I’m writing about tropical islands today. Because tropical islands are not cold. I am not writing about Johannesburg. Because Johannesburg is cold. But that’s not my only reason for writing about tropical islands. As I will never tire of reminding you, I went to the Seychelles recently. I was looking through the photos this morning, because I was cold, and came across this one.
It’s a giant tortoise. And it looks, at first glance, like a most unlikely creature. It really is enormous. But it’s a tortoise. And tortoises are not famous for being exciting. We took a boat trip out to an island reserve one day, where they had established a large breeding population of giant tortoises.
It was a great day out. An adventure. The boat cut through the open sea, bouncing over the swell and scattering flying fish in its path. We stopped a couple of times to jump off the boat and snorkel in the clear blue water, chasing flashing schools of brightly coloured fish through the nooks and crannies of crowded coral reefs, and hanging motionless as clouds over grazing sea turtles.
When we reached the island, we hopped onto a smaller boat and rode up through the gently rolling surf where we jumped off and waded through the water to the beach like the pirates who once hid out here. And there, at the edge of the sand, and receding into the shade of the palms that littered the shore, were the tortoises. Lots of them.
I’m going to share a dirty little secret with you. I love wildlife. I read about it whenever I get the chance. I spend as much time as I can seeking it out. But here’s the thing. It can be boring. It can be earth –shatteringly, teeth achingly, skin crawlingly dull. If you have spent some time in the wild, you know this. And you know the trick. You wait. You fill your head with something else and you sit. And sit. And sit. Often, you find a spot where there is no wildlife to be seen, but where it might be seen later. And you sit.
You sit because it might just pay off. And then it will all be worth it. Lions are the best example of this. Watching lions lie around in the heat of day is like watching paint dry. They just lie there. For hours. A tail might flick. An ear might twitch. If you’re really lucky, a great, battle-scarred head might be lifted for half a second for a quick glance around, before flopping back to the ground, motionless. They can do this for 18 hours a day. But it’s worth sticking around. Because for the rest of the day, they are wrestling buffalos and bringing down giraffes.
Not so much with the tortoises. You can stare at a tortoise for weeks, and it will fail to wrestle with a single damn thing. They were interesting for what they were, not what they did. In their defence, they did rise up on their legs like old fashioned Citroens when you tickled their heads. But that was it. They do, occasionally have sex, but we had children with us, so I’m glad they didn’t that day.
Not that I believe that kids should be sheltered from that sort of thing. Biology is biology, and if I happen to see cows or sheep mating, I don’t clamp my hand over my kids’ eyes or rush over and break up the party. I just explain what’s going on. Not with tortoises though. Tortoise sex is obscene. It’s wrong. It is an affront against all that is good in the world. It will scar your soul and burn your eyeballs. It quite simply shouldn’t be allowed. Look;
And so we stood and looked at the tortoises. We tickled their heads. They rose up on their legs. We stopped. They sank down again. We looked at each other. We looked at the tortoises. We looked at the guide. “Right!” we said, after waiting a little while, more out of politeness than anything else, “We can go back now.”
But that’s another nice thing about wildlife. They don’t have to do anything interesting to be interesting. And it turns out that giant tortoises are pretty interesting.
I grew up thinking that they were examples of “island gigantism”. Island gigantism is where otherwise ordinary creatures wash up on isolated islands and slowly but surely, generation after generation, grow. Huge. Dodos did this. They were huge pigeons. The biggest birds in the world used to live in New Zealand. Komodo dragons live on islands. What happens is that the creatures find themselves in a place with abundant resources and no enemies. They are free to evolve in any direction they please. Pigeons could turn into Dodos because they didn’t need to fly any more.
Oddly enough, the opposite thing happens too, for the same reasons. It’s called island dwarfism. Large animals reach an isolated island and become smaller. Fossils of dwarf elephants have been found on many islands, including Malta. Here, the animals have no need of being big anymore. More than anything else, an elephant’s size is there for self-defence. And it’s expensive. It takes huge amounts of energy to grow that size, and huge amounts of energy to stay that size. And if you don’t need to be too big for anything else to tackle, there’s no point in being big. Especially on an island where resources are limited.
It turned out, though, that I was wrong. Giant tortoises are not examples of island gigantism. They are examples of how we are too smart for our own good. You see, giant tortoises actually used to be fairly common. You found them in the Americas. You found them in Australia. Asia. Africa. They were everywhere. They were obviously just a successful design.
But they are mostly gone now. And there seems to be a single reason for this. Us. There isn’t much direct evidence that we wiped them out, but they seemed to disappear from areas at about the same time we moved into them. And that makes sense. Being a giant tortoise was a pretty good defence against lions and tigers, snakes and birds. But not us. We could think our way past that shell. And that’s not all.
There are very few giant tortoises left in the world. You get them in the Seychelles and the Galapagos. And we very nearly lost those too. They have, you see, a rather profound design flaw. They aren’t just edible. They are the world’s first canned food.
They are reptiles. Reptiles have slow metabolisms. If you have a pet snake, you don’t feed it every day. Or every week. Big reptiles don’t even have to be fed every month. And once the sailors of old discovered this, it was nearly the end for the tortoises. Ships would land on an island and collect hundreds of tortoises. And just throw them into the hold. That’s it. No food, no water, no bedding. They would just lie there. For months. Alive. And fresh.
This must have happened on the continents too. You couldn’t carry live zebras or hippos back to your hut. You killed what you could and ate it before it rotted. And then you had to go and find more food. But if you got yourself a giant tortoise or two, you had insurance. You had a fridge. Tinned food. Drag them home and put them in a pen of low rocks, and you have set something aside for a rainy day. Fail to find food for a day, and you go hungry. Fail to find food for a week, and you eat one of your tortoises.
They could have been the first farm animals. But for one thing. It takes a lifetime to grow a giant tortoise. It’s not worth breeding them. You would just wait until times were tough, eat what you had, and then go and find more. Until they were all gone.
But that’s just my theory. Maybe the truth is more complicated. Just because our ancestors couldn’t read and write, does not make them simple. They would have been as complex as we were. And as sensitive as we are. So maybe they wiped those tortoises out just to stop them from having sex. Because damn! Nobody should have to see that.