Nobody sleeps in on a Hurtigruten cruise to the Galapagos. By 7 a.m., my fellow passengers were on deck, binoculars trained on the sky. Sure, I love to see pelicans, albatross and hawks too, but my heart is with iguanas. If you’re a fellow herpetophile, there no better place to indulge your lizard-loving ways than a trip to the Galapagos.
Continue reading below
Our Featured Videos
Marine iguanas
The Galapagos has at least four different kinds of iguanas, but let’s start with my favorite, the marine iguana. They’re endemic to the Galapagos Islands and are the world’s only sea-going lizards. Supposedly they were the first animal to come to these islands, floating on rafts of debris from the mainland. Estimates vary, but this probably happened about five million years ago, give or take a million. It must have been disappointing to travel 600 miles off Ecuador’s shore only to find a bunch of barren black rocks.
Related: Giant tortoise believed extinct for 100 years is rediscovered
“The only source of food available for those reptiles was located under the water,” explained Hurtigruten guide Daniel Moreano to our group as we stood on Fernandina Island, looking at hundreds of marine iguanas basking on a giant rock near the shore. “They were jumping into the water looking for food. And that’s how they learned that they can get as a food the green and red algae that we can find under the water.”
Thank you!
Keep an eye out for our weekly newsletter.
Join Our Newsletter
Receive the latest in global news and designs building a better future.
The colony of marine iguanas look prehistoric as baby dinosaurs, inert in the sun. Some have their little arms around each other, whether for warmth or affection, I don’t know. Now and then, they eject a stream of salt out of their noses, a weird adaptation their bodies have evolved to rid themselves of excess salt they swallow while feeding on algae.
Other evolutionary details include a laterally flattened tail that acts as a rudder for swimming, and a squared off snout so they can scrape the algae off the rocks with their teeth. Comparing the face of a land iguana to a marine iguana is like comparing a regular cat to a Persian. Marine iguanas are largely black, with their scales serving as solar panels to warm them up quickly after losing body heat from their dives.
You have to wonder what’s going on behind the psycho smiles on their little faces. They can be devious critters. Moreano describes a tactic the second-rate males on Fernandina use to pass along their genes. Instead of competing for alpha status, they lurk in the area where female iguanas feed on algae. “When they identify the female walking down to the feeding area, the medium-sized males, they’re going to use a rock to masturbate themselves to get ready the sperm,” Moreano explains. “So that means when the females passing nearby it will take just a minute to fertilize the female and run away before the big male arrives.”
One super unusual thing about marine iguanas: when weather conditions make algae scarce, they can reduce their size by about 20%, including their skeletons. Scientists are researching this ability, Moreano tells us, in hopes of applying that knowledge to osteoporosis and other human diseases.
Land iguanas
While I’d describe the marine iguanas as cute, land iguanas are absolute beauties. Especially the huge golden males. The biggest can grow up to five feet long and weigh 25 pounds.
Our first afternoon of the Hurtigruten cruise, we explore Cerro Dragon, or Dragon Hill, known for land iguana burrows. We find a few iguanas in the bushes just off the path. Moreano explains that the most successful males are bright yellow.
During mating season, “He will eat a lot of yellow flowers as a way to gain a lot of pigmentation to brighten its coloration more to look very attractive for females.” But we also see a patchy-looking iguana, its skin coming off in pieces like it has mange. Turns out, it’s just molting. Unlike snakes and lizards that lose their old skins in a single day, “Iguanas cannot afford to do that. The reason why, because if they start molting out their whole skin in one single day, they will lose a lot of heat and they will die.”
Instead, they lose skin in patches. “That’s a way to save energy,” Moreano explains. “Actually, the cells that regenerate the skin are located at the base of its belly. So always the new skin is coming from the base of its belly, and the other skin is peeling off from its back. That’s how it works.” But nothing is wasted. Finches, snakes and other iguanas eat the discarded skin.
Pretty as the iguanas are, nature can be disturbing. As Moreano describes how land iguanas mate, it goes from sexy to brutal, “Once the male found a female, the male start moving his head up and down, bobbing his head like this. And every time the male is doing that, he’s also doing some circles around the female body. Every time the male does a circle, they’re smaller in size, smaller in size, with the strategy to have a very nice approach to the females.”
So far, so good. Then it gets nasty. The male bites the female’s neck, then sticks the closer of its two penises into the female’s cloaca. “The copulation lasts for about five minutes up to 25 minutes. And it’s painful for females. Reason why, because the male iguana penis is like a plastic bag full of thorns. When he introduce that it’s painful. It’s even more painful when he retract that. So once the male is done with the copulation, you might see females running away from the males’ territory.”
Ouch, ouch, ouch. Nature is not for the faint of heart. On this trip I’ll also see giant tortoises copulating, and my guide that day will inform us that female tortoises will also get away as quickly as a tortoise can post coitus.
Santa Fe iguanas
This land iguana is only found on Santa Fe Island, a relatively flat nine-square-mile island in the eastern Galapagos. The Santa Fe iguana has smaller dorsal spines than other Galapagos land iguanas, is slightly darker and has a tapered snout. Its muted colors are designed for camouflage. When Charles Darwin visited, he called them “ugly animals,” and found marine iguanas even worse. The man obviously had no taste in lizards.
The iguanas are currently safe from predators on Santa Fe Island, and no humans live there. But since their population is restricted to such a small island, drought, introduced species or other unpredictable events could easily wipe out their estimated population of 7,000, so they’re considered vulnerable.
Pink iguanas
In 2009, scientists discovered a small colony of pink land iguanas living on Wolf Volcano on Isabela Island in the western Galapagos. Pink iguanas are the Galapagos’ rarest iguana. A 2021 survey by scientists and park rangers estimated the total number of pink iguanas to be 211.
According to the Galapagos Conservancy website, the pink land iguana diverged from other land iguana species about 5.7 million years ago, making it one of the Galapagos’ oldest known examples of evolutionary diversification. Scientists have rarely seen juvenile pink iguanas, thanks to predation of hatchlings and eggs by invasive cats and rats.
Why are they pink? Blood. A lack of melanin makes the skin translucent. “You can see the circulation of blood in that iguana,” Moreano told us. They regulate their temperature by moving between the highlands, where it’s cooler, and the warmer lowlands.
Bad news for tourists: You’re not allowed to visit the homeland of this critically endangered iguana. Good news for pink iguanas: An international team of scientists and researchers are developing a conservation plan. They’re planning to construct a permanent hut near Wolf Volcano as an operations base for future fieldwork. Hmm. Is it too late for this lizard-loving writer to retrain as a biologist and have a legit reason to stay in that hut?
Photography by Teresa Bergen
