time to work out is that things are more complicated and that the weather is a major influence on the lives of all birds, not just swallows and Brent geese. Looking back I find it ridiculous that it took time to find this out! After all, birds can fly and birds need to eat so birds will constantly move to find available food supplies if the weather makes feeding impossible where they are. When the going gets tough all birds get going, not just those we associate with long distance migration.
This is clearly evident if you spend any time watching the birds in a garden, especially a garden with feeders. In autumn and early winter the number of birds and range of species visiting is likely to be higher than in the summer but far less than later in the winter. Whilst there are adequate food supplies in the countryside there is no incentive for them to move on but once the colder weather sets in and food supplies are short they search out alternatives and so come into our gardens. We always find siskin scarce before Christmas but in February to April they can be almost daily visitors. In cold weather the number of blackbirds can increase almost overnight as birds arrive from the north.
There is a tendency to think that, birdwise, all winters are the same but that is far from true. A look back over tweets collected over almost four winters shows this quite clearly. This winter is very different to the last two with few storms, hardly any frost and, so far at least, no ‘beast from the east’! The weather has been dull, dreary and whilst hardly warm it has certainly not been cold and this has resulted in a very different array of birdlife.
So far there have been no real rarities turn up which is unusual, we would expect a few vagrants in the course of a normal winter. There have been no irruptions of any species either with no waxwing and certainly no hint of the hawfinch irruption of a couple of years ago.
What it seems we have seen though is larger numbers of some species. Pintail, for example, are around in much larger numbers than usual and Brownsea has an enormous amount of black-tailed godwit with estimates exceeding 2,000 birds. Knot and sanderling, even common sandpiper, would not be expected much beyond the end of the autumn but this year there are still a few around even in February. Divers and grebes are being reported from our harbours and shores in good numbers compared to other years, so too, common scoter. Chiffchaff, blackcap and firecrest crop up frequently across Dorset with Sibernian chiffchaffs often reported as well. On the other hand, spoonbill numbers are down and there are less cattle egrets and great white egrets so they have, perhaps, stayed in other wintering areas and have not needed to venture this far south and west.
The reason for this is, I would venture, that for some species a similar number of birds have arrived here this winter but instead of some moving further south when the weather turns they have not needed to this year and have chosen to stay. If this is true here, then it means that other species that winter further north or on the east coast have not been encouraged to venture further south and west.
Obviously, this could all change in the next few days if the weather changes for the worse but the point I am trying to make to new bird watchers is simple, try and understand the effects the weather has on bird feeding and then you will have a better understanding of what you might see and where.
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