Equipped with headlamps and torches, a group of researchers trekked through a rainforest in central Peru, listening carefully. That’s when they heard a whistling coming from near a road — it was a new species.
Researchers said they collected four of the small whistling frogs and determined that they are a new species known as Pristimantis loeslein, according to a study published Nov. 14 in the journal Vertebrate Zoology.
The frogs have a slender body with a wide head, the study said. Their skin is smooth on their backs, bumpy on their sides and coarse on their underside.
Scientists said the specimens varied in size, measuring between approximately 0.8 inches and 0.9 inches. They have long fingers that are not webbed and a tapered, pointy snout.
The creatures are yellow-green to olive green with a “bright yellow’ belly, according to the study. The frogs have dark markings on their backs — including reddish marbling on their heads, a dark line between their eyes, and two curved lines extending down their bodies.
Their large, bulging eyes are bronze with a copper streak, researchers said. Their limbs vary in color, ranging from brown to a gray-pink.
The frogs’ call sounds “like a short pronounced whistle,” co-author Jörn Köhler told McClatchy News in an email. It was discovered near a main road that connects the Andes mountains to the Amazon rainforest.
Specimens were found calling from bushes and other low shrub vegetation along the road, according to the study. They are only known from the location where they were discovered, but experts anticipate that they likely live in other areas of rainforests in central Peru.
The new species was named after a German family with the last name Löslein in honor of their support of research and conservation in Peru, researchers said.