Iguana is a broad term that describes a variety of lizards and lizard-like creatures. The most common is the green iguana, a common species in parts of North and South America, which is kept by many as a pet. Other iguanas include the marine iguana and the desert iguana. With so many different types of iguanas, as well as so many individual iguanas out in the wild, it's not surprising that the iguana has many predators.
Birds of prey are one of the iguana's main predators. Birds such as hawks, eagles and owls routinely make a meal of both grown iguanas and unhatched eggs. Herons and other water birds also prey on iguanas, particularly marine iguanas. These iguanas are most vulnerable just before giving birth and before they are fully grown.
Snakes are a major predator for both desert iguanas as well as green iguanas and their near relatives. Venomous snakes kill and eat desert iguanas, while the green iguanas fall prey to boa constrictors and their near relatives. Occasionally other reptiles, such as ground lizards, also feast on iguanas.
Mammals are not a natural predator for iguanas, but in their native habitats iguanas fall prey to invasive species such as rats, dogs and cats. This is also the case in areas where the iguana is the invasive species, such as the green iguanas found throughout Florida. These iguanas fall victim to mammalian predators including household pets, rats and raccoons. Humans have also become a predator to the iguana. In some areas iguanas are killed and eaten by people.
Amphibians such as crocodiles and alligators have been observed attacking and eating green iguanas. However, iguanas have also been known to dig up and eat the eggs of these amphibians. Rather than a traditional predator-and-prey relationship, the attacks by alligators and crocodiles on iguanas may be defensive in nature.
For marine iguanas, larger predatory fish represent a threat. Sharks, particularly the tiger shark, which eats a wide variety of prey animals, regularly dine on iguanas.