Tilcayo (Leopardus tilcayo): First New Cat Species in 100 Years

In September 2026, a small spotted cat from the mountain forests of Bolivia became the first living feline formally named and described by science in more than a hundred years. Known locally as the tilcayo, and now carrying the scientific name Leopardus tilcayo, the animal is a type of tiger cat, one of the small South American felines belonging to the genus Leopardus. It weighs less than a typical house cat and lives in the Bolivian Yungas, the humid cloud forest belt where the eastern Andes descend toward the Amazon basin.

The recognition matters because it did not come from an expedition into unexplored territory. Communities in the region had known this cat for generations and already had a word for it. What was missing was the genetic evidence showing that it belongs on its own branch of the cat family tree rather than being lumped in with a familiar, widespread species. That evidence, published in Current Biology, has reshaped how scientists understand an entire group of small wild cats.

Quick Facts About the Tilcayo

Fact	Information
Common name	Tilcayo (tilcayo tiger cat)
Scientific name	Leopardus tilcayo
Genus	Leopardus
Family	Felidae
Order	Carnivora
Weight	Approximately 1.4–2 kg (around 3–4.4 lb); reported figures vary and measurements remain limited
Body length	Roughly 42.5–50 cm (17–20 in) head to body, with a tail of about 25–26.5 cm
Social structure	Not yet well documented
Diet	Small rodent remains have been identified in scat; detailed dietary studies are still lacking
Habitat	Montane cloud forest
Geographic range	Bolivian Yungas; full distribution not yet established
Lifespan	Not yet documented in the wild
Number of offspring	Not yet documented
IUCN Red List status	Not yet evaluated as a separate species
Year scientifically described	2026
Distinctive feature	Light brown coat with irregularly shaped rosettes, larger than those of the closely related oncilla

What Is the Tilcayo (Leopardus tilcayo)?

The tilcayo is a small wild cat in the family Felidae and the genus Leopardus, a group of Neotropical felines that includes the ocelot, the margay, Geoffroy's cat and the Andean cat. Within that genus it sits among the tiger cats, a set of closely related small spotted cats distributed across much of South and Central America.

Tiger cats have long been taxonomically messy. For decades, populations scattered from Central America to southern Brazil were treated as one or two species, largely because they look broadly similar to one another. The 2026 study concluded that the tiger cat complex actually contains five distinct species: L. guttulus, L. emiliae, L. pardinoides, L. tigrinus, and the newly described L. tilcayo.

The formal authority for the new species is Nogales-Ascarrunz, Aliaga-Rossel, Lescroart and Eizirik, 2026. The name itself was chosen deliberately to preserve local knowledge. Researchers asked people in the region why they called the animal a tilcayo and found that the word had simply been passed down without a clear explanation; it does not appear to carry a specific meaning in Spanish or in Quechua.

Discovery and Scientific Recognition

The trail began in 2016, when Bolivian biologist Paola Nogales-Ascarrunz, a National Geographic Explorer, received a call from a wildlife sanctuary that had taken in an odd-looking cat. A local man had found it as a kitten on a road near forest, assumed it was a domestic animal, and kept it at home, feeding it noodles, rice and eggs before the situation was reassessed. The animal was handed over to the Senda Verde refuge in the Yungas around 2017, where it still lives.

At first the cat was presumed to be Leopardus tigrinus. The doubt arrived in 2019, while Nogales-Ascarrunz was preparing an educational booklet about Bolivia's cats. Comparing her own photographs against reference images from Brazil, she noticed the rosettes were noticeably larger than they should have been.

Confirming a suspicion like that requires genetics. Working with Eduardo Eizirik, a geneticist at the Pontifical Catholic University of Rio Grande do Sul in Brazil, and co-lead author Jonas Lescroart of the University of Antwerp, the team assembled whole-genome data from 38 individuals across the genus Leopardus, including roughly 25 to 26 animals from the tiger cat complex. Crucially, eight of those genomes came from museum specimens, including six from the Guianas that provided the first genetic data ever obtained for the type population of L. tigrinus itself. Without that historical material, the researchers would have had no reliable anchor for deciding which populations the original species name actually applies to.

The analysis placed the tilcayo on its own lineage, one that appears to have separated from other tiger cats around 1.4 million years ago. According to Lescroart, a genetic gap of that size is generally treated as a species-level division in cats. The same study also described a new subspecies from the Peruvian Yungas, Leopardus tigrinus antisuyo, named for Antisuyu, the region of the Inca Empire that covered its range.

What the "First in 100 Years" Claim Actually Means

This phrase deserves precision. It does not mean nobody had ever seen the animal. Local Bolivian communities knew it well enough to have named it, and at least one individual had been living in a sanctuary since 2017.

What is genuinely unusual is that L. tilcayo is the first living cat species to be formally named and described as new to science in more than a century. Taxonomic changes within Felidae have happened more recently than that, but those involved splitting or reassigning populations already recognised under existing names. Here, researchers identified a lineage that had never previously been proposed as a separate species, subspecies, or otherwise.

What Does the Tilcayo Look Like?

The tilcayo has light brown fur marked with irregularly shaped rosettes across the body, giving it the appearance of a leopard reduced to roughly housecat proportions, or slightly smaller. Its ears are short and rounded, its whiskers long, and its face has been described as somewhat compressed or scrunched in appearance.

Size figures differ slightly between reports, which is unsurprising when descriptions rest on very few individuals. Commonly cited measurements give a head-and-body length of about 46 cm and a weight near 1.4 kg, while the published description reports a head-body range of roughly 425–500 mm, a tail of 250–265 mm, and a weight of about 1.5 to 2 kg.

Distinguishing it visually from its nearest relatives is subtle work. Compared with the oncilla, or northern tiger cat, the tilcayo has larger spot markings, a longer and more slender tail, and a more muted overall coat colour. These are exactly the sorts of differences that are easy to write off as individual variation in the field.

Where Does the Tilcayo Live?

Documented occurrence is limited to the Bolivian Yungas, a band of montane cloud forest on the eastern slopes of the Andes where the mountains meet the Amazon basin. The environment is characterised by steep terrain, persistent cloud cover and high humidity, and it remains one of the least-studied areas in the Neotropics.

The full geographic range of the species has not been established. Whether it occupies a narrow section of Bolivian cloud forest or extends further along the Yungas corridor is an open question, and answering it will require systematic field survey work.

Tilcayo Diet

Direct dietary research on this species is still minimal. What has been documented is the presence of small rodent remains in scat samples, indicating that rodents form at least part of the diet.

For context, small tiger cats in the genus Leopardus generally prey on small mammals, birds, reptiles and invertebrates. That is a reasonable expectation for the tilcayo, but it describes related species rather than confirmed findings about this one, and should not be treated as established fact until the species itself has been studied.

Behavior and Lifestyle

Very little has been documented. Camera-trap evidence suggests the tilcayo may be more active at night, though this is a preliminary indication rather than a settled conclusion.

Beyond that, its social structure, territory size, home range, hunting technique and movement patterns have not been described. Nogales-Ascarrunz is now deploying camera traps across Yungas forests to record the animal in the wild, work that should begin filling these gaps. Until it does, confident statements about how the tilcayo lives would be guesswork.

Reproduction and Life Cycle

There is currently no species-specific data on mating behaviour, gestation period, litter size, kitten development, age at maturity or wild lifespan for Leopardus tilcayo. None of this has been studied.

Reproductive figures published for other tiger cats cannot responsibly be transferred to this species. Lineages that separated well over a million years ago can differ substantially in breeding biology, and presenting borrowed numbers as tilcayo facts would create exactly the kind of false record that careful taxonomy is meant to prevent.

What Makes the Tilcayo a Separate Species?

The primary evidence was genomic. Rather than relying on appearance, the researchers compared complete genomes and used divergence-time estimates to measure how long the tilcayo lineage had been evolving separately from other tiger cats. The resulting figure of roughly 1.4 million years falls within the range normally treated as a species-level split among felids.

Coat pattern provided the initial clue that something was unusual, particularly the larger rosettes. Museum specimens supplied an essential comparison baseline, allowing the team to determine how the Bolivian animals related to historical populations. Geography matters too, since the tilcayo occupies the Bolivian Yungas while its closest relatives occur elsewhere.

Tiger cats are described as cryptic species, meaning they cannot be reliably separated by appearance alone. That is precisely why the group resisted clarification for so long and why genomic tools proved decisive.

Tilcayo vs. Similar Leopardus Cats

The most relevant comparison is with the oncilla, L. tigrinus, the species the tilcayo was previously assumed to belong to. The documented visual differences are larger rosettes, a longer and more slender tail, and duller fur colouration in the tilcayo.

The other members of the complex are separated primarily by genetics and geography. L. pardinoides, the clouded tiger cat, occupies northern Andean cloud forest; L. guttulus occurs in southern Brazil, Paraguay and Argentina; L. emiliae is associated with drier north-eastern Brazilian habitats. The tilcayo's Bolivian Yungas distribution sets it apart geographically from all of them.

Threats to the Tilcayo

No threat assessment specific to this species has been completed. What is well established is that its habitat is under pressure. The Yungas is among South America's most threatened ecosystems, facing deforestation, agricultural expansion, human-caused fires and mining.

Tiger cats as a group face similar pressures across their ranges as agriculture and development expand. Study co-author Tadeu de Oliveira, an ecologist at the State University of Maranhão in Brazil, has noted that all five of the newly recognised species inhabit habitats disappearing quickly. Because the tilcayo appears to be restricted to a relatively small and heavily pressured region, habitat loss is the most obvious concern, though this remains an inference from habitat conditions rather than a measured impact on the species.

Conservation Status

Leopardus tilcayo has not yet been evaluated on the IUCN Red List as a distinct species. At present the Red List treats tiger cats as two vulnerable species with declining populations, a framework established before this taxonomic revision.

The research team has submitted its findings to the IUCN, and an upcoming review is expected to assess the five lineages independently. Lescroart has indicated that separate assessment could give a far more accurate picture of risk, and that a species such as the tilcayo could potentially warrant an endangered classification when evaluated on its own.

No population estimate exists. Only one individual is known in protective captivity, and no wild population survey has been published. Estimating numbers will require the camera-trap work now under way. This situation illustrates a broader point: when several distinct species are grouped under one name, a genuinely rare lineage can be masked by the apparent security of a wider population.

Why the Discovery of the Tilcayo Matters

The most significant implication is methodological. Whole-genome analysis revealed a division invisible to the eye in a group that had been examined for decades, suggesting that other unrecognised species may be hiding within complexes currently treated as single species. The researchers hope the same approach can be applied to cats elsewhere in the world.

The role of museum collections is also worth noting. Specimens collected long ago provided the genetic reference points needed to sort out which populations the historical species names properly describe. Old collections, in other words, remain active scientific instruments.

Finally, there is a conservation argument. Recognising a species accurately determines how it is assessed, prioritised and protected. Identifying the tilcayo before any documented population collapse offers the chance to act early, rather than responding after decline is already advanced.

Interesting Facts About the Tilcayo

• Only one individual is currently known in protective captivity: a male, roughly ten years old, living at the Senda Verde Animal Refuge in Bolivia.
• Before its true identity was recognised, it was kept as a household pet and fed noodles, rice and eggs.
• Its lineage separated from other tiger cats around 1.4 million years ago.
• The species name comes directly from the local Bolivian term, chosen so that existing community knowledge would be preserved rather than replaced.
• Eight of the genomes used in the study came from museum specimens, including the first genetic data ever obtained for the type population of L. tigrinus.
• The same research also described a new subspecies in Peru, Leopardus tigrinus antisuyo.
• The first clue was not genetic but visual: rosettes that looked too large compared with Brazilian reference photographs.

Frequently Asked Questions About the Tilcayo

What is the Tilcayo?

The tilcayo is a small wild cat from Bolivia's Yungas cloud forest, formally described in 2026 as a distinct species of tiger cat.

What is the scientific name of the Tilcayo?

Leopardus tilcayo, placed in the genus Leopardus within the cat family, Felidae.

Is the Tilcayo really a newly discovered cat species?

It is newly described by science, but not newly encountered by people. Local communities knew the animal and had a name for it. What is new is its formal recognition as a species distinct from other tiger cats.

Where does the Tilcayo live?

It has been documented in the Bolivian Yungas, a montane cloud forest region on the eastern slopes of the Andes. Its complete range has not yet been mapped.

Why is Leopardus tilcayo considered a separate species?

Whole-genome analysis showed it forms its own lineage, separated from other tiger cats for roughly 1.4 million years, a divergence generally treated as a species-level split in cats. Coat differences and geographic separation support this.

What does the Tilcayo eat?

Small rodent remains have been found in scat samples. Beyond that, its diet has not been studied in detail.

Is the Tilcayo endangered?

It has not yet been assessed individually by the IUCN. Researchers have suggested it could potentially qualify as endangered once evaluated separately, given the pressures on its habitat.

Why is the discovery of the Tilcayo important?

It is the first living cat species named in over a century, it clarifies a long-confused group of small felids, and it shows that genomic methods can uncover unrecognised species even in well-studied animal families.

Conclusion

The recognition of Leopardus tilcayo is a reminder that biodiversity is not simply a matter of finding animals nobody has seen. Sometimes it means recognising what a species actually is, after generations of people have already lived alongside it. A cat that fits comfortably in two hands turned out to represent a lineage more than a million years old, hidden inside a group scientists believed they understood.

Much about the tilcayo remains genuinely unknown, including its population size, range, diet, breeding biology and lifespan. Those gaps are not a weakness in the research but a map of where fieldwork needs to go next. What is already clear is that its forest home is under real pressure. Recognising a species accurately is the first step toward protecting it properly, and the tilcayo has arrived in the scientific record early enough for that to still make a difference.