A yellow-striped frog from the Amazon has a special way to live among leaf-cutting ants without getting bitten by them. Furthermore, the ants will even ‘protect’ it from other frogs and animals. These findings have been documented in a paper published in the journal Behavioral Ecology and Sociobiology.
The clever little Amazonian frog (scientific name: Lithodytes lineatus, and known as Sapito Listado in Spanish) is not only protected from ant bites but is also able to make the ants protect him from other potentially harmful animals. How cool is that?! The secret to this lifestyle lies in the skin of the frog: chemicals enveloping it make up a shield of some form against the ants (leaf-cutting Atta ants), allowing it to live among them in their habitat without being harmed. These skin-substances only work because they are very similar to chemicals belonging to the ants.
“It helps the frog blend in, because it imitates the ants own chemical signals,” says the lead author of the new study, André Barros from Brazil-based National Institute of Amazonian Research.
The system used by the frog to infiltrate the habitats of the ants is a combination of mimicry based on chemicals, and camouflage. This is often found in parasitic invertebrates,but not so much in vertebrates. Frogs do not normally display such behaviours; until now, only 2 frog species have been found with this ability.
So, the ants will consider the frog as one of theirs, and this is why they will also provide protection to it from other animals. They even do so quite aggressively. The chemical that both species have in common is a chemical scent molecule known as pheromone. The ants will use this substance to identify members of their own colony, and to establish communication with one another. They are able to recognise the frog because of the presence of the chemical on the skin of the frog.
Were it not for the chemical covering the frog’s skin, it would not have been able to live among the ants. Rather, it would have done what other frog species do: running away from them to avoid being attacked; observations of the team show that other frogs would attempt to jump or climb out of the region where the ants were.
“Our results demonstrate that the skin of frog Lithodytes lineatus has chemicals that prevent the attack of two species of leaf-cutting ants,” says Barros. “It therefore seems that Lithodytes lineatus has chemical skin compounds that are recognized by ants of genus Atta, which may allow for coexistence between ants and frogs.”
What does the frog gain from this “under-cover operation”? The researchers explain that the frog might be benefiting from a more stable microclimate with a higher humidity level that would allow for its reproduction and development of eggs.