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The Arrival of Plants and Animals on the Galapagos Islands

Explore the unique plants and animals of the Galapagos Islands and how they came to be on the Galapagos Islands.

| March 2018

Galapagos: A Traveler's Introduction(Firefly, 2018), by Wayne Lynch, takes readers with him through his travels of the Galapagos Islands. Lynch shares his travel experiences through vivid story-telling and photography. Readers will gain a better understanding of the life that habitats the islands and how the plants and animals may have landed on the islands. Find this excerpt in Chapter 3, Tiny Targets in a Giant Sea.  

Tiny Targets in a Giant Sea

Before I started to study the Galapagos Islands I never thought much about how islands are colonized by plants and animals, and it turns out to be an unexpectedly interesting process. The Galapagos are oceanic islands that arose from the repeated eruptions of underwater volcanoes. As with all volcanic islands, once the lava cooled, life had to settle on a landscape of barren rock. Today the islands boast a varied assortment of reptiles and seabirds but not a single amphibian or freshwater fish, and very few mammals. Biologists describe life on the Galapagos Islands as “unbalanced” — vastly different from Central and South America, where the majority of the colonists originated. How, then, did the Galapagos Islands acquire the unique mix of flora and fauna that they have today?

Think of the islands as a tiny target adrift in the vast eastern Pacific, a thousand kilometers or more from the nearest land. To get an idea of the challenge facing any animal or plant that might settle on these islands, imagine yourself sitting in the top row of a large football stadium. There is a grape lying on the ground in the middle of the field. It is too far away for you to see, but you must hit the grape with a dart. If you fail, you will die. Good luck!

For most successful colonists to the islands, it was indeed sheer luck that determined their fate. Many failed and perished. None of those successful animal pioneers were actively searching for the islands; all arrived by accident. Even so, for some colonists the odds were stacked in their favor — they were good long-distance travelers.



All the plants and animals that settled on the islands arrived in one of three ways: by sea, by air or carried by wildlife. Plants that came by sea either had to float on their own or were carried on a raft of vegetation. Mangrove seeds are famous for their long-distance journeys by sea, and most tropical coastlines worldwide are rimmed by forests of mangroves. Four species grow in the Galapagos: red, black, white and button mangroves. All are tolerant of salt water and their fruit and seeds float, even if only for a limited time, allowing dispersal by ocean currents.

Charles Darwin was very interested in how plants disperse. After his visit to the Galapagos Islands in 1835, he spent several decades making experiments to learn how they do this. Once he started thinking about it, he couldn’t stop; he had become obsessed with knowing. In one experiment he investigated how long seeds could stay alive inside the crop of a bird that had died at sea and then floated with the ocean currents. He discovered that they could survive for a month inside the bird, yet those same seeds would die after three or four days if they were dropped directly into seawater, unprotected.






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