Jack Dumbacher, an ornithologist at the California Academy of Science, describes the discovery of and studies of a neurotoxin produced by this bird from New Guinea. The batrachotoxin that the bird produces is a sodium-channel blocker that is chemically identical to the neurotoxin used by poison dart frogs, and it is potentially lethal in higher doses. One assumes that this evolved as a deterrent to predation, so it's interesting that like monarchs and other toxic butterflies, this bird exhibits a strikingly bright warning coloration.
Since the adverse effects occurred after the toxin entered the mouth, I would define it as a poison. And the toxin is identical to the one in poison dart frogs, which are clearly poisonous.