That's no great error e&t. Dart frogs don't always follow the rules and categories we put them in, and when we compare our limited habitats to a vast rain forest habitat, "terrestrial vs arboreal" in our set-ups loses distinction. You were also probably right in a sense. I don't know of any that are found exclusively in the highest reaches of a forest canopy.
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Patty
Pahsimeroi, Idaho

D. auratus blue, auratus Ancon Hill, galactonotus orange, galactonotus yellow, fantasticus, reticulatus, imitator, castaneoticus, azureus, pumilio Bastimentos. P. lugubris, vittatus, terribilis mint green, terribilis orange.