The story began in 2016 when biologist and National Geographic Explorer Paola Nogales-Ascarrunz received a call from a wildlife sanctuary in Bolivia about what staff described as a weird cat.
The animal had been found as a kitten on a road near a forest by a local man, who initially believed it was a domestic cat. He took it home and cared for it for about a year. However, after realizing that the animal was clearly wild, he decided it would be better off at a wildlife sanctuary.
Nogales Ascarrunz, the lead scientist and founder of the Bolivian Felids Research Program, became interested in the unusual animal.
The cat had a small, scrunched-up face, short round ears, long whiskers and leopard like spots. Its appearance immediately caught her attention, prompting her to visit the Senda Verde wildlife sanctuary on the subtropical flank of the Bolivian Andes.
She took around 100 photographs of the animal during her visit. At the time, Nogales-Ascarrunz believed the animal belonged to Leopardus tigrinus, commonly known as the tiger cat, oncilla, tigrillo or little spotted cat.
The species had been described in 1775 from an illustration of an animal seen in French Guiana and was subsequently believed to occur across parts of Central and South America, including Bolivia.
However, in 2019, Nogales-Ascarrunz noticed something unusual while preparing a booklet about Bolivia's cat species.
The spots on the Bolivian animal were significantly different from those shown in a reference photograph from neighboring Brazil. The animal had much larger rosettes, raising questions about its true identity.
It took several more years before Nogales-Ascarrunz developed the genetic analysis skills needed to investigate the animal's genome.
She later worked with geneticist Eduardo Eizirik of the Pontifical Catholic University of Rio Grande do Sul in Brazil and Jonas Lescroart of the University of Antwerp. Their research helped establish the animal's distinct position on the cat family tree.
The researchers proposed the scientific name Leopardus tilcayo, based on the name used by local people for the animal.
Nogales Ascarrunz asked local residents why they called the cat tilcayo. They explained that the name had been passed down through generations, with one local saying that his grandfather called the animal tilcayo and he continued using the same name.
Scientists currently know that Leopardus tilcayo lives in Bolivia's Yungas forest ecoregion on the eastern slopes of the Andes Mountains.
However, many details about the newly identified wild cat remain unknown, including what it eats, what predators may hunt it, how it reproduces and other aspects of its daily life.
The discovery is significant because it represents the first completely new species of cat discovered in more than a century. The previous new cat species discovery mentioned in the study was the pampas cat in 1923.
The research also changes scientists' understanding of the Leopardus genus, showing that what was previously considered a single tiger cat species was actually a complex of genetically distinct species.
Modern genomic analysis played a major role in the discovery. While physical characteristics such as tail length, rosette size and tooth shape remain important for identifying species, genetic research can reveal differences that are not visible from photographs or field observations.
Researchers compared complete genomes from 38 individuals across the Leopardus genus. The results showed that Leopardus tilcayo was genetically distinct from other tiger cats and had diverged from them around 1.4 million years ago.
That evolutionary separation is comparable to the distance between modern lions and extinct cave lions. The research also provides evidence for a new tiger cat subspecies in Peru, Leopardus tigrinus antisuyo.
Scientists are also investigating whether other small wild cats could contain previously unrecognized species. James Sanderson, founder and director of the Small Wild Cat Conservation Foundation, said the findings could point toward further discoveries.
Sanderson suggested that the margay, which has generally been considered a single species distributed from Mexico to Argentina, could potentially represent several distinct species. However, Eizirik said more focused genetic research on margays would be needed before such a conclusion could be made.
The researchers believe the improved genetic methods used to identify Leopardus tilcayo could eventually help scientists discover other previously unknown small wild cat species in Africa, Asia and other parts of the world.
The discovery of Leopardus tilcayo therefore does more than add another name to the list of wild cats. It demonstrates how modern genomics can reveal hidden biodiversity and reshape scientists' understanding of the evolution and classification of small wild cats.
