Galapagos Animals, Plants & Wildlife
Imagine: Millions of years ago, volcanic eruptions spewing hot lava and ash created the Galapagos Islands. They are barren. There is no grass; there are no trees; there are no animals. However, all the islands now have plants and animals, even the very newest. Where they came from and how did they survived once they reached land is the story of Colonization.
The Galapagos Islands have a low biodiversity (that is, few species), because the islands are 600 miles from the nearest land and this huge expanse of inhospitable ocean in-between makes it very difficult for new kinds of plants and animals to reach the islands. Marine organisms, such as green sea turtles and corals, probably came on their own, swimming, or as floating larvae. Seabirds are all strong flyers that frequently make long journeys across the open sea. But most of the Galapagos life forms reached the islands by accident, and all had a long sea voyage. During that trip, both plants and animals were exposed to saltwater, drying winds, and intense sunlight. They had no fresh water or food. Mature plants could not survive these conditions and those scientists think that most of the Galapagos plant species probably first arrived as seeds that could float or that were attached to birds. Reptiles are also more likely than land birds or mammals to be able to survive under these conditions. As a result, animals and plants of the Galapagos Islands are species whose ancestors were already well suited for its harsh environments. Compared to elsewhere in the tropics there are few birds or mammals, and many important groups of plants are missing. |
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Scientists agree that plants came fist to the islands. They came as seeds, falling unto minute patches of soil where they could grow. Small seeds were carried on the feet and feathers of seabirds, as well, and even inside the stomachs. Some smaller seeds were blown to the islands in the wind and larger seeds floated on currents after being washed out to sea.
Once there were plants to eat, animals that accidentally got to the islands could survive. Insects, like seeds, could have hitchhiked on birds or been blown by the wind. Large animals, like the sea lions or sea birds, swam or flew on their own. However others, like iguanas were unwitting passengers on floating logs or mats of plants. Most land birds were carried by storms to the islands.
Some of the seeds and some of the animals survived and reproduced. Other animals and seeds never made it on the islands. In this way, they established new populations isolated from their ancestors on other islands or on the South American mainland. Now they are thriving, similar to and yet very different from their distant cousins.
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