Helen, you have a photo in sighting 4445905 which makes it look like this poor bird has not moved for almost 2 months! Have you monitored it regularly over that time? The three pairs near me all started nesting at around the usual time, but all three nests failed quite early on (probably due to the terrible weather). Two of the pairs then left and have not been seen again. The third pair started over, and eventually two chicks hatched. If your bird has not started again sometime since your first sighting, then I'd agree, not looking good for eggs ever hatching. Apparently incubation is 28-32 days. Poor birds.