In an unexplored corner of the Andes, researchers have discovered a new species of frog with brown-grey coloring, lanky legs, bright yellow freckles, and a bunch of other unique features. 

The new species of tree frog, known as Hyloscirtus hillisi, was recently described by researchers from the Catholic University of Ecuador in the open-access journal ZooKeys. They found the strange little fella during a two-week expedition to a tabletop mountain in Cordillera del Cóndor, a remote corner of the eastern Andes of Ecuador.

“To reach the tabletop, we walked two days along a steep terrain. Then, between sweat and exhaustion, we arrived to the tabletop where we found a dwarf forest,” Alex Achig, one of the field biologists who discovered the species, details in a blog post. “The rivers had blackwater and the frogs were sitting along them, on branches of brown shrubs similar in color to the frogs' own. The frogs were difficult to find because they blended with their background.”

The species belongs to a genus containing 37 species of tree frog that reproduce along streams and varied geology across Central and South America, from Costa Rica to the Andes of Bolivia, Colombia, Ecuador, Peru, and Venezuela. After tracking down a number of the frogs, the team used a collection of genetic and morphologic data to conclude Hyloscirtus hillisi was a separate species from its close relative, H. tapichalaca.

On top of its distinctive coloration, the bronze-eyed tree frog has another extraordinary feature: an enlarged claw-like hook poking out of its thumb base. The function of the abnormal appendage is unknown, but the researchers suspect it's used to fend off predators or in fights between sexually charged males fighting over a would-be mate.

Unfortunately, although perhaps unsurprisingly, the newly described species is in deep trouble. The team were unable to work out their total population size, but they noted that “scant evidence suggests low abundances.”

To make matters worse, a large Chinese mining company has recently set up shop in the area and threatens to take out their limited habitat. As previous work from Amazon Conservation has shown, this area of the Andes has already taken a brutal battering by infrastructure development, agricultural expansion, logging, and mining.

The plight of the Andes and the adjacent Amazonian rainforest continues to go from bad to worse, with the past year seeing the fastest rate of Amazon deforestation in decades. All this destruction, quite obviously, is terrible news for its once-bountiful biodiversity.