Polarized opinions approach on Feral Cat Management

Lorden, R. (2016). Polarized Opinions and Shared Goals: Feral Cat Management in an Academic Community in Kentucky. In Companion Animals in Everyday Life (pp. 183-200). Palgrave Macmillan US.

Although there is general agreement among government agencies, conservation groups and animal welfare organizations that cat populations need to be managed, the management of cats is frequently a topic of debate between biologists/environmental groups and animal welfare/animal rights advocacy groups. The two groups’ beliefs are polarized in regard to impacts on wildlife, management strategies and efficacy of trap-and-neuter (TNR) programs. Concerns of conservation biologists relate to cats as predators, but welfare proponents feel that humans must take responsibility for free-ranging house pets and their feral offspring. It is not surprising that discussions of feral cat management become volatile. Much of the debate hinges upon whether management solutions should use lethal or non-lethal control strategies. Conservation biologists largely support cat euthanasia, while animal welfare activists support non-lethal treatments such as TNR for free-ranging cats. The issues of this larger conservancy/welfare debate framed the discourse of the cat problem and guided solution strategies at Eastern Kentucky University, where a population of cats has existed on the campus for many years. A tentative agreement has been forged between an administration that subscribed to a trap and remove policy, and a network of TNR volunteers. Both sides have focused on the common goal of a reduction in the number of campus cats. In addition, both sides have realized that each setting has its own particular constraints and that solutions must be tailored to those situations. Instead of resorting to invective, data are being collected. When well-meaning people meet and focus on solutions to a shared goal, positive outcomes become possible.

Inefficient TNR

Kilgour, R. J., Magle, S. B., Slater, M., Christian, A., Weiss, E., & DiTullio, M. (2016). Estimating free-roaming cat populations and the effects of one year Trap-Neuter-Return management effort in a highly urban area. Urban Ecosystems, 1-10.

Free-roaming cat populations are increasing in urban areas around the world. Management strategies remain controversial, as attempts to rapidly minimize the impact of cats may conflict with finding an ethical means of population reduction in this domesticated species. Trap-Neuter-Return (TNR) is a non-lethal strategy which can theoretically lead to population decline with an ethical approach. The present study aimed to estimate free-roaming cat populations and also to measure the efficacy of a one-year TNR campaign in a highly urban area. Using a sight/resight methodology, we examined free-roaming cat populations in four sites across two neighbourhoods (Harlem and Bedford-Stuyvesant) in New York City. Sampling was repeated after 1 year, during which an intensive TNR effort occurred in each of those areas. Results from this study found population estimates range from 2.6-4.1 cats/km. Additionally, we found between 78-98% turnover in each study area. After one year of TNR, the proportion of sterilised individuals in our treatment sites increased to 50%. Model results suggest there is no evidence that sterilised individuals are more likely to be encountered, indicating that sterilisation may not affect movement patterns of cats. Free-roaming cats occur at high densities at all study sites, though populations varied, even within the same neighbourhood. We found evidence of considerable migration within study sites, which further complicates the application of a sterilisation management strategy. Management strategies directed toward free-roaming cats, such as TNR, may require a broad-scale approach, involving different facets of the community and should occur over multiple years.

Urban cat ecology in Barcelona

Guerra, I. D. C. L. (2016). Ecologia urbana do gato doméstico Felis silvestris catus na cidade de Barcelona (Doctoral dissertation, Universidade Lusófona de Humanidades e Tecnologias).


Free life cats (Felis silvestris catus) are now common in urban areas and organize themselves in colonies associated with human presence and food availability. In Barcelona, there is a project of trap-neuter-return (TNR) of these cats.
From the 2013 data, a retrospective study, of the transverse observational type, was done of the free life cats and the ones with an owner. There is a direct relationship between the number of cats and the number of colonies (p = 0,004). The number of colonies is associated with the number of people (p = 0,004). Green areas, which can offer environmental resources, are directly related to the number of cats (p = 0,022) and to large colonies (p = 0,006). On the other hand, the area of the road network, which leads to habitat fragmentation, is directly associated with the number of colonies (p = 0,043) and also with small colonies (p = 0,023). Medium-sized colonies have a direct association with green areas (p = 0,035) and number of people (p = 0,026). The district area has a direct association with average-sized (p = 0,008) and large colonies (p = 0,043) as well as the number of cats (p = 0,005).

Hematological reference values for stray colony cats of northern Italy

Spada, E., Proverbio, D., Baggiani, L., Canzi, I., & Perego, R. (2016). Hematological reference values for stray colony cats of northern Italy. Comparative Clinical Pathology, 1-8.

In additional to significant dietary, lifestyle and hormonal differences, stray cats may have different hematological parameters from pet cats. The objectives of this study are to determine hematological reference intervals (RIs) from a large population of stray cats in northern Italy, to establish whether published RIs for the general pet feline population are valid in stray cats and to evaluate the effects of age and sex on hematological parameters. Hematological data were analyzed retrospectively from the database of a trap-neuter-release program (performed in 2008–2010 in northern Italy) to generate normal RIs. RIs were determined and compared with established pet cat RIs according to the National Committee for Clinical Laboratory Standard guidelines and the American Society of Veterinary Clinical Pathology guidelines. Data from 90 healthy stray cats from 17 colonies were available for determination of hematological RIs. Based on the results of comparison with published feline RIs, new RIs were proposed for RBC count, Hct, MCV, MCHC, and WBC count in stray cats. Male cats had a statistically significant higher value than did females for RBC count (mean RBC count in females 6.5 × 1012 versus 7.4 × 1012/L in males, P = 0.001), Hb (mean Hb concentration in females 9.9 versus 10.9 g/dL in males, P = 0.004), and Hct (mean Hct in females 24.8 versus 28.2 % in males, P = 0.001). Significant differences in five hematological parameters were found between stray and pet cats, for most of which the most plausible explanation is probably anesthetic effect and infections or parasitism. It can therefore be assumed that there is no need to establish a specific RI for most of the CBC variables in stray cats.

Known people affect cats' behaviour at cat colony

Damasceno, J., Genaro, G., & Terçariol, C. A. S. (2015). Effect of the presence of a person known to the cats on the feeding behavior and placement of feeders of a domestic cat colony. Journal of Veterinary Behavior: Clinical Applications and Research.

Knowledge of the organization and dynamics of the relationships between animals and the environment and its resources is important to meet the needs of any species. We analyzed the effect the presence of a person known to the cats had on their feeding behavior, and the effect of how the cats used the feeders on a colony of 35 domestic cats who lived in a sanctuary. Cats were observed for 24 hours per day for 5 days in the feeding area of the enclosure. Our results indicate that the individuals in the colony organized themselves within their feeding area, with some of these individuals using a specific feeder, whereas others used both feeders. Individuals consistently exhibited increased feeding behavior in the presence of a human who provided fresh food (View the MathML source = 4.11 ± 0.62 minutes when humans were present compared with View the MathML source = 0.17 ± 0.01 minutes when that human was absent, P < 0.0079). These data reveal that the members of the colony organized themselves to access existing resources in the environment and that the presence of a person known to the cats influences the feeding behavior of those animals. This information helps promote a potentially comfortable environment, with respect to intraspeficic relationships and the animal-human relationship, an important consideration in management of this species when living in confined environments.

Alternative approach to Feral Cat management

Rising, G. R. Feral Cat Problems: A Reconsideration of Trap-Neuter-Vaccinate-Return and An Alternative Approach.

Cat TNVR (Trap-Neuter-Vaccinate-Return) is widely proposed as a response to problems with feral cats. Unfortunately the R of that acronym, returning the cats into the environment from which they were trapped, creates serious problems: feral cat communities are established where cats are fed and protected by volunteers but otherwise continue to range free. Research shows many negative results of this: (1) these cats continue to kill birds and mammals at an alarming rate; (2) the process not only does not, as widely claimed, reduce the number of feral cats but instead often increases their population; (3) availability of the colonies encourages abandonment of additional house pets; (4) despite vaccination there are human and wildlife health risks associated with feral cats; and (5) the process is very expensive and, because the cat population is not reduced, these costs do not decline over time. A proposal for the removal of feral cats from the environment through containment is offered as an alternative.

Behavioral ecology of free‐roaming/community cats

Slater, M. R. (2015). Behavioral ecology of free‐roaming/community cats. Animal Behavior for Shelter Veterinarians and Staff, Chapter 5. Pp 102-127.

Changes of dominance on neuter and intact cats

Finkler, H., & Terkel, J. (2015). The relationship between individual behavioural styles, dominance rank and cortisol levels of cats living in urban social groups.Applied Animal Behaviour Science.

Individual animals show differences in temperament, often correlated with ecologically important behavioural patterns such as dominance, and with physiological responses to environmental perturbations, such as cortisol levels. Identifying these temperaments in animals may reveal adaptive patterns of behaviour and physiology that could be used to improve their fitness and welfare in human-controlled environments. We examined the possible relationship between individual temperaments, social dominance levels and cortisol levels in regularly fed urban groups of free-roaming domestic cats (Felis catus L.) that are routinely subjected to the Trap-Neuter-Release procedure (TNR). We designed three behavioural tests that aimed at assessing the cats’ boldness levels and determining the individual temperaments using a principle component analysis. Individual social dominance rank was determined from observations of social encounters before and during feeding. Cortisol levels were measured from hair samples collected from the cats. Significant differences were exclusive to females, with the intact females scoring higher on the boldness factor compared to the neutered females (median of 0.47 ± 0.981 and -0.168 ± 1.015, respectively, Post-hoc Chi square, P < 0.05). A positive correlation was found between cortisol levels and dominance scores in the intact females: the more dominant an individual intact female was the higher her cortisol level was (n = 14, Pearson correlation, R²= 0.592, P < 0.05). No correlation was found between dominance rank and boldness or between boldness and food dominance. In summary, our results suggest that in urban cat feeding groups, where cats are dependent on a regular food source and where their individual survival does not absolutely depend on their dominance rank, their social status was independent from their individual boldness. The differences found in the behavioural tests, between the neutered and the intact females are probably rooted in different motivation levels rather than different temperaments.

Colony cats' parasites in an urban area in N Italy

Zanzani, S. A., Gazzonis, A., Magistrelli, S., & Manfredi, M. T. (2015). Pulmonary and intestinal parasites in colony cats as markers for biodiversity in an urban area. Urban Ecosystems, 1-11.

Urban colony cats are part of the vertebrate community in urban ecosystems in the metropolitan area of Milan, Lombardy, Italy (45° 27′ N, 9° 11′ E) their management is mainly based on the practice of their capture/sterilization/release. Aims of this research, performed from May 2013 to March 2014, were to determine the qualitative and quantitative composition of endoparasitic infections in urban colony cats, the spatial distribution of infected colony cats, and the likelihood that parasites of colony cats act as markers for biodiversity in an urban ecosystem. Pulmonary and intestinal parasites were detected in feces of 35.92 % of colony cats specifically, four intestinal nematodes (Toxocara cati, Toxascaris leonina, Ancylostomatidae and Trichuris vulpis), two intestinal cestodes (Dipylidium caninum and Spirometra sp.), one intestinal protozoan (Cystoisospora sp.) and one pulmonary nematode (Aelurostrongylus abstrusus) were isolated. Infected and non-infected colony cats did not show any statistically significant difference as to their distances from the center of the city. However, in urban colony cats infected and non-infected by A. abstrusus, in cats infected and non-infected by parasites presenting an indirect life cycle (ILC) and in cats with or without multiparasitic infections were detected appreciable differences in their distances from the edges of the nearest green urban areas having different sizes. For A. abstrusus, parasites with an indirect life cycle (ILC), and multiparasitic infections, significant differences in distance from green urban areas were detected for infected vs. non-infected urban colony cats particularly, shorter distances for infected cats were observed, suggesting that cats living closer to green urban areas with higher biodiversity were more likely to be infected.

In defense of TNR

Schmidt, R. H. Cat Fight! The TNR Wars. 2012. Proc. 25th Vertebr. Pest Conf. (R. M. Timm, Ed.) Published at Univ. of Calif., Davis. 2012. Pp. 89-94.

Although trap-neuter-return (TNR) programs for feral cats are in use or being proposed in many communities, a number of non-governmental organizations have gone on record as being opposed to them. For example, The Wildlife Society’s (TWS) policy statement on feral cats (2011) includes a comment that TWS “Oppose the passage of any local or state ordinances that legalize the maintenance of “managed” (trap/neuter/release) free-ranging cat colonies.” Similarly, the American Bird Conservancy’s (ABC) resolution on free-roaming cats (feral and tamed) states that ABC “strongly opposes managed free-roaming cat colonies.” Wildlife managers often lament the loss of tools and techniques (e.g., traps, pesticides, regulatory authority) for managing “nuisance” animals. The attack against TNR programs is indicative of an active program to eliminate a management tool. Is the negativity toward TNR justified? Stated another way, do the negative aspects of TNR programs outweight any possitive elements? I argue that the complete rejection of TNR is premature, erroneous, and without merit.

Effect of high-impact targeted trap-neuter-return and adoption of community cats on cat intake to a shelter

Levy, J. K., Isaza, N. M., & Scott, K. C. (2014). Effect of high-impact targeted trap-neuter-return and adoption of community cats on cat intake to a shelter.The Veterinary Journal.

Approximately 2–3 million cats enter animal shelters annually in the United States. A large proportion of these are unowned community cats that have no one to reclaim them and may be too unsocialized for adoption. More than half of impounded cats are euthanased due to shelter crowding, shelter-acquired disease or feral behavior. Trap-neuter-return (TNR), an alternative to shelter impoundment, improves cat welfare and reduces the size of cat colonies, but has been regarded as too impractical to reduce cat populations on a larger scale or to limit shelter cat intake. The aim of this study was to assess the effect of TNR concentrated in a region of historically high cat impoundments in a Florida community. A 2-year program was implemented to capture and neuter at least 50% of the estimated community cats in a single 11.9 km² zip code area, followed by return to the neighborhood or adoption. Trends in shelter cat intake from the target zip code were compared to the rest of the county.

A total of 2366 cats, representing approximately 54% of the projected community cat population in the targeted area, were captured for the TNR program over the 2-year study period. After 2 years, per capita shelter intake was 3.5-fold higher and per capita shelter euthanasia was 17.5-fold higher in the non-target area than in the target area. Shelter cat impoundment from the target area where 60 cats/1000 residents were neutered annually decreased by 66% during the 2-year study period, compared to a decrease of 12% in the non-target area, where only 12 cats/1000 residents were neutered annually. High-impact TNR combined with the adoption of socialized cats and nuisance resolution counseling for residents is an effective tool for reducing shelter cat intake.

Impact of hysterectomy in an urban cat colony

Mendes-de-Almeida, F., Faria, M. C. F., Landau-Remy, G., Branco, A. S., Barata, P., Chame, M., Salim Pereira, M.J. & Labarthe, N., 2006. The Impact of Hysterectomy in an Urban Colony of Domestic Cats (Felis catus Linnaeus, 1758). International Journal of Applied Research in Veterinary Medicine. 4(2): 134–141. 

The easiness with which urban cats form colonies and the exponential growth of these populations are a challenge for all known population control methods. The zoological garden of Rio de Janeiro (RIO- ZOO) has been dealing unsuccessfully with the issue of stray cat populations for more than 10 years. For this reason, it was decided to investigate the structure and composition of the colony of cats populating the RIOZOO and to observe, during 36 months, the impact of hysterectomy of adults, with conservation of the gonads, as a means of population control. Hysterectomy was meant to be performed biennially, though at the beginning of the program, it was performed yearly for 2 consecutive years. The total size of the colony was estimated each year using the capture-mark-recapture tech- nique. During the study's entirety, a total of 96 cats, 80 adults and 16 kittens, were caught. The yearly population estimate of cats showed that between the years 2001 and 2004, the population stopped to grow, strongly tending to decrease. The conservation of the gonads of all animals adding to the fact that no individuals were removed preserved the natural social behavior of the cats living in the colony. Thus, after 2 consecutive years of submitting captured adult females to hysterectomy, planned biennial interventions constitute an animal welfare- friendly, effective model for controlling the urban population of cats that can be proposed to public health authorities as an alternative to the traditional capture and culling in Brazil

Reduction of feral cat colony size following hysterectomy of adult female cats

Mendes-de-Almeida, F., Remy, G. L., Gershony, L. C., Rodrigues, D. P., Chame, M., & Labarthe, N. V. (2011). Reduction of feral cat (Felis catus Linnaeus 1758) colony size following hysterectomy of adult female cats. Journal of feline medicine and surgery, 13(6), 436-440.

The size of urban cat colonies is limited only by the availability of food and shelter; therefore, their population growth challenges all known population control programs. To test a new population control method, a free-roaming feral cat colony at the Zoological Park in the city of Rio de Janeiro was studied, beginning in 2001. The novel method consisted of performing a hysterectomy on all captured female cats over 6 months of age. To estimate the size of the colony and compare population from year to year, a method of capture-mark-release-recapture was used. The aim was to capture as many individuals as possible, including cats of all ages and gender to estimate numbers of cats in all population categories. Results indicated that the feral cat population remained constant from 2001 to 2004. From 2004 to 2008, the hysterectomy program and population estimates were performed every other year (2006 and 2008). The population was estimated to be 40 cats in 2004, 26 in 2006, and 17 cats in 2008. Although pathogens tend to infect more individuals as the population grows older and maintains natural behavior, these results show that free-roaming feral cat colonies could have their population controlled by a biannual program that focuses on hysterectomy of sexually active female cats.

Management recommendations for feral cat within an urban conservancy in South Africa

Tennent, J., Downs, C.T., & Bodasing, M. 2009. Management Recommendations for Feral Cat (Felis catus) Populations Within an Urban Conservancy in KwaZulu-Natal, South Africa. South African Journal of Wildlife Research. 39(2): 137–142.

The ability of cats (Felis catus) to colonize most land habitats worldwide led to an increasing number of feral cat populations in many areas where food resources are easily available. High densities of feral cats in urban areas, particularly in conservancies, have the potential to impact negatively on both human and local wildlife populations. Of particular interest was the Howard College Campus of the University of KwaZulu-Natal, a registered conservancy where there are differing opinions concerning the resident feral cat population. Consequently methods of controlling feral cat populations and the implications of these methods were reviewed. Despite various methods of feral cat population control existing there are two basic categories: either eradication or reproductive regulation. It is suggested that to control the feral cat population effectively in this urban conservancy, a suitable and ongoing sterilization programme, that is run in conjunction with a feral cat feeding programme, needs to be Implemented. Both programmes need to be long-term and overseen by management. The feral cat population needs to be maintained at a level that allows the lowest migration rate into the conservancy, as well as a predation rate that will not negatively affect the resident wildlife populations. This may require some removal of feral cats at the start of a programme. Whatever management actions are followed, a monitoring programme must be put in place to document how effective the actions are.

Urban cat density more depending on shelter than on food

Calhoon, R.E. & Haspel, C. 1989. Urban Cat Populations Compared by Season, Subhabitat and Supplemental Feeding. Journal of Animal Ecology. 58(1): 321–328.

(1) Population densities of free-ranging cats were compared in two contiguous urban subhabitats, in three seasons, and in response to supplemental feeding.

(2) One subhabitat, characterized by voluminous, poorly contained refuse, and many abandoned buildings, supported 4.88 +- 0.82 cats ha-1 (mean +- S.D.), which differed significantly from the 2.03 +- 0.2 cats/ha supported by the other subhabitat (partial refuse containment, few abandoned buildings). 

(3) Neither season nor supplemental feeding had a significant effect on population density. 

(4) The distribution of individuals within the study area varied with the availability of shelter and was not dependent upon food.

Social behaviour in a large multi-male cat colony

Natoli, E., & De Vito, E. (1991). Agonistic behaviour, dominance rank and copulatory success in a large multi-male feral cat, Felis catus L., colony in central Rome. Animal Behaviour, 42(2), 227-241.

The mating strategies of male and female feral cats living in a large urban colony were analysed. The distribution of males around the female being courted, the agonistic and copulatory behaviour patterns of 19 males belonging to the group studied and the copulatory behaviour of 15 females of the same group, were investigated. A linear dominance hierarchy based on the outcome of agonistic encounters was found among males. It did not correlate with copulatory success. Courting males did not fight around the female in oestrus. The optimal mating strategies of male and female cats conflict: females would do best to copulate with more than one male, whereas males should monopolize the female and guard her from other males. In this study, however, females mated polygamously but males did not attempt to monopolize females. Possible explanations for this obscure male behaviour are given.

‘Community cats' are a community hazard

The terms "feral" and "stray cat" are no longer politically correct. "Trap-neuter-and release" advocates demand we henceforth refer to abandoned and wild-born Felis domesticus as "community cats." For honesty's sake, I propose they be called "invasive species" -- because that's what they are, no more and no less. TNR proponents argue it's our duty to assume "community ownership" of deleterious invasive species populations...

via Anchorage Daily News

Read more here: http://www.adn.com/2014/07/06/3548197/community-cats-are-a-community.html?sp=/99/328/#storylink=cpy

The welfare of feral cats

Slater, M. R. (2007). The welfare of feral cats. In The welfare of cats (pp. 141-175). Springer Netherlands.

The  control of feral cats is a controversial issue in many countries, due to the differences in the way humans perceive cats in general and feral cats in particular. As cats spread into a wide rage of habitats, there are concerns regarding the best methods to control their numbers. Predation on wildlife, public health and zoonotic diseases, as well as the welfare of the cats themselves, are issues that drive the need to control the feral cat population. Killing the cats, or letting nature take its course, were the usual historical approaches but in recent years non-lethal methods have been espoused as being more humane and effective. Effors have been made to improve the welfare of feral cat populations through sterilization, the control of infectious disease and ensuring that they are adequately cared for. A combination of approaches are necessary to decrease feral cat numbers, to prevent influx of owned cats into the populations, and to manage established feral cat colonies successfully.

Feeding cats deplates native fauna

Hawkins, C.C., W.E. Grant & M.T. Longnecker. 1999. Effect of subsidized house cats on California birds and rodents. Transactions of the Western Section of The Wildlife Society, 35: 29-33

Cat advocates are establishing feeding stations in public parks, often claiming that well-fed cats pose little threat to wildlife. This claim was tested east of San Francisco, California, in a cat area and a no-cat area. In 1995, more harvest mice were trapped in the no-cat area. In 1996, more harvest mice (Reithrodontomys megalotis) and deer mice (Peromyscus sp.) were trapped in the no-cat area, and more house mice were trapped in the cat area. The numbers of trapped California meadow voles (Microtus californicus) were not different between the areas in either year. More native rodents were trapped in the no-cat area. Birds present during the breeding season were seen more often in the no-cat area. California quail (Callipepla californicus) and California thrashers (Toxostoma redivivum) were present in the no-cat area and absent in the cat area. Cats at artificially high densities, sustained by supplementary feeding, reduced the abundance or native rodent and bird populations, changed the rodent species composition, and may have facilitated the expansion of the house mouse into new areas. Thus we recommend that the feeding of cats in parks should be strictly prohibited. 

Cats, Toxoplasma and public health

Dabritz, H. A., & Conrad, P. A. (2010). Cats and Toxoplasma: implications for public health. Zoonoses and Public Health, 57(1), 34-52.

Cats are popular as pets worldwide because they are easy to care for and provide companionship that enriches the lives of human beings. Little attention has been focused on their potential to contaminate the environment with zoonotic pathogens. One such pathogen, the protozoan parasite Toxoplasma gondii, rarely causes clinical manifestations in cats or immunocompetent humans; however, it can have serious adverse effects on human foetuses and immunocompromised patients. Many human infections are believed to be acquired from eating undercooked or raw meat, such as pork and lamb (Tenter et al., 2000; Dubey et al., 2005). However, the prevalence of T. gondii infection in human populations that do not consume meat or eat it well-cooked suggests that the acquisition of infection from the environment, via oocysts in soil, water or on uncooked vegetables, is also important (Rawal, 1959; Roghmann et al., 1999; Chacin-Bonilla et al., 2001). In the past 20 years, two changes occurred that significantly increased the size of the cat population in the USA. Pet cat ownership grew from 50 million to 90 million animals, and animal welfare activists created feeding stations for abandoned and free-roaming cats. As many cat owners allow their cats to deposit faeces outside and cats maintained in colonies always defecate outside, ample opportunity exists for T. gondii oocysts to enter the environment and be transmitted to humans. Prevention efforts should focus on educating cat owners about the importance of collecting cat faeces in litter boxes, spaying owned cats to reduce overpopulation, reducing the numbers of feral cats and promoting rigorous hand hygiene after gardening or soil contact.