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South Africa Is Increasing Its Wild Cheetah Population

Animals
South Africa Is Increasing Its Wild Cheetah Population
A metapopulation project in South Africa has almost doubled the population of cheetahs in less than nine years. Ken Blum / Wikimedia Commons / CC by 3.0

By Tony Carnie

South Africa is home to around 1,300 of the world's roughly 7,100 remaining cheetahs. It's also the only country in the world with significant cheetah population growth, thanks largely to a nongovernmental conservation project that depends on careful and intensive human management of small, fenced-in cheetah populations. Because most of the reserves are privately funded and properly fenced, the animals benefit from higher levels of security than in the increasingly thinly funded state reserves.


Initiated by the Endangered Wildlife Trust nearly a decade ago, the Cheetah Metapopulation Project recognizes that small cheetah populations may be physically secure in several small reserves, but the likelihood of inbreeding remains high if they are kept separated behind fences. By swapping animals between participating reserves, the trust helps private and state wildlife custodians manage overpopulation and underpopulation on their land and also identify new areas of suitable cheetah habitat. Most importantly, swapping animals reduces the risk of inbreeding among closely related animals.

Vincent van der Merwe, coordinator of the trust's metapopulation initiative, says that when the project began in 2011, there were 217 cheetahs scattered between 41 reserves. Now there are 419 spread across 60 reserves — more than a third of South Africa's total cheetah population.

Vincent van der Merwe at a cheetah translocation. Endangered Wildlife Trust

Under Pressure

Cheetah populations elsewhere in Southern Africa have not prospered over the past 50 years. In Zimbabwe, cheetah numbers have crashed from 1,500 in 1975, to just 170 today. Botswana's cheetah population has held steady at around 1,500 over the same period, but illegal capture for captive breeding and conflicts with farmers and the growing human population are increasing. In Namibia, there were an estimated 3,000 cheetah in in 1975; roughly 1,400 remain today.

In contrast, South Africa's cheetah numbers have grown from about 500 in 1975 to nearly 1,300 today. Van der Merwe, who is also a Ph.D. student at the University of Cape Town's Institute for Communities and Wildlife in Africa (iCWild), says he's confident that South Africa will soon overtake Namibia and Botswana, largely because the majority of South African cheetahs are protected and managed behind fences, whereas most of the animals in the neighboring countries remain more vulnerable on mainly unfenced lands.

Wildlife researchers Florian Weise and colleagues have reported that private stock owners in Namibia still trap cheetahs mainly for translocation, but there are few public or private reserves large enough to contain them. Weise says that conservation efforts need to focus on improving tolerance toward cheetahs in commercial livestock and game farming areas to reduce indiscriminate trapping.

Van der Merwe says fences can be both a blessing and a curse. While these barriers prevent cheetahs and other wild animals from migrating naturally to breed and feed, they also protect cheetahs from the growing tide of threats from humanity and agriculture.

To simulate natural dispersion patterns that guard against inbreeding, the trust helps landowners swap their animals with other cheetah reserves elsewhere in the country. The South African metapopulation project has been so successful in boosting numbers that the trust is having to look beyond national boundaries to secure new translocation areas in Malawi, Zambia and Mozambique.

Cheetah translocations have been going on in South Africa since the mid-1960s, when the first unsuccessful attempts were made to move scores of these animals from Namibia. These relocations were mostly unsuccessful.

"Most of those early attempts were a flop because the cheetahs were not kept in bomas before release and some of the reserves were also poorly fenced — so the cats shot out almost as soon as they were released," van der Merwe said.

Translocated cheetahs are now generally confined to capture bomas, small fenced enclosures, for four to six weeks to allow them to acclimate to their new home environment prior to being set free.

"We have found that four weeks is normally long enough to break the homing instinct and if you keep them in a boma for longer than that, they tend to lose fitness and condition," van der Merwe said.

The Phinda private game reserve in Zululand, one of several private game reserves that began re-introducing cheetahs in the early 1990s, recently swapped some of its animals with the nearby Manyoni private game reserve.

"We have found that when we capture and translocate cheetahs to other reserves, the Phinda cats do very well elsewhere because they grew up in a challenging environment," van der Merwe said. "Because they have to share space with lion, hyena and leopard they have learned to look after themselves — so they are pretty tough animals."

Charli de Vos, a wildlife monitor at Phinda, says when new cheetahs are released into the reserve in small units, at least one animal is fitted with a VHF tracking collar.

For the first few weeks, she says, the animals' movements are tracked on a daily basis to ensure that they are not showing "homing" tendencies and that they are also getting used to the presence of tourist and staff vehicles.

"This will apply until the animals have relaxed within their new environment. Once the animals have established a home range within the reserve (approximately three months after release), the VHF collar will be removed. Thereafter the research and monitoring team will try and get a visual of each individual cheetah at least once every second week," de Vos said.

The reserve also has an online database to record sightings of the animals, with tourist guides, researchers, land managers and land owners able to add sightings.

Despite a cub mortality rate of between 50% and 80% on some reserves, van der Merwe says there are now about 90 cheetahs in the Zululand area. He says cub mortality rates vary according to the number of larger predators such as lions and hyenas.

Charli de Vos uses a VHF antenna to locate cheetahs in Phinda Game Reserve. Tony Carnie for Mongabay

Swinging for the Fences

But other wildlife conservation leaders have a different perspective on cheetah conservation strategy.

Gus Mills, a senior carnivore researcher retired in 2006 from SANParks, the agency that manages South Africa's national parks, after a career of more than 30 years in Kalahari and Kruger national parks. He says the focus should be on quality of living spaces rather than the quantity of cheetahs.

Mills, who was the founder of the Endangered Wildlife Trust's Carnivore Conservation Group in 1995, and who also spent six years after retirement studying cheetahs in the Kalahari, says it's more important to properly protect and, where possible, expand the size of existing protected areas.

He also advocates a triage approach to cheetah conservation, in which scarce funds and resources are focused on protecting cheetahs in formally protected areas, rather than diluting scarce resources in an attempt to try and save every single remaining cheetah population.

"People have an obsession with numbers. But I believe that it is more important to protect large landscape and habitats properly," Mills said.

He suggests that cheetahs enclosed within small reserves live in artificial conditions: "It's almost like glorified farming."

"In the long run we have to focus on consolidating formally protected areas," he added. "Africa's human population will double by 2050, so cheetah populations in unfenced areas will become unsustainable if they are eating people's livestock."

Mills, who was closely involved in a similar metapopulation project for wild dogs, said he tried to encourage landowners to pull down the boundary fences, to create larger areas of habitat.

"But there are many landowners who don't want to do that. They want their own areas and their own management programs. But my philosophy is: Take care of the ecosystem so that the animals can take care of themselves, so that nature can run its course," Mills said.

"Unfortunately, there are so few areas left where nature can have its say these days."

Van der Merwe says the financial costs of metapopulation management are unavoidable and justified, noting that private reserves bear the overwhelming bulk of the translocation and monitoring costs.

"This is 2020. State funding for conservation has collapsed in most parts of Africa and the days of setting aside any new large, wild open spaces are long gone," he said. "We should be celebrating the fact that many more private ecotourism reserves have been established on former cattle ranches in South Africa, outcompeting agriculture as a land use and creating new habitat for cheetah. The best we can do is to try and consolidate smaller private and community-owned reserves with larger national parks."

Sarah M. Durant of the Zoological Society of London and the Wildlife Conservation Society, New York, says cheetahs remain susceptible to rapid decline and that, ultimately, conserving the remaining free-ranging populations in Botswana and Namibia will require "a paradigm shift in conservation toward a holistic approach that incentivizes protection and promotes sustainable human-wildlife coexistence across large multiple-use landscapes."

Reposted with permission from Mongabay.

A net-casting ogre-faced spider. CBG Photography Group, Centre for Biodiversity Genomics / CC BY-SA 3.0

Just in time for Halloween, scientists at Cornell University have published some frightening research, especially if you're an insect!

The ghoulishly named ogre-faced spider can "hear" with its legs and use that ability to catch insects flying behind it, the study published in Current Biology Thursday concluded.

"Spiders are sensitive to airborne sound," Cornell professor emeritus Dr. Charles Walcott, who was not involved with the study, told the Cornell Chronicle. "That's the big message really."

The net-casting, ogre-faced spider (Deinopis spinosa) has a unique hunting strategy, as study coauthor Cornell University postdoctoral researcher Jay Stafstrom explained in a video.

They hunt only at night using a special kind of web: an A-shaped frame made from non-sticky silk that supports a fuzzy rectangle that they hold with their front forelegs and use to trap prey.

They do this in two ways. In a maneuver called a "forward strike," they pounce down on prey moving beneath them on the ground. This is enabled by their large eyes — the biggest of any spider. These eyes give them 2,000 times the night vision that we have, Science explained.

But the spiders can also perform a move called the "backward strike," Stafstrom explained, in which they reach their legs behind them and catch insects flying through the air.

"So here comes a flying bug and somehow the spider gets information on the sound direction and its distance. The spiders time the 200-millisecond leap if the fly is within its capture zone – much like an over-the-shoulder catch. The spider gets its prey. They're accurate," coauthor Ronald Hoy, the D & D Joslovitz Merksamer Professor in the Department of Neurobiology and Behavior in the College of Arts and Sciences, told the Cornell Chronicle.

What the researchers wanted to understand was how the spiders could tell what was moving behind them when they have no ears.

It isn't a question of peripheral vision. In a 2016 study, the same team blindfolded the spiders and sent them out to hunt, Science explained. This prevented the spiders from making their forward strikes, but they were still able to catch prey using the backwards strike. The researchers thought the spiders were "hearing" their prey with the sensors on the tips of their legs. All spiders have these sensors, but scientists had previously thought they were only able to detect vibrations through surfaces, not sounds in the air.

To test how well the ogre-faced spiders could actually hear, the researchers conducted a two-part experiment.

First, they inserted electrodes into removed spider legs and into the brains of intact spiders. They put the spiders and the legs into a vibration-proof booth and played sounds from two meters (approximately 6.5 feet) away. The spiders and the legs responded to sounds from 100 hertz to 10,000 hertz.

Next, they played the five sounds that had triggered the biggest response to 25 spiders in the wild and 51 spiders in the lab. More than half the spiders did the "backward strike" move when they heard sounds that have a lower frequency similar to insect wing beats. When the higher frequency sounds were played, the spiders did not move. This suggests the higher frequencies may mimic the sounds of predators like birds.

University of Cincinnati spider behavioral ecologist George Uetz told Science that the results were a "surprise" that indicated science has much to learn about spiders as a whole. Because all spiders have these receptors on their legs, it is possible that all spiders can hear. This theory was first put forward by Walcott 60 years ago, but was dismissed at the time, according to the Cornell Chronicle. But studies of other spiders have turned up further evidence since. A 2016 study found that a kind of jumping spider can pick up sonic vibrations in the air.

"We don't know diddly about spiders," Uetz told Science. "They are much more complex than people ever thought they were."

Learning more provides scientists with an opportunity to study their sensory abilities in order to improve technology like bio-sensors, directional microphones and visual processing algorithms, Stafstrom told CNN.

Hoy agreed.

"The point is any understudied, underappreciated group has fascinating lives, even a yucky spider, and we can learn something from it," he told CNN.

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