Puerto Rican coqui frogs were accidentally introduced to Hawaii in the 1980s, and today there are as many as 91,000 frogs per hectare in some locations. What does that mean for native wildlife?

Ifrita kowaldi, a blue-capped handful with the tree-poking habits of a nuthatch, concentrates in its feathers and skin the same alkaloids that defend poison dart frogs. This explains why the bird’s ...

Coquí frogs are invasive species in Hawaii. But they don’t seem to bug the islands’ native and nonnative birds. Jason G. Goldman reports. Coquí frogs. They’re named for the sound they make. And though ...