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The Remarkable Iguanas

The iguana - the dragon of the Galapagos, arrived on the Galapagos several million years ago from South America on floating vegetation. One group of iguanas took to the hills and the other to the sea. These marine iguanas are unique in being the only sea-going iguanas in the world.

The Galapagos archipelago of thirteen main islands was formed by volcanic activity within the last five million years. The youngest island Fernandina is no more than 700,000 years old.

The land iguana of the Galapagos

Marine iguana and friend. The lava lizard uses the marine iguana's head as a lookout post!

Lying at the conjunction of a complex system of warm and cold oceanic currents, it is the coolest place at sea level on the equator and home to a truly astounding variety of tropical and temperate animals, many of whom are not found anywhere else in the world. Fernandina Island is one of the most pristine locations on the earth being perhaps the largest island outside the polar regions with no introduced species. Dominating the island of Fernandina is a 1,500 meter volcano with a massive caldera six kilometers across. Despite the harshness of the terrain and the unpredictability of the environment being marked by frequent volcanic eruptions it is home to a vigorous array of wild life.

Penguins and red-footed boobies, fur seals and tropic birds share its shores while the land is dominated by the reptiles - the land and marine iguanas as well as a giant tortoise. Hawks soar on the up-draught and doves and Darwin's finches drink the condensing water droplets from hissing fumaroles. But the most spectacular of all are the land iguanas who appear to have struck an evolution pack with the volcano itself.

During the hot season, the male iguanas gather in small vegetated areas on the lower blanks of the volcano and stake out their territories. The female then arrive to inspect the males and to mate.

Female iguanas compete for scarce nesting sites on the volcano rim and
on the caldera floor. Heat and moisture from the fumaroles keep the
soil at an optimum temperature to incubate the eggs.

Male land iguanas compete with their rivals to stake out territories
and attract females during the mating season. Once the female has mated,
she becomes unreceptive to other males. A land iguana (above) feeds on
leaves of a tree near the volcano rim.

Hatching of the young iguanas occurred in early October. They are only 25 centimeters long and are extremely vulnerable to the attack of the Galapagos hawks. For those who hatch on the crater's rim and for those who have survived the arduous journey up the steep walls of the caldera, another equally dangerous foe awaits. Dozens of snakes position themselves in the nearby grass waiting to see if the young iguanas as they journey towards the patches of vegetation - only a minority every make it.

Marine  iguana venture out several hundred meters to feed on the
rapidly growing algae. They can remain submerged for ten minutes at
a time but as their body temperature drops, they have to head back to shore.

The marine iguanas feed off the nutrition-rich upwelling from the Central Pacific as these are the most productive waters off the Galapagos supporting Fernandina's population of several hundred thousand marine iguanas. In the early morning, the sun's rays reveal thousands of these lizards pile on top of each other on the black lava terrain. By mid morning the iguanas arrive and head towards the rocky steep coast which is pounded by heavy waves. The younger male iguanas plunge into the surf as they have the strength to battle against the swells. Heads held out of the water, they lash their tails from side to side as they swim towards the breakers. to the calmer waters off shore where the submerged reefs are located. There they dive for the ocean floor to craze on the lush meadows of green algae. Some marine iguanas go down as far as twenty meters and stay sub-merged for ten minutes at a time. They can hold their breath for over an hour before drowning.

Stretched on the rock by the shore, the marine iguanas bask in the sun after returning from the sea

Being cold-blooded, the iguanas can only remain in the water for limited periods. They must head back to shore running the gauntlet of the heavy surf once again. Once passed the rugged cliffs the iguanas lie on the land soaking up the reviving warmth of the sun.

While the living patterns of the marine iguanas are quite different from their land cousins, the dangers faced by each are similar. Snakes and hawks are also the enemies of the young marine iguanas.

Low-lying fog and mist known as garua spilled over the rim of the volcano on Fernandina.
The cool air being driven up the side of the volcano condenses and is the only source
of moisture for up to six months of the year.

Life in the Galapagos - as elsewhere - is ruled by the rhythm of the season. July marks the onset of the cool season as clouds scuttle across the sky. Cooler water now bathes the archipelago and the air temperature drops. The trade winds blow from the south-east drive the cool air up the sides of the volcanoes condensing the moisture and forming bands of low-lying fog and mists known as the garua. During the dry period which lasts for six months, the garua will be the only source of moisture for the animals and plants of the archipelago.


Climate                     Tropical heat tempered by the Pacific Ocean breezes.

Clothing                    Casual. Take good walking shoes, bathing suit and a light jacket for evenings.

Electricity                 110 volt generated on cruise vessels only.

Time Zone                GMT minus 6 hours.

Currency                  American dollars or Ecuador sucres

Tipping                     Expected on cruise vessels.

Visas & Health        An entrance fee of US$100 is payable on arrival.


Aerolineas Argentinas and LanChile to South America, then to Equador where the Government-run TAME Airline flies from Quito to Galapagos. San Airlines (non-government) also flies to the Galapagos Islands from Quito.

Galapagos Undersea
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