Sorry to but in on the thread nightshade
The woods are not far at all from Bedminster down. They are situated behind Ashton Court which your son will know for sure as all people in Bristol know this area. Its a great wood for birds and im sure bats too. Also if you are in that area make sure you take a walk along the top of the Avon gorge past the suspension bridge THE OPPOSITE SIDE TO LEIGH WOODS. as the two resident perigrines could well be about....Also try eastville park and walk along the river Frome to my neck of the woods which is also very good for birds.
Take care
Ian