Mona and Monito are home to a number of unique animal and plant species found nowhere else in the world. This reserve represents one of the last remaining large tracts of
Puerto Rican dry forest along with the
Guánica State Forest and the
Caja de Muertos Nature Reserve. This type of biome is considered critically endangered.
Flora Mona is home to the largest population of the rare and
Critically Endangered Puerto Rico applecactus or
higo chumbo (
Harrisia portoricensis). This species of cactus is only found on the islands of the Mona Passage (59,000 individuals in Mona, 148 in Monito and 9 in
Desecheo), This cactus is locally known as
higo chumbo, meaning "weighed-down prickly pear", due to the leaning cactus arms caused by the weight of their fruit.
Fauna The Mona ground iguana (
Cyclura stejnegeri) is the largest native land animal, not only in Mona but in the whole archipelago of Puerto Rico, in length. It is critically endangered with an estimated population of 1,500 and only found in the island of Mona. Its numbers have greatly decreased due to the presence of invasive species such as cats which predate on the young, and boar which threaten their nesting sites. Although it inhabits the whole island it only nests in a small region in the southwestern coast as it is the only suitable nesting area with loose sand and direct sunlight. They are primarily herbivorous with a diet consisting of leaves, flowers, berries, and fruits from different plant species. Mona represents the largest nesting site for hawksbill sea turtles (
Eretmochelys imbricata) in the Caribbean.
Extinct species Mona used to be home to the Puerto Rican amazon (
Amazona vittata), now only found in small communities in the main island of Puerto Rico, and the Puerto Rican parakeet (
Psittacara maugei), an extinct species of parrot that was found in the island until its extinction during the first half of the 20th century. == Recreation ==