By Rocío Lloret, La Región:

Leopardus tilcayo: Bolivia Gives the World a New Wildcat Species, the First in More Than 100 Years

A scientific team from several countries, with a leading role played by Bolivian researchers, described this small feline through genetic analysis. The discovery will be published in the prestigious journal Current Biology and is the most important finding of recent years, not only for the country but for the world.

Un ejemplar de Leopardus tilcayo, nueva especie de felino identificada en Bolivia. Fotografía: © Fernando Faciole/National Geographic.
A specimen of Leopardus tilcayo, a new feline species identified in Bolivia. Photograph: © Fernando Faciole/National Geographic.

It is smaller than a domestic cat. It lives in the cloud forests of the Yungas of La Paz, and local communities have known it for decades as the tilcayo. But to science, it did not exist. Today, after a five-year investigation with strong participation from Bolivian scientists, Leopardus tilcayo is being presented as the first new wildcat species described anywhere in the world in more than a century.

This is a discovery that contributes not only to Bolivian wildlife but also to global science. It did not happen during an expedition, but rather by comparing photographs and descriptions that simply did not match.

It all began back in 2021. Bolivian researchers Enzo Aliaga-Rossel and Paola Nogales-Ascarrunz—a National Geographic Explorer—collected genetic samples from a male specimen that was being protected at the Senda Verde Wildlife Sanctuary, in the municipality of Coroico, one hundred kilometers from the city of La Paz. This feline, which had been taken into the sanctuary around 2017 after being handed over by a local family, officially became the holotype, or reference specimen, of the new species.

Paola Nogales Ascarrunz durante una exploración en busca de señales de Leopardus tilcayo. Fotografía: © Fernando Faciole/National Geographic.
Paola Nogales Ascarrunz during an expedition searching for signs of Leopardus tilcayo. Photograph: © Fernando Faciole/National Geographic.

Nogales-Ascarrunz, lead co-author of the study, told La Región that she noticed something unusual while preparing educational material about the feline. When reviewing the description of Leopardus tigrinus, the scientific name under which it had been classified, she found that the shape of the spots and the tail of this individual did not resemble those of the wildcat species she knew from Bolivia. Instead, it looked more like Leopardus guttulus, a more robust species with a flatter face. The problem was that guttulus “had never been recorded in the country.”

“I told my colleague: ‘This must be a guttulus, but guttulus is not recorded for Bolivia,’” she recalls. That contradiction triggered the genetic analyses. The original question was not whether a new species existed, but whether a known species had expanded its geographic range. Years later, the answer turned out to be far more surprising.

A Study Based on Genetics

Paola Nogales Ascarrunz trabaja con muestras de ADN de un gato silvestre. Fotografía: © Fernando Faciole/National Geographic.
Paola Nogales Ascarrunz works with DNA samples from a wildcat. Photograph: © Fernando Faciole/National Geographic.

To determine that the individual still living under protection at Senda Verde was not Leopardus tigrinus, the team—led by Jonas Lescroart and Paola Nogales-Ascarrunz as lead co-authors, together with Eduardo Eizirik of Brazil—sequenced the complete genomes of 38 individuals from the genus Leopardus. They combined modern samples—blood and tissue from rescued or road-killed animals—with DNA extracted from historical museum specimens, some more than half a century old. This technique is known as museomics.

This procedure proved essential in resolving a gap that had hindered the taxonomy of the group since 1775. There were no genetic samples from the original population of Leopardus tigrinus in the Guiana Shield (Guyana, Suriname, and Venezuela), the species’ recognized range. Researchers recovered DNA from fragments of the petrous bone—the densest part of the skull—from specimens preserved at the Smithsonian Institution in the United States and the Naturalis Biodiversity Center in the Netherlands.

Using this material, they reconstructed phylogenetic trees and calculated evolutionary divergence times. According to Nogales-Ascarrunz, taxonomy—the science that classifies living organisms—generally uses one million years of genetic separation as a benchmark for recognizing a distinct feline species. The populations from the Bolivian Yungas were found to have diverged from their closest relatives approximately 1.4 million years ago, a separation even deeper than that observed in Leopardus pardinoides, another species in the group that had already been validated.

Ultimately, the study demonstrated that what science had historically regarded as a single tiger cat species (Leopardus tigrinus) actually comprises at least five distinct wildcat species.

Un ejemplar de Leopardus tilcayo, nueva especie de felino identificada en Bolivia. Fotografía: © Fernando Faciole/National Geographic.
A specimen of Leopardus tilcayo, a new feline species identified in Bolivia. Photograph: © Fernando Faciole/National Geographic.
  1. Leopardus tilcayo(Tilcayo): New species officially described in this study, native to the cloud forests of Bolivia’s Yungas.
  2. Leopardus tigrinus(Northern / Guiana tiger cat): Species whose definition is now limited and restricted to the Guiana Shield. Within this species, the study also describes a new subspecies: Leopardus tigrinus antisuyo, native to the Peruvian Yungas.
  3. Leopardus pardinoides(Clouded tiger cat): Revalidated and elevated to the rank of an independent species for the cloud forests of the northern Andes (in countries such as Colombia and regions of Central America).
  4. Leopardus emiliae(Eastern tiger cat): Formally reinstated as a valid species, inhabiting the Caatinga and Cerrado ecoregions of eastern Brazil.
  5. Leopardus guttulus(Southern tiger cat): Revalidated as an independent species, native to the Atlantic Forest in southern South America.

The procedure used to reach this conclusion was so exhaustive that it gave the study “much greater taxonomic strength than even that of other species.” In fact, the paper underwent peer review by independent researchers, including Andrew Kitchener, a world-renowned authority on feline taxonomy, who formally endorsed the recognition of Leopardus tilcayoas a new species.

Difficult to Find and Easy to Confuse

Skins of Leopardus tigrinus antisuyo and Leopardus pardinoides, preserved at the Museum of Natural History of the UNMSM, Lima. Photograph: © Paola Nogales-Ascarrunz.

However, obtaining genetic samples of Leopardus tigrinus in Bolivia for comparison was not easy. According to the Bolivian researcher, the only museum specimen labeled as such is preserved at Bolivia’s National Museum of Natural History in La Paz. When it was analyzed, it turned out to be a margay (Leopardus wiedii), a different species.

The error is not accidental. The tiger cat and the margay are notoriously difficult to distinguish in camera-trap photographs, she explains. The most reliable difference—the direction of the fur on the nape, which in the margay grows in the opposite direction—is virtually impossible to detect without having the animal in hand. This confusion, also documented in the study that will be published next October in the renowned journal Current Biology, “artificially inflated” the geographic range attributed to the “tiger cat” in field records throughout the region.

After completing the entire procedure, the team finally obtained two confirmed samples of Leopardus tilcayo in Bolivia. One came from a female rescued by the Senda Verde Wildlife Sanctuary, injured after being struck with stones when she became trapped in a tree near a local community. Veterinarian Rodrigo Cantuta collected hair with the root attached and a blood sample before the animal was returned to its habitat. The other sample came from the male, who is now ten years old and remains under care at the same sanctuary. This means that the latter is the only known individual of the species currently living in a protected facility.

A Major Discovery for Bolivia and the World

La exploradora de National Geographic Paola Nogales Ascarrunz observa un ejemplar de Leopardus tilcayo. Fotografía: © Fernando Faciole/National Geographic.
National Geographic Explorer Paola Nogales Ascarrunz observes a specimen of Leopardus tilcayo. Photograph: © Fernando Faciole/National Geographic.

Enzo Aliaga-Rossel, one of the study’s authors and a Bolivian biologist with extensive experience in research and conservation, emphasized the specific significance of the finding for the country. This is not a microorganism or an invertebrate—groups where there is still much to discover—but a feline, a group about which “very little is known, almost nothing in Bolivia,” he warns.

“The fact that we were able to identify that it has genetic and morphological characteristics different from the rest means that we can name it as a new species for science,” he explains to La Región. The record keeps the number of mammal species documented in Bolivia at 407, with the difference being that there would no longer be Leopardus tigrinus, but rather Leopardus tilcayo.

Regarding its ecological role or function in nature, as a small feline it is a mesopredator. This means it occupies an intermediate level in the food chain, regulating populations of rodents and other small vertebrates. “When you eliminate these small carnivores (such as the tilcayo), there can be an overpopulation of mice (…) and this leads to a reproductive boom, followed by pest outbreaks. We have seen this many times in Bolivia,” he explains.

Aliaga-Rossel also confirmed that, for now, the species is considered endemic to the Bolivian Yungas, although experts still need to expand sampling to the north and south to confirm the actual boundaries of its distribution. Its small size, speed, and ability to remain motionless in a tree for hours explain why there are almost no previous records of the species.

The Paradox: Born Under Threat

Both Nogales-Ascarrunz and Aliaga-Rossel agree that, barely having been described, the species already faces dangers. Habitat loss—due to pressure on the forests where it lives and on its prey—is the main threat to the tilcayo and to much of Bolivia’s wildlife.

In this context, the discovery serves as a reminder of what is at stake. A feline that has lived alongside Bolivian communities for generations—long enough to have its own name in the local language, tilcayo, which the researchers decided to preserve as part of its scientific name in recognition of this ancestral knowledge—required the most advanced genomics for it to finally be recognized by science.

With the new record and the reclassification of the tiger cat complex into five independent species, a new assessment of each species’ extinction risk will be undertaken. Likewise, this discovery will help develop targeted conservation strategies and plans and, above all, further highlight the role of local communities in preserving animals such as the tilcayo, which, for now, has only been recorded in the Yungas of La Paz and is unique in the world.

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