Famous Reptiles of the Galapagos Islands
On the Galapagos Islands, most animals with four legs are going to be reptiles. In fact, reptiles are so dominant on the islands, people who came here used to think the Galapagos were an ancient refuge for prehistoric reptilian beasts. The reptiles on the Galapagos, however, are actually just variations on reptilies found in South America. Two thirds of the reptiles on the Galapagos Islands are now endemic to these islands, which means they are found nowhere else on earth.
Reptiles on the Galapagos Islands
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- Iguanas
- Lava Lizards
- Snakes
- Geckos
- Giant Tortoises
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Iguanas
There are two types of Iguanas on the Galapagos Islands: Marine Iguanas and Land Iguanas.
Land Iguanas
The Land Iguana is an endemic species of the Galapagos Islands, and perhaps also one of its most famous representatives to the outside world. There is a type of land iguana on South America and on the Caribbean, which are the origins of the land iguana on the Galapagos. The ancestors (iguana iguana) are green, while those on the Galapagos are yellow-orange-brown colored. The ancestors fear man, while those on the Galapaogs have no natural fear of humans. There are two species of land aguanas in the Galapagos: Conolophus pallidus, which is whitish or brown, and Conolophus subcristatus, which is yellow-orange colored. The former are the largest, and have red eyes. The latter are found on Santa Cruz, Plaza, Isabela, and Fernandina but not on Santiago Island.
Land Iguanas are different from Marine Iguanas in that they do not have a square nose. They have pointed noses, and they get to be around three feet long. they eat grass, centipedes, and plants. Their favorite is the opuntia cactus. In some areas of the Galapagos, the land iguanas eat mostly fruit and flower of a vine called Ipomea alba, commonly known as the Morning Glory. In some areas, the land iguanas eat grasshoppers, dead birds, or sea lion afterbirth.
Marine Iguanas
Marine Iguanas are endemic to the Galapagos Islands, and are descended from South American land iguanas. They probably rafted to the islands nine million years ago, so had to adapt to a vegetarian and seafood diet. The Marine Iguana is one of the best-known symbos of the Galapagos Islands and the endemic species found here. Not only is this an endemic species, but it's alsot he only Marine Iguana in the world. These are the famous iguanas seen lounging on lava rocks along the coastal areas of the Galapagos Islands. They lounge in amazingly large groups, piled on top of each other, and range from 60 cm to three feet long. Half their length is their tail, and they have a spiny fan along their backs the whole length of their bodies. They can live in very cold temperatures or very hot temperatures as well: they are very adaptable in this way. This is called poikilothermic. The body temperature drops at night, and during the day it rises, to help with digestion. They eat algae and feces of sea lions or their own. They dive into the water sometimes, up to over 60 feet deep to find food. They can spend up to an hour under water and they swim very well. They can spray salt through their nostrils to warn off enemies. They are territorial and live 25 to 30 years, and lay eggs only once every two years. There are about 200,000 to 300,000 Marine Iguanas on the Galapagos Islands.
Lava Lizards
Lava lizards are found only in South America and the Galapagos Islands. There are a total of seven species of lava lizards that are endemic to the Galapagos. There is one species on each island...how's that for Darwinism? The biggest one grows to be 25 cm long. The smallest gets to be only around 12.5 cm long. The male is larger than the female, and he's usually gray-colored with dots. The female is easier to tell: she's red-orange in the throat area.
Lava lizards eat insects, leaves, seeds, and flowers. They prefer to be vegetarians and they love to lay out in the sun on the lava rocks. To cool off, they stand up on all fours. They sleep on leaf-dirt nests at night, which they make in lava cracks.
They are pretty peaceful, but will fight same-sex members for territory. Like the gecko, lava lizards have the ability of autonomy, so if something grabs their tail or other parts, oops it falls right off they can escape. The tail will grow back multiple times, but other parts won't. The males show off their aggressiveness with each other by standing sideways to each other so each can see the spiny crest display of the other. They might circle each other and bite each other and draw a little blood, but they don't take it much further than that.
Their natural enemies, or predators, are mostly birds: hawks, owls, herons, mockingbirds, and snakes.
Snakes
Two tpes of snakes are found on the Galapagos Islands. One lives on land and the other lives in the sea.
The first is the Galapagos Land Snake, which is a constrictor. It's a small snake, at only a bit over three feet, but it can catch prey up to 4 or 5 feet long. It eats insects, lizards, small birds, and baby marine iguanas. Its coloration is brown with yellow stripes or dark gray with yellow spots. The origin of this snake, which is of the Colubrideae family and the Philodryas genus, is the Caribbean. There are actually eight different subspecies on the Galapagos Islands, and you will find at least one type of gecko on all the islands except the ones in the north part of the Galapgaos archipelago.
Subspecies of Land Snakes on the Galapagos Islands
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- three subspecies of philodryas biserialis
- two subspecies of philodryas slevini
- three subspecies of philodryas dorsalis
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The other type of snake found in the Galapagos Islands is the Yellow-bellied Sea Snake (Pelamis platurus). The tail section has spots, and the body is yellow and black, this snake gets to be up to 85 centimeters long. The venom is dangerous, even more poisonous than the venom of the cobra snake. Fortunately, the Yellow-bellied Sea Snake is pretty rare, except for during the El Nino times, when waters get warmer because of the Nino current.
Geckos
A gecko is actually a small lizard that lives on land, from the Geckonidae family. There are several different types of Geckos on the Galapagos Islands, and six Gecko species are endemic to the Islands. The endemic species are of the genus Phyllodactylus, and found on Santa Cruz, San Cristobal, Baltra, Isabela, and Floreana.
Only about 5 cm long, with light brown colored-skin, geckos are super climbers. They find ways to climb ultra smooth surfaces, which you might think have no toe holds at all. In fact, geckos don't need crevices or toe-holds to climb becaue they have adhesive pads on their toes, which makes it very easy to climb anything. Geckos also prefer to come out at night, but you can see them during the day, too, if you look in crevices like under rocks or cracks in the lava. Their eyes are interesting: they have permanent eyelids, like a contact lense that is never removed. They lick their contacts once in a while, which is a famous behavior of the gecko. They lay eggs in late fall, just one or two, and they moult, too. After moulting, they'll eat their own dead skin. More interesting behavior from the Gecko! If something grabs a gecko by the tail, the gecko has the ability to detach itself from its tail in order to get away, leaving the predator holding onto just a tail. This ability is called autonomy.
Giant Tortoises
Also called the Galapago, the Giant Tortoise, or Geochelone elephantopus, exists only on the Galapagos Islands and on Adabra Island, which is in the Seychelles. Femaales weight up to 110 pounds and males up to 500 pounds!. There used to be lots and lots of these on the Galapagos Islands, say up to a quarter of a million but now there are around 15,000 because of slaughter by humans who ate them on ships. Today, humans don't hunt them anymore, but introduced species in the Galapagos Islands pose a danger to the Giant Tortoise. In fact, some of the species that used to exist no longer exist today. On Pinta Island, there was just one lonely tortoise surviving, and he now lives at Darwin Station. There are no known females left in his species but there is a reward for anyone who can bring her to the lonely guy. Isabela Island has the most giant tortoises.
Types of Giant Tortoises on the Galapagos Islands
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- Saddleback
- Intermediate
- Dome-Shaped
- Geckos
- Giant Tortoises
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The types of giant tortoises are based on the shape of their shells. They can store water and fat in their bodies, making them very adaptable to dry conditions. This is what led to their near destruction, since pirate ships could take them away and keep them alive in the bottom of their boats for long periods of time, with little care given. They live to be very old, some say as old as 170 years old. They eat grass and other types of vegetation and sleep a lot. They like to wallow in watery areas, too, during the wet season. The hide at night, in vegetation. They have lots of enemies besides pirates: rats and wild pigs will eat their eggs, feral dogs kill the little ones, and dig up the nests. Galapagos National Park and Darwin Station are doing all they can to protect the Giant Tortoises. They manage protection programs, breeding, and conservation initiatives.
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