That's a bit of an odd combination, isn't it? I can't remember ever having seen poison dart frogs mixed with larger reptiles than, say, smaller geckos or lizards, let alone with snakes.
@KevinB It is odd, yes. I like the mix a lot, though. The tree boa will mostly eat small rodents and birds, and while they will eat frogs, they're likely well fed enough at the zoo that they wouldn't bother.
I have also seen a similar arrangement of poison dart frogs mixed with large snakes in the large Neotropical exhibit at Fresno Chaffee Zoo's Reptile House.
