The fauna of the reserve is characterized by having several species of birds, among which 81 have been described and are endemic species such as the chucao – which only inhabits the temperate rainforest – and the black woodpecker. Mammals such as the puma, the pudú, marsupials such as the monito del monte and endangered amphibians such as Darwin’s frog also inhabit the area.
Darwin’s frog is an amphibian of the Rhinodermatidae family and an endemic animal of the temperate forests of Chile and Argentina. In its adult stage, it does not exceed 3 cms. and is characterized by having a triangular figure. Its color varies from intense green to brown, this allows it to mimetize in the forest and flee from its predators. Its song is similar to that of a bird due to its high tones similar to a whistle.
The carancho, is a bird of prey that measures between 55 and 60 cms. of length and that is characteristic of the zones of the center and south of South America. It presents the top of the head in black tonalities, grayish neck, chest with wide brown lines and whitish tail that ends with a black band.
The chucao, also known as tricao, is the emblematic bird of Huilo Huilo. Endemic to the temperate forests of southern central Chile, it feeds mainly on insects, worms and fruits. Its chest is brick-colored and has a stain on the forehead of the same color.
The Monito del monte, is a marsupial and endemic species of Chile that is found between the VII region and continental Chiloé (X region). It lives in the Nothofagus type forests and temperate hydrophilic forests of the south of the country. It is omnivorous and feeds mainly on insects, seeds, fruits and plants.
They are the smallest members of the deer family. They measure between 60 and 90 cms. long and reach 40 cms. high, with a weight ranging between 7 and 10 kilos. They inhabit temperate-rainy forests of southern Chile and Argentina and feed on the understory of ehelechos, shrubs, leaf and fruit shoots.