Galápagos Marine Iguanas: The Lizards That Learned to Live From the Sea
Galápagos marine iguanas are unlike any other living lizard. In this video, I explore how they evolved to exploit the algae growing along the islands’ rocky coastline, and the remarkable adaptations that allow them to swim, dive, cling to rocks in heavy surf and feed in an environment that most reptiles could never use. Their flattened tails, powerful toes, specialised teeth and blunt snouts are all part of a body shaped around life beside, and partly within, the sea. I also look at the challenges that come with this unusual lifestyle. Marine iguanas have to remove huge amounts of salt from their bodies, cope with cold ocean temperatures and carefully regulate their body heat once they return to land. Their behaviour changes with temperature, and at night they can gather together in enormous groups to conserve warmth. Across the islands they also vary dramatically in size and colour, including the striking red and green animals sometimes known as “Christmas iguanas.” Perhaps their most extraordinary adaptation appears when food becomes scarce. During severe El Niño events, the algae they depend on can disappear, causing huge population declines. Some surviving marine iguanas can actually become shorter by reabsorbing bone material, reducing the amount of energy their bodies need, before growing again when conditions improve. I also explore their breeding battles, nesting behaviour, the dangers facing hatchlings and why I consider the marine iguana one of the greatest evolutionary success stories in the Galápagos. ________________________________________________________________________________ Planning a trip to the Galápagos Islands? 🏝️ Paul McFarling is a Galápagos guide and tour organiser with over 30 years of experience helping travellers explore the islands, wildlife, landscapes, and natural history of this extraordinary destination. Since 1992, he has worked with leading cruise and tour operators across the Galápagos and now organises personalised adventures for private travellers, families, student groups, alumni groups, and educational expeditions. Whether you are planning your first visit or looking for expert guidance on creating the right itinerary, Paul can help you make the most of your time in the Galápagos. 📍 Plan your Galápagos adventure: www.galapex.com ✉️ Contact Paul: info@galapex.com Subscribe for more Galápagos wildlife, island insights, travel advice, and stories from over three decades of guiding. _____________________________________________________________________________________________ 00:00 Why Marine Iguanas Are So Successful 01:24 How Marine Iguanas Adapted to the Sea 02:12 The Tail, Teeth and Head Built for Feeding 02:52 About Paul McFarling 03:40 How Marine Iguanas Feed 04:03 The Iguana That Survived an Hour Underwater 04:25 How They Remove Salt From Their Bodies 04:58 Surviving the Cold Galápagos Ocean 05:28 How Marine Iguanas Control Their Body Temperature 05:55 Why They Huddle Together at Night 06:45 Why Marine Iguanas Vary Between Islands 07:13 The Famous “Christmas Iguanas” 07:37 What El Niño Does to Marine Iguanas 08:19 How Marine Iguanas Actually Shrink to Survive 08:52 Breeding, Territories and Male Battles 09:20 Nesting and Competition Between Females 09:57 The Dangerous First Minutes of a Hatchling’s Life 10:43 Predators of Marine Iguanas 10:53 Why Marine Iguanas Are an Evolutionary Success Story