In the Galápagos islands, you’ll likely find many iguanas during your explorations. There are four main species – three live on land and the fourth exhibits unique lizard habits by frequenting the cold sea.
These iguanas are thought to have come from South America, floating to the Galápagos islands on vegetation. Here, an estimated 10.5 million years ago, they split into two main sub-species – land and marine.
Iguanas of the land
There’s three species of land iguanas. Two are yellow, and the third is mostly pink. The yellow iguanas are the most common, and distinguished by which islands they are native to.
The Conolophus subcristatus iguanas are spread across six of the Galápagos Islands, with the Conolophus pallidus found only in Santa Fe. They are mostly yellow, but also have blotches of white, black and brown.
Meanwhile, the third species of land iguana, Conolophus marthae, is pink, and therefore also called rosada iguana. Little is known about this small species, with the iguanas only first studied in the 2000s. These land iguanas are found on Wolf Volcano, the northern end of Isabela Island. They have a black body with a pink head and legs and sometimes black stripes. Scientists estimate that rosada iguanas diverged from their yellow cousins around 5.7 million years ago.
Land iguanas can grow to over a metre in length, with males weighing up to 13.6 kilograms! When you explore the Galápagos Islands during your expedition, you’ll find them on dry parts of the islands, soaking up the heat from the sun in typical reptile fashion.
In terms of food, land iguanas eat low growing plants, shrubs, fallen fruits and cactus pads – these provide the necessary water to sustain them through drier periods. If you’re lucky, you may spot them lift themselves up so that small birds called Darwin’s finches can consume the ticks from their scaly skin.
The male iguanas are territorial, defending specific areas and have more than one female mate. They lay eggs in nesting burrows, around 2-20 eggs, and gestation period is 3-4 months.
There has been a great effort to save them from extinction, as cats and dogs will hunt them. Land iguanas were moved to different islands to avoid predators, and breeding centres were even established. These efforts have paid off, and today, you’ll find that all populations are relatively healthy.
Meet the lizards of the sea
Keep your eyes peeled – on almost every rocky shoreline in the Galápagos islands, marine iguanas will rest. These Amblyrhynchus cristatus are the only lizard that’ll frequent the sea although they live on land, as they eat a diet consisting mainly of seaweed grown on the sides of rocks. It’s an abundant food source, to which their blunt heads are well-adapted, as they dive deep into the sea with a strong tail propelling behind.
However, being cold-blooded creatures, marine lizards can’t stand the temperatures of the chilly ocean for long, so routinely surface on land to warm up.
They also mate and nest on land, hatching eggs under the sand. When the babies are born, they are prey to many hawks, herons and birds as well as racer snakes. The arrival of cats has also impacted population numbers, feeding on vulnerable young.
Marine iguanas change colour as they mature. The young are typically black, slowly picking up many colours when they age – red, green, grey, usually differing depending on the island they live on. Some iguanas on Española Island are extremely colourful, even more so during breeding season.
When food is scarce, these reptiles will literally digest their own bones, shrinking in both width and length. This can happen many times during their life, adapting to the amount of resources in the environment around them to survive.
Although typically docile herbivores, the males can get aggressive when defending the land where they mate. Marine iguanas can live to around 60 years, whereas their yellow counterparts live to only 50.
Much of the population was wiped out during the 1980s El Niño seasons, but you’re likely to see many of them as they laze around in the sun. Both land and marine iguanas are some of the fascinating wildlife you’ll encounter on the abundant Galápagos Islands.
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