appear to be opportunistic carnivores, as individual animals have been observed eating small lizards, snakes, and insects. Ecology The rhinoceros iguana's only confirmed native predator is the Hispaniola racer (Haitiophis anomalus), a large snake which has been recorded to give chase to juvenile iguanas, as well as wait for them outside the exit holes of their burrow. However, most predation of iguanas comes from invasive species like feral dogs (Canis familiaris), feral cats (Felis catus), small Indian mongooses (Urva auropunctata), and feral pigs (Sus domesticus), which all feed on eggs, adults, and juveniles. Mating and reproduction Male rhinoceros iguanas, unlike other members of the genus Cyclura, reach sexual maturity at four to five years of age. Females become sexually mature at two to three years of age. Male rhinoceros iguanas are territorial and the most aggressive males will have the largest range of territory. Mating takes place at the beginning of, or just prior to, the first rainy season of the year (May to June) and lasts for two to three weeks. 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. Notably, despite rhinoceros iguanas exhibiting some sexual dimorphism in size and horn development, they exhibit comparatively less sexual dimorphism than most other iguanas. Both male and female rhinoceros iguanas lack prominent mid-dorsal spines on their neck, which are typically very large in male iguanas of other species, both have well-developed dewlaps, and both develop horns. By contrast, in many other animals that exhibit horns such as ungulates or rhinoceros beetles, horns are often only present in males. Rhinoceros iguanas are also reported to show less dimorphism in size than other iguana species. This reduced dimorphism has been suggested to be due to intense female-female competition in rhinoceros iguanas, given the scarcity of nesting sites in their island environment, and females will use their horns to fight with one another over access to nesting sites much as males fight for access to females. Similar female-female combat over nesting sites has been documented in other island iguanas such as the marine iguana. Conservation Although rhinoceros iguanas are the most common species of Cyclura kept in captivity, approximately 10,000-16,000 iguanas remain in the wild. A successful breeding program existed at the Parque Zoológico Nacional of the Dominican