Galápagos Iguanas and Lizards

There are mainly two species of iguana in the Galapagos Islands. They are the Land Iguana and the Marine Iguana. The main species of lizard is the Lava Lizard. Galapagos iguanas are thought to have had a common ancestor that…

Galápagos Iguanas and Lizards

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There are mainly two species of iguana in the Galapagos Islands. They are the Land Iguana and the Marine Iguana. The main species of lizard is the Lava Lizard.
Galapagos iguanas are thought to have had a common ancestor that floated out to the islands from the South American continent on rafts of vegetation. The divergence between land and marine iguanas has been estimated at 10.5 million years ago. Geneticists estimate that the pink iguana diverged from the other land iguanas approximately 5.7 million years ago — before most if not all of the current islands existed, while the divergence between the two yellowish iguanas is fairly recent.
The well-known yellowish land iguanas include Conolophus subcristatus, native to six islands, and Conolophus pallidus, found only on the island of Santa Fe. Land iguanas are large — more than 3 feet long — with males weighing up to 30 pounds. They live in the drier areas of the Islands, and in the mornings can be found sprawled beneath the hot equatorial sun. To escape the heat of the midday sun, they seek the shade of cacti, rocks, trees or other vegetation. At night they sleep in burrows dug in the ground, to conserve their body heat. They feed mainly on low-growing plants and shrubs, as well as fallen fruits and cactus pads.
Just about every rocky shoreline in the Galapagos Islands is home to the marine iguana (Amblyrhynchus cristatus), the only sea-going lizard in the world. The marine iguana is an extraordinary animal that lives on land but feeds in the sea, grazing on a variety of seaweed – on exposed rocks, in subtidal areas, or by diving deeper into the cold seawater. This habit, totally unique in iguanas and in fact all lizard species of the world, provides them with an abundant food source. However, they cannot withstand the cold temperatures of the sea for too long and must pull out on land to warm up.
Galapagos lava lizards can be found on all major islands in Galapagos, but some species only live on certain islands. Their coloration varies based on which island they live on, as well as by gender. Those that live on islands with dark lava are usually darker in color than those living on light, sandy islands. Male lava lizards tend to have darker bodies than females, often with yellow-green markings, whereas females typically have red cheek patches when they reach maturity and are reddish-brown. Males are also larger than females (as much as two-three times as large).

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