I will pose the question again what percentage of woodland large raptor nests do you know of that are public areas compaired to private woodland?
I have found that it is unusual for a landowner to turn down a request to visit their ground though there may be a few restrictions , such as keeping out of the woods a few days before a pheasant shoot.
Ok, I'll bite in response to this
I cannot speak for all parts of the country - I have no figures to back this up but based on personal experience these arguments about access somehow preventing raptors nesting are incorrect:
I Have experience of birding mainly in 2 areas:
1) South Devon - most woodlands private with no access whatsoever legally.
Buzzards very common, Sparrowhawks fairly numerous and peregrines fairly numerous. No idea where most of these are nesting but it will be on private land since as as already stated vast majority of woodland private with no access and often not even nearby access to enable viewing from afar. Peregrines I know of all in areas frequented by public with public access. For obvious reasons I will say no more except that peregrines do not seem at all bothered by nearby footpaths etc provided there is a good cliff/building.
2) Forest of Dean, Gloucestershire - most woodland public access owned by forestry commision or if not then cut through by many footpaths.
Again buzzards common, sparrowhaks common, goshawk present, peregrine in several sites.
Peregrines in a few more secluded sites but equally in some very prominent sites with public access. Buzzards, Sparrowhawks and Goshawks all breeding in woodland with public access - this is essentially status of entire forest of dean.
In my opinion giving the public access has no impact at all except where numbers of people accessing a site are very high and unfortunately I often think this is actually because of generally restricted access elsewhere:
Locations with public access in areas of otherwise very poor access do have a significant numbers of visitors simply because they cannot legally go anywhere else!
Personally I do not trespass often; I have entered private land without permission on occasion - sometimes accidentally, but mainly in order to circumnavigate a landowner's deliberate blockage of legal public rights of way ie barbed wire strung across stiles etc.