The unkenreflex is a passive defense posture adopted by toads, frogs and salamanders. When threatened by predators, they twist their bodies, or arch their backs and limbs to expose brightly-colored aposematic skin. The normally-concealed red, yellow, white and black patterns on the underbelly, inner surfaces of the limbs or underside of the tail serve as a visual warning to predators. To reinforce the warning, unkenreflex is sometimes accompanied by toxic and malodorous secretions from glands in the skin.
This behaviour is named after the Fire-bellied toad (German: Unke, plural: Unken) which exhibits this reflex. The same behaviour may be observed in other amphibians that do not have any warning colours.[1]
