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Fri June 7, 2013
South Africans strive to limit damage to landscape as elephant populations grow
We’ve reported frequently on efforts to control wildlife numbers in Wyoming, through hunting, contraception, and other means. In southern Africa, wildlife managers face similar challenges, with elephants. In some parts of Africa, elephants are threatened by poaching, but in South Africa they’re flourishing. Some wildlife reserves say they’re multiplying too fast, but others say controlling their numbers is the wrong solution. Wyoming Public Radio’s Willow Belden traveled to South Africa and filed this report.
WILLOW BELDEN: It’s a sunny afternoon at Makalali Game Reserve. Giraffes graze at the edge of savannahs; wildebeests gather beneath flat-topped trees; and elephants amble through leafy thickets. The reserve is home to all of South Africa’s big game species, and visitors pay top dollar to go on safaris here. My driver stops his jeep near an elephant herd.
DRIVER: So the elephants, they eat 24 hours. Wherever you find them, they will be eating.
BELDEN: And sure enough, the elephants wander from tree to tree, wrap their trunks around branches, and pull off huge mouthfuls of leaves. Sometimes, they even knock over a tree to reach high-up branches.
BELDEN: The animals at Makalali seem to be living in the wild. But this is a fenced-in reserve, and the wildlife is closely managed. Most notably, many of the elephants are on birth control. Audrey Delsink is in charge of them. She explains that when elephants were reintroduced to Makalali in the 1990s, their population ballooned.
AUDREY DELSINK: And it’s simply because the resources are so phenomenal. You know, elephants hadn’t been here for many, many years, and so their vegetation is ideal. In most instances, there’s artificial water, and so this makes for wonderful breeding grounds.
BELDEN: Those conditions are common in South Africa. The elephants all live in parks and game reserves, where there’s almost no poaching, few predators, and abundant water. So the animals live long, and multiply quickly. Henk Bertschinger, an expert in veterinary science and animal reproduction from the University of Pretoria, says the problem with that is that game reserves have a finite amount of space.
HENK BERTSCHINGER: And if you don’t control the elephant numbers, they’re going to destroy the habitat.
BELDEN: Destroy the habitat, as in eat every plant in sight. But controlling elephant numbers is tricky. Sending the animals away is rarely an option, because South Africa’s parks are full, and moving them to other countries would be expensive and a political nightmare. And killing elephants is often considered inhumane. So Bertschinger wanted to find a different way to keep elephant numbers down. He knew that a birth control vaccine had been used on wild horses in the western United States, so he decided to try the same drug on elephants. Soon, Makalali Game Reserve signed on. Delsink says the contraceptive works well: they have about 60 elephants – which is half the number they would have had without birth control.
DELSINK: There’s no ways that a 24-thousand-hectare reserve could sustain an additional 60 elephants over and above what they already have.
BELDEN: Delsink says they still let the elephants have some babies, so as not to mess up herd dynamics. But the birth rate is low, there have been no behavioral changes, and if they ever want more babies, they can simply take elephants off the pill.
Makalali started doing contraception before they had too many elephants, but other reserves had already reached a crisis point: the elephants had devoured all the trees and other vegetation. So some of those reserves have opted for a more drastic – permanent – solution: elephant vasectomies. Mark Stetter, the American veterinarian who developed the technique, says unlike the birth control vaccine, you only have to vasectomize an elephant once, and you only have to vasectomize a few elephants in each game reserve.
MARK STETTER: All these different matriarchal herds are serviced by a dominant bull, and so by doing this one dominant bull, you’re going to have a huge effect in the population.
BELDEN: Then again, it can take decades before the population actually shrinks, even if there are no new babies, because elephants live so long.
Some experts say tinkering with elephant reproduction – regardless of the method – is misguided. Rudi Van Aarde heads the Conservation Ecology Research Unit at the University of Pretoria. He says South Africa doesn’t have too many elephants; just insufficient space. He says micromanaging elephant numbers is treating the symptoms of the problem, when we should be treating the causes.
RUDI VAN AARDE: When you have a toothache, you don’t take a pain killer. You may take it for an hour or two days or whatever, but you go and see a dentist, and you solve the problem.
BELDEN: Van Aarde has pushed for the creation of “ecological linkages,” which allow elephants to move from one park to another. South Africa now offers incentives to landowners who let elephants travel through their property. They’ve also eliminated fences between certain parks, and surrounding areas.
One of those parks is Kruger, an enormous national park the size of Denmark. Sam Ferreira is a large mammal ecologist there. He points out a tree whose bark has been scraped away, and says male elephants sometimes do that kind of damage just because they don’t get to mate until they’re in their 40s.
SAM FERREIRA: So what the hell do you do with yourself, seriously sexually frustrated, for 45 years?
BELDEN: Kruger has spent decades trying to manage elephants. In the past, they killed entire herds. Now, instead of controlling elephants directly, park officials manage the landscape, for instance, by restricting water. Ferreira drives to a clearing with a water trough, fed from a well.
FERREIRA: Alright, so this is an example of one of these places where we … provide additional water to the animals. This is a functional one still. We’ve probably closed down about half of the existing ones that we had – there were up to 300 bore holes in the park.
BELDEN: Because the park has taken away some of these bore holes, or man-made water holes, elephants have to travel longer distances to find water. As a result, more elephants die during droughts, and fewer elephants are born. Plus, the animals no longer spend all their time in one place.
FERREIRA: So that kind of variability is what we’re after, because that variability in how elephants use landscapes gives a tree a chance to actually recover.
BELDEN: And indeed, in most areas, the landscape at Kruger looks healthy. Vegetation is plentiful, and you have to look closely to see instances of elephant damage. Ferreira says that’s an indication that the park service’s new approach – of restoring natural processes, rather than manipulating elephant numbers directly – is working. And in fact he expects this method to become the new norm for wildlife management not just in South Africa but also in neighboring countries. For Wyoming Public Radio, I’m Willow Belden.