Whilst one could not describe the green sandpiper (Tringa ochropus) as a common winter visitor it is not unusual to find them in Dorset. Like many other waders they come south from northern breeding grounds, where they actually nest in woodland, to over winter in our warmer climate.
This photograph of one taken at Radipole Lake in Weymouth shows typical characteristics of an encounter with one of these birds. Firstly, they are almost invariably found, in my experience anyway, on exposed mud near reeds.
They are very similar in size and shape to a common sandpiper but have a much darker back which in summer is much greener in appearance than in winter. They have quite a distinct white eye stripe which is visiable from some distance, if you look closely you can ven see it my long range photograph.
Finally, they are nervous, wary birds that are difficult to get close to and unless you have much better photographic equipment than I have this is about as good as a view as you can get but then this is typically what you are likely to see!
Many fly much further south on migration so numbers in Dorset are probably higher in late autumn and early spring although some do stay here, especially if we avoid a really cold snap.