That will hopefully make it easier to spot the peregrines when they do return!
Last year there were 6 or 8 eggs in that nest as I recall, but they seemed too small and white for ravens (or crows for that matter) but I honestly don't see that many corvid eggs, parents are too protective and appear to prefer spots I would rather not try to reach
There should also not be anything nesting in the rooftop nestbox here or at the Tower site - Dennis and I put screening across the openings to keep the pigeons from taking up residence in the "off" season. Cleaning up after the winged KD is not a pleasant experience, particularly not in the hot summer sun!