The Full Impact of Namibia's Decade-Long Drought on it's Biodiversity

One of the many casualties of Namibia's drought

The vast Namib and Kalahari deserts are ecosystems that have evolved to withstand being constantly parched. From the Camelthorn Acacia to the herds of Gemsbok, each organism is adapted to make the most of every drop of water the landscape has on offer. But the lengthy drought that's currently gripping Namibia over the past 10 years, it's pushing life to the very edge of the ability to adapt to change. And quite a few ecologically essential species are suffering the consequences.

The Full Scope of the Drought

Namibia is a country that has experienced constant arid conditions for thousands of years. Most of the country experiences an average annual rainfall of 280 mm, ranging from 650 mm in the Northeast to just 50mm in the southwest along the coast. As such, the nation's wildlife has always been dependent on the annual rains (usually between November and April, though sometimes only lasting a month) to fuel brief periods of rapid vegetation growth, and to support the area's expansive megafauna herds.

But the last 10 years of rain patterns have taken this lack of water to an extreme. Exacerbated by an extended El Niño event causing severe water shortages in many areas, especially in 2019 (widely regarded as the worst drought in 90 years) saw the national average rainfall to drop 221 mm, an almost 21% decrease. That might not sound like a lot, but especially in the arid pastoral areas that bore the brunt of the drought, it can be life or death for entire herds of wildlife. Similar instances of abnormally low rainfall (combined with abnormal temperatures also occurred in 2013, 2015 & 2017.

In the past few years, rainfall has risen significantly from 2019 lows, but it's still below the long-term average, which has flow-on effects regarding both the health of vegetation and the state of available groundwater. Trees that are usually adapted to 1-2 year periods of dry conditions, combined with several years of ample rainfall usually allow trees to recover, and grow at a sufficient rate. But this extended drought stresses them excessively, causing stunted growth and sometimes death, even when not exposed to browsing herbivores. As local farmers and ranchers continue to utilize below-ground water tables as a backup water source, slowly these are being drained, and bit by bit, water is getting harder to find.

The Impacts on Wildlife

2 of the 25 Elephants relocated to Angola due to Namibia's decade-long drought.

The first and largest impact of this devastating drought is just the overall decrease in carrying capacity across the country, caused by stunted tree growth and grasses completely dying off. In national parks and wildlife reserves with long-standing stocking rates used for the past 20 years, it's meant that destocking through relocation, trophy hunting and culling becomes the only option to ensure that the animals left on the landscape don't starve to death, or cause excess damage to already stressed vegetation. Instances of large culls of species like Elephants, Hippo, Zebra and Buffalo are tough pills to swallow, but likely in the long run reducing stocking densities will guarantee the well-being of the remaining population, and provide an opportunity for recovery when (and if) the drought ever ends. This is especially true when there either isn't a place to relocate them, or the process is prohibitively expensive.

But the impact on wildlife extends far beyond the borders of protected areas, and into areas where wild herbivores and livestock share the landscape. A reduction in feed of course means that livestock producers are beginning to feel the pressure, and understandably, they turn to wildlife as a way to reduce the competition for an ever-limited resource. Species that are currently thriving on private land such as Gemsbok, Springbok, Red Hartebeest and Kudu are all experiencing significant increases in hunting rates to compensate for the reduced carrying capacity of the habitat, especially in areas where Hunting & Ecotourism isn't used as an economic driver for land use.

The catch with such a desperate situation where an entire country is feeling the pressure of the drought, is that areas with little to no wildlife (both inside and outside of the country) have the perfect opportunity to restock. Live sale prices of common species of gemsbok, springbok, Impala and zebra have all experienced all-time price lows, and for some species, the only option to keep the animals alive is to simply give the animals away. This was the tactic used by Mount Etjo Safaris in July of 2024 when they assisted with the relocation of 25 of their elephants to a private game reserve in Angola. With the 10-year-long drought dramatically reducing the local vegetation, reducing the number of elephants by finding a partner reserve where elephants had been extirpated for over 70 years was the best-case scenario, and a win-win for everyone involved. The new owners, Cuaitir Conservation Area, aim to use these elephants to revive the area's once legendary elephant populations and help reverse the species's currently rapid rate of decline. Mount Etjo Safaris has also provided other species like Giraffe, Impala, Zebra and Kudu to help revive the area's megafauna, whilst reducing the stocking rate of their reserve.

Find out more about the 700 km cross-country relocation of this Elephant herd on Cuatir reserves profile page, right here. Both Cuatir Nature Reserve and Mount Etjo Safaris are partner reserves of Faunus Biodiversity Management.

The Winners and Losers of Drought

Iconic megafauna like Bush Elephants, Southern Giraffe or Cape Buffalo have stolen the limelight during this tumultuous period, but other smaller herbivores have been equally impacted, all be it with a lot less conservation attention in response. First and foremost is the Red Hartebeest.

Historically one of the most plentiful and widespread Bovid species in Namibia, and usually one very well adapted to a human-adapted environment, they are particularly vulnerable to extended periods of drought. This is due to their preference for short, fresh grasses triggered by rainfall, and their inability to drink from artificial water sources that aren't at ground level (therefore excluding cattle troughs, the most widespread water sources available to most wildlife). Combined with the fact that they often refuse to consume artificial feed provided by game ranchers and landowners to compensate for low rainfall, the drought has spelled disaster for the species.

In some areas, like the expansive Namib Rand Nature Reserve, one of the largest privately owned protected areas in Southern Africa, hartebeest populations have fallen from thriving herds of between 400-600 to just 25 individuals. Of the 950,000 acres of habitat Faunus Surveys where Red Hartebeest Roam, we've seen populations fall from around 2,500 to just 725 in just the past 5 years, and the decline seems to only be getting worse. Because even if a small number of adults are surviving each successive drought year, the calf recruitment rates are so low populations can never bounce back. A few farmers have implemented protective measures, such as ground-level waterholes and specific types of feed, but it's likely this drought will extirpate the species from the Southern and Western quarters of Namibia, and will make them increasingly rare in their historic strongholds in the Kalahari Desert to the east.

Blue Wildebeest, Greater Kudu and Common Warthog have also all seen considerable population decreases during the past decade in low rainfall areas, likely due to the impacts of little rainfall, and the ecological niches that these species occupy. Warthog, in particular, has suffered, with Faunus recording several subpopulations in the Hardhap region being reduced by 90% in the past 10 years, and 2 populations of around 150 individuals completely dying off.

Gemsbok, arguably the most drought-adapted herbivore in Namibia

But the drought hasn't been bad news for all species. Two in particular, Gemsbok and Plains Zebra, seem to have benefited from the demise of their fellow competing herbivores, with some significant population increases in areas that have been impacted heavily by drought. Gemsbok in particular are remarkable in that they don't need access to surface water to survive, gaining what little moisture is needed from the parched vegetation. Combined with their lack of territoriality, meaning whole populations can move large distances to access fresh pasture, means they are supremely adapted to a drought-stricken landscape. Plains zebra also exhibit a similar ability to adapt to dry conditions, especially when fences don't impede their movements (more on that later). For instance in the Namib Rand, whilst red hartebeest populations were crashing, the Plains Zebra population increased from just under 1,000 to over 3,400 individuals, likely due to their ability to draw sustenance from low-quality grasses, better than their ruminant counterparts.

In fact, the success of Gemsbok seems to be perfectly correlated with the demise of Blue Wildebeest and Red Hartebeest, as illustrated in this 2021 study. The lack of water and extreme temperatures puts the latter two species under greater nutritional success, which significantly impacts body weights, which has flow-on effects regarding birthing success and their ability to avoid predation. In short, the hotter and drier it gets, the better the world is for gemsbok and other arid-adapted species. And whilst it's great to see that some species can adapt to the changing climate, it's important to note that an overall decrease in carrying capacity is occuring in all of these areas, and therefore a decrease in prey biomass available to threatened carnivores in the region, such as Leopards, Cheetah and Brown Hyena.

Human Factors Exacerbating the Drought:

Aside from the fact that this current drought has been exacerbated by the rapid rate of anthropogenic climate change that's gripping the entire planet, the overall impact it's having on wildlife is being made worse by a number of factors. And one of the biggest impacts is competition with livestock.

Overgrazing:

Namibia has a proud history of preserving wildlife alongside working landscapes since its independence in 1990, but it's always been a tenuous relationship, with wildlife being only able to exist under the premise that they don't impact existing wildlife, or otherwise provide enough income to offset those conflicts. But drought intensifies these conflicts, it leads to farmers prioritizing livestock production over the wildlife. Many farmers resort to cull permits to reduce the wildlife carrying capacity, which is sometimes needed, but without also reducing the size and impact of their own herds. Combined with widespread overgrazing in community conservancies where low-income communities are unable to reduce the number of cattle that their incomes and diets depend on, it creates a perfect scenario for environmental degradation and biodiversity loss.

It's part of the reason why we are so supportive of sustainable use of wildlife, both through hunting and ecotourism. These economic incentives ensure that when landowners have to make the tough decision between livestock and wildlife, wildlife can be given the upper hand. Making that choice is also better for our food system, with even species like wildebeest and hartebeest consuming significantly less water per kg of biomass than cattle, meaning that most areas can support more wildlife biomass compared to livestock. Harvesting a small percentage of these herds can provide communities with a healthy, affordable and low input alternative to beef, which benefits everyone.

Fencing:

Game fencing can be both a blessing and a curse, depending on how it's used

Fencing can be both a blessing and a curse for wildlife, depending on the scale, scope and type of structures erected. In many scenarios, high fencing protects vulnerable species from poachers, and ensures that wildlife also can't transmit diseases to neighbouring cattle. They can even protect communities from rogue predators and giant herbivores. But for species that are evolved to move across the landscape in search of the best pasture, they can be a curse. Species like Blue Wildebeest, Common Eland, Hartebeest, and both Zebra species (Plains and Mountain Zebra) use large landscape level movements to find the areas of best grazing, to survive the direst times of years, and high fencing (usually 2m+ tall and semi-electrified) undermine this ability.

But even cattle fencing can have profound impacts on the movement of wildlife. If not designed to allow animals to slip underneath (something especially important for species like Springbok, Gemsbok and Hartebeest with limited jumping ability), wildlife can get tied up in the fence or simply refuse to move, leading to animals starving to death in cattle pastures. This has flow on impacts to the landowners themselves, with this reduced movement ability meaning wildlife is forced to compete with cattle more intensely, which of course leads to further conflict. Wildlife friendly fencing that allows movement (either under or over) of non-target species can help with exactly this.

Another drawback with high fencing revolves around the cost of reducing densities when periods of intense drought do occur. Since game have no ability to migrate to areas of higher rainfall, mass capture is the only way to artificially facilitate this movement. Doing this for even a medium sized herd of common species like springbok or gemsbok can cost over NAD 100,000, and significantly more depending on the species, topography, and the numbers to be collected. For most operations, simply culling the excess animals and selling the meat is far more economically viable in the long run.

Whilst game fencing certainly has a place in modern Namibia, especially when protecting economically valuable species like Roan or Sable, or poaching vulnerable species like Black & White rhino, the protection of free range areas with abundant wildlife needs to be prioritized more, as a way to "drought proof" the countries wildlife populations. This comes with it's own set of challenges, such as working closely with neighbouring landowners that often have a differing ethos of land management, but the long term benefits greatly outweigh the short term drawbacks.

Summary:

If the current drought continues on in Namibia, the current impacts the country is already experiencing will only be exacerbated, and will continue to push it's megafauna to the brink. But the fate of this wildlife is not entirely out of our control. Promoting economic models across the country where wildlife is prioritized over other land uses is just part of this response, combined with more responsible land use regarding fencing, and targeted supplemental feed/water for vulnerable species like Red Hartebeest. All of this should help the county's wildlife get through this devastating drought, and prepare it for when the rains actually arrive.

Lakhan Clark

1/02/2024