Mimic Poison Frog

It copies the warning colours of other poison frogs that live alongside it. In one part of its range the mimic is yellow-striped and matches Ranitomeya variabilis; in another it is spotted and matches R. summersi; near Varadero it has an orange head and matches a striped morph of R. fantastica. Because all of these frogs are toxic, a predator that samples any one of them and gets sick learns to avoid that colour pattern, and every species wearing it benefits — the classic logic of Müllerian mimicry. Where the mimic is less toxic than its model, it is closer to Batesian mimicry, a harmless-ish cheat riding on a dangerous species' reputation. The mimic poison frog is unusual in being able to match several different models in different places.

It was the first amphibian shown, with evidence, to be a mimic. A 2011 study by Yeager, Brown, and colleagues used genetics and field data to demonstrate that the different colour forms of Ranitomeya imitator evolved specifically to resemble the local model species — the patterns track the models geographically, and the resemblance is too precise and too well matched to be coincidence. This made the frog a model system for studying how mimicry drives the splitting of a single species into distinct-looking populations (a "mimetic radiation"), a process usually studied in butterflies like Heliconius.

Yes, and genuine monogamy is extremely rare among amphibians — most frogs mate with whoever is available and provide no parental care. Genetic paternity testing of wild mimic poison frog families found that essentially all the offspring in a clutch were fathered by the resident male, meaning pairs are sexually faithful. The reason appears to be their choice of nursery — they raise tadpoles in tiny pools inside plants that hold only a few millilitres of water and no food, so a single parent cannot do the job. The male ferries and guards the tadpoles while the female must repeatedly visit each one to lay unfertilised eggs for it to eat. That workload locks the pair into a committed partnership.

It is listed as Least Concern and is one of the most popular poison frogs in the hobby, precisely because it is bold, active by day, has a pleasant birdlike call, and — like all captive-bred dart frogs — is non-toxic, since the poison comes entirely from wild ants and mites the frog never eats in a terrarium. Responsible keepers use only captive-bred animals, which are now abundant and have largely displaced wild-caught imports. The wild frog still faces habitat loss as Peruvian forest is cleared for agriculture, and its reliance on specific plants for breeding makes it sensitive to forest degradation, but it is not currently considered at risk of extinction.