that was the time of the complete redesign of the outside area which confined them for a good time inside. have been to there multiple times since then and haven't seen any stress signs since then.
It was indeed construction time. Remember zoo's arent perfect yet but its important to have a fault full of species incase they go extinct or have a genetic diversity shortage in the wild. They now have a sand bottem inside. And the outside is gonna get huge. Please make a distinction between good zoo's and bad zoo's because bad zoo's do exist. You put yourself in the line to Support better animal welfare in zoo's and then you'll figure out that the people who work with those animals really love them and they really do want to make their lives amazing. But sadly complaining wont make it better but just worse because its slows visitor amounts and then there is no money to make enclosures better so then we cant release happy elephants in the wild. Look into it even gorillas can be released in the wild and even reproduce and Gorillas that are being kept wrong wont adjust to the wild. Same goes for elephants (although they are more resilient then grate apes).