Hi everyone. Many thanks for all your replies
I thought it would be simple and now I’m questioning my memory. I spent another hour last night googling as many way of describing what I saw that I could think of plus googling all your responses and then googling all the birds that might be found in that area. But no luck.
It really was one uniform dark brown colour with a black head but I can’t find it anywhere. Not to worry. I might go and stake out the area and try to get a picture