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In the summer of 2012, we traveled to the Galapagos Islands, located 600 west off the coast of Ecuador in South America. The Galapagos Islands are known for their exotic and endemic wildlife that include the world’s largest tortoises which can live to be over 100 years old and grow to over 250 kilograms.  Other unique wildlife we encountered and filmed were the Galapagos iguanas. There are both land and marine iguanas in the Galapagos. Both have originated from the mainland of South America. They are thought to have traveled to the Galapagos Islands by sea rafts of vegetation blown westward during storms. Galapagos Land Iguana The Galapagos land iguana can be quite large, measuring up to 3 feet long and weighing up to 30 pounds. They live in the drier parts of the island and feed on low lying plants and shrubs eating fallen fruit and small cactus pads. These plants and fruits provide them with all the moisture they need. They are most active in the morning and late afternoon during the hot season. During mid-day they hide in cracks between rock and shady areas.  Land Iguanas become mature between 8-15 years of age. Males are territorial and will fiercely defend an area where several females are present. After mating, the female will lay between 2-20 eggs in small nests in sand and then defend the nest for a short time. This is done to ensure no other females will nest in the same area. Baby iguanas will hatch 3-4 months later. During their first few years of life, land iguanas are most susceptible to numerous predatory animals and birds. However, if they survive these early years, they can live up to 50 years of age. Today, populations of land iguanas are thriving, due mostly to conservation efforts. This includes control of imported dogs that eat large and small iguanas as well as cats (that eat only small iguanas), and goats that eat all vegetation on the islands.  Galapagos Marine Iguana The rocky shorelines of the Galapagos Islands contain a large population of marine iguanas which numbers 200,000-300,000. The marine iguana started as a land reptile that later migrated to the sea to obtain a more plentiful food source. It is estimated that these species of iguanas separated as far back as 10 Million years ago. They are excellent swimmers, propelling themselves forward through the water by moving their large tails from side to side. Galapagos marine iguanas dive to eat sea algae on rocks in the cold waters of the Humboldt Current, but cannot withstand dives of more than 10 minutes at a time before their muscles seize.  During periods of famine caused by El Nino events, marine iguanas have been seen eating alternate food sources such as crustaceans and grasshoppers. In essence they are considered to have remarkable capability for adaptation. One such adaptation shows marine iguanas grow shorter during El Nino famine events, and grow longer during good growing seasons when food is plentiful. It is likely that this ability to adapt has helped the marine iguana survive and flourish so well. The source for this information is The Galapagos Conservancy. Another amazing adaptation of marine iguanas is their ability to remove excess sea salt from their bodies. Marine iguanas can be seen spraying sea salt from their nostrils while sunning themselves on the rock shores. The Galapagos land and marines iguanas are amazing creatures and were also quite calm while being approached by humans. Perhaps they have grown accustomed to the thousands of humans now visiting the islands every year. I would definitely recommend a trip to the Galapagos Islands. It’s a trip you will never forget. Maddalena Environmental Inc. Al Maddalena  |
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