Wildlife
Fauna
One of the best known is the Galápagos tortoise, which lives on seven of the islands. It has an average lifespan of more than 150 years. The Marine Iguana is also extremely unusual, since it is the only iguana adapted to life in the water. Land iguanas, lava lizards, geckos and other harmless snakes can also be found in the Islands. The large number and range of birds is also of interest to scientists and tourists. Around 56 varieties live in the archipelago, of which 27 are found only in the Galápagos. Some of these are found only on one island.
The most outstanding are penguins, which live on the colder coasts, Darwin's finches, frigatebirds, albatrosses, gulls, boobies, pelicans and Galápagos Hawks, among others. The Flightless Cormorant, a peculiar bird which has lost the ability to fly, is also part of this rich fauna.
On the other hand, there are many mammal species, mostly sea mammals such as whales, dolphins and sea lions. A few species of endemic Galápagos mice (or Rice rats) - the Santiago Galápagos Mouse and the Fernandina Galápagos Mouse - have been recently rediscovered.
Flora
On the larger Galápagos Islands, four ecological zones have been defined: coastal, low or dry, transitional and humid. In the first, species such as myrtle, mangrove and saltbush can be found. In the second grow cactus, the incensé tree, carob tree, poison apple tree, chala and yellow cordia, among others. In the transitional zone taller trees, epiphytes and perennial herbs can be seen. The best known varieties are the cat's claw, espuela de gallo. In the humid sector are the cogojo, Galápagos guava, cat's claw, Galápagos coffee, passionflower and some types of moss, ferns and fungus.
Theories About The Uniqueness of Wildlife on the Galápagos
Many theories exist regarding the unique nature of the flora and fauna on the Galápagos islands. While no single definitive answer exists regarding the unique dispersal of plants and animals, a popularly held belief is that the original species that evolved into the unique Galápagos variety found their way to the island on flotation rafts of vegetation and other waste and were carried to the island via wind and sea currents. An explanation exists regarding the variety of birds on the Galápagos which posits that birds in flight were disoriented while making their regular migratory journey, and that they came to rest on the Galápagos carrying seeds and invertebrates on their feathers