In reading this article it seems as if feral cats are the cause of all of our ills. I am interested in learning how factual this article is, and whether it is a lot of hyperbole. It was interesting to see that a bull terrier was the champion in killing rats.

The problem
Scientists estimate that between 60 and 160 million feral cats roam the United States. A recent letter to the editor at NOLA.com | The Times-Picayune claimed cats are the "answer to New Orleans' rat problem," and suggested increasing their local numbers. Scientific studies, however, say otherwise.

Feral, free-roaming cats have been documented by dozens of studies to be indiscriminate killers of wildlife and the cause of at least 63 species extinctions, according to a 2016 analysis of invasive species impacts. But while the evidence of their hunting prowess is overwhelming, there is little proof that cats are effective at controlling urban rats, which studies have shown are not their primary prey.

Outdoor cats also carry a dangerous parasite that has been linked to schizophrenia, Alzheimer’s, memory loss and learning problems. Many Americans support programs to protect wild cats in our midst. Here's what science has to say about why we love a species that might be making us sick.

1. Feral cats are ecological serial killers
Feral cat with a rabbit kill. (Photo by Eddy Van 3000 in Flanders fields - Belgiquistan - United Tribes ov Europe)
1. Feral cats are ecological serial killers
In our current age, termed the 6th mass extinction by ecologists, we are losing biodiversity faster than ever – between 10 and 100 times faster, scientists estimate. Our support of feral cats, tenacious or tacit, might be among the worst ways humans contribute to this problem.

A 2013 study by the U.S. Fish and Wildlife Service and the Smithsonian Conservation Biology Institute found that free-ranging, domestic cats (mostly unowned) are the single largest human-caused threat to wildlife. A 2011 review of wildlife crises on islands determined that cats helped cause the decline or extinction of 123 species of songbirds, parrots, seabirds and penguins; 25 species of reptiles and 27 species of mammals, including a lemur and a bat. That hurts biodiversity, which has been shown to play a role in food security, the control of infectious disease and successful adaptation to climate change.

2. Feral cats kill for fun, abandoning dead animals that become food for more rats
A cat moves near an old house in Pilottown. (Photo by Chris Granger, NOLA.com | The Times-Picayune)
2. Feral cats kill for fun, abandoning dead animals that become food for more rats
Cats are what scientists call "surplus killers," meaning they kill more prey than they eat. Surplus killing depletes the overall food supply and creates an excess of material for scavenger species, which can transmit diseases from feeding on carcasses, scientists say. Honey badgers, bears, dogs, orcas and other animals also engage in surplus killing. But feral cats are the primary surplus killers in urban environments, while rats are a common urban scavenger. This means that kills by feral cats may directly benefit rats.

Scientists at the University of Georgia and The National Geographic Society put cameras on 55 outdoor cats and recorded their activities for seven to 10 days. They found that a third of these cats averaged about two kills per week, and the cats left nearly half of their prey uneaten. The scientists estimated -- based on a conservative tally of 84 million outdoor cats in the country -- that nearly 1.5 billion animals are killed and abandoned by outdoor cats every year. Cats kept primarily indoors were not considered to be part of the problem.

3. Outdoor cats kill between 1.4 billion and 3.7 billion songbirds every year
A summer tanager on a branch near the Rockefeller Wildlife Refuge in southwest Louisiana. (Photo by Frank Moore, Smithsonian Conservation Biology Institute)
3. Outdoor cats kill between 1.4 billion and 3.7 billion songbirds every year
Scientists at the U.S. Fish and Wildlife Service and the Smithsonian Conservation Biology Institute determined that feral cats kill more wildlife than other human-caused threats including poisoning, vehicles, and collisions with buildings, though a separate U.S. Fish and Wildlife fact sheet also lists habitat loss as a major cause of songbird decline.

Referring to a 2016 study that evaluated the impacts of invasive predators, Kauskik Narasimhan, a New Orleans resident and PhD student in Ecology at Tulane University, said he found it "astounding that cats have been linked to 63 extinctions, 40 of which are birds."

4. Outdoor cats kill at least 6.9 billion mammals per year, most not rats
A rabbit watches visitors on the nature trail at the Audubon Louisiana Nature Center in eastern New Orleans. (Photo by Michael DeMocker, NOLA.com | The Times-Picayune)
4. Outdoor cats kill at least 6.9 billion mammals per year, most not rats
Cats are able to hear higher-pitched sounds than dogs, which scientists say may be an adaptation for hunting very small rodents. By tracking cat kills in mainland areas, scientists found that, after the American Robin, the animals most at risk from cats were mice, shrews, voles, squirrels and rabbits. Another study of feral cat kills on islands found that rabbits made up 73 percent of their prey, followed by house mice and birds. Rats did not make either list.


Captain Lord Mountbatten, left, greets mascots of the British aircraft carrier Illustrious at Portsmouth, Virginia, in 1941. (NOLA.com | The Times-Picayune archive)
5. So where does the idea of cats as rat killers come from? Ships in the 1800s.
A June 11th letter to the editor published at NOLA.com | The Times-Picayune praised cats’ rat-killing prowess by citing a historic practice of taking cats "on board ships to control the rat and mouse population to keep them from eating the food on the ship." Indeed, the practice of taking cats aboard ships has led to the spread of cats to shipping ports where as invasive species they decimated native biodiversity.

As for how effective the cats were at controlling rats onboard these ships? Science has helped uncover a lot of facts since the 1800s, and that cats are great at keeping rats out of your food is not one of them. Mice, sure, but not rats.


This one-year-old, male Jack Russel terrier was photographed at the St. Tammany Humane Society. (Photo by Chuck Cook, The Times-Picayune archives)
6. Jack Russel Terriers might be better at killing rats anyway
Nineteenth-century London had an abundance of both cats and rats. So, naturally, rat baiting became a popular sport, in which a man or animal was pitted against hundreds of rats while spectators watched. The record of rat kills was set in 1862 by Jacko, a 13-pound bull terrier who killed 100 rats in just 5 minutes, 28 seconds.


A feeding female Anopheles stephensi mosquito crouches forward and downward on her forelegs on a human skin surface. (Photo by James Gathany/CDC via AP)
7. Feral cats decimate the primary consumers of mosquitos and other insect pests
Birds and bats are major consumers of mosquitos. Some songbirds eat up to 300 insects per day in summer months. By taking out birds and bats, feral cats may contribute to increased rates of mosquitoes and mosquito-borne diseases like Zika, West Nile Virus, yellow fever and malaria (which scientists say could be coming soon to New Orleans and other southern U.S. cities).

Cats also take out reptiles and amphibians that consume a variety of small insects. A study published in June 2018 in the journal Wildlife Research calculated that feral and owned outdoor cats kill 649 million reptiles in Australia every year, with the remains of 40 reptiles found in the stomach of a single outdoor cat.


Jazz, a short hair tuxedo cat, struggles while getting a rabies shot from veterinarian Dr. Wally Ansardi. (Photo by Matthew Hinton, The Times-Picayune archives)
8. Cats are the top carriers of rabies among domestic animals in the U.S.
The Centers for Disease Control and Prevention name cats as the single greatest source of rabies risk to humans in the United States, with dogs as the largest source of rabies infections worldwide. A 2012 review paper published in the journal Zoonosis and Public Health tracked a trend since the turn of the century of cats spreading rabies at twice the rate as dogs, probably due to differences in how we manage (or don’t) feral cats versus stray dogs.

Since 2008 there has only been one Louisiana case of rabies in humans reported by the CDC, and only 23 cases throughout the U.S. This low infection rate is maintained through efforts to observe or test hundreds of thousands of feral animals every year and administer post-exposure medication to between 30,000 and 60,000 people.

Treatment for humans exposed to rabies can cost up to $1,000 per person, a price more than 6,000 people pay every year after encounters with rabid cats. In 1994, a single rabid kitten cost a New Hampshire community more than $1.1 million in medical expenses.

The Louisiana Society for the Prevention of Cruelty to Animals (SPCA) currently has funding that covers rabies vaccinations for feral cats that are trapped and brought into the shelter by residents.


Homeless pet populations can contribute to the spread of flea outbreaks and other diseases. (Photo courtesy of Louisiana SPCA)
9. Cats spread toxoplasmosis
According to records from the American Bird Conservancy, three out of four outdoor cats carry the parasite Toxoplasma gondii, which is in the same family as the malaria parasite. T. gondii is transmitted to warm-blooded hosts, including humans, through contact with cat feces or by ingesting undercooked meat. Toxoplasmosis, the resulting infection, has been linked to deafness, seizures, schizophrenia and other diseases. In the United States, 1.26 million people have lesions on their eyes thought to be caused by toxoplasmosis. Millions of others experience only very mild symptoms – and scientists say reasons for these differences are not yet fully understood.

Sara Dawdy, feral cat coordinator at the Louisiana SPCA, works with individuals worried about T. gondii exposure to keep cats out of gardens by setting up chopstick barriers and building outdoor litter boxes to encourage feral cats to confine their feces to these areas. Dawdy says "humans are more likely to contract Toxoplasmosis from undercooked meat, pork I think, than from cats."

Fuller Torrey, a psychologist and the associate director of research at the Stanley Medical Research Institute, thinks the risk from cats has been underestimated.


Any cat owner will tell you that felines are not known for following orders, even if it means trespassing at a motel on the day of its demolition. (Photo by Michael Democker, NOLA.com | The Times-Picayune)
10. The parasite in cat poop stays in the soil for a long time, especially in climates like Louisiana’s
"I was frankly shocked to realize the magnitude of the problem," said Torrey in reference to feral cats. He added that oocysts, the infectious agents shed in cat poop, are hard to kill and remain active in the soil for many years in warm climates like New Orleans. He was lead author on a 2013 study that estimated the annual environmental deposit of cat feces in the U.S. at 1.2 million tons.

"Until we know more than we know now, I think it’s very foolish to allow this toxin to accumulate in play areas where children are being exposed," Torrey said.

Pregnant women have been advised to avoid interacting with cat poop for decades.


Pet Refuge holds a summer camp where children are introduced to various aspects of animal care in South Bend, Indiana. (Santiago Flores/South Bend Tribune via AP)
11. Living with cats during childhood has been linked to increased risk of schizophrenia
Torrey, inspired by seeing the toll his sister’s struggle with schizophrenia had on his family, has been researching environmental causes of the disease for more than 30 years. He broke away from colleagues in his conclusion that environmental factors, rather than genetics, are a large determinant of who develops the disease.

Determining a causal link for a rare disease with so many variables is statistically complex – because there are so few examples to weigh against many possible causes. But Torrey said the correlative evidence is shocking.

"Children that had cats when they were small are more likely to develop schizophrenia or bipolar disorder," Torrey said. "New results suggest that people who commit suicide are also more likely to have antibodies to T. gondii."

He thinks the lack of public reaction to this danger stems from a lack of awareness and a reluctance to implicate cats rather than a lack of evidence.


Cat car painted by artist Zac Maras for the Crescent City Cat Club. (Photo by Doug MacCash, NOLA.com | The Times-Picayune)
12. Exposure to feral cats could make you a bad driver, or a poor student
Torrey went on to discuss correlations between data on exposure to oocysts from cat feces and documented problems with both learning and decision-making.

"Research suggests that exposure to this parasite impairs mental functioning in lots of ways," Torrey said. "Studies in humans and mice suggest it slows reaction time. People who have been the cause of auto accidents are more likely to have antibodies to Toxoplasma gondii."

Parasitologist Joanne Webster conducted a now-famous study that found rats may suffer from impaired judgement after being infected with Toxoplama gondii, a phenomenon Webster termed "fatal feline attraction." Infected rats lost their self-preserving fear of cats and even began approaching their predators, defying their own evolved defenses. The finding has led researchers to wonder what effects this parasite might have on human brains.


Feral cats are seen in the area of the Bayou Corne sinkhole, where the neighborhood had to be abandoned. (Photo courtesy of Teleca Donachricha)
13. Food left out for feral cats likely feeds city rats, too
A frequently asked question on the Louisiana SPCA’s feral cat page is about food left out for cats being eaten by other animals, including rats.

"You are correct that if the food is left out, it will potentially become food for rats, insects, raccoons, or possums," said Dawdy of the SPCA. She councils people caring for feral cats to leave food out only during the morning to avoid supporting nocturnal rats, raccoons or possums. She said that Louisiana’s "rat harborage law" makes it illegal for people to leave food outside overnight.


Several cats wander around the back shelter area of a Mid-City home in New Orleans that was turned into a cat refuge. (Photo by Jennifer Zdon, The Times-Picayune archive)
14. Outdoor cats are overwhelming not only wildlife, but animal shelters
Animal shelters nationwide are overflowing with feral cats, limiting their abilities to care for the animals they have.

"There certainly are a lot of shelters, especially in rural areas of the state, that do take in a lot of feral cats and they do have to euthanize pretty much all of them," said Dawdy.

According to wildlife biologist Tessie Offner, feral cats are sometimes released from shelters to make room for other animals, which can create a false impression that the cat problem is being managed.

"There’s this under-the-radar issue of 'fixing' a problem by hiding it under the bed," Offner said. "By that I mean shelters are overflowing with cats, especially during kitten season. Releasing them can cause a social misunderstanding that the stray/homeless cat issue is under control but in reality, that is far from the truth."


After a feral cat is trapped and treated, it is released back into the population. (Photo courtesy of Louisiana SPCA)
15. Studies suggest most trap-neuter-release programs don't reduce cat populations
Trap-neuter-release (TNR) programs aim to humanely reduce feral cat populations by trapping cats, sterilizing them (by spay/neuter) in a safe and humane way, then releasing them back into the neighborhoods where they were trapped. In theory, by limiting cat reproduction, these programs reduce the growth of feral populations without having to euthanize any kitties. But some scientific studies raise questions about the effectiveness of these programs to reduce populations.

A 2012 review of research-to-date in the journal Zoonoses and Public Health noted that TNR programs sometimes caused increased immigration of dominant cats into areas left undefended by less territorial neutered-and-released cats, leading to a higher density of feral populations and greater risk of disease transmission. A separate 2011 review of research-to-date published in The Wildlife Professional concluded that TNR efforts often make matters worse by giving the appearance of community action while failing to reduce cat populations or predation on wildlife.

A 12-year study of feral cats in California and a 6-year study of feral cats in Florida concluded that, to overcome the rate at which new kittens are born into the population, between 71 and 94 percent of outdoor cats would need to be sterilized.

Countering that, SPCA's Dawdy pointed to studies in Florida, Australia and Rome that have achieved sterilization rates of up to 70 percent and seen declines in feral populations. However, a 2018 analysis by researchers at the University of Maryland and the University of Guelph, estimated that typical sterilization rates in feral cat populations subjected to TNR range between 0.7 and 3.5 percent, with most achieving less than 1 percent sterilization of the population.

Lindsey Gardner is a Research Coordinator at the University of Florida, a former wildlife rehabilitation professional and a self-professed "crazy cat lady who loves her indoor cats." She said she can see both sides of the issue.

"The shelters tell me TNR programs don't help the cat population outdoors," Gardner said. "But they have seen a reduction of animals coming in to the shelters, resulting in less euthanasia."

Dawdy said trap-neuter-release programs still outperform local cat removal efforts.

"For the past 100 years, the strategy for controlling feral cat populations has been to trap and remove, which means to trap and euthanize," Dawdy said. "Obviously that strategy doesn’t work because the cat population continued to grow due to something called the ‘vacuum effect’—new cats (who may not have otherwise survived) just move in to fill the space."

Thesis research at the University of North Carolina in 2005 supported Dawdy's assertion that removing and euthanizing feral cats at local scales is only a temporary fix. But saying that removal doesn't work isn't the same as proving TNR does. In the same study, a simulated TNR model did control feral numbers, but only once it reached a sterilization rate of 75 to 80 percent.

Meanwhile, ethical debates continue about the higher incidence of injury, parasites, disease, exposure, malnutrition and vehicle collisions among outdoor cats, raising questions about the benefits of returning feral cats to a life on the streets. Of the feral kittens in the UNC thesis, 75 percent did not make it past six months, with trauma as the leading cause of death.


A colony of stray cats in Laketown. (Photo by John McCusker, The Times-Picayune)
The take-home
Decades of research calls for greater measures to control feral cats. Meanwhile, evidence that cats can control rat populations or can be controlled by trap-neuter-release programs is lacking. Scientists suspect the disconnect between the public perception and the reality of the risk derives from our emotional attachment to cats.

As schizophrenia researcher Torrey put it, "It’s hard for people to make the connection that something as cute as a little kitten could be that dangerous. But frankly, I told my daughter not to get a cat for my grandchildren."

"Lots of people just enjoy their company," Dawdy at the SPCA said in reference to cats.

Despite our love for cats, they still exhibit little evidence of domestication, with only small changes from their ancestor in diet and behaviors. According to Torrey, cat’s endearing wildness may be the root of its risk to our health. While dogs do get sick, "whatever we might get from dogs, we got a long time ago," he said.

The Wildlife Professional review recommended discontinuing legal and financial support for ineffective trap-neuter-release programs, which may worsen the problem by perpetuating the notion that cats can be sustainably allowed outdoors. A scientist in Australia recently argued that total eradication of feral cats will be necessary to protect biodiversity. Still, many hate to see their feral, furry, feline friends go.

The debate about ethical control and animal welfare is complex and unsettling.

Peter Monte, a wildlife ecologist now based in Florida who has worked in animal welfare and shelter medicine for a dozen years thinks the problem of outdoor cats is more serious than most people are aware.

"This should be a bigger part of the wildlife discussion," said Monte.


Jester, a 3-month-old, neutered kitten wakes up ready to play at the LA/SPCA in Algiers. Animals are offered for adoption Mondays through Saturdays, from 10 a.m. to 4 p.m. and Sundays from noon to 4 p.m., visit www.la-spca.org or call 368-5191. (Photo courtesy of Louisiana SPCA)
The upside
Your indoor cat is probably innocent when it comes to the risks outdoor cats pose for wildlife and human health. If you are determined to let your outdoor cat roam, putting a bell around its neck can decrease, but not eliminate, its hunting success, experts say.

Torrey adds that the risk to human health from indoor cats is low, and primarily limited to childhood.

"Once you’re beyond 25 to 30 years of age, I don’t think we get (health) problems from the cat," he said. “If you’re going to have a cat, make sure it’s an indoor cat.”

Indoor cats may also be more effective at keeping rats at bay than outdoor cats are at killing them. Keeping an indoor cat may infuse your home with a feline pheromone that discourages vermin from hanging around, Torrey said.

For all the dreary, failed attempts at feral control on the mainland, outdoor cats in Hawaii may have found their haven. In 2006, billionaire Larry Ellison bought most of a small island near Maui and had it converted to a cat kingdom. Lana'i is now home to 600 free-roaming felines and hosts 10,000 of their biggest fans each year who travel to the island to exchange treats, cuddles and even marriage vows.

Upon arrival, cats are microchipped, vaccinated and spayed or neutered. The sanctuary is monitored by veterinarians, supported by donations from around the world and operates under a mission statement of "removing all free-roaming cats from the landscape."

Joan Meiners is an Ecology PhD candidate at the University of Florida and a summer environmental reporter for NOLA.com | The Times-Picayune under a fellowship from the American Association for the Advancement of Science. Contact her at jmeiners@nola.com, and on Twitter at @beecycles.



https://www.nola.com/expo/news...ence_says_feral.html

Australia has a $10 bounty on feral cats.

I don't doubt that feral cats are not great for the natural environment. They aren't natives, and that almost never goes well. In a confined place, like Hawaii, it can be a real problem.

All in all, it would probably be better if they weren't out there. But they are, and people like to keep pet cats. It is impossible to get rid of them, so . . .

Not the first time I've read some of this, especially the part about killing songbirds.

We have 14 cats at the moment, all feral, ranging in age from 17 years to ~3 months, all fixed and vaccinated except the young one who will be in a few months.

Since we moved here 5 years ago, several have come and gone, mainly the parents of 12 of the 14. Those were fixed and vaccinated before they disappeared.

There is a feral cat coalition in San Antonio where one can get help, traps, low cost medical to spay/neuter, etc. Those are found in most larger cities and towns, I believe.

"Pregnant women have been advised to avoid interacting with cat poop for decades."

Interacting for decades IS a bit extreme

The sooner we can get rid of all these feral cats the sooner we can start on the domesticated ones. Ohhh was that my outside voice.....sorry bout’ that.

I kid, I kid....mostly.

We all know “cat women” who are at least a litte nutty. So which came first, the cat or the craziness?

More seriously, here’s an article from NOAA on the harm that feral cats do in Hawaii to native Monk Seals due to toxoplasmosis spores being washed into the ocean:

Link

The cute and fuzzy factor is the real problem. Feral cats are a serious problem and have been for years. In my area the shelters won't take them and it's illegal to do away with them yourself. What the hell are people to do. Even domestic cats that are allowed outdoors kill many species of animals because they do hunt for thrills. The only thing that helps cut down the number of feral cats in our area is the increased number of coyotes.

cats.....the other other white meat....

When I was in Haifa Israel. It was pointed out to me that they have a huge ferel cat problem.

quote:

Originally posted by Lunasee:
When I was in Haifa Israel. It was pointed out to me that they have a huge ferel cat problem.

I remember watching a special where they showed that the Roman Coliseum was filthy with feral cats.

Feral cats are devastating to the natural fauna in this country. They take dirt naps in my neck of the woods.

quote:

Scientists estimate that between 60 and 160 million feral cats roam the United States.

Most of them are in my neighborhood

I feed 3 regular feral cats in my back yard, all of which have been neutered. One is the mother of 3 of my 6 indoor cats. Occasionally there will be an "outsider" come to feed, but typically there are only the 3. I do also get an occasional opossum and raccoon, but they don't bother the cats.

flashguy

quote:

Originally posted by RogB:
"Pregnant women have been advised to avoid interacting with cat poop for decades."

Interacting for decades IS a bit extreme

Yes decades.

My oldest is 32, and I remember even before that friends who had preregisters wives back in the 70s and the hubby having to clean the litter box because "the Doctor said so." Toxoplasmosis, and stirring up contaminated clay litter dust.

So, that takes us back four decades.


Oh, wait, now I see it.