What follows is the full text version of an article which was written in response to a recent FACA newsletter article . 


RE: ‘The Truth About Trap-Neuter-Return and Feral Cat Colony Movement’ by Frank Hamilton


Frank Hamilton is an adjunct professor of management and leadership at University of South Florida, Tampa, FL.  He is also the Vice Chairman of the Hillsborough County Animal Advisory Committee (AAC) charged with advising the county commissioners on animal related issues and policy.




Free-roaming cats are the targets of bird enthusiasts who fail to note that the solution that they are proposing [Cats Indoors] does not address the problem.  The underlying issue of free-roaming cats is failure of humans to take full responsibility for animals that were domesticated thousands of years ago.  These cats are not wild animals [The Florida Fish and Wildlife Commission (FWC), has provided a legal opinion that FS 372.265 which requires a permit to release non-indigenous species does not apply to free-roaming cats.  If it did, all owners of cats and dogs in the state of Florida would have to get a permit from the FWC to put their animals into carriers to transport them to the vets and then release them back in their homes]. 


The Scope of the Problem


It is hard to characterize the cat population.  The total cat population consists of both ‘owned’ and free-roaming [of which feral cats are a subset] cats.  It is difficult to determine both the numbers and the flow between the populations [Patronek, 1998].  There are a number of methods proposed in academic journals.  In Florida, local governments tend to use the word ‘harbor’ as one means to identify owed cats.  Harbor as defined in Hillsborough County, FL Ordinance 00-26 ‘Shall mean to perform any acts of providing care, shelter, protection, refuge, food or nourishment in such a manner as to control the animals actions’ [p.7].  Unfortunately, there is a vast gap between ‘harboring’ and licensing, the other legal method used to count owned animals.   Again, using Hillsborough County as an example, the 2004 total owned companion animal population has been estimated by Hillsborough County Animal Services [HCAS] at over 508,500 animals [239,500 dogs and 269,000 cats].  Of these, only 148,000 are licensed [29%][HCAS Monthly Calendar Year Statistical Status Resulting from Operations Report, April 2004]. 


The campaign currently be waged in Florida, although aimed at all cats, is focused on free-roaming cats.  The size of this population is unknown.  There have been at least four studies done to estimate the magnitude of the problem.  Johnson et al [1993] in California included a question about the number of unowned cats that were fed but not owned by the household.  The response rate found 10% of the households surveyed fed unowned cats.  This study was repeated in 1995 in San Diego County, CA and found that 9% households fed unowned cats.  In 1996, in Massachusetts, Luke found in a three-year study, that 15% of the households fed unowned cats.  In 2003, Levy, Woods, Turick, and Estheridge repeated this study in a Florida county.  They found that 11.9% of the households in the county fed an average of 3.6 unowned cats each.  Of these households, only 11% had attempted sterilization.  Extrapolating these numbers to Hillsborough County for 2004 means that there are 54,823 households feeding 3.6 cats each or over 197,000 free-roaming cats in this county.


Control or Management of Free-Roaming Cats


            Slater (2002) identified four approaches generally used in dealing with free-roaming cats (1) Wait and See, (2) Trap, Remove and Euthanize, (3) Trap, Remove and Relocate and (4) Trap, Neuter and Return (TNR).   As she further elaborated, responses to complaints of free-roaming cats depends on the local agencies [and ordinances] involved; the resources available; the sophistication of the community regarding cats; the proportions of socialized, free-roaming and feral cats; and the nature of the complaints.  Socialized, unowned cats may be either adopted or euthanized in any of these four approaches.


  1. Wait and See Approach


Doing nothing or wait and see has been one method communities have used to deal with the issue of free-roaming cats.  According to Slater (2002): “[this] approach results in continued breeding, increased cat mortality, continuing complaints by those near colonies, public health concerns, animal welfare concerns [often generated by high kitten mortality rates], and eventual financial costs in personnel, transportation and euthanasia to animal care and control agencies and local governments” [p. 15].  Clearly an option, it does not address the issue in a systemic, long-term view with an aim of solving the problem.


  1. Trap, Remove and Euthanize


This solution is at best a short-term answer for any location unless the food and shelter that first attracted the cats is removed from the habitat [Neville and Remfry, 1984, Zambrecker and Smith, 1993].  If dumpsters, outside feeding by other people, and other nearby sources of food are not removed, cats from nearby areas will move into the vacuum left by the cats trapped and euthanized [Tabor, 1983, Passanisi and MacDonald, 1990].  Total elimination is usually unsuccessful because 2 or 3 extremely wary cats will evade capture and will eventually repopulate the area.  On moving into the abandoned territory, new cats will breed to fulfill whatever population the area will support.  Relinquishment and abandonment of pet cats, resulting from excessive births and lack of owner commitment supply a continuous source for the stray cat population (Mahlow & Slater, 1996, p.2017).


Euthanization as a means of population control has not worked.  Except on isolated island ecosystems [Howell, 1984; Biodiversity Group, 1999], there is not one scientifically documented study that indicates trap, remove and euthanize works as a means of population control in an open environment, such as mainland Florida.  Yet, this continues to be the short-term answer applied by county, state and federal officials when confronted with the issue of free-roaming cats. 


That euthanization is an ineffective means of population control is also supported by 130 years of animal control statistics.  Trap, remove and euthanize has been the traditional method for animal control organizations.  Yet, the numbers of animals euthanized continued to rise until animal welfare programs such as the 1990’s spay/neuter initiatives started to make a dent in the number of companion animals flowing into the shelters.  The key to controlling euthanization numbers is in slowing the number of animals going into the shelters.  Municipalities as diverse as San Francisco, San Diego, Phoenix, AZ, Richmond, VA and the states of New Hampshire and Utah have reduced the numbers of animals going into the shelters and have noted a concurrent reduction in the number of animals euthanized.  Additionally, a study done in Orange County [Orlando] FL noted an increase in spay/neutering of free-roaming cats decreased the number of nuisance calls noted by Animal Control (Hughes, Slater and Haller, 2002).


Using Hillsborough County as an example, in order to trap, remove, and euthanize the free-roaming cat population, 197,000 cats would have to be trapped, removed and euthanized in one breeding cycle.  The estimated cost per trap, remove and euthanized in Hillsborough County is $168 [HCAS internal document] per animal.  This places the cost [given that manpower and time are not included] at $32 Million dollars of the county taxpayers money.  This is five times the annual budget of HCAS and clearly not practical in a political sense.


  1. Trap, Remove and Relocate


Transferring to a new location is rarely recommended [Slater, 2002].  This is due to a number of reasons such as high cost, finding a suitable location, and stress on the cats.  Additionally, orienting the cats to a new location is critical.  This includes confining the cats to a building or enclosure for at least twenty-one days [Slater, 2002, p.12].  This allows the cats to consider the new location permanent.


Sanctuaries are enclosed outdoor spaces that can be utilized for the long-term housing of free-roaming cats.  There are several sanctuaries in the state of Florida.  One located in Southwest Florida, charges $400 per animal.  One of the issues that has become apparent in the recent study of free-roaming cats, is that they tend to live longer than originally estimated.  Levy, Gale, and Gale, (2003) found that free-roaming cats in managed colonies lived a median of 4.7 years [range 0 to 8.3 years].  The implications are that planning for sanctuaries needs to be on a long-term basis in terms of feeding, housing and medical care.  Best Friends Sanctuary (www.bestfriends.org) currently houses approximately 400 cats in Wildcat Village.  They state the cost of building the enclosures, food, medical and staff support was $602,000 for the first year [they already owned the land].  This is clearly an expensive proposition. 


Again, using Hillsborough County as an example, the Animal Services Director estimated that 2500 cats entering his facility each year are ‘feral’ [personnel communication].  By applying Best Friends costs to the 2500 cats in the first year, it would cost $3.75 million dollars to Trap, Remove and Relocate only the cats identified by HCAS in one year [provided that the land for the sanctuaries was donated].   This method has been suggested as a means to ‘control’ the population by both the FWC and bird supporters, where does this money come from?


  1. Trap, Neuter and Return (TNR)


The most basic form of TNR [return, not release as some use] involves low-cost or subsidized sterilization, as well as ear-tipping or notching and a rabies vaccination [Slater, 2002].  For TNR to be successful the colonies must be monitored by a caretaker, on at least an every other day basis [p. 13].  Without continuous monitoring, new cats will move into the colony and undo the efforts to sterilize the population.


There have been a number of scientific studies that supported the long-term efforts of TNR [Hughes, K. & Slater, M., 2002].  Implementation of a feral cat management program on a university campus.  JAAWS 5(1), 15-28 [conducted in Texas over two years];  Levy, J., Gale, D. & Gale, L. (2003).  Evaluation of the effect of a long-term trap-neuter-return and adoption program on a free-roaming cat population.  JAVMA 222(1), 42-46 [an 11-year study conducted in Florida]; and Zaunbrecher, K & Smith, R (1993).  Neutering of feral cats as an alternative to eradication programs, JAVMA, 449-452[a three-year study conducted in Louisiana]].   In all three studies, the long-term effects of TNR and managed colonies effectively stopped breeding of cats in the wild and the number of cats decreased over time.  The Zaunbrecker study noted specifically that past attempts to eradicate the colony by trap, remove and euthanize was unsuccessful and that only though the application of TNR were the numbers stabilized and then reduced [study was over a three-year period].  The Levy et al study [2003] was over an eleven-year period.  The colony decreased in size 66% with no new kittens being born after the fourth year.  As new cats arrived they were neutered and returned or adopted before they could reproduce.

Additionally,  municipalities as diverse as Maricopa County [Phoenix, AZ], Richmond, VA and Tompkins County [Schenectady, NY] have implemented TNR programs as part of aggressive spay/neuter programs and have watched the number of cats entering the shelters plummet.  Additionally, a study done in Orange County [Orlando] FL noted an increase in spaying/neutering of free-roaming cats decreased the number of nuisance calls received by Animal Control [Hughes, Slater, and Haller, 2003].


Opponents to TNR cite Castillo [2003] as scientific evidence that TNR does not work.  The Castillo study was a 1000 hours of observation.  It did not mention or use any of these three studies as references.  The Castillo study had several potentially fatal flaws.  These include: (1) study limitations and findings not addressed that directly affect the validity of the findings; (2) a potential legal issue; and, (3) a demonstrated lack of understanding of Trap/Neuter and Return (TNR) as a nonlethal means of population control which places the scientific validity of the results in doubt. 


This study did not mention two key study limitations that directly affected his findings.  First, the county ordinance required signs to be posted stating that dumping of feral cats or another nuisance animal was punishable by a fine.  Since the colonies were located in a remote area, this encouraged dumping of animals.  As animal control officials continue to note, dumping, although illegal, occurs where humans can do it and not be caught.  Second, the Castillo study mentions little if any management techniques to control the population that was present.  He watched the cats, not the caretakers.  As a sidebar, it should be noted that he only saw two examples of predation during his observation.


Castillo states he saw cats dumped during his study.  Since his study is being used to support the idea that cats should be indoors, were these instances reported to the proper authorities?  This could be a potential violation of USC 45 CFR 45 and CFR 46 that regulates researchers.


The third issue is the claim that TNR does not work.  He states that it does not work, yet does not really explain how it works and of what colony maintenance consists.  His conclusions are that education of cat colony proponents and humane trapping and removal of all cats from public lands be accomplished.  Elimination of cat colonies from parks needs to be accomplished.  Castillo evidently failed to review the literature that states very specifically that elimination except in isolated ecosystems does not work.  Irresponsible pet owners dump their pets no matter if feral cats are present or not. In most localities and states it is a crime to abandon pets, yet it continues to happen. This is a separate issue from that of TNR, although some try to combine them into a single issue. There are numerous laws on the books making this illegal; catching them in the act of dumping unwanted pets is an enforcement issue. Unfortunately, catching dumpers in the act is extremely hard.


Working toward a Solution: Trap and Neuter Programs Work Both in Theory and Practice


This is a public policy issue much larger than cats vs. birds.  People created the problem to begin with and as a community we must develop means to address it.  Currently, proposed policies appear to be aimed at solving the ‘claimed’ hunting activities of free-roaming/feral cats.   Numerous claims are made of the “millions of birds” that die due to cat predation.  In 1979, a US Fish and Wildlife report stated that 196 million birds in the United States died annually as a result of human activity.  At that time, miscellaneous causes of bird mortality, indirectly related to human beings and including predation by cats, were 1.75% of the total (3.4 million)(see chart below) (US Fish and Wildlife, 1979).  Two studies in



Australia  (Wildlife, 24 and 25) found that predatory behavior by housecats appeared largely opportunistic with respect to the availability and accessibility of prey.  Further, these studies found that the mean number of prey actually counted was less than half that estimated by owners before the survey began.  70% of the cats caught less than 10 prey over the year of the study, whereas 6% of the cats caught over 50 prey. Therefore, using averages in extrapolations is likely to substantially overestimate the number of prey caught.  Perhaps, a more systemic and comprehensive approach would be to include restricting, reviewing, or stopping human activities in natural habitats.  Development appears to be a major cause of bird deaths.  This would be a larger systemic view of the challenges.  Even Castillo noted only two examples of predation by cats during his entire study.


            Using the ‘take’ formulation that Endangered Species Act [ESA] as outlined in another article could also be applied to all situations pertaining to the number one reason why endangered species are endangered.  Development.  There is a case in Hillsborough County where a developer paid $1000 a hole to fill in 32 gopher tortoise holes.  Since only 1.75% of bird mortality can be related to cats; let us join together as a community to stop habitat loss instead trying to eradicate cats [which for reasons noted above, is short-term and doomed to failure].


            If the entire community were involved in the development and execution of just and fair laws to regulate companion animals, the solution would create a community working together to solve the issue.  The Humane Society of the United States (1998) has found that TNR programs are an effective way to build bridges between the animals, the animal care and control agencies and the public.  They further state that communities have a choice to either harness the compassion of the animal caregivers and work together to reach common goals or attempt to work against it.  By working together, the community can develop comprehensive programs that break the breeding cycle thereby stopping the prolific breeding.  As progressive states and communities across the nation have found, it takes a community to prevent overpopulation.  Punitive legislation has not worked; lets not reinvent the wheel in Florida.


TNR addresses the problem as an intrim nonlethal means until other methods are developed to address the cats that are already free-roaming. Cats-in-doors is a great theory that will never work in practice because it does not address those animals already outside. These animals will continue to breed unless something is done to interrupt the cycle. Biologists have realized that you cannot really exterminate a population unless bounties (such as was done on wolves in the western states earlier in the 20th century) are placed on the animal in question and the community gets involved.

            The Humane Society of the United States (HSUS) (1998) has found that TNR programs are an effective way to build bridges between the animals, the animal care and control agencies and the public.  They further state that communities have a choice to either harness the compassion of the animal caregivers and work together to reach common goals or attempt to work against it.  By working together, the community can develop comprehensive programs that break the breeding cycle thereby stopping the prolific breeding.  As progressive states and communities across the nation have found, it takes a community to prevent overpopulation.  Punitive legislation has not worked; let’s not reinvent the wheel in Florida.  Organizations as diverse as the ASPCA, HSUS, American Association of Feline Practitioners, American Veterinary Medical Association and Cat Fanciers Magazine do support the concept of TNR.  

Currently TNR advocates are an unpaid force that works behind the scenes to aid those free-roaming cats. If that force could be effectively harnessed and assisted (using the money currently spent on trap, remove and euthanize [$168 an animal] and the vast amounts of money being spent on cats-in-doors program) a nonlethal solution to this problem could be realized. Until then, the problem will continue to exist and caretakers will continue to work to help those animals already free-roaming.

It took a community of humans to create the situation we have now in Florida.  We need to create a community of humans working together to solve the problem.  Until that time, creating laws and trying to enforce the unenforceable will only create dissention and underground groups of people without the benefit of either legislation or financial assistance to solve the problem.

Eradication and cats-in-doors are not the answer, both have proved to be unworkable.  It is time to work together as a community to solve the problem.


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