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In 2010, an aerial survey revealed a catastrophic decline in game populations in the Okavango Delta. Sophie Stafford asks where the wild things are.
A turf war had broken out, and there could be only one winner. Two opponents glared at each other like battle-weary pugilists before a prize fight.
Under normal circumstances the odds would favour the older leopard, known locally as Lebadi (‘Scar’) for the years of experience etched across his body. But he carried fresh wounds and was in poor condition, whereas his rival, new on the scene, was in his prime.
As we nudged our vehicle through the bushes towards the feuding pair, it was clear to me that the old male was trying to make a dignified exit.
The trespasser, though, was in no mood to show respect for his elders; irritation was written in every line of the upstart’s proud head and powerful body. He raked his scent into the ground with his hind legs and rubbed his musk into the grass, his menacing, throbbing growl growing ever louder.
All morning the interloper hounded poor old Lebadi, determined to run him out of town. As we watched the pair lying, panting, just metres from each other after hours of posturing, the young male began to drool and blow saliva bubbles.
“He’s so worked up that his mouth is watering,” whispered my guide, Thuto Moutloatsi, whose extraordinary depth of knowledge seemed to extend even to the thoughts of a big cat. “If a leopard charges you, it will sometimes try to spit on you,” he added, as if this was something I should be prepared for.
In that predicament, I wondered, would a bit of spit really be my main concern?
As if in answer, the younger cat yawned, exposing very long and very shiny white fangs. Apparently not!
“The younger cat will not rest until Lebadi has been driven out – he wants this patch,” Moutloatsi explained. “It’s a battle of wills that could go on all day. Let’s leave them to it and head back to camp.”
Weaving through the acacia-thorn scrub, we passed a large herd of impala, rutting males uttering hoarse croaks as they chased off rivals. “The leopard’s bread and butter,” he observed, explaining that the small antelopes are trapped on the island each year by rising floodwaters, and that this is the main reason why Chief’s Island is prime leopard territory.
For Lebadi and his rival, it represents an amply stocked game buffet – a prize well worth fighting for.
And it’s a story repeated across the Okavango Delta: a verdant oasis in the Kalahari, where an opulent array of herbivores attracts a range of equally abundant predators.
Inland wetland wonderland
The Okavango Delta is a near-unique phenomenon: a delta in the middle of the Kalahari Desert. Each January, rains in the Angolan Highlands send deluges surging 1,250km south-east along the Okavango River into Botswana.
The water does not reach any sea or ocean. Instead, when it reaches a flat, depressed area of around 15,000km2, it simply washes across a vast floodplain. Here, dammed by two faultlines, it backs up and creates a swamp.
The floodwaters reach their peak between June and August, when the delta expands to cover an area three times its summer extent. Reed-fringed channels, forest glades and rich grasslands attract animals from vast distances, creating some of Africa’s densest concentrations of wildlife.
At least, that’s usually the case.
Ecotourism – in particular, luxury safaris to experience the epic game of the Delta – is vital to Botswana’s economy. So when, three years ago, conservationists reported declining numbers of game species in protected areas, the government was keen to investigate.
In 2010, Botswana’s Department of Wildlife and National Parks commissioned Elephants Without Borders (EWB) – a not-for-profit organisation dedicated to conserving the country’s wildlife – to conduct a detailed aerial survey of northern Botswana’s game populations.
The shocking results revealed that, over the past 17 years, 11 large mammals had declined by on average 61 per cent. In distal reaches of the Okavango Delta wildebeest numbers had crashed by 90 per cent.
That species’ plight highlighted a general trend in ungulates: tsessebe, for example, had declined by 83 per cent, kudu numbers by 81 per cent, and giraffes by nearly two-thirds. So why had large mammal populations in the Delta fallen so drastically?
Migration or extirpation?
The EWB survey prompted heated debate and a variety of plausible explanations. The government responded by funding further conservation research, introducing bold conservation legislation, and increasing anti-poaching patrols. But a definitive answer to this question remains elusive.
Indeed, many experts claim that it’s not even clear whether the recorded declines actually represent dramatic losses of animals, or reflect large-scale movements of populations within, or out of, the region.
In search of answers, I planned to visit two key locations: one in the heart of the Delta, and the other on its outermost fringes. Here, I would speak with experts in the field to hear their theories regarding the ‘vanishing’ wildlife.
Location, location, location
When I flew in to the Delta one bright May morning, the floodwaters had already begun to rise. Looking down from my small plane, the hippo grass below spread like a rippling green blanket, creating an illusion of solid ground rent only by sparkling trails forged through the vegetation by hippos – known as the ‘engineers of the Delta’ for this very reason.
The first stop on my journey was Chief’s Island, the hunting ground of Lebadi and his rival.
One of the largest of some 50,000 islands in the Delta, it’s perched high on a faultline, so it never floods. But, due to a prime position in the heart of the swamp, Chief’s has access to water year-round, making it an important refuge for wildlife.
Perhaps not surprisingly, the EWB survey did not record a significant depletion of game here – though that’s not to say the wildlife is static. Ecologist Map Ives of Wilderness Safaris, an ecotourism company that manages about 520,000ha of the Delta, has seen the island’s game species move lower down the island and over to the east.
Animals migrate around the island – and the Delta – in response to rising water levels, changes in the flow of channels as sediment deposits build up, and bushfires that produce irresistible flushes of fresh new vegetation.
However, Ives is convinced that game has declined in peripheral areas of the Delta – those closest to community settlements – and points to hunting for bushmeat as the principal cause.
“This ubiquitous trade has increased dramatically over the past 10 years or so,” he told me. “It’s now as great a threat to wildlife in Botswana as it is in many other African countries.”
He believes that areas in the heart of the Delta, including Chief’s Island, are better protected against overhunting because they’re far from most settlements and a strong tourist presence acts as a shield.
Other experts argue that the most potent factor is the recent breaking of a 20-year drought that began in the late 1980s. From 2008, both Angola and Botswana experienced heavy annual rains, which recharged the Delta leading to a ‘superflood’ in 2010.
For the first time in decades, waters spilled over into once-dry distributaries and restored parched floodplains, drastically altering the movements of game.
Going with the flow
So could the Delta’s wildlife have merely expanded its range back into these newly verdant peripheries? If so, you might expect this to be a regular occurrence: peaks and troughs in flood levels, and the accompanying overflows into neighbouring channels and lagoons, may cycle over periods lasting several decades.
Nowhere has the return of the floodwaters wrought more astonishing changes than in Selinda Game Reserve, on the eastern fringes of the Delta, my second stop.
As I gazed out from Zarafa Camp across the glassy waters of the Zibadianja Lagoon, its reedy edges dotted with hunting egrets and basking water monitors, the change in topography was marked. Where the lake now stands, the lodge’s owners once landed their plane.
And Zibadianja isn’t the only local water body restored by the superflood.
For 30 years the Selinda Spillway was but a ribbon of grassland. Then, in 2009, it began to flow again, relinking the Okavango Delta to the Linyanti and Chobe river systems. It now provides a major thoroughfare for game migrating between these two areas.
David Murray, Zarafa’s manager, was keen to show me the changes he’s observed. First we went in search of Selinda’s lions, famous for their habit of hunting the lagoon’s hippos. Typically, we found the 12-strong pride doing what lions do best – lazing around.
We watched them quietly as a big male roused himself and slinked off through the tall grass, followed obediently by the rest of the pride, five cubs pouncing, tumbling and wrestling all the way, like children pinching each other behind their parents’ backs. But they weren’t heading to the lagoon.
Now that the resurgent Spillway has lured easier prey back to the reserve, the lions no longer need to work so hard for a meal.
The hippos aren’t hanging around tempting fate, though; they have dispersed from Zibadianja into the Selinda Spillway, the Savute Channel and east towards the Linyanti Marshes – and they are flourishing, with numbers increasing in many areas by 50 per cent since 2010.
Other species, too, have arrived to graze on the sweet new grasses of Selinda’s floodplains. We saw huge herds of sleek, fat buffalos and groups of 20–30 eland, a magnificent antelope that has arrived in the area for the first time Murray can remember.
I even glimpsed my first roan antelope – a species that, along with its beautiful black cousin, the sable, is now much more common here.
Everywhere, large – and growing – herds of elephants splashed playfully through the water. Over the dry winter months, he tells me, this once-transient population now stays in Selinda, where it is safe from poachers.
For the first time in living memory skimmers have nested here, and numbers of slaty egrets – one of the Okavango’s specialities – are rising. Murray is also hopeful that the Pel’s fishing owl, an aspirational sight for birders in Southern Africa, may return to the reserve after a 25-year absence.
Indeed, a recent survey of the Selinda Reserve recorded substantially more wildlife than EWB recorded in 2010, with many species doubling in number. Murray believes that this impressive and rapid increase in game can only be due to migration into the area, as animals follow the returning water.
But Mike Chase, EWB’s director, warned that, as game moves into the Delta’s peripheries, it will be closer to communities and international borders, and consequently more vulnerable to bushmeat hunters, competition with livestock and bushfires.
Of course, no one knows just how long the Spillway and other restored waterways will flow. Some experts predict another great flood, but if the channels dry up, the wildlife will presumably abandon the Delta’s hinterlands and return to its core once more.
Chase said, “No single factor operates in isolation here. Indeed, EWB is now trying to determine the drivers of wildlife declines. Only time will tell if the rejuvenated habitats can restore species that have decreased due to human-wildlife conflict. But we are optimistic.”
During my visit to the Okavango Delta, I was given hope that its big game may not have suffered quite the catastrophic decline feared, and confidence that, whatever threats the area’s wildlife may face, committed conservationists will be on hand to help.
It’s clear that the Delta is an incredibly dynamic ecosystem that is constantly changing – and this is what makes it so special.
TERMITES: TINY ARCHITECTS OF THE DELTA
Termites play a critical role in island formation in the Okavango Delta. Every island has, at its heart, a termite mound.
Termites live in large colonies, the workers building elaborate waterproof towers made of soil, chewed wood and saliva. When the floods arrive, these mounds are often the only land above water level.
As such, they provide a useful vantage point for passing birds and mammals. The visitors often leave a calling card in the form of faeces and the seeds in their dung take root, growing into nutritious grasses.
Over time, more plants colonise the termite mounds as the rushing waters of the flood deposit seeds on their margins – and in this way an island forms and grows in size.
Eventually neighbouring islands join up to form larger land masses, which may even support big trees.
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Sophie’s trip was kindly accommodated by:
View a gallery of Botswana's Bushmen by Neil Aldridge.
View a gallery of Botswana's Okavango Delta by Neil Aldridge.
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