It can't be easy to spot the owls in a large, well planted aviary. I hope there are no Strix species in there, they can be very dangerous in the breeding season.
In the first section two species: Bubo bubo bubo, Bubo scandiacus
The latter one has it own smaller aviary inside the first section, so it is actually a walk-through-section with Bubo bubo bubo.
Second section: Asio otus otus, Tyto alba guttata, Strix aluco, Strix nebulosa lapponica
The latter one was rearing youngs which was resulted in agression towards the visitors, so the staff put many branches just next to the visitor pathway (see the enclosed link, page 17.).
It can't be easy to spot the owls in a large, well planted aviary. I hope there are no Strix species in there, they can be very dangerous in the breeding season.