Paul, as you will be seeing, most Friends of x don’t currently take a wider view, even where it makes ecological sense etc to encourage cycling. There is a good deal of old prejudices simply covering as conservationism around that need to be answered with evidence.
I suspect bikes are in and out too quickly and quietly to disturb bird life, which in woodlands are less ground nesting than in moorland . This would be seasonal of course, as should then be all access.
Whilst there is a Bambi effect, deer are very destructive of new tree & shrub shoots, which is just what you don’t want in a regenerating woodland. As a non-expert, I’d guess the numbers of all species present would drop with many such higher mammals present and no natural predators.
We work closely with Bradford Ornithological Group and I can pose the general question.
David
Chair, Friends of Baildon Moor
CTC Right to Ride volunteer