Not sure what will happen if you do push food through the bars. They seem to have brought their own, so they can't be starving.
The dig is taking place in the quadrangle of the University of Edinburgh's Old College. The current buildings date from 1789, and were built on top of Kirk O'Fields, the site of the murder in 1567 of Lord Darnley, second husband of Mary Queen of Scots.
Two skeletons have been uncovered, found in the coffin-shaped indentations immediately to the right of the green netting in the shot below. With the naked eye, but less so in a photo, you can make out the indentations where the bones lay. The remains have now been interred in a graveyard. There's no suggestion that I've seen that the remains were those of Darnley and his valet, and I think they're likely to remain unidentified after so long.