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Galapagos Expedition Journal: Face to Face with Giant Tortoises

This is the fourth post in my account of a ten-day exploration of the Galapagos, on board the National Geographic Endeavour. You can read all posts for this expedition here.

I report on our visit to the Charles Darwin Research Station on Santa Cruz Island, where a decades-long breeding program has restored the iconic giant tortoise to the wild. We also visit Puerto Ayora, the largest settlement on the islands, a plantation where farmers distil moonshine from sugar cane, and the Santa Cruz highlands for encounters with wild tortoises in their natural habitat.

In earlier posts, I described our arrival on the island of San Cristobal and our first visit to a Galapagos beach, what it was like to swim with sea lions, and following Charles Darwin’s footsteps to Floreana Island.

The video at the top of this fourth post presents some of the work National Geographic is doing to support conservation of the Galapagos giant tortoise.

 

NASA image courtesy of MODIS.

 

Giant tortoise at Charles Darwin Research Station, Santa Cruz, Galapagos. Picture by David Braun.

 

At one time there were an estimated 250,000 giant tortoises on the Galapagos islands. They descended from South American ancestors that were probably swept out to sea during floods, floating hundreds of miles on the Humboldt current to the archipelago on the Equator. Tortoises can survive for extraordinarily long periods without food or water and the largest specimens would have the extra bouyancy and longer necks required to keep their heads above water as the strong current swept them west. Once they gained a foothold on the Galapagos, localized currents probably helped tortoises disperse to half a dozen of the islands, where over time they adapted to each island’s unique habitat and microclimate, becoming subspecies.

 

Galapagos tortoise distribution map shows islands with surviving subspecies shaded. Courtesy of Wikimedia Commons/Fallschirmjäger

 

Sadly, the very characteristics that helped tortoises survive the perils of a long ocean voyage to the Galapagos, and adapt to the islands’ harsh ever-changing climate of extended periods of drought, made them ideal food for the pirates and whalers who discovered the Galapagos in centuries past. Tortoises could grow up to 800 pounds. They could survive on ship decks for months without food or water. That was a lot of fresh meat for sailors at sea for very extended periods.

All too soon, giant tortoise populations that had built up over many millennia were in free fall. If they weren’t taken for food, their eggs and young were eaten by introduced rats, cats and dogs. Goats, donkeys and pigs trampled their nests. Tortoise numbers crashed to as few as a couple of thousand, and some subspecies became extinct . Some of the islands lost tortoises entirely. Today, ten sub-species hang on, ranging in conservation status from Threatened to Vulnerable. (For really good information about all the subspecies of the Galapagos giant tortoise, visit the Encyclopedia of Life.)

 

Photo by David Braun.

 

Photo by David Braun.

 

Photo by David Braun.

 

The Charles Darwin Foundation‘s Research Station on Santa Cruz Island is supported by Lindblad and National Geographic, in part through donations made by passengers on Lindblad-National Geographic expeditions in the Galapagos. The Station has run a successful program to restore giant tortoises to their natural habitat for decades.

Today, perhaps 20,000 tortoises are again roaming the Galapagos, a significant and encouraging rebound from near extinction. Rigorous efforts have been made to rid the islands of larger alien species like donkeys, dogs and goats. But the threat remains from rats and cats, which is why tortoise eggs are collected from the wild, incubated and hatched under protection at the Research Station, and baby tortoises are raised until they are sufficiently predator-resistant for reintroduction into their natural habitat. There is a high rate of survival.

 

Hatchlings from eggs collected from Espanola Island are kept safely under a heavy cover at night, to keep rats from getting at them. When they are around five years old they will be returned to their natural habitat, but only after they have been given a little orientation to learn how to survive in the wild. Photo by David Braun.

 

 

Photo of giant tortoise hatchling by David Braun.

 

At the Research Station we toured the enclosures for the different tortoise subspecies and age groups, and for the endangered land iguanas, which are also hunted by feral cats and other animals introduced by humans to the Galapagos.

 

A land iguana under protective breeding in the Galapagos Research Station. The reptile has suffered greatly from predation by feral dogs and cats. Photo by David Braun.

 

We visited the empty enclosure of Lonesome George, the last of the tortoise subspecies from Pinta Island. He died only a few months ago, probably at the age of around 100. (Read our National Geographic News story: Lonesome George, Last of his Kind, Dies on Galapagos.)

 

In memory of Lonesome George, this plaque was erected alongside the last Pinta Island giant tortoise’s now empty enclosure. Photo by David Braun.

 

Researchers are looking at the possibility of isolating the DNA of Lonesome George’s subspecies from hybrid tortoises. It’s a process called selective breeding, and research into how it might succeed is also funded in part by National Geographic. (Read my blog post: Can Extinct Galapagos Tortoise Be Bred from Living Hybrids?) Hybrid tortoises are the product of pirates and whalers dumping tortoises from one island on other islands. The hybrids preserve the DNA of all their ancestors.

We met another famous giant tortoise in the center, Diego, who was donated to the research facility by San Diego Zoo (hence his name Diego). Diego was one of 13 Espanola tortoises exported from the Galapagos to the zoo in the 1930s. He was returned to the Galapagos in 1977. He has earned admiration and the title of Mighty Diego at the Charles Darwin Research Station because of his prodigious breeding success. Some 1,700 of his offspring are said to be living, providing a big boost for his subspecies, which came very close to extinction.

 

Diego is still going strong at the estimated age of 130. Giant tortoises have been known to live in zoos for as much as 170 years. It’s thought that they live to around 100 in the wild. Photo by David Braun.

 

From the Charles Darwin Research Station we strolled through Puerto Ayora, home to some 18,000 people. Much of the settlement’s activity appears to center on tourism and fishing. There are many gift shops, tour operators, restaurants and bars. The town’s main street is flanked on each end by statues of a giant tortoise and an equally giant land iguana. If it’s tee-shirts of boobies, shot glasses to toast Lonesome George, or stuffed toy sea lions and hammerhead sharks you are looking for, Puerto Ayora is your town.

 

Puerto Ayoro main street. Photo by David Braun.

 

Puerto Ayoro tourist store. Photo by David Braun.

 

The tiny Puerto Ayora fish market displayed a pile of freshly caught fish monitored intently by a small flock of pelicans and gulls eager for any scraps that might somehow fall off the counter. There was a bit of a buzz in the town because Ecuador was playing Venezuela in an international football match. Many of the townsfolk were wearing yellow, the team color, and sidewalks were thronged by local residents trying to watch the game on television in the bars and restaurants. A couple of women set up a sidewalk table with a yellow cloth piled with snacks for sale.

 

Puerto Ayora fish market picture by David Braun.

 

Picture of brown pelican at the fish market by David Braun.

 

Our group met at a bar called “The Rock,” which was decorated for Halloween with skeletons, witches, and a portrait of Saddam Hussein. After enjoying an Ecuadorian beer, we boarded buses that took us to a small plantation of sugar cane and coffee trees. The owners had an unusual press to squeeze the juices from sugarcane, powered by tourists doing the work! The liquid is processed into a very pleasant but potent moonshine, best consumed with freshly squeezed orange juice. The locally grown coffee was also delicious. I had a swig of both ‘shine and coffee and definitely got a bit of a buzz.

 

Sugar cane press photo by David Braun.

 

Sugar syrup in the process of becoming moonshine. Photo by David Braun.

 

After we lunched at “Aquelerre” restaurant, the buses took us higher into the hills to visit the heart of the ancient giant tortoise migratory route. Tortoises migrate up and down the volcanic slopes of the Galapagos islands to take advantage of different vegetation in wet and dry seasons. There is also a theory that female tortoises migrate to different altitudes for nesting sites, which might have a bearing on the gender of their offspring. Like crocodiles, tortoises hatch into females or males depending on the temperature of incubation of their eggs. It’s not known if female tortoises determine the gender selection through their choice of nest sites. That’s the subject of another research project supported in part by National Geographic.

We encountered numerous giant tortoises in the wild. I could see why they could be so easily hunted for food by whalers and pirates. The lumbering giants do nothing to ward off danger other than hiss and pull in their heads. They appear to be oblivious to anyone approaching them from behind. They are easily found by their enormous carapaces glistening brightly in the sun. Retreating into their shells probably made it only easier for a team of burly men to pick them up and carry them off to their fate.

 

Tortoise heaven amid the greenery in the highlands of Santa Cruz. But in recent centuries this has been no paradise for the giant reptiles, which nearly became extinct from over-harvesting and habitat destruction. Photo by David Braun.

 

The tortoises are so old that lichens grow on their carapaces, giving some of them a greenish hue. Photo by David Braun.

 

Giant tortoise carapaces shining in the equatorial sun. They’re like sitting ducks for anyone wanting to capture them. That’s no longer allowed on the Galapagos. Tourists may not molest them in any way. The threats against giant tortoises today are invasive species that prey on their young and ongoing destruction of their habitat. There is also some poaching. Photo by David Braun.

 

Giant tortoise feet resemble those of an elephant. Picture by David Braun.

 

Our naturalist guides gave us plenty of time to wander around scores of giant tortoises foraging in the lush foliage around us. I can confirm that giant tortoises eat a lot, for they certainly leave giant mounds of poop for unwary visitors to step in.

Tortoised out, we descended to Puerto Ayora and the Zodiacs waiting to take us back to our ship. After-dinner entertainment was provided in the lounge by musicians and dancers from the town.

 

Evening commuter rush hour in Puerto Ayora harbor. Photo by David Braun.

 

Next time on my Galapagos Expedition Journal: Life on board the National Geographic Endeavour. Take a tour of one of the best-equipped vessels in the Galapagos, a comfortable hotel for passengers that also serves as a National Geographic platform for research and reporting.

 

Photo by David Braun

Comments

  1. DL
    November 19, 2012, 7:10 pm

    Pretty amazing. My son and I were there this summer and lucky enough to see Lonesome George before his demise. Makes sense how other tortoises may have been moved around by various ships using them as food. So George may not be the end of the line after all.

  2. shamayita
    india
    November 5, 2012, 5:02 pm

    Sir very nice and lucide to read…

  3. maria patricia
    philippines
    November 5, 2012, 4:27 pm

    a place to see. thank u.

  4. Lonesome George & Co
    San Francisco
    November 5, 2012, 4:02 pm

    Here at Lonesome George & Co in San Francisco, we support everything the Charles Darwin Research Station is doing to prevent further extinction of subspecies of tortoises. We hope to never come across the last of its kind again, like Lonesome George. Galapagos is a great place to preserve and help grow the tortoise population back up. It will be interesting to see what researchers can really find by isolating the DNA of Lonesome George’s subspecies from hybrid tortoises, in the process of selective breeding. We look forward to hearing more about the exploration and what can come of hybrid tortoises to save the subspecies of tortoises.

    • David Braun
      November 6, 2012, 7:16 am

      Thanks and keep up your good work at Lonesome George & Co. Thank you for raising awareness of an important species and issue of conservation. DB