Despite how it sounds, TNR is not the latest $100 wrinkle cream. TNR stands for “Trap-Neuter-Return”, and it’s a humane and effective population control strategy used to reduce reproduction and stabilize the population in community cat colonies.
What are Community Cats?
Community cats (also known as “feral” or “alley” cats) have lived alongside people for more than 10,000 years. They live outdoors in groups known as colonies, and they can thrive in every type of environment, even in cold climates. Community cats are the offspring of other feral cats, or former pet cats who got lost or were abandoned.
Community cats survive on small prey, food scraps from dumpsters or garbage cans, and food provided by people. They can be just as healthy as pet cats – with equally low rates of disease.
Challenges with Outdoor Cat Colonies
Because community cats are not officially owned by one person, there is no one to ensure that they are spayed or neutered, so they continue to breed. The math is staggering: if one female cat gives birth to six kittens in one year, that one cat and her offspring could produce between 100 and 400 cats by the end of seven years*. Now multiply that by hundreds of cats in one area, plus the fact that unspayed female cats can have more than one litter per year, and the numbers become mind-boggling.
The resulting overpopulation causes competition for available resources, including food, water, shelter, and territory. This may result in members of the colony exhibiting territorial behavior, such as fighting and spraying (raise your hand if you’ve ever found mysterious cat urine on your front door!)
So the best thing to do would be to trap these cats and take them to shelters, right? Unfortunately, no. Community cats brought to shelters are almost always deemed unadoptable (since they have learned to be cautious to survive and are even more terrified once in a shelter setting), and their rate of euthanasia once they enter the shelter system is extremely high. Even no-kill shelters experience great difficulty with placing feral cats in homes.
*Data collected from Dr. Michael Stoskopf’s population studies of feral cat colonies in North Carolina.
“Catch and Kill” Does Not Work
One strategy that has traditionally been employed by animal control agencies is “Catch and Kill” (yes, it’s exactly what it sounds like). However, this cruel policy simply does not work.
Cats usually reside in locations where there is both a food source and shelter from the elements. When cats are removed from a location, surviving female cats tend to have larger litters of kittens, and new cats move in. The colony’s population will continue to increase until it reaches a number that can be supported by available food and shelter.
This well-documented phenomenon is called the “vacuum effect”, and it leads to an endless cycle of cats breeding, then being removed and killed.
Trap-Neuter-Return DOES Work
Trap-Neuter-Return (TNR) is beautiful in its simplicity. Once the cats are trapped and sterilized, they are released back into the colony, where they can no longer breed. The colony’s population stabilizes, territorial behaviors (such as fighting and spraying) and mating issues decrease, and best of all, there are no more unwanted kittens!
After sterilization, the overall health of the colony also improves. The health of the female cats isn’t compromised from having litter after litter of kittens, and the incidence of Feline Immunodeficiency Virus (FIV, also known as Feline AIDS), which is transmitted through deep bite wounds sustained when cats fight, decreases. Feline Leukemia Virus, which is often transmitted from infected mothers to their kittens, also decreases.
And because the cats are also vaccinated against Rabies Virus, public safety also improves.
What Happens During the TNR Process?
First, community cats are humanely trapped using wire cage traps (these are equipped with a trip plate; food is placed at the back of the trap, and when the cat enters the trap and walks across the plate, the door closes). The trapped cats are then taken to a local facility staffed by volunteer veterinarians, where they are anesthetized and surgically spayed or neutered.
Veterinarians use strong surgical wire in these procedures (which remains in place inside the cat), rather than using nylon suture material on the outside of the skin. This is safer for these outside kitties and eliminates the need for suture removal later.

While the cats are still anesthetized, they are also ear-tipped. Ear-tipping involves surgically removing about ¼-inch of the top of the cat’s left ear (which is the universal symbol of a neutered cat). This way, the cat carries a visible mark that he or she has already been sterilized and does not need to be trapped.
Once awake, the cats are returned to either TNR volunteers or caretakers and monitored overnight. If they’re awake enough the next day, they are released into the area where they were originally trapped.
Benefits of a Healthy Community Cat Colony
Although some people consider feral cat colonies a nuisance, community cats can help keep rodent populations down in both commercial and residential areas. Just the scent of cats can keep rodents away, and many restaurant and hotel owners are grateful for the ensuing lack of rats around their kitchen and dumpster areas.
There is also a program sponsored by Tree House Humane Society called “Cats at Work”, in which Tree House finds cats in overcrowded colonies or dangerous situations, traps them, makes sure they are neutered, vaccinated, health-screened, and medicated (if needed), and relocates them to a new location where people really want them to assist with rodent control.
During the Cats at Work relocation, a home base area is set up for the cats, where they live in large acclimation crates for 3 weeks so they can adjust to their new surroundings. After they are released, the person requesting the cats provides food, litter boxes, and veterinary care.
How Can You Help Community Cats?
In addition to TNR programs, there are many other ways to help the community cats in your area. Once the cats are neutered, you can provide food, water, and outdoor shelter, especially during the winter months. (Read more about how to create cold weather shelters here.) Additionally, you can work with your veterinarian in some cases to help provide medical care.
You can also become an advocate for TNR programs, volunteer for an organization that helps feral cats, provide a holding space for cats pre- and post-surgery, foster and/or socialize feral kittens, and support your local TNR organization with donations of food or dollars.
Everyone Wins with TNR
TNR not only improves the quality of life for community cat colonies, prevents the birth of additional cats, and reduces the number of cats over time, it also spares the lives of these cats and allows them to live in the environment they are accustomed to. And, perhaps most dramatically, it impacts the lives of ALL cats: the Feral Cat Coalition of San Diego reported that in a 5-year coordinated, collaborative program using TNR, the number of cats killed in San Diego shelters dropped by nearly 50%!
Community cats belong to all of us. And all cats deserve the chance to live a long, full life – not just the ones who are fortunate enough to live indoors.
Have you ever cared for community cats? What are some of the things you did to help them? Please share your stories with us in the comments below!
As always great content and helpful advice
Thank you, so glad it was helpful! I have a special place in my heart for community cats…2 of my own cats were previously feral kittens, and my third cat was a neighborhood stray. I truly believe we have a responsibility to look after these kitties, who, unfortunately, many times are viewed as societal cast-offs.
Have local wild cat black named Shadow ,wont get close to anyone much less take to Vets for HC screening alone. Very healthy NOT the mangy wild feral cat everyone sees daily or by locale.
Very clean & has manners.
Long hair black cat.