The kodkod (Leopardus guigna) (), also called guiña, is the smallest felid species native to the Americas. It lives primarily in central and southern Chile, as well as marginally in adjoining areas of Argentina. Since 2002, it has been listed as Vulnerable on the IUCN Red List as the total population may be less than 10,000 mature individuals; it is threatened by persecution, and loss of habitat and prey base. Characteristics The kodkod's fur color ranges from brownish-yellow to grey-brown. It has dark spots, a pale underside and a ringed tail. The ears are black with a white spot, while the dark spots on the shoulders and neck almost merge to form a series of dotted streaks. Melanistic kodkods with spotted black coats are quite common. It has a small head, large feet, and a thick tail. Adult kodkods are in head to body length with a short tail and a shoulder height of about . Weight ranges between . Melanistic phenotype The melanistic phenotype is caused by the deletion of a single cysteine residue at position 126 of Agouti-signaling protein. This disrupts one of the four disulphide bonds in the normal protein, altering its tertiary structure and reducing its ability to bind to the melanocortin 1 receptor. Normally this interaction upregulates the production of orange pheomelanin and downregulates the production of black eumelanin, however, in the mutated form, this interaction is prevented, resulting in darker coat color than normal. Taxonomy Felis guigna was the scientific name used in 1782 by Juan Ignacio Molina who first described a kodkod from Chile. Felis tigrillo was the name used in 1844 by Heinrich Rudolf Schinz. The genus Leopardus was proposed in 1842 by John Edward Gray, when he described two spotted cat skins from Central America and two from India in the collection of the Natural History Museum, London. The subgenus Oncifelis was proposed in 1851 by Nikolai Severtzov with the Geoffroy's cat as type species. The kodkod was subordinated to Leopardus in 1958, and to Oncifelis in 1978. Today, the genus Leopardus is widely recognized as valid, with two kodkod subspecies: L. g. guigna (Molina, 1782) occurs in southern Chile and Argentina L. g. tigrillo (Schinz, 1844) occurs in central and northern Chile Distribution and habitat The kodkod is strongly associated with mixed temperate rainforests of the southern Andean and coastal ranges, particularly the Valdivian and Araucaria forests of Chile, which