The Rhinoceros iguana is an endangered species of iguana that lives on the Caribbean island of Hispaniola, shared by Haiti and the Dominican Republic. The largest in their genus, these iguanas vary in length and skin colors that range from a steely grey to dark green and even brown. Their name derives from the bony-plated pseudo-horn or outgrowth which resembles the horn of a rhinoceros on the iguana's snout.
Rhinoceros iguanas range throughout Hispaniola (Haiti and the Dominican Republic). They prefer to live in scrub woodland, shrubland, and moist forests. They also inhabit dry forests characterized by xeric, rocky habitats of eroded limestone in coastal terraces, lowlands of the mainland, and several offshore islands and small cays.
Rhinoceros iguanas are solitary creatures that are active during the day. They live primarily in rocky outcroppings with little vegetation for cover where they spend their days warming in the sun perfectly blending into their environment. At night they retreat in caves or hollow trunks where they can sleep. Although quick to flee when attacked or threatened, Rhinoceros iguanas typically aggressively attack; they will bite and repeatedly strike with their thick tail if cornered.
Rhinoceros iguanas are primarily herbivores, consuming leaves, flowers, berries, seeds, and fruits from different plant species. However, they will also eat small lizards, snakes, insects, and even carrion.
Rhinoceros iguanas are polygynous meaning that males mate with multiple females. Their breeding season takes place at the beginning of, or just prior to, the first rainy season of the year (May to June) and lasts for 2 to 3 weeks. During this period the males become territorial and the most aggressive males usually have the largest range of territory. Females lay from 2 to 34 eggs, with an average clutch size of 17, within 40 days. Females guard their nests for several days after laying their eggs, and incubation lasts approximately 85 days. The young hatch fully developed (precocial) and are very active from the moment they were born. They don't require parental care and are able to fend for themselves. Males reach reproductive maturity at 4 to 5 years of age, while females are ready to breed when they are 2 to 3 years old.
Rhinoceros iguanas are threatened by habitat loss due to deforestation, hurricanes, and human clearing practices. They also suffer from illegal poaching for food and medicinal use and are often collected for the pet trade. Predation by snakes and feral animals, such as mongooses, pigs, or cats also pose a serious threat to these endangered reptiles.
According to International Iguana Foundation (IIF) resource the total population size of the Rhinoceros iguana in the wild is 10,000-17,000 individuals. Currently, this species is classified as Endangered (EN) on the IUCN Red List and its numbers today are decreasing.
Rhinoceros iguanas play an important role in distributing these seeds to new areas (particularly when females migrate to nesting sites) and, as the largest native herbivores of their island's ecosystem, they are essential for maintaining the balance between climate and vegetation.