/ 19 November 2008

Robben Island rabbits on the run

Since it’s matric exam time, here’s a question to pop into the life sciences (formerly known as biology) paper. Problem: there’s an island in a bay, surrounded by cold, rough, possibly shark-infested waters; you’re 8km away on the mainland with a box of tortoises. How do you get those tortoises on to the island without using human technology?

Solution: either Natalie du Toit swims them across for you — but she’d have to do it without shark spotters or a boat for backup, or you could wait for the next ice age. This’d drop the sea level as water gets sucked up into polar ice caps. Your tortoises could simply walk across the new muddy flats and colonise the island themselves. Once the ice age was over, the water would trickle back into the bay, cutting the island off from the mainland once more. Any animals trapped on the island would have the place to themselves. They’d be the true original residents.

That’s probably how the angulate tortoise got to be on Robben Island in the first place, with some lizard, gecko and snake species, possibly during the last ice age about 18 000 years ago. Anything else living on the island with them today — leopard tortoises, ostriches, bontebok, steenbok, eland and springbok, which are indigenous to South Africa, and the ”exotic” fallow deer and rabbits from Europe — were introduced later by humans to ”beautify” the place.

But here’s a problem that’s probably too distasteful to include as an exam question: what do you do when some of those animals breed so prolifically that they overrun the island and eat all the food to the point that they end up on the verge of starvation and threaten the other animals with a similar fate?

Solution: either you sterilise them and feed them until their community dies out or you put them up for adoption or you euthanase them.

This past weekend the first offensive against the 10 000-strong wild rabbit population on Robben Island came to a close.

As upsetting as the solution is for animal lovers, it’s the only way — trap and euthanase. It would be impossible to sterilise that many animals, which are half-starved and mangy anyway. And, in spite of an uproar about the culling from many Capetonians, only about five people came forward to adopt rabbits. And we don’t want these rabbits running amuck on the mainland.

Truth is, it’s our own fault that they’re there and now they’re a threat not only to their own welfare, but to the other animals, too.

It’s interesting, though, how often we flip-flop around these kinds of ethical matters — we may eat bulk-slaughtered meat, or use leather, or even eat mass-produced eggs (the ethicist Peter Singer says that expecting a chicken to lay an egg in an open space, such as a battery cage, is like asking a human to defecate in public). We may put out rat poison to nab the pests in the shed, or turn a blind eye to the fact that our pet cats have laid waste to the neighbourhood’s birds, geckos, mice, insects and the like. But put bunny ears and a twitching nose on the animal and it becomes distasteful to cull.

Here’s something else many of us don’t think about: if we eat wheat that comes from the Swartland, we’re as complicit as the next person in the virtual extinction of the geometric tortoise, the habitat of which has been almost entirely overrun by wheat fields. There are only three or four fragmented communities of geometrics that are likely to be genetically viable in the long term.

This is the horrid truth about living in an overcrowded world. Humans have changed the global landscape so much, as our urban and agricultural footprints have spread, and as we’ve moved different plants and animals around the globe with us. The same species of rabbit that is causing the mess on Robben Island was taken to Australia in the late 1700s and has since become such a problem animal in that it has outcompeted many other species, causing more extinctions there than any other organism.

Like the fallow deer on Robben, the rabbits are typical ”invader” species — without their natural predators, they’re overly successful, even to their own demise. We’ll only know after this weekend whether the trap-and-euthanase method has worked. If the animals become trap shy, which they often do, hunters may need to be brought in as a second offensive.

Bottom line is this: we’ve changed the world around us, sometimes disastrously and irreparably. Someone has to take responsibility for the mess we’ve made — we should be thankful that someone else is prepared to do the dirty work for us, so it’d be hypocritical to demonise them for doing it. In the end there’s blood on all of our hands.