Does that mean they are chosing the ledge instead of the box? Did we not chant loud enough? 
Both Ivy and Princess have been doing alot of scraping in the nestbox which is an excellent sign and they are spending time on the west side everyday so at this point I can't say that it looks like they will nest in one spot more than the other yet. Also can't "see" what Ivy and Princess are doing on the ledge ... if they are just sitting, not so worried. If they are making nestscrapes, I worry more ...
Hey Pam, are the birds playing around in the dust or are they just sitting and waiting?
There is a point in the week-ish before laying where they seem to get very lazy ... maybe we are at that point though it does seem a bit early for that. Having said that, the copulatory sessions we have observed over the last week have been prolonged and intense, so maybe they just got down to business as soon as they both got back ... we'll have to wait and see I'm afraid.
