Hi DGRW,
I would be very interested to hear more of your Corn Bunting record(s) at Willington. As far as myself, and the county recorders, are aware, Corn Bunting is virtually extinct in Derbyshire, the last confirmed sighting being 2years ago at, I believe, Eggington SF. They used to occur regularly at Etwall, and, going further back in time, along the River Trent at Aston and Weston, as well as a few sites on the other side of the river, but, alas, no more.
Also, Merlin would be a superb record in South Derbyshire in July. Not to sound disrespectful, are you certain that they were not immature Hobby's?
Cheers
Will