A Common Ecuadorian Frog Went Unnamed for a Century — Until a Museum Visit Solved It

Scientists at the Pontifical Catholic University of Ecuador have formally described a new frog species, Pristimantis milpe, that spent more than a century being mistaken for another species — even though it is common, widespread, and easy to detect by its nighttime call.

The mix-up was resolved when lead author Santiago Ron travelled to the Natural History Museum in London to examine "type" specimens: the original frogs collected in Ecuador during the 19th century and preserved there ever since. Comparing these historical specimens with living frog populations in Ecuador's Chocó region, the team found that the old museum specimens had been wrongly linked to a different species. As a result, a frog regularly seen and documented for decades had never received a scientific name of its own.

"That such a common species has gone unnoticed under the wrong name for decades highlights the importance of correctly connecting scientific names with living populations in nature," said Jhael Ortega, a PhD student at Virginia Tech and one of the study's authors.

Known as the Milpe Robber Frog, the species is active at night, with males calling from leaves on shrubs and bromeliads several meters above the ground in a loud, click-like sound. Females and males also look different: females show orange or light-blue coloring with black spots around the groin and thighs, while males are more uniformly colored. The frog's known range covers more than 67,000 square kilometers across the Chocó forests of western Ecuador and southern Colombia, from sea level up to 1,200 meters elevation.

The formal description was published in the journal ZooKeys, which focuses on biodiversity and taxonomy.