Zoology

Conserving the Galapagos Giant Tortoises



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"Conserving the Galapagos Giant Tortoises"
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"A Success Story, andLast of the Line" or "Tortoise Recovery, andLonesome George." These were common headlines until recently, to be replaced by "Fabled Bachelor May Finally Be a Father."



But, first let's focus on why the discussion about Galapagos Giant Tortoises is so important.

Galapago' in Spanish means saddle', so the islands have taken their name from these creatures, as the Spanish thought their shells resembled saddles. The Galapagos Islands are home to a wonderful variety of unique animals, birds, and plants, all of which are special in their own way. We marvel at the strangeness of the creatures on these desolate volcanic islands, 1,000km off the coast of Ecuador, much as Charles Darwin did nearly two centuries ago. But, I'd like to focus on the tortoises-these creatures that have captured people's imaginations, the oldest and largest turtles in the world, living up to 150-200 years and weighing up to around 600 pounds.

The Galapagos Giant Tortoises, these huge lumbering creatures that move with ponderous grace, are a visible sign of a species brought back from the brink of extinction, an example of conservation success. It seems most visitors like the tortoises too. In the shops are many curios with a tortoise motif, as well as of those amazing birds, the blue-footed boobies (of course, T-shirts, bags and hats have the inevitable play on words!).

These gentle giant creatures, whose arrival on the islands is still a mystery, once numbered about 250,000. Before the arrival of humans the tortoises had no predators but, starting in the 17th century, pirates and whalers discovered these islands and used them as a safe haven. They introduced foreign animals and plants but, worse, they began the process of decimating the tortoises. We read horrific stories of thousands of tortoises being loaded onto ships and stored alive, upside down on their backs, as they could survive a long time and would be a source of fresh food for the ships' crews.

By 1980 tortoise numbers were down to about 15,000. Numbers decreased with competition from introduced species, such as goats, rats and cats, which threaten their natural habitat and eat the eggs. In the 1960s, Galapagos National Park, and the Darwin Research Station on Santa Cruz Island, began programs of protection, conservation and breeding of giant tortoises, programs that have begun to see success, some species saved from extinction.

The exception was Lonesome George.

Lonesome George is a symbol of the extinction that could be waiting. He is thought to be over 80 years old, a Saddleback Tortoise from Pinta Island, where he was found in 1971, decades after scientists thought that the Pinta Tortoise was extinct. He was rescued and brought to the Charles Darwin Station's Tortoise Breeding Center on Santa Cruz Island. In one way, he's not lonely as he has two female tortoises of a different, but closely related, species in the large enclosure with him. But, no mating ever occurred until recently and scientists worried that Lonesome George would be the last of the line. However, this July (2008) a clutch of eggs was found in their enclosure. The eggs are due to hatch in November and scientists hope that some are fertile.

We visited the Galapagos a number of times in recent years, including in May-June 2008, before the eggs were found. At that time, we watched George as though he were the last of his line. George stretched his neck up and munched on a cactus pad dangling from an opuntia cactus tree, moving very slowly to another pad on the ground. We sat and watched him sadly for a long time, privileged that we could see the last of a species, but frustrated as we thought that man could now do nothing to save his species. Man created this problem and man cannot fix it. But, happily it seems this might not be the case.

For more than 30 years the Charles Darwin Research Station and the Galapagos National Park Service have worked together in the Tortoise Breeding Centers on Santa Cruz, and more recently on Isabela and San Cristobal Islands, with the aim of preventing the extinction of threatened races of giant tortoises and ultimately re-establishing healthy populations of tortoises throughout the archipelago. The tortoise breeding and repatriation program has been very successful, with over 2,000 young tortoises back in the wild, complemented by habitat protection through the study and eradication of aggressive introduced species that prey on, and compete with, the native tortoises. Goats and donkeys have been removed from Isabela Island. But there are still threats. Developing an effective quarantine system to keep new invasive species from making their way onto the islands is a top priority.

TYPES OF TORTOISES:

Way back in 1835, the governor of the prison colony on Floreana (or Charles) Island told Charles Darwin that tortoises differed from island to island. This fact (plus many others) helped in Darwin's development of his evolution theory, which was presented in his On the Origin of Species.

There are three main groups of tortoises, based on the shape of the shell. The Saddleback Type has a carapace raised in the front and very long neck and legs, so this type looks for food high above the ground (like Lonesome George). The second is the Dome-shaped Type, which is heavier and bigger, and grazes directly on the ground. It is found mostly in the highlands with rich vegetation. The third group is the Intermediate Type, which is a variation on the Dome shape.

WHERE TO SEE THE TORTOISES:

On our visits to the Galapagos Islands we had opportunities to see and watch these legendary creatures, and were lucky enough to see each of the three types.

First, on San Cristobal Island, the Galapaguera de Cerro Colorado, past the small village of Progresso and El Junko Lake, is on an extensive protected area for Intermediate Tortoises, and about 60 thrive here. Supposedly this spot has trails used by wild tortoises in the past. Visitors walk on gravel, stone-bordered paths that wander through very dry vegetation. The director's wife, Tania, said she's been to the Galapaguera many times and often doesn't see any tortoises, so we were very lucky to see many hiding in the bushes, well camouflaged by the light and shade.

The high point was one water hole where we got a close look at a large group of tortoises. We could see the markings on the shells, the huge claws, the long necks, and heads that look exactly like ET! We could even get close enough to see the scales on the neck. They amble around clumsily it seems, but one moved quite quickly when another attacked it from behind and tried to bite its back foot.

We watched a couple eating an Otoy stalk by systematically stripping off the outside green bark and chewing it. This was interesting to watch, as they seemed to be holding down the end of the stalk with one front foot. Apparently the tortoises are often fed Otoy, which they really like (it's small branches and twigs of the flame tree, Erythrina velutina.) It was fascinating, and a real privilege, to see those great creatures in the wild in their natural habitat. We were very close to them, but they were unafraid and unconcerned about us.

A small Interpretation Center explains what Darwin Foundation is doing here and why it's important, and what the threats to these tortoises are-mainly feral goats, cats, rats, and damage to their habitat. The Galapaguera is a fun place to visit, but bring lots of water and use sunscreen as the sun is directly overhead, and very hot.

Secondly, on Santa Cruz Island, we visited a private ranch and then the Darwin Research Station.We drove from the port town of Puerto Ayora, north along the main road, to Rancho Primicias to walk in a lava tunnel and see tortoises. As we drove, it was wonderful to see numerous tortoises in the wild, on the road, next to the road, or walking across a field-signs that tortoise breeding and preservation are working well.

Rancho Primicias is mainly a cattle ranch, but is also a small tortoise reserve. The Visitors Center, where you pay (a couple dollars per person) has a caf, shop, and bathrooms. In the tortoise reserve are lots of Dome-shaped tortoises, in the bushes, walking on the path, or chilling out in the small (very smelly) pond. We felt lucky and privileged to see so many and to get so close to them. They are amazing prehistoric-looking creatures with lovely patterned shells, and sweet faces with beady eyes that seem to stare at you.

The Darwin Station is on the edge of Puerto Ayora and overlooks Academy Bay. It's a fairly long walk from the entrance gates, and the weather is usually hot and sunny, so be prepared. Along the path we saw other Galapagos animals such as land iguanas, lava lizards with distinctive red heads, and even black marine iguanas-amazing, as the path is quite far from the sea.

The station is huge and spread out, various buildings scattered in the many acres of natural vegetation. The main focus is tortoise breeding, so there are many very large natural pens and we see many tortoises of various sizes, from young hatchlings, to one-and-two-year-olds, to adults. We also see Lonesome George. In reality, he doesn't look that different to the others, but genetically he is. So, it would be the end of the line, the end of an era, if these eggs are not fertile.

We're all waiting and hoping.

For more information:

www.galapagos.org (Galapagos Conservancy, previously the Darwin Foundation)

www.galapagos-islands.net

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