Counting Feral Cats

Now that feral dogs have virtually disappeared in the United States and the supply of homeless dogs is approaching balance with demand, attention is increasingly turning to feral cats. Cats in general, and feral cats in particular, are now the great issue in the effort to save all healthy and treatable shelter animals.

One practical problem we face at the outset with feral cats is that we do not know how many there are. We do not even have any good estimates – just guesses.1

There is a way to work around this, though. The absolute number of feral cats today is less important than the trend in their numbers over time. So how can we figure out the trend? The first step is to go where the cats are. Free-roaming cats, including feral cats, are highly concentrated in urban environments.2 The reason is that urban environments provide far greater opportunities for scavenging and far greater concentrations of food resources and shelter than agricultural and uninhabited areas. In fact, the number of free-roaming cats per unit of ground in cities is more than 20 times the number of free-roaming cats in rural areas.3

The second step is to look at shelter intake of cats over time. If, after correcting for variations in enforcement, the trend in cat intake is up, then we know that whatever the community is doing as to feral cats is not working. If the trend is down, then we know the community is on the right track.

You might be wondering how shelter intake of cats in general can indicate the trend in feral cat populations in particular. After all, the majority of shelter intake of cats is owner surrenders and strays. And lots of shelters do not take in feral cats at all. The reason that shelter intake of cats reflects the number of feral cats is that the feral cat population is not separate from the cat population as a whole. Gary J. Patronek, one of the premier experts on population dynamics in both cats and dogs, has pointed out that there are seven common lifestyles for a cat: indoor-only, indoor-outdoor, community cat, stray, managed colony, barn cat, and feral cat.4 The key to cat population dynamics is that these categories are not hard and fast. In fact, cats frequently move from one category to another. Thus, the feral cat population will tend to rise and fall with the general cat population. And the intake of cats at the shelter is an even better indicator of the trend in the feral cat population than the number of owned cats in a community because shelter intake is limited to homeless cats, which is the category that includes feral cats.

The Jacksonville, Florida, city shelter provides a good example of how shelter intake over time can track the free-roaming cat population. Florida, with its balmy weather and relative lack of mesopredators, is heaven for feral cats, so Jacksonville is second to none in the difficulty of the feral cat problem it has to solve. Yet cat intake at the city shelter began to decline when the Feral Freedom shelter-neuter-return program was started in 2008, and is now at its lowest point since accurate shelter statistics began to be kept.

To sum up, all we need to do to determine whether we are making progress in reducing feral cat numbers is look at shelter intake trends in cities. We look at cities because that’s where the feral cats are, and we look at shelters because that’s where the homeless animals go. We look at trends rather than worrying about absolute numbers because trends tell us whether we are making progress or not. We don’t have to be fussy about what types of cats a shelter takes in, because all cats are part of the overall cat population that feeds the feral cat sub-population.

In recent years there has been debate about whether we need to keep putting resources into further reducing shelter intake of dogs in communities where live releases of dogs are high. With cats we clearly do need to keep putting resources into spay-neuter efforts, because ideally we would like to reduce the number of feral cats to zero. The problem of feral dogs was solved long ago in most places in the United States. The problem of feral cats has been harder to solve, but the results in Jacksonville show that not only can we solve the problem, we can solve it rather quickly, without any mass roundup or mass slaughter of cats.

1. Scott R. Loss, Tom Will, and Peter P. Marra, “The impact of free-ranging domestic cats on wildlife of the United States,” Nature Communications 4, January 29, 2013, Supplementary Information: doi:10.1038/ncomms2380.
2. Terry O’Connor, Animals as Neighbors: The Past and Present of Commensal Animals (East Lansing, MI: Michigan State University Press, 2013), 57-66.
3. John W. S. Bradshaw, The Behavior of the Domestic Cat, 2nd ed. (Wallingford, UK: CAB International, 2012), 140.
4. Gary J. Patronek, “Special Report: Free-Roaming and Feral Cats – Their Impact on Wildlife and Human Beings” Journal of the American Veterinary Medical Association 212, no. 3 (January 15, 1998), 218.


  1. Very true. Not only are more and more communities documenting similar trends to the pattern observed in Jacksonville, decreasing cat intake (and doa pickups) in conjunction with a return to field (shelter neuter return) program has also now been published in a peer reviewed journal: By contrast, to my knowledge no documented case exists of decreased intake resulting from even the most vigorous euthanasia-only programs.

    • Was any consideration given to the fact that people are now more inclined to abandon their cats into feral colonies where they know people will be feeding them as opposed to taking them to a shelter? This will artificially lower the number of shelter intakes for euthanasia but by no means does it equate to less cats in the streets.

    • Andrew Rowan, who is one of the most prominent experts on dog population dynamics, told me that he believed that feral dogs disappeared from most places in the United States in the years from 1970 to 2000 because private veterinarians began to recommend spaying and neutering to their client pet owners as part of routine health care. At the same time, there was a push in many areas to change the culture of dog owning, so that it was no longer acceptable in many places for dogs to roam off-leash and unsupervised. We saw sharp declines in free-roaming dogs from 1970 to 2000, including the virtual disappearance of feral dogs from all but a few places.

      • That is a very misleading reply Susan. The question was how the population of feral dogs was reduced in the United States. This was achieved by aggressive control efforts and euthanasia. Of course, spaying and neutering your pet and being a responsible owner and not abandoning that animal will reduce the amount of dogs becoming feral, but that’s not how you manage an existing population of feral animals. Even to this day, animal control aggressively manages feral dogs in the following ways. (1) public education about proper care and confinement of dogs; (2) laws that identify that dog owners are legally responsible for damage caused by dogs; (3) laws that prohibit abandonment of unwanted dogs and require humane disposal of unwanted dogs; (4) holding facilities and personnel trained to handle unwanted or nuisance dogs; and (5) assistance by professional control specialists where feral dogs are established.

  2. Let’s see some data showing a correlation between shelter intake and running-at-large population. In Florida, as described in Julie Levy’s 2014 paper, shelter intake was decreased by persuading residents to accept running-at-large cats in the neighborhood. That is not reducing the number of running-at-large cats, although shelter intake did decrease. Similarly, Albuquerque NM reduced its cat intake at the shelter by not admitting feral cats, but instead returning them to where they were caught, sometimes but not always after neutering. Decreased shelter cat intake could be, and in some cities probably is, correlated with more running-at-large cats. The easiest way to count cats is to watch the feeding stations.

    • In Jacksonville the cats are counted as impounds before they are turned over to FCNMHP for RTF. So the fall in intake is real and has nothing to do with the shelter changing its impound practices.

      • To Susan: In Albuquerque, feral cats are never formally admitted to the shelter and never counted as intake, even though they may be physically inside the shelter while being prepared for release. Also, lots of shelters, including several in New Mexico and West Texas, make relinquishing an owned pet difficult, by requiring interviews, counseling, or paying a fee. Such a policy can lead to pet owners abandoning their unwanted pets, rather than going through the hassle at the shelter. The shelter can show improved (lowered) intake numbers, but the number of stray animals goes up.

  3. Shelter intake is a proxy variable for stray animal numbers, and not a good proxy. Without a careful assessment of the correlation between the two variables, we should just stick with direct counts of stray cats, easily done at cat feeding stations. Urban feral cats have to eat, and the obvious place to eat is at a feeding station.

  4. Reference: Levy, J.K., N.M. Isaza, and K,.C. Scott. Effect of high-impact targeted trap-neuter-return and adoption of community cats on cat intake to a shelter. The Veterinary Journal. 201(2014) 269-274. The paper says, “Instead of encouraging impoundment by the shelter, the shelter’s animal control officers referred calls regarding stray cats in the target area to the study team for resolution. In nearly every case, the team was able to find a solution in which residents agreed to allow the cats to stay in the site following sterilization.” Levy et. al. were pleased to report a drop in shelter intake, but they did not count stray cats. They estimated the initial stray cat population by calling people on the telephone and asking them how many stray cats they fed. They did not estimate the number of stray cats remaining at the end of the study. Since some cats that would have otherwise been removed were allowed to stay, it seems reasonable that the stray cat population increased, but without a count of actual stray cats, we don’t know.

    • Every cat that was not impounded was sterilized; thus, they were taken out of the cat population just as effectively as if they had been impounded at the shelter and killed. The RTF movement deals with population dynamics, most particularly with the reproductive potential of the population.

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