Goats gotten, South African National Park Service scopes in on feral cats
CAPE TOWN, South Africa––Have feral cats succeeded feral Himalayan mountain goats, called tahrs, as the purported greatest threat to native South African wildlife at Table Mountain National Park?
The few remaining Table Mountain tahrs, a cause celebré from 2001 to 2004, are descended from a pair who escaped in 1935 on their first day at Groot Schnur Zoo. The zoo operated from 1931 to circa 1980 on the former Cecil John Rhodes estate in Rondebosch, a Cape Town suburb.
Declaring war on the tahr in 2001, as a purported invasive species, Table Mountain National Park management at last declared the tahr extirpated in 2004, after killing 138 tahr in a six-month “final solution.”
Tahr cull became global embarrassment
The killing was conducted amid international hue-and-cry over the self-evident cruelty of the campaign. At one point a wounded tahr plummeted from a cliff in full view of a crowd of upscale restaurant-goers.
The tahrs were also killed to the huge dismay of Indian conservationists, who have been trying to recover the rare species in their native Himalayas for decades and had hoped funds could be raised to repatriate the Table Mountain population.
Rangers tracked and killed an alleged last lone tahr in 2011, but hiker and videographer Kyle Mijlof in 2017 distributed newly taken photos of a trio of tahr grazing on the mountainside.
The tahrs having become a global embarrassment, dead or alive, Table Mountain National Park management have not said much about them in recent years.
Do cats scale 1,000-foot cliffs?
Feral cats, however, have lately become the talk of Cape Town as result of a claim by researchers affiliated with the South African National Biodiversity Institute and the University of Cape Town that domestic cats kill more than 200,000 animals every year in or near the park.
How near the cats can actually get to habitat for the most sensitive Table Mountain species is open to question.
Looming over Cape Town, just north of the second largest city of South Africa, with residential suburbs creeping up the lower slopes, beneath 1,000-foot cliffs that are difficult for cats and even citified baboons to scale, Table Mountain National Park at 62.5 square miles dwarfs 45-square-mile Nairobi National Park, an almost flat plain on the southern outskirts of the national capital of Kenya.
The two huge wildlife reserves are often compared.
Wildlife conservation in urban settings
Nairobi National Park, with lions, rhinos, elephants, buffalo and zebras, has more spectacular wildlife. Table Mountain National Park advertises only the presence of “porcupines, mongooses, snakes, lizards, tortoises, and a rare endemic species of amphibian that is only found here: the Table Mountain ghost frog.”
Klipspringer antelope and caracals are also occasionally seen.
Both Nairobi National Park and Table Mountain National Park are unique experiments in wildlife conservation adjacent to intensely developed urban centers. The Cape Town greater municipal area houses about 4.6 million people; Nairobi and suburbs house 4.3 million.
Both national parks have abundant feral and free-roaming pet cats skulking through the tall grass and brush forming the no-man’s-land between the parks and the cities crowding in on the native animals and plants. Mostly the cats control non-native mice and rats.
Cats in no-man’s-land
The no-man’s-land around both Table Mountain National Park and Nairobi National Park includes some of the neighborhoods where neuter/return feral cat population control was first demonstrated, between forty and fifty years ago, inspiring global emulation when the early results proved positive.
But those early programs, partially funded by British charities and maintained mostly by volunteers, long ago aged out of whatever formal existence they ever had.
The feral and free-roaming cats in and around Nairobi National Park seem to be of little concern today to anyone. While some hunt native wildlife in the park, and/or mate with African wildcats, who are their ancestors, some also become prey for jackals.
The feral and free-roaming cats who venture into Table Mountain National Park, by contrast, are of intense concern to the estimated million-odd birders per year, many from the U.S., who fly to Cape Town in hopes of rapidly adding species to their “life lists” of birds seen.
Having attracted little if any opposition abroad, neuter/return became explosively controversial among birders almost immediately when formally introduced to the U.S. in 1991.
Fear and loathing of cats had become entrenched among birders and mainstream conservationists more than a century earlier, chiefly through the efforts of longtime Massachusetts state ornithologist Edward Howe Forbush (1858-1929).
Forbush erroneously blamed cats who never inhabited various offshore islands for predation on roseate terns and other sea birds which, years after his death, turned out to be the work of gulls.
Even though Forbush was spectacularly, catastrophically wrong, the views he inculcated in generations of followers soon spread to Australia and New Zealand, where they prevail to this day.
The Forbush view of cats was also instrumental in building the American Bird Conservancy, founded by ornithologist George Fenwick in 1994, three years after the formation of Alley Cat Allies and Alley Cat Rescue, the first U.S. neuter/return advocacy groups of national influence.
Eventually, inevitably, the ailurophobia infecting conservation in the U.S. reached South Africa.
The estimated 3,400 feral cats of Marion Island, 1,340 miles south of the South African mainland, were targeted first. Nineteen years of shooting, poisoning, and hunting surviving cats with dogs finally eradicated the last of the cats in 1991, resulting in a population explosion of mice. The mice soon became a greater threat to nesting sea birds than the cats ever were. A 30-year attempted purge of the mice is still underway.
After Robben Island, the former prison colony island off Cape Town, was granted World Heritage Site status by the United Nations in 1999, feral cat extermination campaigns were waged in 1999, 2005, and 2006 in the name of protecting sea birds, especially black oystercatchers, a threatened species.
Neuter/return was briefly attempted at Robben Island in 2005-2006, in hopes that sterilized feral cats would help to control black rats, who prey upon sea bird eggs and nestlings, and feral rabbits, thriving on the island since introduction in 1654.
The neuter/return effort, however, was abandoned when the Robben Island cats proved to be exceptionally difficult to trap.
Eventually fifteen feral cats from the former Robben Island prison colony were relocated to Pollsmoor Prison in Tokai, a Cape Town suburb, initiating a neuter/return program among the feral cats already at Pollsmoor Prison.
The remaining cats on Robben Island, of a population once believed to be as high as 3,400, were shot in 2007.
Attempts to exterminate rabbits, black rats, and the remnants of a European fallow deer herd introduced in 1869 were at last report still underway.
The South African National Biodiversity Institute and the University of Cape Town claims about free-roaming cats and Table Mountain National Park were made public on August 4, 2020 by Tiara Walters of the Daily Maverick, an online newspaper founded in 2009.
Headlining her article “Apocalypse Miaow,” Walters reported that the researchers estimated the Cape Town cat population “to be some 300,000-strong,” which “translates into a prey count of some 90 animals per cat each year. Nearly 30 million animals across the city end up in cat claws every 12 months, the scientists announced. The vast majority are indigenous.”
The actual study finding projected an annual toll of 27 million animals killed by cats throughout Cape Town, including 203,500 killed within Table Mountain National Park, to which few Cape Town cats actually have access.
“An owl or mongoose would be far preferable”
“Table Mountain National Park is a World Heritage Site,” Walters continued, “designed to protect endemic life, such as the endangered western leopard toad, vulnerable Cape rain frog and orange-breasted sunbird. Each of these species was recorded [by the researchers} as being mauled by local cats.
“Reptile activity coinciding with nocturnal cat hunting times meant that species such as the marble leaf-toed gecko were most popular,” Walters said, citing a “paper first published in the journal Global Ecology & Conservation on July 20, 2020,” billed as “The culmination of multiple studies over a decade,” and “the first African research project deploying KittyCams,” or small cameras strapped to cats, “to record hunting jaunts on film.”
Charged study co-lead author Colleen Seymour, “Cats are kept at densities far higher than those at which natural predators occur – about 300 times denser. Such predation is unlikely to be sustainable. An owl or mongoose in the garden would be far preferable.”
Seymour overlooked that mongooses are also persecuted over much of their range, both native and non-native, for much the same reasons as cats.
Call for “effective trash management”
Claimed University of Cape Town researcher Robert E. Simmons, also credited as a lead author of the study, “Typically predators will move out, switch to other prey, or die off as prey numbers diminish. Domestic cats don’t do that. They stay and they continue to kill whatever they can find. This will suppress populations [of prey species recovering after the lean dry season.”
A third study author, Justin O’Riain, of the Institute for Communities & Wildlife, recommended “Not having a cat if you live on or near the urban edge; restricting the cat to an outside catio; or keeping the cat in at night when hunting wildlife is more likely.”
Cape Town ornithologist Ross Wanless, not involved in the study, recommended “effective trash management,” Walters wrote, “to reduce the need for cats as mousers and, by implication, help endangered species.”
“Investigation of restricting cat ownership”
Except for “not having a cat,” all of these are recommendations promoted for decades by humane organizations, both in and around Cape Town and throughout the world.
Said a South African National Park Service media release, “We strongly support initiatives to minimize wildlife impacts from domestic cats. This includes investigation of restricting cat ownership along the boundaries of protected areas.”
The ensuing heated discussion has to some extent reprised an earlier debate reviewed by economist Nicoli Nattrass, co-director of the Institute for Communities & Wildlife, in a paper entitled Contested natures: Caracals, cats and the boundaries of nature in the Atlantic Beach Estate, South Africa.
Cat vs. caracal
“In the mid-2010s,” wrote Nattrass, “residents of the Atlantic Beach Estate––a relatively high-income residential and golf estate about 20 kilometers [12.4 miles] north of Cape Town on the South African west coast––became embroiled in a dispute over how to respond to a caracal, or perhaps caracals, killing domestic cats. Between early 2013 and mid-2018, 66 domestic cats reportedly went missing. During this time, the remains of 31 domestic cats were found, of which 21 could be linked to an owner on the estate.”
Among the Atlantic Beach Estate residents, found Nattrass, “Just over half (53.4%) had a ‘pro-nature without cats’ world view. That is, they were opposed to removing the caracal and in favor of restricting cats to their owner’s property. Almost a fifth (19.2%) had a ‘pro-nature with free cats’ world view,” meaning they “were opposed to removing the caracal and were opposed to restricting domestic cats to their owner’s properties.
“Just over a fifth (20.7%) of the sample had a ‘protect free cats from caracals’ world view,” Nattrass reported. These people “wanted the caracal removed and to allow cats to roam freely.
“Some residents built walled gardens”
“At stake was not whether to live in or with nature,” assessed Nattrass, but rather “what kind of nature was suitable for an eco-friendly estate. Some residents worried that the caracal posed a threat not only to their pets/companion animals, but also to children, though this view was not supported by conservation officials,” since caracals are about the size of bobcats or coyotes, and rarely conflict with humans.
“Most residents,” Nattrass reported, “valued the presence of the caracal and as the debate evolved, more critical attention was placed on the impact of domestic cats on small wildlife within the Atlantic Beach Estate,” which are also prey and an attractant for caracals.
“Some residents built walled gardens and ‘catios,’” Nattrass continued, while caracals are apparently still occasional visitors to the upscale neighborhood.
“Figures hugely distorted”
“Judging by responses [to the Table Mountain study] on social media, as well as those received in a small, impromptu survey,” National Cat Action Task Force spokesperson Anneke Malan told ANIMALS 24-7, “some cat advocates believe that cats should indeed be managed better, e.g. by keeping pet cats in at night or keeping them on one’s own property. Others feel that this would be unnatural and inhumane, and that it would make ferals even more vulnerable to persecution.
“Most believe, however, that the figures [cited] were hugely distorted by several factors,” Malan said, such as that “Cats fitted with KittyCams were more likely to have been cats that roamed and were known to be hunters. As the cats were volunteered for the study by their humans, it is unlikely that cats who sleep 23 hours a day and never leave the house would have been volunteered.
“Extrapolations were gravely incorrect,” Malan charged, “e.g. the inference that all cats behave in the same manner as those fitted with KittyCams. A number of advocates believed that only a small percentage of pet cats actively hunt.
“Most domestic cats do not live adjacent to nature reserves”
Said Cats of South Africa spokesperson Niki Moore, “’This survey was specifically performed over a very narrow band of terrain that abuts a nature reserve, and therefore an area where domestic cats, if they did hunt, would have indigenous prey to hunt. However, most domestic cats do not live adjacent to nature reserves, and would therefore not have access to that kind of prey, but would instead prey on rats, mice, cockroaches, geckos, garden lizards, garden snakes and the more accessible of garden birds,” such as “doves and pigeons,” both larger than the normal cat prey range.
“While we support the advice that people who live adjacent to nature reserves could perhaps take more trouble to confine their cats’ hunting activities in the reserve,” concluded Moore, “this is not advice that would be all that relevant to people who do not live adjacent to a reserve.”
Responding to the Table Mountain study, Malan said, “We, Cats of South Africa, a network of cat-care organizations and individuals in South Africa, have launched an international survey aimed at determining the truth, once and for all, about questions such as cat predation, the impact of cats on the environment, the most effective feral cat management methods, and other issues of importance in regards to cats worldwide.
“To our knowledge,” Malan added, “no study of this nature has ever been undertaken using a large, international sample over the long term. Therefore, studies of cat behavior, management and care have frequently been based on extrapolations and assumptions that were little more than guesswork. In undertaking this survey, Cats of South Africa hope to provide some real numbers instead of the estimates that researchers currently rely on.
“This will be an open-ended survey,” Malan said, “in order to ensure the widest possible participation over the long term. We will publish our findings every six months, and we hope in this way to build up real knowledge about domestic cat ownership and feral cat management and care worldwide.”
The Cats of South Africa survey form is posted at https://docs.google.com/forms/d/1SMPPtS2dglet7YSmJzI6iLYYBbt4jEJtEfiZyqWsi64.
Projections from small samples
The Table Mountain study was meanwhile extensively critiqued on September 12, 2020 by Vox Felina blogger Peter Wolf, a retired science teacher who is now research and policy analyst for the Best Friends Animal Society.
Wolf pointed out that the first of the three separate surveys from which the extent of cat predation on Table Mountain wildlife was projected had attracted only 32 responses from among 600 questionnaires distributed, for a response rate of just 5.3%, back in 2009.
The second survey, by University of Cape Town graduate student Koebraa Peters, drew responses from 18 households with a total of 27 cats among them.
The KittyCam survey, the third in the series, conducted by Frances Morling, documented just 15 cat kills of mammals, 31 of reptiles, 11 of invertebrates, one bird, and one amphibian.
Distortion from “correction factor”
Morling used the KittyCam data “to determine the proportion of prey caught that is brought back to the home,” and then applied the relative frequency of species caught among the 59 cat kills in his sample “to predation studies that have focused only on prey brought back to the home.”
Remarked Wolf, “This is not uncharted territory, of course. Nor is it unwarranted. What is problematic is the constant misuse of such correction factors to inflate predation rates.
Most problematic, Wolf found, “is the authors’ application of their correction factor across all prey species—in contrast to their own findings.
“Ten of the 15 mammals predated by cats were brought home; the other five were not,” observed Wolf. “Applying the author’s correction factor (5.56) would lead us to believe that 56 mammals had been predated—nearly four times what was documented. A similar situation arises if one ‘corrects’ for the number of amphibians brought home.
Cat habitat is best where people are
“For reptiles and birds, on the other hand, none was returned home—at least not as part of the KittyCams research. Both Peters and George documented bird predation, which raises questions about the KittyCams possibly interfering with the hunting of birds. Obviously, the true predation rates were greater than those estimated via prey return surveys, but multiplying by 5.56 (or any other number) is of no use, as it suggests a result of zero.
“Faced with this conundrum,” Wolf objected, “[Colleen] Seymour et al apply their correction factor across all prey categories and to all of Cape Town’s pet cats.”
The resulting annual predation estimate of 90 animals per cat per year is consistent with other studies, and is perhaps on the low side for outdoor cats who hunt for a living.
However, the overwhelming majority of Cape Town cats, as among cats elsewhere, almost certainly live where humans provide food sources or leave food waste to attract mice and rats.
Relatively few cats would have reason to venture up into the sparse, seasonally arid slopes of Table Mountain, miles from grocery stores, restaurants, and other mouse and rat attractants.
Australia doesn’t let facts interfere with culling
With the Table Mountain feral cat discussion simmering, Australian House of Representatives Standing Committee on the Environment and Energy chair Ted O’Brien on September 5, 2020 cited comparably flimsy data in declaring his determination to “find a way to wipe two million feral cats from the landscape,” reported Krystal Gordon and Kelly Butterworth of the Australian Broadcasting Corporation.
“We know that feral cats have been implicated in the extinction of around 20 animals,” O’Brien said, not actually knowing any such thing.
Feral cats “threatened 124 of our listed threatened species,” O’Brien continued, lamenting that “we’re falling behind on reaching that target” of two million cats to be killed within five years.
(See How killing cats helped to keep Aussie Liberal Party in power, Why killing cats on remote islands will not help biodiversity, and Culling cats increases the feral population, Australian study finds.)
British study replicates Nattrass’ findings
Science Daily on September 2, 2020 meanwhile reported that “University of Exeter researchers surveyed 56 United Kingdom cat owners,” finding––as Nattrass found earlier at the Atlantic Beach Estate––that “they ranged from ‘conscientious caretakers’ concerned about cats’ impact on wildlife and who feel some responsibility, to ‘freedom defenders’ who oppose restrictions on cat behavior altogether.
“Although we found a range of views,” said lead study author Sarah Crowley, of the University of Exeter Environment & Sustainability Institute in Cornwall, “most U.K. cat owners value outdoor access for their cats and oppose the idea of keeping them inside to prevent hunting. Cat confinement policies are therefore unlikely to find support among owners in the U.K.
“However,” Crowley continued, “only one of the owner types views hunting as a positive, suggesting the rest might be interested in reducing it by some means. To be most effective, efforts to reduce hunting must be compatible with owners’ diverse circumstances.”
“Diverse perspectives of cat owners”
Published in the journal Frontiers in Ecology & the Environment, the Crowley study is entitled “Diverse perspectives of cat owners indicate barriers to and opportunities for managing cat predation of wildlife.”
South African cat advocates are hoping the British research, confirming that of Nattrass, will influence South African National Park Service policymakers more at Table Mountain than the past claimed success of extirpating cats from Marion Island and Robben Island, and the long history of failed cat purges in Australia, New Zealand, and other mainland habitats.