Tilcayo

The fur of the tilcayo is light brown with irregularly shaped rosettes. Its rosettes are large and dark brown to black in color, and are either open or partially closed –they do not coalesce. It also has short, round ears, long whiskers, and a scrunched-up face. Like many species in the Leopardus genus, it is smaller than a domestic cat. It has a head–body length of 42.5–50 cm (16.7–19.7 in), with a tail length of 25–26.5 cm (9.8–10.4 in). It weighs 1.5–2.0 kg (3.3–4.4 lb). The tilcayo so closely resemble other tiger cat species they are considered a cryptic species, difficult to distinguish from others by morphology alone.

The tilcayo was found near the town of Arapata in Nor Yungas province, in the Bolivian department of La Paz, at an elevation of 1,570 m (5,150 ft). This locality is positioned in the mountainous Yungas forest region, a cloud forest, on the eastern slope of the Andes mountain range.

The name "tilcayo" was already used for the species by local communities in the region. Publications on Bolivian fauna predating 2026 associate the term tilcayo with Leopardus tigrinus. It was originally reported that the exact etymology of the term is unknown, as it did not appear to be of Spanish, Quechuan, or Aymara origin. The term has been passed down in the local communities through generations, with its meaning reportedly lost in transfer. However, in an interview following the announcement of the species identification, Nogales-Ascarrunz stated that native Aymara speakers had reached out through social media suggesting that the term likely comes from t'ili kayu (lit. 'tiny foot').