Camera trapping of college's feral cats

Bainum, III,M., K.E. Sieving, R. McCleery, & D Wald.2015. Demonstrating camera trap techniques and their application for identifying feral cats across a college campus. University of Florida-Journal of Undergraduate Research, 16 (3)

Urban and suburban wildlife can be difficult to study through traditional wildlife techniques using direct, in situ human involvement. The use of remote sensing technology like trip cameras (or camera traps) can allow researchers to obtain high quality photographs of target species to be used to confirm the presence of species and even indentify individuals of a local population. A study at the University of Florida campus employed eight camera traps at four sampling locations to attempt to identify individuals of the feral cat (Felis catus) population as well as survey local mesopredator diversity. High-resolution photographs were used to select distinguishing characteristics of each cat in order to assign it an identification code and determine if individuals were moving among the sampling sites. Ten individuals were identified out of 118 total photographs with confirmed feral cat appearances. Only one individual appeared at more than one sampling site. The trip cameras captured photo evidence of four other species, all of which appeared at sites alongside cats suggesting some degree of resource competition may exist between these opportunistic predators. 

Different perception of stray cat risks in Florida and Hawaii

Wald, D.M. & C.A. Lohr. 2015. A comparison of cat-related risk perceptions and tolerance for outdoor cats in Florida and Hawaii. Conservation Biology doi: 10.1111/cobi.12671


Perceptions of risk and attitudes toward animals predict tolerance for wildlife and management preferences. Little is currently known about how these relationships vary across different geographic regions and interest groups. In this study, we combined data collected independently in two different states that are recognized centers of the outdoor cat management debate (Florida and Hawaii). We then identified differences in tolerance for outdoor cats and risk perceptions between key interest groups and the public using a consistent methodology to draw conclusions about how public perception of the risks presented by outdoor cats, group membership and state of residence influenced people's tolerance for outdoor cat populations across widely separated geographical, cultural, and political regions. Our results indicate that there were significant State and group differences in tolerance for outdoor cats, perceived cat-related risks, and experiences with outdoor cats. Our findings suggest that public tolerance for cats is susceptible to the influence of local or geographical concerns; but strongly held beliefs, risk perceptions and feelings about cats are more important predictors of stakeholder tolerance.

Resolving the urban nest predator paradox: the role of alternative foods for nest predators

Stracey, C. M. (2011). Resolving the urban nest predator paradox: the role of alternative foods for nest predators. Biological Conservation, 144(5), 1545-1552.

Urbanization is a leading cause of species endangerment in the United States; however, certain species thrive in urban habitats. The loss of key predators or the addition of new predators in urban areas could alter the structure of urban communities. A reduction in nest predation is hypothesized to explain the high density of urban birds, yet urban areas typically have increased populations of avian nest predators. The loss of important nest predators in urban habitats, prey switching of urban predators, or successful nest defense against avian nest predators could explain this urban nest predator paradox. To assess these hypotheses I compared nest predation rates of Northern mockingbirds (Mimus polyglottos) in parking lots and residential neighborhoods to populations in pastures and wildlife preserves during 2007–2009 in Florida, USA and placed video cameras on a subset of nests in 2008–2009. Data do not support the hypothesis that urban nest predation rates are consistently lower than non-urban nest predation rates. Of the 56 nest predation events recorded, cats were the dominant urban predator and Cooper’s hawks (Accipiter cooperii) were the dominant non-urban predator. There was no evidence for a loss of important nest predators in urban habitats; however, prey switching by Cooper’s hawks likely occurred. There was also indirect evidence for the importance of nest defense. Furthermore, some of the cats recorded as nest predators in residential neighborhoods were owned cats and all but one cat predation event occurred at night. To reduce nest predation rates, cat owners should keep their cats indoors at night.

Feral cat vaccination and TNR

Fischer, S.M., C.M. Quest, E. J. Dubovi, R. D. Davis, S.J. Tucker, J.A. Friary, P.C. Crawford, T. A. Ricke, & J.K. Levy. (2007) Response of feral cats to vaccination at the time of neutering. Journal of the American Veterinary Medical Association 230 (1): 52-58

Objective—To determine whether administration of inactivated virus or modified-live virus (MLV) vaccines to feral cats at the time of neutering induces protective serum antiviral antibody titers.

Design—Prospective study.

Animals—61 feral cats included in a trap-neuter-return program in Florida.

Procedures—Each cat received vaccines against feline panleukopenia virus (FPV), feline herpes virus (FHV), feline calicivirus (FCV), FeLV, and rabies virus (RV). Immediately on completion of surgery, vaccines that contained inactivated RV and FeLV antigens and either MLV or inactivated FPV, FHV, and FCV antigens were administered. Titers of antiviral antibodies (except those against FeLV) were assessed in serum samples obtained immediately prior to surgery and approximately 10 weeks later.

Results—Prior to vaccination, some of the cats had protective serum antibody titers against FPV (33%), FHV (21%), FCV (64%), and RV (3%). Following vaccination, the overall proportion of cats with protective serum antiviral antibody titers increased (FPV [90%], FHV [56%], FCV [93%], and RV [98%]). With the exception of the FHV vaccine, there were no differences in the proportions of cats protected with inactivated virus versus MLV vaccines.

Conclusions and Clinical Relevance—Results suggest that exposure to FPV, FHV, and FCV is common among feral cats and that a high proportion of cats are susceptible to RV infection. Feral cats appeared to have an excellent immune response following vaccination at the time of neutering. Incorporation of vaccination into trap-neuter-return programs is likely to protect the health of individual cats and possibly reduce the disease burden in the community.

Prevalence of pathogens in feral cats in Florida

Luria, B. J., Levy, J. K., Lappin, M. R., Breitschwerdt, E. B., Legendre, A. M., Hernandez, J. A., Gorman, S.P. & Lee, I. T. (2004). Prevalence of infectious diseases in feral cats in Northern Florida. Journal of Feline Medicine and Surgery, 6(5), 287-296.

Objectives of this study were to determine prevalence of infection in feral cats in Northern Florida with a select group of infectious organisms and to determine risk factors for infection. Blood samples or sera from 553 cats were tested with a panel of antibody, antigen or PCR assays. Male cats were at higher risk for FIV, Mycoplasma haemofelis, and M. haemominutum. Infection with either FeLV or FIV was associated with increased risk for coinfection with the other retrovirus, M. haemofelis, or M. haemominutum. Bartonella henselae had the highest prevalence and was the only organism that did not have any associated risk for coinfection with other organisms. Feral cats in this study had similar or lower prevalence rates of infections than those published for pet cats in the United States. Thus, feral cats assessed in this study appear to be of no greater risk to human beings or other cats than pet cats.

Two examples of cat colony management in Texas and in Florida

Hughes, K. L., & Slater, M. R. (2002). Implementation of a feral cat management program on a university campus. Journal of Applied Animal Welfare Science, 5(1), 15-28.

In August 1998, Texas A&M University implemented on campus a trap-test-vaccinate-alter-return-monitor (TTVARM) program to manage the feral cat population. TTVARM is an internationally recognized term for trapping and neutering programs aimed at management of feral cat populations. In this article we summarize results of the program for the period August 1998 to July 2000. In surgery laboratories, senior veterinary students examined cats that were humanely trapped once a month and tested them for feline leukemia and feline immunodeficiency virus infections, vaccinated, and surgically neutered them. They euthanized cats testing positive for either infectious disease. Volunteers provided food and observed the cats that were returned to their capture sites on campus and maintained in managed colonies. The program placed kittens and tame cats for adoption; cats totaled 158. Of the majority of 158 captured cats, there were less kittens caught in Year 2 than in Year 1. The proportion of tame cats trapped was significantly greater in Year 2 than in Year 1. The prevalence found for feline leukemia and feline immunodeficiency virus ELISA test positives was 5.8% and 6.5%, respectively. Following surgery, 101 cats returned to campus. The project recaptured, retested, and revaccinated more than one-fourth of the cats due for their annual vaccinations. The program placed 32 kittens, juveniles, and tame adults for adoption. The number of cat complaints received by the university's pest control service decreased from Year 1 to Year 2.

Hughes, K. L., Slater, M. R., & Haller, L. (2002). The effects of implementing a feral cat spay/neuter program in a Florida county animal control service. Journal of Applied Animal Welfare Science, 5(4), 285-298.

In 1995, a county animal control service implemented a feral cat sterilization program with the goal of reducing the number of healthy cats euthanized, complaints, and the county's costs. Theservice collected data from a 6-year period both before and after the program's implementation. The service totaled the numbers of both cat and dog impoundments, surgeries, adoptions, euthanasias, and complaints for each year; standardized both sets of numbers on a per- 10,000-person basis to compare trends between dogs and cats; and calculated estimated costs for neutering versus impounding and euthanizing the feral cats. Changing from a policy of euthanasia of feral cats to support for trap-neuter-return did not result in an increase in the number of complaints or cat impoundments. The percentage of impounded cats euthanized decreased between the periods before and after the program began, and the percentage adopted increased. The ratio of complaints to impounds decreased between the 2 periods, and the ratio of surgeries to impounds increased. Impoundments of cats were relatively steady in spite of the continually increasing human population. Euthanasias decreased for both cats and dogs since 1997. Since 1996, complaints decreased for both. Surgeries for both cats and dogs increased over the 12 years. Adoptions for cats and dogs increased greatly in fiscal year 1998/1999.

Perceptions on outdoor cats

Wald, D. M., Jacobson, S. K., & Levy, J. K. (2013). Outdoor cats: Identifying differences between stakeholder beliefs, perceived impacts, risk and management. Biological Conservation, 167: 414-424.

Conflict over the management of outdoor cats has contributed to debate between animal welfare and wildlife advocates and stymied efforts to control outdoor cats. We distributed a mail survey to a random sample of participants in Trap-Neuter-Return programs for outdoor cats, Audubon Society members and the public across four counties in Florida (N = 1363) to identify differences between these stakeholders’ perceptions and support for the management of outdoor cats. We used a perception of risk framework to evaluate group differences in attitudes and beliefs about outdoor cats, perceptions of positive and negative impacts, ecological risk perceptions, and support for management options. Multivariate Analysis of Variance results indicated significant differences between groups across all of our measured scales. Discriminant Function Analysis helped identify two distinct groups; explaining 79% and 21% of the variance between groups. Group membership was predicted by cat ownership, attitudes toward and beliefs about outdoor cats, perceived impacts, risk perceptions, and management attitudes. This research is the first to explore differences in cognitions and preferences related to outdoor cat management with three important stakeholder groups. To reduce response bias, our survey included both positive and negative impact items and neutral terminology. Our findings suggest that surveys, based solely on public opinions about outdoor cats, do not reflect the diversity of opinion of all relevant stakeholder groups.

TNR ineffective in controlling cat colonies

Castillo, D. and Clarke, A.L. 2003. Trap/neuter/release methods ineffective in controlling domestic cat "colonies" on public lands. Natural Areas Journal. 23 (3): 247-253. 

Domestic cat (Felis catus L.) advocates have formed coalitions whose goals are to promote the welfare of cats through the use of a specific nonlethal population control method. This method consists of trapping, neutering. and releasing cats into supervised cat colonies located on private and public lands, including state and county parks and natural areas. Advocates believe that this method will help reduce the number of unwanted cats and stabilize the population of unwanted cats over time. Furthermore, advocates claim that established colonies are temporary in nature and will decrease in size over time through death and adoption. This claim was tested through photographic and observational capture-recapture technique.~ in Miami-Dade County, Florida, USA, in two Metro-Dade County parks (A. D. Barnes Park and Crandon Marina). Although the number of original colony members decreased over time, illegal dumping of unwanted cats and the attraction of stray cats to provisioned food offset reductions in cat numbers caused by death and adoption. Furthermore, overall population size of the colony at A. D. Barnes Park increased over time, and at Crandon Marina neither decreased nor increased over time. Our study suggests that this method is not an effective means to control the population of unwanted cats and confirms that the establishment of cat colonies on public lands encourages illegal dumping and creates an attractive nuisance. We recommend that advocates of cat colonies seek a longterm solution to the pet overpopulation issue by redirecting their efforts toward the underlying problem of managing irresponsible pet owners.

Conservation in Florida Keys campaign

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PVA supports cats' control to manage endangered mammal

Forys, E. A., & Humphrey, S. R. (1999). Use of population viability analysis to evaluate management options for the endangered Lower Keys marsh rabbit. The Journal of wildlife management, 251-260.

We conducted a population viability analysis (PVA) for the federally endangered Lower Keys marsh rabbit (Sylvilagus palustris hefneri). We estimated parameters via livetrapping, radiotelemetry, and fecal-pellet counting during a 2.5-year study. Historically, this subspecies ranged throughout the Lower Keys of Florida, but today the marsh rabbit is limited to 41 subpopulations occurring in 3 distinct metapopulations. To evaluate this subspecies' risk of extinction, we used VORTEX, a simulation modeling program, that combined deterministic and stochastic birth and death events, differing migration rates based on spatially explicit patch structure, and extinction and recolonization. Our simulation calculated the chance that each metapopulation would go extinct under current conditions and several management scenarios. Under current conditions, the model predicted there is a 100% chance that all metapopulations will go extinct. The metapopulation with many small patches went extinct faster than the metapopulations with fewer, larger patches. The most effective strategy to decrease the risk of extinction of all 3 metapopulations was to increase the survival rate in several age and sex classes by eliminating predation by domestic cats.

Population dynamics of a population of free roaming cats

Taylor, B. (2013). Population Dynamics of Free-Roaming Cats in Florida's Lee County. Undergraduate Journal of Mathematical Modeling: One+ Two, 3(1), 16.

We investigate whether the Trap-Neuter-Return (TNR) program can be effectively used to control the population of free-roaming cats in Florida's Lee County. We do this by estimating the number of cats that must be spayed/neutered in order to keep the population from increasing.

Our analysis shows that keeping the population of free-roaming cats in Lee County (98,000 individuals) from growing requires spaying/neutering of at least 370 cats per week. We suspect that this estimate is high because the model we considered is density independent. Nevertheless our results underline the rate at which the cat population can explode if not properly controlled.

Two papers on cat colonies and TNR

Levy, J. K., Gale, D. W., & Gale, L. A. (2003). 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, 222(1), 42-46.

Objective—To evaluate the effect of a long-term trapneuter-return program, with adoption whenever possible, on the dynamics of a free-roaming cat population.

Design—Observational epidemiologic study.

Animals—155 unowned free-roaming cats.

Procedures—Free-roaming cats residing on a university campus were trapped, neutered, and returned to the environment or adopted over an 11-year period.

Results—During the observation period (January 1991 to April 2002), 75% of the cats were feral, and 25% were socialized. Kittens comprised 56% of the original population. Male cats were slightly more numerous (55%) than females. At the conclusion of the observation period, 47% of the cats had been removed for adoption, 15% remained on site, 15% had disappeared, 11% were euthanatized, 6% had died, and 6% had moved to the surrounding wooded environment. Trapping began in 1991; however, a complete census of cats was not completed until 1996, at which time 68 cats resided on site. At completion of the study in 2002, the population had decreased by 66%, from 68 to 23 cats (of which 22 were feral). No kittens were observed on site after 1995, but additional stray or abandoned cats continued to become resident. New arrivals were neutered or adopted before they could reproduce.

Conclusions and Clinical Relevance—A comprehensive long-term program of neutering followed by adoption or return to the resident colony can result in reduction of free-roaming cat populations in urban areas.

Foley, P., Foley, J. E., Levy, J. K., & Paik, T. (2005). Analysis of the impact of trap-neuter-return programs on populations of feral cats. Journal of the American Veterinary Medical Association, 227(11), 1775-1781.

Objective—To evaluate 2 county trap-neuter-return (TNR) programs for feral cat population management via mathematical modeling.

Design—Theoretical population model.

Animals—Feral cats assessed from 1992 to 2003 in San Diego County, California (n = 14,452), and from 1998 to 2004 in Alachua County, Florida (11,822).

Procedure—Data were analyzed with a mathematical Ricker model to describe population dynamics of the feral cats and modifications to the dynamics that occurred as a result of the TNR programs.

Results—In both counties, results of analyses did not indicate a consistent reduction in per capita growth, the population multiplier, or the proportion of female cats that were pregnant.

Conclusions and Clinical Relevance—Success of feral cat management programs that use TNR can be monitored with an easily collected set of data and statistical analyses facilitated by population modeling techniques. Results may be used to suggest possible future monitoring and modification of TNR programs, which could result in greater success controlling and reducing feral cat populations.