Where are they in the zoo exactly? I don't recall seeing an indoor enclosure for them and I can't imagine the zoo would give them a bare space, especially considering many of the zoo's other primates in this exhibit have plenty of climbing space and a few of the enclosures span both floors.
When I visited, I saw the animals outside inside a chute system that leads from the indoors to the outdoor enclosure, which has three quite large natural trees in them. Despite the appearance here, I would definitely say the zoo's gibbons get a good amount of climbing availability.
This picture could have been taken in almost any gibbon enclosure I think I have seen. It's quite a cropped view, with no height. No way to judge climbing opportunities, definitely not fair.
(Of course, it could be bad, but sounds like it's fine from TA's description)
The indoor exhibit does have many climbing opportunities including fire hoses, platforms, and "jungle gym" style climbing structures. Something I find interesting about the gibbons is that their outdoor exhibit has three huge sycamore trees that they have access to, as well as a metal jungle gym, and I see them utilizing the jungle gym at least as much, if not more, than the trees. It always makes me consider the arguments of naturalistic vs. functional furniture.
