Poisonous Frogs Evolve to Sing Louder and Longer
by Penny Sarchet
The little South American devil frog is noisy in pursuit of a partner, and doesn’t care who hears him.
The little devil frog’s fearlessness in the face of hungry predators could be down to his toxicity. The little devil, Oophaga sylvatica, is a member of the dendrobatid group of poisonous frogs. His bright colours warn predators that he is unsafe to eat, which Juan Santos of the University of British Columbia in Vancouver, Canada, believes has allowed the evolution of more flamboyant mating calls.
Santos and his colleagues examined the calls, colourings and toxicity of 170 species of frog, including the little devil. They found a strong relationship between the volume of a frog’s call and its aposematism – markings that warn of its toxicity. In general, the more toxic a frog, the brighter and more noticeable it is – and the louder and more rapidly it sings (Proceedings of the Royal Society B ).
Non-toxic frogs are camouflaged and call from less exposed perches, says Santos…
(read more: New Scientist)
photograph: Pete Oxford/NaturePL