UPDATE (2nd March 2008)
Nothing major to report yet but things are certainly looking hopeful
Yesterday I called in at our local farm for some free range eggs and the farmer's wife told me that earlier this week she was walking by one of the Owl boxes (it's the one on the edge of the wood - the 3rd photo in my opening post) when she saw a white face appear at the opening. Later on she saw a Barn Owl quartering over the field that particular box looks out onto.
Of course it may just be a roosting bird but a promising sign none the less.
She also mentioned having seen a Little Owl several times on the edge of the wood. We know that Little Owls nested in the wood last year (and we think we know where) so I'm hopeful of getting some good shots of our smallest Owl as well.
Hopefully the Barn Owls will be pairing up over the next 2 - 3 weeks - I'll keep you posted.
Jeff