Wasn't the dumeril's boa and the hog-nosed snake the two recent escapees? Two snakes recently went missing from the Calgary Zoo for about 24 hours.
its interesting that they could keep those two different species in the same cage, i wonder what other snakes you could do the same thing.
Originally it was just the Rock, Ball and the two hog noses. The boas were in the rainforest building with malagasy tree boas and helmeted mud turtles,but all have since moved to smaller terrariums, of display or into the walk through aviary for the turtles. Their former exhibit is now home to two black throated monitors. The reptile collection at the zoo is a bit lacking, and the majority of the species are Malagasy so I guess they are just filling space.