The fauna of this privileged site is the most diverse of the island. Among the vertebrate species we can find the rare almiquí (Solenodon cubanus), representative of Cuban Pleistocene fauna; the royal woodpecker (Campephilus principalis bairdii); the Cuban parrot (Amazona leucocephala leucocephala), and the catey (Aratinga euops), endemic species belonging to the same family of the parrot. Another curious species that lives here is the sapito guantanamero (Peltoplrine ramsdeni), a tiny tailless amphibious species about 3 cm (1.2 in) long.
In the zones of Baracoa and Maisí, the easternmost of the province, there is a mollusk having arboricole habits, the polimita picta. This species, producing extraordinarily beautiful and colorful shells, is quite sensitive to changes in luminosity, humidity, temperature and salinity of the environment reason why it has not adapted to live in other territories.