Scientists found the toxic, electric-orange amphibian in a single hilly area near the Caribbean coast, according to a study published this week in the journal Zootaxa.
Measuring just 12.7 millimeters in length, the newly described Andinobates geminisae remains something of a mystery, according to the study team.
For one, the mini-amphibian “looks nothing like” its closest genetic relatives in the region, mainly because of its orange color, study co-author Andrew Crawford, a professor of evolutionary genetics and biostatistics at the University of the Andes in Bogotá, Colombia, said by email. (See more pictures of poison dart frogs.)
Instead, “the new species superficially looks much more like the strawberry poison dart frog (Oophaga pumilio),” Crawford said. “Perhaps A. geminisae had been observed previously but was confused with Oophaga.”
The two frogs may also share the same orange warning signal to predators in an evolutionary tactic known as Müllerian mimicry. This occurs when two or more poisonous or unpalatable species adopt the same colorful warning system so predators are more likely to avoid them.
“But this is pure speculation at this point,” Crawford added.
Little Frog, Big Risks
Likewise, very little is known about the newfound frog’s behavior, although the discovery of an adult with a tadpole stuck to its back suggests that it cares for its young.
Other poison dart frogs in the same genus share this trait: After the tadpoles hatch, adults piggyback them one by one to small pools of water, where they develop into froglets. (See pictures of animal mothers and babies.)
Though no other tadpoles were found by the team, they suspect that A. geminisae also carries its young to water trapped in tree hollows or leaves.
The tiny frog’s toxins have yet to be analyzed, Crawford said, but he thinks it unlikely that they have ever been harnessed as a chemical weapon by rain forest hunters.
Indigenous people in the Americas have used the toxins of a few species—notably the golden poison dart frog (Phyllobates terribilis) from Colombia—to tip hunting weapons such as blowgun darts.
Poison dart frogs, which often have very small ranges, are imperiled by habitat loss, climate change, and the deadly chytrid fungus.
The team warns that the newfound frog is at risk from both pet trade collectors and deforestation.
“It is important we save some of this frog’s tiny habitat to be able to study this unusual species more,” Crawford said.