Letter to the Editor: Scientific American

In response to: https://www.scientificamerican.com/article/cats-kill-a-staggering-number-of-species-across-the-world/​ 

Dear Mr. Tamisiea and Editors:

Alley Cat Rescue (ACR) is an international nonprofit focused on compassionate treatment of all cats.

We are concerned that your December 12th article, “Cats Kill a Staggering Number of Species across the World,” is contributing to the demonization and scapegoating of cats that is pervasive in conservationist dialogue. Such theorizing is dangerous because it obfuscates far more significant threats to biodiversity, such as fragmentation of habitats by human development, and certainly puts a target on the backs of cats.

Christopher Lepczyk is quoted as saying that the problem with cat predation can be solved by keeping pet cats indoors. ACR agrees that this should be the standard as a safety measure for both the cats and the wildlife they might hunt. However, feral cats are a different matter. As it is not possible to keep them indoors, claiming that cats are a grave threat to biodiversity turns public opinion against them and threatens their lives. (We feel compelled to add that this is a highly debated and debatable claim. Even the implications of the study examined by this article are questionable since, as you admit in the article, cats scavenge in addition to hunt. Therefore, isn’t it important to factor into any analysis of their prey the numbers of each species of animal, not just the number of species, cats killed themselves versus scavenged?) 

For now, the major point we would like to make is that, though some people may not appreciate them or even think much about them as they do pet cats, feral cats are equally sentient and deserving of life. Driven by this belief, we at ACR have been working for nearly three decades to reduce and manage feral cat populations through the only humane method, trap-neuter-return (TNR). 

Aggressively practiced TNR is not only effective but the MOST effective means of population control while catching and removing (often by killing the cats) is actually more expensive and only a temporary solution. When cats are trapped and removed from an area, new cats quickly move in to fill the vacated territory and take advantage of the resources that had been sustaining the cats there before them and start the breeding process all over again. This phenomenon is referred to as the "vacuum effect." 

One example of the vacuum effect is a 2015 study conducted in the forests of Tasmania, Australia. Over 13 months, researchers trapped and killed cats and by the end of the period, they found that the number of feral cats at the two target sites had actually increased by 75% and 211%. When the cat culling stopped, the researchers saw the cat population return to the same level as before the experiment had begun.*

Whatever one’s concerns about outdoor cats’ effect on the environment, one cannot deny that 1) feral cats exist and 2) they have nowhere else to live. By using buzz terms like “terrorized” to describe cats’ interaction with native species and calling cats “biological invaders” and , this article is promoting anti-cat attitudes amongst the large audience of Scientific American. The fallout of this is persecution - killing - of feral cats. 

We hope that you will explore opposing information about cat predation from other scientists, as well as the well-studied efficacy of TNR programs, and spread that information. If you would like to be pointed to sources, please Email [email protected]. 



Sincerely,

Louise Holton 
President / Founder of Alley Cat Rescue, Inc.




*Reference: Lazenby, Billie T., et al. “Effects of Low-Level Culling of Feral Cats in Open Populations: A Case Study from the Forests of Southern Tasmania.” Wildlife Research, vol. 41, no.5 2014, pp. 407-20.