Voyage of Iguanas: How they travelled from Americas to Fiji

Iguanas are herbivorous lizards native to tropical regions, known for their distinctive appearance, strong claws, and ability to thrive in diverse habitats.

Context: The latest research published in Proceedings of the National Academy of Sciences has solved a long-standing mystery of how iguanas reached the Pacific islands.

About Iguanas

Iguanas are large, herbivorous or omnivorous lizards.
They are cold-blooded reptiles, primarily found in tropical and subtropical regions.
Most iguanas are arboreal (tree-dwelling) and have strong claws and tails for defence.
They are known for their scaly skin, long tails and dewlap (flap of skin under the chin), which helps in thermoregulation and communication.
Iguanas are native to tropical regions of Central and South America, Mexico, and the Caribbean.
Iguanas are not naturally found in India but exist as pets and in captivity.
Iguanas spotted in India: Green iguanas and American green iguanas.

The Puzzle of Fijian and Tongan Iguanas

Native iguanas of Fiji and Tonga have long posed an evolutionary mystery.
All other living iguana species are found in the Americas, from the southwestern US to the Caribbean and parts of South America.
Scientists were unsure how these reptiles reached islands in the South Pacific, thousands of kilometres away.
The research suggests that Fijian iguanas’ ancestors travelled on floating vegetation (rafting) across the Pacific Ocean.

What is Rafting?

Rafting is a process where animals cross oceans by clinging onto uprooted trees or plant debris.
This is commonly observed in invertebrates, as their small size allows them to survive long periods in floating vegetation.
Among vertebrates, lizards and snakes are known to raft better than mammals due to their slower metabolism.