Iris patterns offer a noninvasive way to recognize individual Amazonian treefrogs

The Quick Take

Identifying individual animals in the wild has long meant tagging, branding or clipping. For amphibians, the standard approach has often been toe-clipping, a procedure that can affect survival, physiology and behavior. A new study suggests that, for at least one species of treefrog, nature has already provided a more humane solution: the eyes.