In reply to Monk:
The problem with these birds is that they have minds of their own and, though they tend to favour the same sites each year, they may and do sometimes set up nest in a different place. The guides can mention the current situation at the time of going to print but this will probably have changed ten years later when the same guide is still being sold.
Actually I think most of the restrictions are signed, and certainly all the ones that are popular with climbers. Putting out the signs and retrieving them is a lot of work for the National Park, so arguably not really required on this particular bit of crag where hardly anyone ever climbs.
When on holiday in the Lakes you never quite know where you might end up climbing, so I'd print off the Bird Restrictions at:
http://www.frcc.co.uk/conservation_birdrestrictions.asp
before you go and take them with you. Very few restrictions are added during the course of the season, they are more likely to be lifted as nests fail or chicks fledge, so you should be OK with this, but if you still want to be sure you could always ring us at Needle Sports and we will check the latest position on any crag for you (017687 72227). I'm sure most other climbing shops would do this for you too.
Obviously you may also come across peregrines nesting where there are no climbing restrictions and sometimes you just have to walk away and go somewhere else. There is advice on what to do here:
http://www.frcc.co.uk/conservation_access.asp
Please also let the BMC know - the Gillercombe restriction was introduced as a result of reports from climbers.