Unfortunately I was wrong about the duck and instead of finding her sat on an egg, she was dead when I went to let them out yesterday. There were no signs of any damage or illness, and she didn’t feel thin (we’ve been putting down extra food for them since the ground has been frozen as they can’t rootle for their grubs and things). Don’t know what to make of it. All the others look OK so perhaps it was a one off.
Heard nothing from the people who came to view on Saturday, although someone was outside taking photos today, so I don’t know what that was about.