This exhibit is in Sun Bear Forest between the entrance of the exhibit and the sun bears. When you were there it exhibited Gabriella's Crested Gibbon, not Silvered Leaf Langurs.
I'm not sure. That exhibit was the only one for them at the zoo, however there was a large group in an exhibit at the WAP, so maybe they transferred over there. According to ISIS however SD has 2.1 and SDWAP has 3.1.
Last time I checked, this enclosure was empty for a long time. The Silver Leaf langurs are in the other enclosure next to it which is a sealed off environment. Both enclosures were meant for Douc Langurs to give them a controlled and then open environment.
The gibbons are at the end of monkey trail before the turn to hippo trail. One female named Gaby and her brother named Chewie. I love listening to them sing. You can hear them all over the zoo.
