African Vignette: Afoot Among the Wild Animals
Dangerous game
The average visitor to Kruger National Park in South Africa is restricted to seeing this world-class wonder strictly from the inside of a car. In a park the size of Massachusetts, the visitors’ feet may touch soil only in the rest camps and in a few selected and widely spaced picnic areas. By dark, all visitors must be safely locked inside the fence of the rest camps, or face a stiff fine or even banishment from the park in the future. The park does offer backpacking tours under armed guard, but these are small groups and are fully booked over a year ahead. So the vast majority of visitors must see the animals from their cars. So accustomed have the animals become to guys-in-cars that, should you attempt to get out of your car, having checked up and down the road as far as you can see and you’re sure that no one is within 20 kilometers of you, the animals bolt as soon as your silhouette breaks the outlines of the car. Getting out is both highly counterproductive and illegal, a rare intersection of these two qualities, without a doubt.
So when Cliff asked if I wanted to come along to survey the prickly pear biocontrol research plots in Kruger National Park, and that this would require being “on the ground” and on foot, I leaped at the chance. Animals from close-up, all natural. Wow. Bring ‘em on!
So mid-afternoon of a warm winter Wednesday found us at Kruger Park Headquarters in Skukuze Rest Camp, checking in and picking up field help and an armed guard. If there is one rule in Kruger that cannot be broken, it is that no one steps out of a vehicle in the park unless accompanied by a guard with a loaded rifle. His job is to protect you should a lion ponder eating you. Later, my friend Clarke told me that he once made the mistake of peeking down the barrel of one of these rifles to find it blocked by nesting sphecid wasps. If accelerated to high velocity by a powder charge, would a sphecid wasp pupa in its mud cocoon stop a charging lion? For that matter, would any guard be fast enough to stop a determined lion leaping out of ambush? A lion in a thicket is practically invisible. That thought is not comforting, especially as our guard had leaned his rifle against a tree 30 feet from where he was eating his lunch. Still, lions rarely eat park personnel or tourists. Illegal immigrants from Mozambique is another story--- these regularly end up in a lion’s belly, a few sad scraps of clothing and bloody soil the only witness to their terrible end.
Piling into the back of a bakkie (pickup truck to you) and a land-rover, we rocked and bumped through the thorn forest on dirt tracks, finally arriving at a dry stream bed. Being on the ground in the wilds of Kruger National Park is quite a different experience than being in a car. No waterbuck peered at us through the stream-side brush, no lions stalked us, their curiosity pequed, no zebras crowded around a waterhole, and no elephants shuffled through our midst unconcerned. No, in the two days that it took to check the biocontrol plots, we saw no animals other than a troupe of baboons. Mostly there is a warm silence, or the soft sigh of wind through trees, or the muted call of birds.
What we did see in rank profusion was “sign,” both tracks and dung. In the dry stream bed, which I explored while the others were readying their equipment, hardly a square centimeter was free of the footprints of animals, layer upon layer, lion on top of wildebeest on top of impala on top of baboon on top of mongoose. And the whole palimpsested ribbon of sand was liberally decorated with dung of all descriptions. Sorting this out would lead to terminal confusion. Better to wait for the summer rains to wipe the stream bed clean. The uplands too bore abundant tracks and dung, and many shrubs, grasses and trees showed signs of creatures helping themselves to lunch.
Biocontrol researchers had set up many plots, some fenced, most simply marked for repeated sampling. These plots were sited with regard to the vegetation, not the animals. One of the plots overlaid the territory of a white rhino, who had created several carefully tended middens there— large patches covered with dung kicked into heaps. Sharing territory with a rhino is problematical--- the rhino molests anything that smells foreign, including all corner markers, posts and distance markers. Repeatedly, we came upon stout iron pipes that had been anchored into two feet of concrete below ground, lying uprooted and forlorn on their sides, marking nothing but the rhino’s victory over corner markers. Iron bars as thick as a carpenter’s thumb were bent like paper clips, rock cairns scattered and trampled. The will of a rhino is hard to resist, and negotiating with a rhino is pretty much a one-way conversation--- rhinos don’t bargain with intruders or their marks, physical or olfactory.
Within sight of the first prickly pear biocontrol plot, among the thorn trees, lay a fenced enclosure that would have done a high-security prison proud. A seven-foot-high chain link fence topped with a two-foot border of outward leaning razor wire. At ground level, and again every foot or so higher, electrified wire invites the careless animal to a shocking experience. Nearby, a solar panel and a set of batteries assures that this fortress is protected both night and day. Inside the fence is the most luxuriant stand of prickly pear, deep green and studded with hundreds of purple fruits, from fence to fence.
What, I asked, is going on here? Oh that, says Helmut, is our elephant and baboon exclosure. The theory is that prickly pear is spread when elephants and baboon nosh on the sweet fruits, then drop the seeds elsewhere in their dung. So here, Helmut said, is an exclosure to keep the fruits from being eaten by large animals. The difference between the prickly pear inside and outside the fence was the difference between access and no access. The cactus inside the fence revealed the reproductive potential of this invader.
And the results? Well, said Helmut with just a hint of irony, we proved that baboons are really crazy about prickly pear fruits. They leap over the wire, both young and old. No illusions, they are fully aware that they will get the hell shocked out of them. The adult baboons launch the little ones over the fence, and the little baboons start squealing in mid-air before they hit the electrified wire. The electrified fence seems to keep the elephants out, and that’s something, concludes Helmut. Surveying the luscious fruits inside, I try to imagine myself as a baboon. The temptation is palpable. Would I leap over the fence? Maybe. To the baboons, the prickly pear fruits are clearly a much deeper purple on the other side of the fence. It looked that way to me too.
As we surveyed the research plots, a foraging troupe of baboon moved into our midst. Babies clung to the belly fur of mothers, older baboon kids romped and chased one another, squealing in fear or anger, as the occasion demanded. Adults kept a wary eye on us, moving away only when approached within a few meters, otherwise going about their quotidian tasks. Rocks were turned, insects eaten, various delectable parts of plants were sought out for munching.
Prickly pear fruits were especially attractive. Anyone who has eaten them (they are very popular in Mexico and the southwestern USA) knows that they are studded with clusters of almost microscope, barbed spines called glochids. Get them in your skin and you won’t get them out again. Your best hope is shaving off the projecting ends and committing the rest to the natural sloughing process of the skin. Baboons seem unconcerned by these dangers--- the ground is littered with the skins of prickly pear fruits, glochids still attached. The technique is simple and requires no tools—the baboon pierces the side or end of the fruit with one finger, then strips the delectable pulp out of the skin. Yum. But surely the method is not perfect? Perhaps a few glochids in the tongue or the fingers is a cost baboons are willing to bear for this treat.
The problem arises at the other end of the baboon, when, having traveled some distance, it defecates the undigested seeds in a prickly pear free place. I suppose if Gallup Polls surveyed the baboons of Kruger, 78% of them would approve, and would favor doing even more of it. After all, humans have spread innumerable exotic plants because they served our purpose. But we humans pretend to be less self-centered, or maybe we can see further into the future, and feel alarm. It is this alarm which motivates the powers of Kruger National Park to dedicate a good deal of effort toward prickly pear control. For years, they have been using herbicide on prickly pears visible from the road, keeping the growing problem from public view, and maintaining something of the illusion that the park is wild nature. Herbicide treatment is difficult and expensive, and biocontrol offers a long-term, low-cost solution.
The results from the biocontrol plots gave hope that this prickly invader could be brought under control through the introduction of the natural enemies it had left back home in Peru. The most promising of these was a cochineal bug whose fat, wax-covered, blood-red, immobile females took up residence on the cactus pads to suck their juices. Their newly hatched offspring crawl out from under the mother’s wax pillow, the females crawling to lay claim to their own spots, the tiny, flimsy males drifting on the wind to find mature females under whose wax fortress they can crawl for mating. Because they don’t disperse very far, cochineal bugs are very locally adapted to particular, also local, cactus strains. Several earlier introduced cochineal strains had faded out because the match between the bug and the cactus was not precise and compatible enough. But Helmut had located the Peruvian parent population of Kruger’s prickly pears and had seeded the plots we were checking with cochineal bugs from this source population. And indeed, the cactus pads were covered with thousands and thousands of cochineals whose sucking had converted the pads into shriveled, brown remnants. Moreover, the bugs had spread to neighboring cactus patches on their own, suggesting spreading future control. The baboons may be understandably alarmed, but the humans are gambling that the easy life of Kruger’s prickly pears was coming to an end through a spreading epidemic of cochineals.
Wonderful essay! The prickly pear can, indeed, be a forbidden fruit, at least to the unsuspecting. I recall my first encounter on our drive out west decades ago, and the irritation from the plucked fruit still feels palpable. Thanks also for introducing me to the word "palimpsest." You scraped up a good one!
love this! really puts us in the scene - but am wondering when this was (did I miss something?) The reason I ask is whether any of this has changed over time - rules and regs, changes in the plant life/cacti, etc., populations of the wildlife. would love to know more, even given the importance of brevity for your accounts ----a difficult decision at times!