Counting Cats

Years ago, it was common for media accounts about community cats to remark—typically with a tone of some astonishment—that a caregiver had a name for every cat in their care. For caregivers, of course, and anybody familiar with TNR, this was no surprise at all. Indeed, it would be surprising not to have names for the cats you see on a regular basis.

For whatever reason, I don’t see this element included in news stories anymore. It’s not because caregivers have stopped naming cats, though—I’m sure of that much. Such frequent, close interactions also allow caregivers to track the regulars, identify newcomers, and note disappearances. As a caregiver myself, I find this ability—to provide a reasonably accurate count of the cats we see regularly, often on a daily basis—rather unremarkable.

For some TNR opponents, though, there is simply no way that such counts can be trusted. After all, they argue, most of us lack the training to provide accurate and reliable population estimates. This is apparently what it’s come to: faced with empirical evidence that poses a direct threat to their dogmatic belief that “TNR doesn’t work,” these people have begun to dispute our ability to count cats.

In Cat Wars: The Devastating Consequences of a Cuddly Killer, for example, longtime TNR opponent Peter Marra complains about the methods used for a 1991–2002 study conducted on the University of Central Florida campus.

“The Levy et al. report [1] includes only one brief mention of a census of the colony, in 1996, and it includes no details of how the count was done. Counting free-ranging cats is notoriously difficult; for a study aimed at examining the impact of TNR on the numbers of outdoor cats, the absence of details on census procedures suggests a first serious flaw… Levy and colleagues do not explain how or when the cats were counted, so it is not clear how reliable any of these figures actually are” [2].

In fact, the study in question provided considerably more detail than Marra suggests.

“Beginning in 1991, volunteers began an organized effort to capture free-roaming cats on campus for neutering and to keep records of cat sightings and human interventions. Additional colonies were added to the control program as they were discovered. Cats were recorded as kittens if they were believed to be ≤6 months of age. Cats were classified as feral if they avoided human contact… By 1996, all cats on campus were identified and cataloged, including photographs and written descriptions of each cat, socialization status (feral vs. socialized), colony affiliations, and final outcomes. Data from the daily observation logs were condensed into quarterly reports” [1, emphasis added].

Obviously, the people involved with this campus TNR program were (as is typically the case with such programs) far more involved than would be required of a one-time annual census. That much is clear from reading the paper. And if Marra had any questions, he could have reached out to those involved—as Dan Spehar did a few years ago, to gather updated census data for a study he and I had published in 2019. What we learned expanded on what had been reported earlier, both in terms of documented population reductions (spanning 28 years) and detailed tracking information.

“Cats were recorded and their presence tracked as they were discovered on the UCF campus. Each cat was assigned a name and tracked by colony affiliation on a Microsoft Excel spreadsheet. The enrollment date, description (as well as a photograph), sex, age category (adult or kitten), perceived level of socialization at first appearance (socialized or feral), date neutered/neuter status, departure date (if applicable), and final outcome (if applicable) for each cat was documented” [3].

The reliability question raised by Marra seems to betray a profound ignorance of TNR at its most basic level. Or perhaps it merely betrays a desperate attempt to discredit the methods used to document its efficacy—in the face of mounting evidence. Of course, the two aren’t mutually exclusive.

Unfortunately, this question-that’s-not-a-question continues to come up. In 2020, Mark Hostetler and four colleagues in the Department of Wildlife Ecology and Conservation at the University of Florida’s Institute of Food and Agricultural Sciences Extension, charged down the same path in their publication, “How Effective and Humane Is Trap-Neuter-Release (TNR) for Feral Cats?,” questioning the accuracy of population estimates associated with TNR studies (including the one cited by Marra).

“Many of the above studies (e.g., [1,4]) were conducted with volunteers and used surveys of caretakers or veterinary clinic records to estimate abundance. These studies did not use standardized field observations; thus, results are likely not accurate” [5].

It’s difficult to imagine how daily interactions with cats aren’t every bit as valid as “standardized field observations,” but again, the authors don’t seem to understand TNR at its most basic level. Nevertheless, Hostetler and his colleagues continue:

“To highlight the discrepancy in data collection, we present data from a study where only one caretaker surveyed cats at various feeding stations in Key Largo from 1999 to 2013 [6]. This caretaker did not report how often each feeding station was sampled. The number of feeders changed from year to year, and many of the feeding stations were located near each other, so that cats very likely ate from multiple stations, yet the caretaker provided no rationale for how double counting was avoided” [5].

Once again, the study in question provides more detail than is suggested here. Kreisler et al. note, for example, that “the status of MIA was assigned to cats that had not been sighted at their usual feeding station for an unusual period of time, as determined by the caretaker” [6, emphasis added]. And although the authors acknowledge that “multiple population census methods would have been ideal, as caretakers may underestimate the number of cats,” they also note that the caregiver responsible for the censuses “was highly knowledgeable of the entire population, which she interacted with on a daily basis.” Moreover, “20 cats were added to census estimates by the caretaker to account for potential undercounting. The small size of each colony, particularly in later years, should also have made count estimates more accurate” [6, emphasis added].

I contacted Hostetler with several questions, pointing out that caretakers typically know each cat in their care, observe the cats daily, and can provide a significant level of detail for tracking them over time. “We absolutely do not agree that caretakers of TNR colonies can give reliable estimates,” he responded, “as they have not been trained on population ecology field protocols.”

Again, such protests suggest that Hostetler and his colleagues lack a basic understanding of TNR or are simply determined to undermine such programs. Or both. In fact, the authors reveal something important about their analysis by accepting at face value nuisance complaint data “measured indirectly and… based on citizens’ description and not on objective measures” [7].

In other words, the real test of any data is whether it can be used to throw the cats under the bus. This is exactly what Hostetler and his colleagues are trying to do, as can be seen in their 2019 op-ed for The Gainesville Sun (co-authored by the American Bird Conservancy’s Grant Sizemore):

“We (the authors) love cats and hope more funding is directed towards prevention; we maintain, based on the best available science, that TNR is not a viable solution. Overall, we view TNR strategies as inhumane to the cats themselves and potentially dangerous to humans, pets and wildlife.”

Not surprisingly, the authors fail to acknowledge that TNR is, in fact, the best “prevention” available. And—again, not surprisingly—they offer nothing in the way of an alternative to TNR— though, of course, readers familiar with the topic can certainly read between the lines.

University of Georgia graduate student Heather Gaya, however, has been more direct. In a comment responding to a December 15 post on Project Bay Cat’s Facebook page, Gaya, too, challenged the validity of caregivers’ population estimates, suggesting that the alternatives to TNR are adoption or “TNE” (presumably trap-neuter-euthanize). TNR? “Maybe not.”

Like Marra and Hostetler, Gaya—who “really enjoys cats”—justifies her opposition to TNR in part by attempting to discredit well-documented population reductions. Referring to a study published last year,* documenting a reduction from 175 cats to just one over 16 years [8], she is incredulous:

“I want to believe in this study but there are some alarming issues with their data collection and results that make me hesitant to accept the study at face value. It’s clear nobody on the paper is a wildlife statistician—they inappropriately use the word ‘population census’ (ouch) and their population estimate process in their methods is shaky. Just because you don’t see cats doesn’t mean the cat population isn’t there.”

“I’m glad those cats were fixed and aren’t out and about causing issues,” Gaya continues, “but it doesn’t mean TNR is the answer.” Never mind the fact that her “answer” has been the default approach for managing free-roaming cats in the U.S. for generations now [9]. And, just like the TNR studies cited here, you don’t need to be a “wildlife statistician” to interpret the results.

*In the interest of full disclosure, this is another one of the studies I’ve co-authored with Dan Spehar.

Literature Cited

  1. Levy, J.K.; Gale, D.W.; Gale, L.A. 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, 42–46, doi:10.2460/javma.2003.222.42.
  2. Marra, P.P.; Santella, C. Cat Wars: The Devastating Consequences of a Cuddly Killer; Princeton University Press: Princeton, N.J., 2016;
  3. Spehar, D.D.; Wolf, P.J. Back to School: An Updated Evaluation of the Effectiveness of a Long-Term Trap-Neuter-Return Program on a University’s Free-Roaming Cat Population. Animals 2019, 9.
  4. Centonze, L.A.; Levy, J.K. Characteristics of Free-Roaming Cats and Their Caretakers. Journal of the American Veterinary Medical Association 2002, 220, 1627–1633, doi:10.2460/javma.2002.220.1627.
  5. Hostetler, M.; Wisely, S.M.; Johnson, S.; Pienaar, E.F.; Main, M. How Effective and Humane Is Trap-Neuter-Release (TNR) for Feral Cats?; University of Florida, Institute of Food and Agricultural Sciences Extension, 2020;
  6. Kreisler, R.E.; Cornell, H.N.; Levy, J.K. Decrease in Population and Increase in Welfare of Community Cats in a Twenty-Three Year Trap-Neuter-Return Program in Key Largo, FL: The ORCAT Program. Frontiers in Veterinary Science 2019, 6, doi:10.3389/fvets.2019.00007.
  7. Gunther, I.; Raz, T.; Berke, O.; Klement, E. Nuisances and Welfare of Free-Roaming Cats in Urban Settings and Their Association with Cat Reproduction. Preventive veterinary medicine 2015, 119, 203–210, doi:10.1016/j.prevetmed.2015.02.012.
  8. Spehar, D.D.; Wolf, P.J. The Impact of Targeted Trap–Neuter–Return Efforts in the San Francisco Bay Area. Animals 2020, 10, doi:10.3390/ani10112089.
  9. Wolf, P.J.; Hamilton, F. Managing Free-Roaming Cats in U.S. Cities: An Object Lesson in Public Policy and Citizen Action. Journal of Urban Affairs 2020, 1–22, doi:10.1080/07352166.2020.1742577.


1 Comment

As a Dairy inspector I came across farmers who knew all their cows by name. Either you love people and animals or you don’t. Even the biologists on PBC TV that study animals in depth, name them. also A lot of stats show Confirmation bias.

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