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Tortoises in Residence at the Charles Darwin Research Centre, Puerto Ayora, Santa Cruz

My last post left me being pursued (slowly!)  by a giant tortoise as we went from the El Chato Ranch where the Santa Cruz subspecies roams free, to the Charles Darwin Research Centre where people work on the survival of the species.    They’re heroes … working with commitment and science to undo what other people have unwittingly done.

We know it well in New Zealand  –  the animals and plants introduced either accidentally or with good intentions which went deliriously wild.  Then there were the transfers of giant tortoises from one Galapagos island to another, mixing up genes that had developed in isolation to create a clear demonstration of evolution.  And in our own time, the risks of misjudging how many tourists and tourist-support services a place can accommodate without unintended consequences. 

Apart from shipwrecked sailors, and the boat-builders who stayed to fix them up, people have only lived here for a hundred years.  When one of our guides came to the Santa Cruz Island 49 years ago, the population was 100.   Now it’s 25,000.  Hmmm.

Coming to understand the Galapagos conservation challenge was one of the big surprises of this trip.  You look at the nature documentaries, and see what looks ‘original’, ‘unspoilt’. And some of the 21 Galapagos islands still are.  But – as we also know in New Zealand – there’s a lot else going on.

So to the Charles Darwin Research Centre.   It started its breeding programme in 1965, when it was clear that the Pinzon Island subspecies of giant tortoise was in trouble.  Rats breed much faster than tortoises – there was no contest for the tortoise hatchlings and eggs.  Fortunately, the old tortoises plodded on, and once in their refuge, kept breeding.   Pinzon is now rat-free, the Pinzon tortoises are back, and there are babies running wild (well, ambling wild). 

It’s been harder to save other subspecies.  Lonesome George (the last from Pinta Is) became the pin-up boy for the Charles Darwin Centre – sadly there was no-one of his kind left to mate with, and attempts with females from other subspecies failed to produce viable eggs … a sad indication of species separation, and maybe lack of practice. 

Lonesome George still fulfilling a role.

Still-Lonesome-but-now-Stuffed George is still a draw-card though.  Since I visited Tito’s Mausoleum in the former Yugoslavia I’ve been a bit squeamish about such places – not because of the deceased, but because it seems a bit psychically unhealthy for the living.  However, George had to be visited.  A clutch of equatorially steaming tourists are sealed into a small chamber to cool down, then released into George’s presence.  Photos are taken, and we’re let out through another airlock. Happily, no overt outpourings of emotion!   

Super Diego taking a well-earned rest.

We met a more successful stud, who has sired 800 young and is still at it – Super Diego.  The island of Espaňola had ended up with a non-breeding population – there were apparently a dozen females and two males spread over the island, and they weren’t ‘bumping into each other’ (so to speak).  Even when they were captured and relocated into close proximity in the Recovery Centre, they weren’t making much of a job of making out.  There’s a suggestion that a lack of numbers means a lack of role models for how to have tortoise sex, which is a cumbersome business.  Enter our hero.   Genetic testing around the zoos discovered one of the Espaňola race at San Diego Zoo.  He was repatriated, and has been doing sterling paternity service ever since.  Espaňola is again well-tortoised.

Such excitement! We thought we were seeing a seminal moment, until the guide pointed out it was a pen of males. Still it’s good to see they’re getting practice.

A 2017 clutch of Santa Cruz hatchlings

Keeping the subspecies separation matters.  Each enclosure of hatchlings is labelled with their name and year, and covered against rats and hawks until they’re big enough to stand up for themselves. 

As they grow, the differences become obvious. 

Those from arid islands have

Evolved differences.

developed a saddleback shell shape, raised at the front so they can crane their necks up to reach the cactus and branches they eat. Their necks and front legs are longer – aspiring to be the giraffes of the tortoise world.  Those from islands with good grazing vegetation are bigger, with shorter legs and necks, and domed shells.  Interestingly, Charles Darwin almost missed out on noticing this, but that’s another story.

 

 

The Charles Darwin Research Centre is also about more than tortoises … amongst other things they’re making sure the different plants are also maintained, and there’s a little demonstration garden designed to encourage the locals to plant native rather than introduced species.   

Land Iguanas

 

 

 

 

 

If you’re visiting, two pieces of advice: have space to buy one of their excellent books, and take your passport with you.  They’ll stamp it with a picture of Lonesome George.   He‘s still fulfilling a role.

A clever photomontage of the young Charles at his eponymous centre

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