Hybridised mallard... they are able to interbreed with a number of domestic varieties and give all sorts of non standard patterns. Also known as a mucky mallard
Thanks Chipchopper, Rowanwitch. I have sent off the photos to Rutland Water and Slimbridge to get a view from them. The pictures of the Swedish Blue on the web do match it well, though they vary quite a lot on colour form
It was a bit quiet on the Osprey front yesterday Tilly. The Osprey chicks in all the nests are doing well. The male (5R) had been away from the nest when I got to the hide, came back with a trout, then disappeared off again.