The Sierra Caral’s remaining forests are home to many endangered species, including 12 amphibians classified as Threatened with extinction on the World Conservation Union’s Red List of Threatened species, five of them listed as Critically Endangered. Three of these are salamander species found only in the remaining forests of the Sierra Caral, and five of the Threatened frogs are found only in Guatemala. New amphibian species, probably more endemics, are anticipated from the Sierra Caral, if the global conservation community can secure the forests before they are lost.
The Sierra Caral is also an important area for bird diversity, providing an ideal refuge for many migratory Neotropical species due to its geographic location and orientation. Along with other forested sites in the region, the Sierra Caral contains critical overwintering and stopover sites for 120 species of Nearctic migratory birds, including 33 priority migratory species with declining populations. This forest harbors 13 bird species considered as regional endemics and 40 species listed in global conservation priority lists.
The spectacular Blue Pitviper (Bothriechis thalassinus) is endemic to the Sierra Caral. Its recent description indicates that additional reptiles, as yet unknown to science, likely occur in these mountains. Furthermore, the remaining forests are an important component of the “Paseo Pantera”, the proverbial path of the panther, conceived as a biotic corridor through the narrow Central American isthmus between South and North America. Notable mammals include the Endangered Black Howler Monkey (Alouatta pigra) and the Central American Spider Monkey (Ateles geoffroyi).