I live in a village in nottinghamshire and my cats have brought in 3 dead fledglings over the last month. The fedglings are big, about 10 cm long, are covered in ginger almost orange down apart from their faces, had no evidence of feather development, They had almost black faces and beaks, beaks were straight, blunt, and deep with a prominent groove in the upper element. The feet were skin-pink, and the toes thick. What might they have been?
Very interesting suggestion but I don't think it was a jay judging by the pics. There were no wing feathers forming and there was no evidence of any dark colouring of the down. Also the crown of the head was covered in down.
The only big birds I've seen around here are rooks, it may sound silly, but what does very young rooks look like?