Iguanas are large, herbivorous lizards native to Central and South America and the Caribbean islands. These reptiles can reach lengths of over six feet and weights exceeding 20 pounds in some species. Despite their size, iguanas are a regular food source for a variety of predators throughout their lives, especially during their vulnerable early stages. Their survival depends on defensive behaviors and physical adaptations to counter these constant threats.
Threats to Iguana Eggs and Hatchlings
The earliest stages of an iguana’s life are the most perilous, with very low survival rates for eggs and newly emerged hatchlings. Females bury their clutches in shallow nests, which are often discovered by ground-level predators using their sense of smell. Raccoons, feral pigs, and even crows and vultures are known to dig up these nests to consume the eggs before they hatch.
Once the tiny hatchlings emerge, they become easy targets for opportunistic hunters. Snakes, smaller predatory lizards, and wading birds like egrets and herons will readily snatch them up. These young iguanas are small enough to be viewed as bite-sized meals by many animals that would not dare approach an adult.
Native Predators of Adult Iguanas
In their native ranges, adult iguanas face a variety of large, specialized predators capable of overcoming their size and strength. Large raptors such as hawks, eagles, and owls regularly prey on both juvenile and sometimes fully grown iguanas. The arboreal nature of many iguana species means they are always at risk of an aerial attack while basking in the canopy.
On the ground, native mammalian predators like jaguars, pumas, and ocelots can ambush iguanas, especially when the lizards descend to the forest floor to nest or move between trees. Large constricting snakes, including anacondas and boa constrictors, also pose a threat in tropical regions. In aquatic habitats, alligators and crocodiles will take advantage of iguanas that venture too close to the water’s edge or dive into the water to escape a land-based threat.
The Danger Posed by Introduced Species
In areas where iguanas have been introduced, such as in Florida and various Caribbean islands, the threat landscape shifts dramatically due to non-native species. These invasive predators often target the lizards with efficiency because the iguanas have not evolved natural defenses against them. Feral cats and dogs are particularly impactful, with cats voraciously consuming hatchlings and dogs occasionally killing adult iguanas in open areas.
Another destructive introduced species is the mongoose, which was brought to many islands to control pests but became a significant predator of native fauna, including iguana eggs and juveniles. This disruption means that iguanas in these non-native ranges face sustained predation pressure, leading to conservation challenges for native rock iguana species.
Physical and Behavioral Defenses
Iguanas survive this constant threat by employing a suite of physical and behavioral defenses aimed at evasion and deterrence. The most common tactic is escape; iguanas are quick runners and proficient climbers, often living in trees that overhang water. When cornered or threatened, Green Iguanas will often dive into the water and swim away, sometimes holding their breath for extended periods to evade submerged predators.
If forced to defend themselves, iguanas utilize their powerful tails as weapons, capable of delivering a painful, whipping blow to an attacker. They also use sharp claws to scratch and strong jaws to bite in self-defense. For smaller iguanas, a specialized defense is autotomy, the ability to shed a portion of their tail when grasped by a predator, allowing the lizard to escape while the detached tail distracts the hunter.