Not that I'm not enjoying this thread

, and am certainly finding useful information to improve my own consideration of when it is appropriate to use flash as sometimes information can be conflicting (for example, I've been told flashing bats is totally fine at Cotswold Wildlife park, and totally out of the question at Edinburgh Zoo). And of course some of it is degree - a few flashes on a dark night may be no worse than a lightning storm and as easily ignored by an animal.
However, I felt I had to pick up on this one point.
Peregrine Falcons eat and spend the energy gained in eating at a fast rate (I learned that from a talk at Banham Zoo

) and when in the wild, if they don't eat they run out of energy to find another meal .. then die. Are you telling me that you would get in the way of a Peregrine hunting, to get a shot using flash? What if the meal it was trying to get, was its last chance before it ran out of energy, and you standing there, suddenly triggering a flash put it off catching its meal? I don't know if that would happen, but I don't think anyone really does TBH. I do know that I wouldn't take the risk, as my love for animals is stronger than my love for photography
But should you interrupt a peregrine feeding, knowing that it might be its last chance before dying? Given the fact that peregrines often feed on wading birds which have experienced massive decline, then possibly the best thing for biodiversity would be to flash rural peregrines as often as possible - photos or not

. Though I still don't think it would make much difference.
For general information, I believe that all birds of prey, (and possibly all birds, but I've only discussed it at raptor centres and birds of prey demonstrations) have to cope with the delicate balance of eating enough to keep up with their energy needs, and staying light enough to fly. David Attenborough's "Life of Birds" mentions that small birds will try to ensure that they go to their winter evening roost with a full crop so they can survive the night. Our local raptor centre loses its eagle owl every now and then (it was previously trained to hunt rabbits, and gets tempted away by the local bunnies who have myxomatosis). They go and collect him when he's got too greedy and fat to fly away. So there is nothing special about disturbing a peregrine.
That said, in my case photographing the local birds has made me much more sensitive as to whether I am causing a problem. As a general guide (advice from my local RSPB warden), birds aren't disturbed it they stop paying attention to you. If you can set up, or get closer, and they go back to feeding or preening - then you have caused no harm. And the number of times I've worried about disturbing a bird, seen it settle to then have it fly away as someone totally unaware of its presence has walked by makes me realise how little impact I have in comparison.
My only real issue would then be persistence as photographers stick around longer than normal people. Which is why they put protection in around nest sites for endangered birds with the schedule licencing :rules: - and given how closely they monitor this, I trust the experts.
Which is a very long way of saying I agree with G. badger and Mr. CT - people giving the licences know much more than I do and are the better judges. If they say its fine then unless I have good reason to think otherwise, I'll believe it is fine. And sounds like when checked specifically, the experts say its fine.