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Talk about giant tortoises

Talk about giant tortoises

The discovery of the Galápagos might have been the most important leap in natural science we ever made, its wonders originally uncovered by the Spanish in the 1500s. This archipelago off the coast of Ecuador was volcanic in origin and each of its islands harboured countless variations of the same basic flora and fauna, demonstrating the transformative powers of natural selection like nowhere else.

It was Charles Darwin who first recognized the significance of this variety; these animals were in fact being moulded by their differing environments to produce several species where previously there had only been one. Of all the organisms here, which would later inspire his theory of evolution, one kind would come to define this archipelago in ways the others simply wouldn’t — the giant tortoises.

We counted 15 different species of them, one of which occupied this archipelago’s northernmost island of Pinta. Before the onslaught of human beings we estimate this modest upwelling of Earth was home to 2,500 Pinta tortoises, as they’re now know, but with the passing of fishermen, whalers and even pirates this island was picked clean. The crews of these ships discovered giant tortoises could live for over a year below decks and so offered them a source of fresh meat, and given the island’s opportune location at the entrance of the Galápagos, it was tapped often.

By 1906, so thoughtlessly had these Pinta tortoises been exploited it was assumed they’d become extinct. This was a tragedy for the island’s ecology which depended on these tortoises to maintain open spaces with their grazing and bulldozing movements. In the same vein they spread seeds throughout their habitat, earning them the distinction of being ecosystem engineers. As though their absence wasn’t harmful enough, in 1959 passing fishermen released three goats onto the island hoping to encourage a small population from which to periodically draw. There plan was ill-conceived.

By 1970 the island was in ruins, its goat invaders multiplying to 40,000 strong and laying waste to a kingdom of green. I’ve seen photographs, of the forests and grasslands protected behind fences contrasted wildly with the trampled ground of the goats just beyond. Far gone were the days of the gentle grazing tortoise, at least for the most part.

In 1971, a scientist studying snails paid Pinta a visit and entirely by accident, he encountered the very last local tortoise known to have lived. Lonesome George, the world came to call him, in recognition of the years or decades he’s been without the company of his own kind. A year later he was conveyed to Galápagos National Park and conservationists tried hastily to find him a mate. If another Pinta tortoise could be found, a female, on neighbouring islands or in zoos around the world, perhaps the species could be saved.

For decades thereafter, goats were systematically eradicated from Pinta Island and its vegetation restored for the homecoming of George, but alas, no Pinta tortoise female could be found. Attempts were made to mate George with another Galápagos species so at least his genes could be preserved, but it was not to be. George took no mates before passing away on June 24, 2012. His species was now extinct . . . technically.

On this archipelago’s Isabela Island stands Volcano Wolf, around which roams yet another species of giant tortoise, but genetic analysis of this distinct group in 2008 showed something bizarre. A few of them, by some miracle of human meddling, carried genes from the extinct Pinta tortoise. As it would turn out, the ships robbing these islands of their tortoises occasionally needed to lighten their loads, and Banks Bay on Isabela Island’s northwest shore was a popular dumping ground. A few of the individuals they captured at Pinta were unloaded in just this way and managed to swim ashore, breeding with the tortoises they found on Volcano Wolf and leaving their legacy in the genes of living hybrids.

And we found these hybrids, in a recent expedition which gathered several for the purposes of back-breeding. In this way the Pinta tortoise might be remade, at least 95 per cent pure, and reintroduced to its island home so the restoration can be completed.

It’s hoped back-bred members of this extinct species will be introduced to Pinta Island sometime in the next five or ten years, which, if it proves successful, will be an astonishing conclusion to what appeared a hopeless story. People working on this project have said it demonstrates the ability of our species not just to destroy paradise but also to restore it. It’s that word, restore, with fills me with hope most of all. It should be in our mission statements more often. To restore is to bring back, and we need to bring back as much as we possible can.

Zack Metcalfe is a freelance environmental journalist, an author, and writer of the Endangered Perspective. He operates out of Halifax, Nova Scotia.giant tortoises