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Galapagos Expedition Journal: In Search of Giant Iguanas on Dragon Hill

Day five of our expedition to the Galapagos islands took us to the northwest slope of Santa Cruz for a walk up Cerro Dragon, “Dragon Hill.” This place was once home to a thriving colony of the massive Galapagos land iguana, Conolophus subcristatus. The lizard is making a comeback here after being nearly wiped out by cats, rats, and dogs introduced to the Galapagos by humans.

This is the seventh post in my account of a ten-day exploration of the Galapagos, on board the National Geographic Endeavour. In my previous post I interviewed award-winning photographer Terry Goss about the underwater wonders of the Galapagos islands. (See all the posts here.)

We saw only two land iguanas on our walk — one dead alongside the trail and another we could glimpse resting in the shade of a bush a short distance into the thick undergrowth.  We did see quite a number of their burrows, which looked as if they were being well used.

 

Galapagos land iguanas grow up to five feet in length and weigh as much as 25 pounds. This one is kept in the Charles Darwin Research Station on Santa Cruz, where the reptiles are bred for release into the wild part of the island once they are considered to be too big to be preyed on by feral cats and rats. Photo by David Braun.

 

The land iguana is listed as Vulnerable to extinction by the International Union for Conservation of Nature, largely because introduced species like rats, dogs, and cats have come close to exterminating it throughout the Galapagos. International controls regulate collection and trade of the species, and only a few months ago a tourist was arrested for trying to smuggle four land iguanas out of the Galapagos.

Aside from habitat loss and trafficking, the biggest threat to the iguanas continues to be the introduced predators that nearly wiped them out. After the last few dozen iguanas were evacuated from Cerro Dragon for emergency protection in the 1960s, the authorities made valiant efforts to eradicate the predators from Santa Cruz. The feral dogs were all rounded up, and there have been ongoing attempts to reduce and manage the populations of cats and rats. Even so, we saw a kitten on our walk up Dragon Hill. We all remarked on its cuteness, but I also knew that it represented a deadly menace to the island’s naive birds and iguanas, which have lived on the Galapagos for millennia without any major predators. If the cat lives and breeds, it will probably have a direct role in the deaths of countless numbers of birds and other small endemic species. I observed our naturalist discreetly talking to someone on her radio phone about the kitten. It’s a tough business trying to protect the native species from alien invaders.

 

Photo of feral kitten in the iguana sanctuary courtesy of Anthony Braun.

 

Cerro Dragon habitat for Galapagos land iguanas. Photo by David Braun.

 

Cerro Dragon. Somewhere in there be dragons. Photo by David Braun.

 

Land iguanas are bred under captive protection at the Charles Darwin Research Station on the southern side of Santa Cruz. We saw several of them in pens the previous day we were on the island. Once the iguanas have safely reached a cat-proof size they are released into the wild on the northwestern side of Santa Cruz, so that the species can again take up residence on Cerro Dragon.

According to some estimates there are as many as 10,000 wild land iguanas on the Galapagos. They are a striking yellow/orange with bristling spiny backs and heads, and they can grow to an impressive five feet in length. Dragon Hill is an appropriate name for their home.

Read more about this magnificent animal on the Encyclopedia of Life Galapagos Land Iguana website, where you may find details about their morphology, mating rituals, diet, and the efforts being made for their recovery.

 

Photo of gull feeding on a fish head by David Braun.

 

In the dry season, the Galapagos land iguana eats cactus for food and moisture. The cactus on the islands has evolved into a treelike structure, to escape the reach of herbivores like iguanas and giant tortoises.  The tortoise in turn evolved upturned shells and longer necks to reach the lowest branches. Photo by David Braun.

 

The walk up Cerro Dragon started with a Zodiac landing onto a rocky path that led us to a white sandy beach. We passed a gull feeding on the head of a parrot fish dropped presumably by a sea lion, then picked our way through a grove of giant cactus trees to a small lagoon where we could watch a solitary flamingo skimming the water for tiny shrimp.

Although we didn’t get much in the way of sightings of the land iguana on our walk, the views were spectacular and there were plenty of birds, marine iguanas, insects, and plants to enjoy.

 

Photo of flamingo by David Braun

 

Photo by David Braun

 

Marine iguana near the Cerro Dragon landing site. Photo by David Braun.

 

Lunch on the ship after our morning excursion was a special “Ecuadorian Buffet,” the centerpiece of which was roast pig. It reminded me a little of the Hawaiian luau, although this pork was not baked in sand.  The catering staff came out of the galley to talk to us about traditional dishes and local produce. Ecuadorian food is delicious, and the cuisine on board Endeavour certainly helped give the Galapagos expedition an exotic flavor.

 

Photo by David Braun

 

While we dined on the Ecuadorian feast, the galley staff gave us a lively talk about local foods and dishes. Many of them are wearing traditional hand-woven hats, known as Panamas but made in Ecuador. Some of the finest examples of the craft sell for as much as U.S.$1,000 per hat. Photo by David Braun.

 

I made my second presentation to passengers in the Endeavour lounge after the feast, and I was pleased to note a good turnout in spite of the soporific effect of the lavish meal. Part of what I talked about was how National Geographic News covers the Galapagos, including research the Society supports in the archipelago.

In the afternoon we steamed north, along the way passing Daphne Major islet,  made famous by Princeton University’s Peter and Rosemary Grant and their long study of the ecology of Darwin’s finches. A documentary about their work was screened in the ship’s lounge. “The Grants’ empirical research has made the most important contribution since Darwin toward making evolutionary biology a science in which proof is possible,” the Inamori Foundation of Japan said of the Grants when it awarded them the Kyoto prize for their work in 2009. National Geographic News reported on their work in the 2006 story “Instant” Evolution Seen in Darwin’s Finches, Study Says. I thought of them when we sailed past where they spent so many years observing the evolution of the finches.

One can’t helping thinking a lot about evolution when you’re in the Galapagos, from the stories of Darwin to the many explanations by the naturalists of how the different species adapt to the unique environment and one another. It’s a fascinating story still unfolding.

 

Daphne islet at sunset. Photo by David Braun.

Next time on Galapagos Expedition Journal: Bartolome and the Penguins of the Chinese Hat Volcano.

Comments

  1. Deborah Guido OGrady
    Rome, Italy
    December 9, 2012, 3:32 am

    What a wonderful excursion with NatGeo! This post does much to raise awareness of the plight of endangered species on the island, and the difficult things that must be done to keep species safe from encroaching man and even kittens!