In 2016, a wildlife refuge in the Bolivian Yungas took in an unusual animal. A local man had found a spotted kitten on a road near a forest and brought it home, assuming it was a domestic cat. After about a year, it was clear the animal was wild, and he handed it over to La Senda Verde Animal Refuge. The staff named him Tigrino.

Paola Nogales-Ascarrunz, a cat conservationist and National Geographic Explorer who works with the refuge, photographed him soon after he arrived. In 2019, while putting together a booklet on Bolivia's wild cats, she compared her photos with a guidebook image of a tiger cat from Brazil. She told National Geographic that something looked wrong: Tigrino's rosettes were much larger. It took years of genetic work to find out why.

On September 17, 2026, the answer was published in Current Biology. Tigrino is a tilcayo, a species new to science, and he is now its holotype, the individual that formally defines it. He still lives at the refuge. When he dies of natural causes, his body will be preserved at Bolivia's National Museum of Natural History.

Tiger cats are small spotted cats that range from Costa Rica to northern Argentina. The first one was described in 1775, based on a single illustration of an animal from Cayenne in French Guiana. Because they look so alike, tiger cats across the continent were long treated as one species, and even experts struggle to tell them apart from photos.

The new study, co-led by Nogales-Ascarrunz and evolutionary biologist Jonas Lescroart of the University of Antwerp, sequenced complete genomes from 38 cats in the genus Leopardus, about 25 of them tiger cats. The results show five species: the southern tiger cat of Brazil's Atlantic Forest, the eastern tiger cat of the Caatinga and Cerrado, the clouded tiger cat of the northern Andes and Costa Rica, the northern tiger cat of the Guiana Shield and Peru, and the tilcayo of the Bolivian Yungas.

The hardest piece of the puzzle was the northern tiger cat itself. Tiger cats from the Guiana Shield are so rare that no DNA from that region had ever been published. So the team turned to museum collections.

At the Smithsonian's National Museum of Natural History, they sampled specimens collected in Guyana between 1965 and 1967 by Stanley Brock, a former cowboy at the Dadanawa Ranch in the Rupununi savannah and a co-host of "Mutual of Omaha's Wild Kingdom." For several skulls, the researchers drilled through the ear canal to reach the petrous bone, a dense bone around the inner ear that preserves DNA unusually well. Other specimens gave up DNA from a tail vertebra, the root of a molar from the Naturalis Biodiversity Center in the Netherlands, or a sliver of dried skin. All of it was processed in a dedicated clean lab at the University of California, Santa Cruz, where cleanroom suits keep modern DNA from contaminating the samples.

"Museum collections offer huge value for present-day genetic research," Lescroart said.

The tilcayo's lineage split from its closest relatives about 1.4 million years ago, during a period when shifting climates broke up the Andean cloud forests into isolated pockets. That's roughly as long as the kodkod and Geoffroy's cat, two long-accepted species, have been separate.

Adults measure 42.5 to 50.5 centimeters (16.7 to 19.9 inches) from head to rump and weigh 1.5 to 2 kilograms (3.3 to 4.4 pounds), smaller than most house cats. Their rosettes are large, irregular, and mostly open. The tail is fuller than in most other tiger cats, marked with blotches rather than rings for most of its length, and ends in a pale tip. Their nape hair slants backward, while a margay's slants forward. The difference is hard to spot in camera trap images, which is why tilcayos are easily mistaken for margays.

The tilcayo's genome also carries traces of old hybridization. Its mitochondrial DNA comes from an ancestor shared with Geoffroy's cat, and about 15 percent of its nuclear genome reflects past gene flow from Peru's tiger cats.

The study also describes a new subspecies, the Antisuyo tiger cat, named after Antisuyu, one of the four regions of the Inca Empire. It lives in the Peruvian Yungas, just north of the tilcayo's range. Researchers expected it to group with the clouded tiger cats of the northern Andes.

Instead, its closest relatives turned out to be the northern tiger cats of the Guiana Shield, on the far side of the Amazon. The two lineages separated about half a million years ago. How they ended up so far apart is still an open question.

So far, tilcayos have been genetically confirmed only in the cloud forests of Nor Yungas in La Paz, Bolivia. The researchers suspect the species occupies the entire Bolivian Yungas, but the true range is unknown. The region is losing forest to coca plantations and illegal gold mining, which also releases mercury into rivers and soil.

The study's genomic estimates suggest the tilcayo's effective population size has dropped by about 63 percent since the Pleistocene. Until now, tiger cats were assessed on the IUCN Red List as a single species, so the tilcayo has never had a conservation status of its own. That will have to change, and the same is true for each of the five species.

The name tilcayo comes from what communities in the Bolivian Yungas have long called this cat. "We decided to keep the name 'tilcayo', the name used by local communities for this cat," Nogales-Ascarrunz said. "For us, it was also a way of recognizing and preserving the local knowledge connected to this species."

The study is Lescroart, Nogales-Ascarrunz, et al. (2026), "Phylogenomics and museomics reveal five distinct species of tiger cats in South America," Current Biology 36. https://doi.org/10.1016/j.cub.2026.08.059