‘Thumbless’ creature caught for the first time ever outside of Amazon rainforest
On the western slopes of the Ecuadorian Andes, researchers spent the nighttime hours monitoring the nearly invisible mist nets they hung over creeks and streams.
They were conducting a six-night bat survey in the lush cloud forests of the Rio Manduriacu Reserve — and their work yielded surprising results.
The team captured two Furipterus horrens — a type of “thumbless bat”— marking the first time the species has ever been recorded in the Ecuadorian Andes or found outside the Amazon rainforest, according to an April 11 study published in the peer-reviewed journal Check List.
Researchers said the species is “rarely caught in mist nets,” a common surveying tool.
The finding extends the geographical range of the species by about 180 miles northwest of its known Amazonian habitat, including the altitude at which it is capable of surviving, according to the study. The bats were captured at an elevation of about 3,757 feet, higher than the lowland forests where they’ve previously been found.
Researchers said DNA analysis of the bats revealed they had a “high genetic divergence” from their Amazonian populations, suggesting they may be part of an undescribed species.
Geographic isolation of the Rio Manduriacu Reserve bats may have led to this genetic branching, according to researchers.
More research is needed to verify if the bats are a new species, according to the study.
One of the defining features of the species is its “thumbless” appearance, according to researchers. Bats have five finger-like digits on their forelimbs, with the first and shortest digit acting like a thumb.
Furipterus horrens, however, lacks a well-defined first digit, according to researchers. It has no nail, like its other fingers do, and is almost fully covered by muscle.
The species also has characteristic wart-like growths on its chin. The bats are small, weighing three grams — about as much as one penny.
The Río Manduriacu Reserve is about a 100-mile drive northwest from Quito.
The research team included Isabel Warren, Laura Simba and Jorge Brito.
This story was originally published April 11, 2025 at 5:17 PM with the headline "‘Thumbless’ creature caught for the first time ever outside of Amazon rainforest."
