In the tropical forests of Chocó in western Ecuador and southern Colombia lives a common nocturnal frog whose loud clicking call has been heard from bushes and bromeliads for over a century. Scientists long considered it a known species, until museum specimens from the 19th century helped reveal the truth: it is a distinct species, Pristimantis milpe, described only in 2026.
Researchers from the Pontifical Catholic University of Ecuador examined type specimens collected in Ecuador in the 19th century and housed in the Natural History Museum in London. Comparison of old specimens with living populations showed that the previous classification was erroneous. As a result, the species, which was regularly encountered and documented, never received its own scientific name.
The range of Pristimantis milpe covers more than 67 thousand square kilometers, from sea level to an altitude of 1200 meters. The frog is active at night; males emit characteristic clicking signals from leaves several meters above the ground. Females are distinguished by bright coloration of the inguinal region and thighs—orange or bluish tones with black spots—while males appear more uniform.
The discovery underscores the value of natural history collections: specimens that have lain for decades allow old identifications to be revised and scientific names to be linked to real populations. In this case, the combination of historical specimens with modern observations made it possible to recognize the species as distinct.
The Chocó region is renowned for its high biodiversity, and the finding shows that even widespread and easily detectable animals can harbor surprises. The description was published in the journal ZooKeys and is based on field data and museum materials.
Such cases remind us how important it is to carefully cross-check old identifications with living nature so as not to miss the obvious.
