Changing Planet

Feral Cat Debate: The Case for Large-scale, non-lethal Interventions

American citizens, like people the world over, are fascinated by cats, big and small. We admire them for their strength, their stealth, and their hunting prowess, and for their ability to blend in to their surroundings. And in the case of domestic cats, we value them for their companionship and the unique traits that make them endlessly fascinating to watch and interact with.

Whether you feel cats, social or feral, have a place in our outdoor environment or not, the truth is that cats are already there. In most areas across the globe cats are already living in proximity to humans and fending well for themselves.

At The Humane Society of the United States we think about the issue of domestic cats being outside every day, taking into account their predation impacts on vulnerable wildlife species, or assessing associated public health risks, and of course considering the cats’ welfare and the potential dangers they face. We strongly urge cat owners to keep their cats safely confined, whether inside or spending part of their time in outdoor enclosures specifically designed for them. To a growing number of those concerned with this topic, the issue is not whether cats who are not someone’s pets should be tolerated in outdoor environments, the issue is implementing effective, humane and practical approaches to reducing the number of unowned animals, curbing their rate of reproduction, and diminishing related risks.

These three parameters–humane, effective and practical–seem simple enough. However, once you take a step back to consider the scale of intervention needed to address approximately 30-40 million unowned cats living outdoors, you realize that very few tools are up to the task. If we’re serious about reducing the number of domestic cats outdoors, we need to have pro-active, targeted and methodical programs, or else the continued reproduction of cats left behind will outpace our efforts.

When viewed through this lens it is very clear to see that only one tool, scaled up to the level needed, is going to meet these criteria and be palatable to the public. That is non-lethal management through trap/neuter/vaccinate/return, otherwise known as TNVR, programs.

Non-lethal strategies have been utilized by animal welfare advocates for the past few decades, garnering such wins as colonies reduced by half, working waterfronts with no new kittens being born, or increased conversion on the part of those skeptical of the approach’s efficacy. Over time, TNVR has been honed and refined as a strategy: targeting interventions to reach high enough levels of sterilization to ensure a decline in reproduction is now the gold standard. Communities such as Newburyport, Mass.; Alachua County, Fla.; Albuquerque, N.M.; San Antonio, Texas; San Jose, Calif.; and more are seeing massive drops in intake and euthanasia of cats when such initiatives are well implemented.

Within the animal welfare field, comprised of an estimated 5,000 shelters and rescues across the country, we spend approximately $800 million on cat work every year. That is an amazing amount of resources required to cover everything from strategies to keep cats in their homes, housing and medical care of both lost and relinquished cats, and sterilization programs for both owned and unowned cats in the community.

Studies and surveys have shown that approximately 10-12 percent of American households feed and provide basic care to cats they do not own. That means we have a ready-made army of three-five million caring citizens who can be enlisted to assist with effective non-lethal management strategies. Even more advocates donate towards effective humane cat programs in their communities that align with their values. You will never see this scale of financial and volunteer support going towards other intervention such as trap and remove, since that effort will lead to a massive increase in euthanasia, which the public and animal advocates alike do not support. Given the scale of the unowned, outdoor cat population, we will never reach our shared goal of a massive reduction in numbers unless there is a large system of support and engagement.

We have the knowledge and the will; what remains is the need to pull together all who care about cats, wildlife and public health, to commit to large-scale, non-lethal interventions. The debates about whether domestic cats are native, or the exact number of songbirds predated upon are not helping. We should drop the unproductive arguments and get to work.

Katie Lisnik is the director of cat protection and policy at The Humane Society of the United States. She focuses on increasing interventions for and reducing community cats populations through sterilization and vaccination programs, as well as keeping more cats in their homes and preserving a strong human-animal bond. Katie has a BS in Animal Science with a focus on Wildlife Biology from the University of Vermont and an MS in Animals and Public Policy from Tufts University. She is the former President of the New England Federation of Humane Societies and former Board Member and Advisor to the Maine Federation of Humane Societies. Lisnik currently resides in central Vermont with her husband and two indoor cats.

Opinions are those of the blogger and/or the blogger’s organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic’s community rules and other terms of service. For those who don’t read the community rules, we remind you that comments that are abusive towards others (individuals or institutions) are not approved for publication. Differences of opinion are okay; personal attacks are not.

This post forms part of the conversation about what to do about the growing problem of feral cats, which wreak large-scale havoc on birds and other wild species, according to numerous scientific studies. Other posts in this conversation include:

Feral Cat debate: Trap-Neuter-Return Is Sound Public Policy

TNR Is Dangerous Both to Cats and to Other Animals

Big Love for Small Cats


  • Duff Smith

    Well I have no idea where TNR has ever been a success. My area was the focus of an illegal TNR program that neither succeeded nor maintained the vaccination schedules for the cats. Frustrated citizens trapped the cats themselves, brought them to the pound, and demanded that the protocols for dealing with nuisance animals be followed.

    It seems to me we’re all having to listen to the pet food industry scream up the trailer park right now. The demand for RESPONSIBLY kept cats is in a state of contraction due to bad news about the public health and environmental consequences of too many cats. Some people have enjoyed selling cat food to people who go into our already-fragmented habitats and bomb the ground with kibble to support artificially high numbers of highly destructive mid-sized predators. This too has run its course. We have a field of science called CONSERVATION BIOLOGY to tell us about the effects of human activities like that, and NatGeo has historically been a great platform for that field. This author does not speak for the public in any general sense. I am the community too, and I didn’t order any colony cats. They need to go, without stopping to pollute any children’s playgrounds any more, ever. New Zealand and Australia are getting it right, while the United States seems to be modeling itself after countries that have terrifying rates of zoonotic disease.

  • Patricia Bachi

    Wehave a very successful TNVR (trap/neutered/vaccinate/release) program. We haven’t had a kitten in many years. Our cats are fed 7 days a week, 365 days per year, receive vet care, and are much loved. It’s a labor of love, but certainly doable with enough volunteer support.

  • Kerry Rayson

    Duff Smith. Australia and New Zealand have it wrong. Melbourne had an eradication program for the street and feral cat populations. This seemed to work until they found that they now have a rat and mouse plague.
    Our eco system isn’t they same as it was over two hundred years ago. We have many introduced species including rats and mice. In Australia and New Zealand there are few predators other than cats to control these pests. Trap, neuter, release programs keep the populations in check.

  • TylerT

    One SLIGHT problem: The very same reason that trap & kill fails is the very same reason that TNR fails. You just cannot trap them faster than they breed, are dumped by criminally irresponsible pet-owners, or as fast as they out-adapt to any trapping method ever invented by man. ANY method dependent on trapping is doomed to fail before you even start. But hunted-to-extinction most certainly works. It even worked on something as small and prolific as The Rocky Mountain Locust that used to darken they skies of half of N. America at one time. A simple 50-cent per bushel bounty on them made them no-more, forever, extinct, in only a few years. It’ll work even better and far faster on something that breeds even slower and is easier to target — like cats.

    Here is glaring proof of how, as cat-hoarders so often and mindlessly respew, “Trap-Neuter-Release is the most effective means of managing feral cat populations. In fact, it is the only proven way to do so.”

    The residents of the UK who invented TNR in the 1950’s have been relentlessly practicing that failed ideology nationwide for over 60 years now. And all they have managed to do with TNR is DOUBLE their vermin cat populations — from 4.1 million vermin cats in 1965 to 8.1 million vermin cats in 2015. (One site claims 10.5 million today!) And to help, all this time they are still killing them in shelters and legally shooting them in rural areas under their animal depredation-control laws. By foolishly hoping and praying that their very own TNR concept will reduce vermin cat populations someday they have now even driven their one and only NATIVE cat species to extinction with their invasive-species vermin “moggies” (feral house-cats) — with less than 19 “Scottish Wildcats” left in the whole world. (Along with 421 other species that they have already made extinct in the UK in the last 200 years — OVER TWO SPECIES PER YEAR GONE FOREVER just due to British cultural beliefs, practices, and values.) All the while they still insist that practicing their failed TNR policies will still save their “Scottish Wildcat” from being wiped from the earth forever. You can kiss their “Scottish Wildcat” good-bye too now because 19 individuals is not even enough RNA diversity for a viable/successful species anymore — they are already EXTINCT. (Laughably ironic if it weren’t so pathetically, globally, and permanently sad. The population of the UK have made themselves into the ecological-laughingstocks of the whole world.)

    Nice plan. TNR sure does work, doesn’t it!

    You know that saying about doing the same thing over and over again and expecting a different result. The British have proved the failure of their vermin cat-insanity for over 60 years now. You too can be just as ecologically destructive, ignorant, and just as insane as the inbred mentalities of the Toxoplasma gondii brain-damaged moggie-licking British by practicing and promoting their failed-belief in their TNR concept.

    Here too are some wonderful quotes from an article published by their most revered TNR promoters — the very “scientists” that TNR imbeciles always quote out of context to try to support their TNR insanity. Read it and weep.

    “Virtually no information exists to support the contention that neutering is an effective long-term method for controlling free-roaming cat populations.”

    “Free-roaming cats do not appear to have sufficient territorial activity to prevent new arrivals from permanently joining colonies.”

    Levy, Julie K., David W. Gale, and Leslie A. Gale. “Evaluation of the Effect of a Long-Term Trap-Neuter-Return and Adoption Program on a Free-Roaming Cat Population.” Journal of the American Veterinary Medical Association 2003, 222(1)

    Or these comments from Julie K. Levy’s other study::

    “In both counties, results of analyses did not indicate a consistent reduction in per capita growth, the population multiplier, or the proportion of female cats that were pregnant.”

    “Implementation of the stage-structured model suggested that no plausible combinations of life history variables would likely allow for TNR to succeed in reducing population size, although neutering approximately 75% of the cats could achieve control (which is unrealistic), a value quite similar to results in the present study.”

    Levy, Julie K; “Analysis of the impact of trap-neuter-return programs on populations of feral cats”

    Pretty damning conclusion regarding the efficacy of TNR.

    “No plausible combinations…. would likely allow for TNR to succeed…”.

    In other words – It can’t work.


    Feral cats, wild cats, stray cats
    to name them we have many names for the mysterious felines we sometimes see
    peeking out from under our porch or darting into abandoned buildings. Yet most of
    them share single destiny mainly short and difficult lives. Fortunately,
    helping feral or abandoned cats isn’t difficult.

    Feral cats often live in vacant lots, dodge cars, and eat from trash cans, face
    infection, disease, and an endless cycle of pregnancy more so suffer extremes
    in treatment and weather. The life of a feral, stray, or abandoned cat is often
    short, sometimes lasting for just two or three years.

    Of course, feral cats also leave issues on the human doorstep including noisy
    fights, odour, staining any surface through urinating, flea infestations, and
    the inevitable breeding that creates even more unwanted cats.

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