I don't have mush experience with Tawny Owls Helen. But I understand they nest well down in cracks and crevices. Up on Langholm last year, I went with the ringers when they were going to ring some Tawny Owl young who were down inside a hollow tree trunk. So far down they couldn't be reached, so the ringers had to come back another day with a litter picker to very carefully get the young out! That was a regular nest site so the young must have fluttered up when they wanted to branch out.
Incidentally during that visit, the female just flew off and perched a little bit away watching us. None of the attacks they are noted for. Maybe she had nested there a few times before and was used to the ringers!
Anyway. Fingers crossed yours will be ok and get you nesting Tawnys again.
Cheers,
Bryan
Young tawny owls just like little owls can climb very well indeed even if they cannot fly, but the design of my little owl boxes have an elevated tunnel above the brooding area to help prevent the young from leaving the box too early and branching thereby falling out of the box / tree. Plus a perching ledge that runs along the front of the box and down both sides to preen, build up flight muscles, and roost on. After spending many hours in the field I have also designed and fitted a predator control devise to prevent undesirable visitors from entering my boxes as well.
Although both these species of owls can climb back up into their tree to safety they are still picked up by well minded people and taken to rescue centres but the adults will still look after them even if the young owls cannot make it all the way back to the nest itself.
Of course not all tawny owl exhibit the same behaviour although in my opinion only a silly fool would get too close to its nesting territory, Eric Hosking a photographer lost his left eye from the attack from this fiercely territorial predator and even the much smaller little owl has been known to deliver the very occasional attack.
Tawny owls have also been known to nest on the ground in some areas as well as chimneys, inside old buildings, holes, crevices,’ purpose made boxes, squirrel drays, and old crows’ nests. In fact my local pair regularly use old magpie and squirrel drays as a nesting site as suitable holes in trees are at a premium here. Stick nests are not entirely safe though as young tawny owls have an instinctive habit of walking backwards to defecate over the side of the nest often resulting in the birds death from falling from a great height.
I have yet to see a young Sparrowhawk fall from the nest while defecating, although it has been known to happen. Hygiene is the reason they do it this way rather them fouling the nest itself, but this can be very unfortunate for anyone who maybe passing by at the time.
Alan