The first monogamous amphibian has been discovered living in the rainforest of South America.
Genetic tests have revealed that male and females of one species of Peruvian poison frog remain utterly faithful.
More surprising is the discovery that just one thing – the size of the pools of water in which they lay their tadpoles – prevents the frogs straying.
That constitutes the best evidence yet documented that monogamy can have a single cause, say scientists.
Details of the frog’s sex life is to be published in the journal The American Naturalist. …
Many animals appear to be monogamous, with males and females forming pairs that can often last a lifetime.
But the recent explosion in genetic analyses has revealed many of these so-called monogamous relationships to be a sham.
While many animals might stay together and breed, they will often sneak off and cheat on their partners when they get a chance.
So Dr Brown and his colleagues decided to check out the mimic poison frog more closely.
They sampled the DNA of many pairs of adult frogs, and the subsequent generations of tadpoles they produced.
Of 12 frog families, 11 had males and females that remained continually faithful to one another, together producing all their offspring. In the twelfth family, a male frog mated with two females.
“Others have found evidence of social monogamy in amphibians where parents remain paired, however they didn’t look at the genetics of these couples and their offspring to confirm this,” Dr Brown told the BBC. …