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.

Ecology of stray dogs in the Republic of Karelia

Sedova, N. 2014. Ecology of stray dogs in the Republic of Karelia. 9th Baltic Theriological Conference. Book of Abstracts, p. 73. Daugavpils, 16 – 18 October, 2014

The study was carried out between 2002-2007 in three cities in Karelia: Petrozavodsk, Belomorsk and Kostamuksha. During this period 669 dogs were censused in Petrozavodsk, 162 dogs in Belomorsk and 82 dogs in Kostamuksha.
Depending on the nature of owner control and the degree of socialization we distinguished three types of stray dogs; these were «neglected pets», «homeless» and «feral». In Petrozavodsk there were 232 individuals of the first type, 669 of the second type and about 20 of the third type. In Kostamuksha and Belomorsk numbers of «neglected pets» were 148 and 40 individuals respectively. «homeless» dogs were 162 and 82 individuals respectively, and «feral» dogs were not found. In the research we have identified 135 morphotypes of dogs in Petrozavodsk, and of these the dominant type is so called «laykoid» of black color, medium height, short-haired, upstanding ears with a log-like form tail (wolf form). In Kostamuksha there were 48 morphotypes identified and 58 in Belomorsk. Comparing between these cities has explored the same morphotype of stray dogs – red colored «laykoid», medium height, short-haired, upstanding ears and log-like tail.
The spatial structure of the stray dogs’ population in Petrozavodsk is characterized by aggregated distribution. It is expressed as a formation of various groups with large unpopulated areas between. For the packs in the industrial territories, small home ranges size (0.02 - 0.1 km²) were typical, with a low degree of variability within this. In residential territories the home range sizes did not exceed the foresaid (0.02 - 0.1 km²). Grouped distribution is mostly typical in the industrial territories where 75% of all dogs were gregarious. For residential territories solitary individuals were mainly typical: in Petrozavodsk - 90%, in Kostamuksha - 100 %, and in Belomorsk - 100%. However, packs did sometimes occur.
All contact of stray dogs with other species can be reduced to direct contact and mediated interaction. By direct contact the dogs demonstrate active predatory behaviour, or research activity. Mediated interaction can be described as commensalism, for instance when dogs consume cats - the main predators of rats in towns, as well as improve access of rodents and birds to feed. Competitive relations of stray dogs with other animals have not been identified.
The average number of stray dogs in Petrozavodsk was about 36.8 ind/ km² (1300 individuals in total). Analysis of number dynamics (2003-2007) showed that annual differences are insignificant. Changes tended to be small, indicating numbers to be fairly stable. The average number of stray dogs in Kostamuksha is 1.22 ind/km², and in Belomorsk - 5.91 ind/ km².
Analysis of samples within 2003-2007 showed that in Petrozavodsk the overall sex ratio among adults is 1:1. In Belomorsk and Kostamuksha there is a predominance of males. One explanation behind this is that the number of stray dogs are replenished by negelected domestic dogs, which are dominated by males.
In general the stray dog population within the studied cities was characterised by low numbers. One can also note the dependence of dog number on the area and layout of the city. The high numbers of neglected dogs observed in the streets indicates a culture of low pet care.

Increasing impact of feral dogs on wild ungulates in Urals

Korytin, N,, V. Bolshakov & N. Markov. 2014. Effect of mammalian predator on the populations of ungulates in Middle Urals. 9th Baltic Theriological Conference. Book of Abstracts, Daugavpils, 16 – 18 October, 2014

Wild ungulates are the main food source for large carnivores in Russia and particularly in Urals. Here we present the results of the analysis of the effect of carnivores on ungulates populations according to the official statistics of ungulate mortality not related to legal hunting (“natural” mortality). Predation of wolf accounts for 16 and 19% of wild boar and moose mortality respectively, for the pair “lynx” – “Siberian roe deer” this index equals 19%. Another important predator of roe deer is feral dogs. Their impact on ungulate populations has increased in recent years. Prey preferences differ between predators. The proportion of young among animals killed by feral dogs is higher than that for other carnivores.

The role of veterinary epidemiology in the study of free-roaming dogs and cats

Slater, M. R. (2001). The role of veterinary epidemiology in the study of free-roaming dogs and cats. Preventive veterinary medicine, 48(4), 273-286.

Free-roaming dogs or cats are domestic dogs and cats that are not confined to a yard or house. Free-roaming dogs and cats have long caused major public-health problems and animal-welfare concerns in many countries. Free-roaming dogs have been considered to be more of a problem than cats for several reasons, but the literature addressing dogs focuses primarily on their role in rabies spread and control. Free-roaming cats are becoming more of an issue in countries where free-roaming dog problems are coming under control. The change in perception of pets, beyond their value as a commodity, has also contributed to the increase in concern and attention focused on free-roaming dogs and cats. Epidemiologists have contributed much to these studies of these populations and have potential to contribute even more. The epidemiologic methods and approaches, the experience of epidemiologists in interdisciplinary teams and the importance of considering the separate sub-populations in study design and analysis all are critical in designing and evaluating interventions for free-roaming dogs and cats. In this paper, I will (1) describe a set of useful definitions regarding free-roaming dogs and cats, (2) summarize past and present topics of study in free-roaming dogs and cats, using selected examples, (3) describe the limitations of existing work and how epidemiologists might strengthen and improve this work, and (4) outline areas needing more attention by epidemiologists and why these are important.

Feral cat behaviour influence monitoring techniques and control methods

Fisher, P., Algar, D., Murphy, E., Johnston, M., & Eason, C. (2014). How does cat behaviour influence the development and implementation of monitoring techniques and lethal control methods for feral cats?. Applied Animal Behaviour Science.

Highlights
•Feral cats utilise the ‘wild’ end of the predatory and social behavioural spectrum of Felis catus.
•Efficacy in lethal control of feral cats is strongly influenced by prey resources.
•Cryptic habits and low densities in large remote areas make feral cat behaviour difficult to study.

Abstract
The need for lethal control of feral cats will remain in some contexts and potentially increase in others, alongside an obligation to develop and apply methods that are as cost-effective, humane and target-specific as possible. Drawing on practices particularly used in Australia, New Zealand and on offshore islands we review current lethal techniques applied for feral cat removal, such as shooting, trapping and poison baiting, and how our understanding of feral cat behaviour has influenced their development and application.

Attitudes of residents and tourists towards stray dogs in Samoa

Farnworth, M., Blaszak, K., Hiby, E. F., & Waran, N. K. (2012). Incidence of dog bites and public attitudes towards dog care and management in Samoa. Animal welfare. 21 : 477-486.

In many developing nations, dogs (Canis familiaris) present a significant issue in terms of human health, safety and animal welfare. We assessed attitudes towards dogs and their management in Samoa, a developing South Pacific island nation, using a questionnaire. It demonstrated that Samoa has one of the world’s highest recorded levels of household dog ownership (88%) but a comparatively low rate of vaccination (12%) and sterilisation (19%). Those interviewed believe dogs were important and should be considered part of the family; however most households reported that their dogs were kept for protection (79%). There was a clear skew in the sex distribution. The dog population showed a strong male bias (71%) suggesting females are removed from the population. Of those surveyed only 16% had received any education about dogs and their management and overall the respondents showed a clear disparity between attitudes and behaviour (eg the majority believe dogs should be vaccinated [81%] yet most dogs in this sample [72%] had never been to a veterinarian). Overall, there was a willingness to manage the free-roaming dog population which was considered by many to be a nuisance, however there were few enforceable mechanisms by which this could occur and most dogs were not confined. Harm or killing of dogs was relatively commonplace with 30% of households reporting they knew someone who had harmed or killed a dog and 26% of respondents indicating they believed harming or killing dogs was good for Samoan society, presumably by reducing problems associated with the free-roaming population. Dog bites were relatively frequent in Samoa and reports from two hospitals indicated a frequency of 37 new bites per annum requiring hospitalisation per 10,000 head of population. Furthermore, this paper outlines strategies and further research that could be considered to improve dog welfare and reduce the need to harm or kill dogs, namely improvements in veterinary provision and dog-focused education. It also considers the need for legislative controls and more research and funding to be made available for small developing nations to explore their animal welfare obligations.

Beckman, M., Hill, K. E., Farnworth, M. J., Bolwell, C. F., Bridges, J., & Acke, E. (2014). Tourists’ Perceptions of the Free-Roaming Dog Population in Samoa.Animals, 4(4), 599-611.

Simple Summary: For travelers, the way in which people in other nations interact with animals may be different to that in their home nation. This research explores how the treatment of dogs impacted upon the holiday experiences of tourists visiting a developing island nation. In general, and where tourists encountered dogs, their treatment was perceived as less positive than in their home country and had a negative impact upon the holiday experience. Although it is important to recognize that the local population will have a different worldview, tourists felt that the dog population required more effective management and were most supportive of techniques that were non-lethal and humane.
Abstract: A study was undertaken to establish how visiting tourists to Samoa perceived free-roaming dogs (Canis familiaris) and their management, additionally some factors that influence their perceptions were assessed. Questionnaires were administered to 281 tourists across Samoa over 5 weeks. Free-roaming dogs were seen by 98.2% (n = 269/274) of respondents, with 64.9% (n = 137/211) reporting that their presence had a negative effect on overall holiday experience. Respondents staying in the Apia (capital city) area were more likely to consider dogs a problem (p < 0.0001), and there was a significant association between whether the respondent owned a dog and if they thought dogs were a nuisance in Samoa (p < 0.003). Forty-four percent (20/89) of non-dog owners agreed that dogs were a nuisance compared to 22% (80/182) of dog owners. The majority felt that dogs required better control and management in Samoa (81%, n = 222) and that there were too many “stray” dogs (67.9%, n = 188). More respondents were negatively affected by the dogs’ presence (64.9%, 137/211), and felt that the dogs made their holiday worse, than respondents that felt the dogs’ presence improved their holiday experience (35.1%, 74/211). Most respondents stated that the dogs had a low impact (one to three; 68%, 187/275) on their stay in Samoa, whilst 24% (65/275) and 8% (23/275) stated they had a medium or high impact, respectively, on their stay. Respondents showed strong support for humane population management. Free-roaming dogs present a complex problem for Samoa and for its tourism industry in particular. The findings of this study further support the need for more discussion and action about the provision of veterinary services and population management for dogs in Samoa. It also provides information complementing an earlier study of the attitudes of local Samoans.

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Conservation solutions regarding owned outdoor cats

Gramza, A. (2014). Applying social science to inform conservation solutions regarding owned outdoor cats in urbanizing landscapes (Doctoral dissertation, COLORADO STATE UNIVERSITY).


Free-ranging domestic cats (Felis catus) incur and impose risks on ecosystems and represent a complex issue of critical importance to wildlife conservation and domestic cat and human health. There is an inherent social dimension to the issue of owned free-ranging cats, as humans are their caregivers and can contribute to the cause as well as the solution to this issue. To address this social component, we examined public risk perceptions, attitudes, and beliefs towards owned free-ranging cats along a gradient of urbanization via a survey of residents in two study areas in Colorado. Residents did not view all types of risks uniformly; they viewed the risks of cat predation on wildlife and carnivore predation on cats as more likely than the risks of disease transmission to and from wildlife. Additionally, risk perceptions were related to such factors as attitudes and general beliefs about cats, prior experiences with cats and their interactions with wildlife, and cat owner behavior. These findings provide support for the notion that changes in risk perceptions can result in behavior change, and they offer insight for development of communication campaigns aimed at promoting risk aversive behaviors and cat management strategies that are both acceptable to the public and have direct conservation implications. Our study can also be used as a model for further research focused on integrating social and biological information to promote conservation of wildlife and habitats.

Seattle households have more cats than children

Balk, G. 2013. In Seattle, it’s cats, dogs and kids – in that order. Seattle Times. February 1, 2013.

Seattle has more dogs than children. We’ve practically become famous for it. OK, not as famous as we are for coffee or rain, but still. The nation has certainly taken notice. Our canine-to-kid ratio has been written about in USA Today , The New York Times – even the National Postof Canada.It’s not just out-of-towners. Seattleites find it fascinating that we have more dogs than kids, too. The fact has reverberated through the local media since at least 1997, when The Seattle Times first noted that the scales had tipped in favor of dogs here. And it shows no signs of abating; just last year, public radio station KPLU devoted a segment to the phenomenon. Seems like we never tire of talking about it...

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Domestic dogs as a disturbance agent on the natural environment

Holderness-Roddam, B. (2011). The effects of domestic dogs (Canis familiaris) as a disturbance agent on the natural environment (Doctoral dissertation, University of Tasmania).


This study assesses the impact of domestic dogs on the natural environment. The principal issue investigated is that of disturbance and the consequences for native wildlife, particularly vertebrate species. In addition to the catastrophic effects of killing, maiming and orphaning of wildlife; disturbance can contribute to energetic loss through premature flight or reduced feed intake and reproductive disruption due to nest disturbance. Dogs have been implicated in disease transmission to native wildlife; with faecal contamination of waterways having potential negative affects for marine mammal health. Hybridisation with other canid species is also an issue of concern, as is expropriation of land for the production of food for pet dogs. The study commences with an overview of ecological disturbance. The literature review then assesses the role of domestic dogs in ecological disturbance, public attitudes towards compliance with dog management legislation and the remediation and mitigation of disturbance by dogs. Data obtained from the Resource Management and Conservation section of the Tasmanian Department of Department of Primary Industries, Parks, Water and Environment regarding native wildlife presenting for care was analysed in order to determine the principal reported causes of death and injury to native wildlife in Tasmania. These results were then compared with data from the Australian Wildlife Health Centre - Wildlife Hospital at Healesville Sanctuary in Victoria and the data submitted by Tasmanian veterinarians through a three month diary of wildlife presentations recorded by ten practices.

Dog predation and disturbance on wildlife

Holderness-Roddam, B., & McQuillan, P. B. (2014). Domestic dogs (Canis familiaris) as a predator and disturbance agent of wildlife in Tasmania.Australasian Journal of Environmental Management, (ahead-of-print), 1-12.

Domestic dogs are potentially a threat to the wellbeing of Tasmania's native wildlife in urban reserves, possibly comparable to cats. Dogs disrupt feeding and breeding in wildlife. Greater Hobart has 33,000 registered domestic dogs, concentrated in the more densely populated areas. Datasets of the Resource Management and Conservation Division of the Tasmanian Department of Primary Industries, and the Australian Wildlife Health Centre, Wildlife Hospital at Healesville Sanctuary, Victoria, were used to compare the effects of dogs as predators with cats. These datasets indicated that dogs were responsible for more reported attacks on wildlife than cats. These findings have management implications for local councils, who are typically responsible for such areas. They need to review the urban natural areas where dogs are permitted, both on leash and off leash, and then consider monitoring dog owner behaviour at peak dog walking periods – in evenings and at weekends – and prosecute non-compliant dog owners. At the planning stage for new subdivisions, particularly those near sensitive wildlife areas, councils should consider mandating bushland reserves with larger buffer zones to reduce the effects of residential development.

Reasons for relinquishment and return of domestic cats to rescue shelters

Casey, R. A., Vandenbussche, S., Bradshaw, J. W., & Roberts, M. A. (2009). Reasons for relinquishment and return of domestic cats (Felis silvestris catus) to rescue shelters in the UK. Anthrozoos: A Multidisciplinary Journal of The Interactions of People & Animals, 22(4), 347-358.

Significant numbers of cats enter rescue and re-homing facilities each year, over half of which are relinquished directly by owners. Identifying the reasons why owners decide to give up their pet is an important step in the development of education strategies to encourage retention of cats by their owners. In addition, identifying why adopting owners fail to retain their new cats is important in the refinement of homing policies. Characteristics of 6,089 cats relinquished and returned to 11 rescue facilities in the UK were recorded over a year. In addition, information was collected on the reason why owners gave up, or brought back, their pet. Sixty percent of cats and kittens entering shelters were relinquished by owners, with 19% being due to owner circumstances, such as moving to rented accommodation or changes in family circumstances. Seven percent were for behavioral reasons, and 5% because of the occurrence of allergy or asthma in owners. Returned cats were significantly more likely to be older (Mann Whitney U, Z = –9.167, p < 0.001) and neutered (Pearson χ² = 110.0, df = 2, p < 0.001) than the general relinquished population. The reasons for original relinquishment and return of owned cats were also significantly different (Pearson χ² = 84.4, df = 6, p < 0.001), with 38% of cats being returned for behavioral reasons, and 18% because of allergy or asthma. The commonest behavioral reason for both relinquishment and return was aggression between cats in the household.

Bias against adoption of stray cats

Dybdall, K., & Strasser, R. (2014). Is There a Bias Against Stray Cats in Shelters? People's Perception of Shelter Cats and How It Influences Adoption Time. Anthrozoos: A Multidisciplinary Journal of The Interactions of People & Animals.

The determination of adoptability is a fundamental issue facing shelters wishing to rehome cats. Many shelters in the United States cannot keep a cat indefinitely and increased time in the shelter environment may lead to reduced animal welfare due to chronic stress or euthanasia. In a series of studies, we examined whether entry type (whether a cat came to the shelter as an owner-surrendered or stray) as well as a cat 's perceived social behavior influenced adoption times and people 's ratings of adoptability. In study 1, we used archival data from 1,089 cats in a Midwest shelter and found that owner-surrendered cats were adopted significantly sooner than stray cats. In study 2, we further explored the difference between owner-surrendered and stray cats by measuring the social behavior of 56 shelter cats and their time before adoption. Similarly, we found in this sample that owner-surrendered cats were adopted on average nine days sooner than stray cats. Hierarchical regression analysis indicated that entry type was a significant predictor of days to adopt, and that latency to approach a human significantly improved the prediction model. Further, how quickly stray cats, but not owner-surrendered cats, approached a human experimenter correlated significantly with a shortened adoption time in the actual adoption scenario. Finally, in study 3, we used an on-line survey to present 12 dual-image pictures of cats and manipulated whether the information about the cat listed each as owner-surrendered or stray cat. We asked 120 college students to rate their likelihood of adopting each pictured cat. When participants were asked about reasons they would adopt a particular cat, 81% reported friendly behavior toward them; yet when viewing the mirror images in the survey (no behavioral information available), cats received higher adoptability ratings when presented as owner-surrendered compared with the flipped image of that cat presented as a stray. Taken together, these studies suggest that adopters' perception of stray cats, as well as cats' interactions with humans, influence the amount of time a cat remains in the shelter prior to adoption.

Lack of mesopredator release after top-predator control

Allen, B. L., Allen, L. R., Engeman, R. M., & Leung, L. K. (2013). Intraguild relationships between sympatric predators exposed to lethal control: predator manipulation experiments. Frontiers in zoology, 10(1), 39.

Introduction
Terrestrial top-predators are expected to regulate and stabilise food webs through their consumptive and non-consumptive effects on sympatric mesopredators and prey. The lethal control of top-predators has therefore been predicted to inhibit top-predator function, generate the release of mesopredators and indirectly harm native fauna through trophic cascade effects. Understanding the outcomes of lethal control on interactions within terrestrial predator guilds is important for zoologists, conservation biologists and wildlife managers. However, few studies have the capacity to test these predictions experimentally, and no such studies have previously been conducted on the eclectic suite of native and exotic, mammalian and reptilian taxa we simultaneously assess. We conducted a series of landscape-scale, multi-year, manipulative experiments at nine sites spanning five ecosystem types across the Australian continental rangelands to investigate the responses of mesopredators (red foxes, feral cats and goannas) to contemporary poison-baiting programs intended to control top-predators (dingoes) for livestock protection.

Result
Short-term behavioural releases of mesopredators were not apparent, and in almost all cases, the three mesopredators we assessed were in similar or greater abundance in unbaited areas relative to baited areas, with mesopredator abundance trends typically either uncorrelated or positively correlated with top-predator abundance trends over time. The exotic mammals and native reptile we assessed responded similarly (poorly) to top-predator population manipulation. This is because poison baits were taken by multiple target and non-target predators and top-predator populations quickly recovered to pre-control levels, thus reducing the overall impact of baiting on top-predators and averting a trophic cascade.

Conclusions
These results are in accord with other predator manipulation experiments conducted worldwide, and suggest that Australian populations of native prey fauna at lower trophic levels are unlikely to be negatively affected by contemporary dingo control practices through the release of mesopredators. We conclude that contemporary lethal control practices used on some top-predator populations do not produce the conditions required to generate positive responses from mesopredators. Functional relationships between sympatric terrestrial predators may not be altered by exposure to spatially and temporally sporadic application of non-selective lethal control.

Allen, B. L., Allen, L. R., Engeman, R. M., & Leung, L. K. (2014). Sympatric prey responses to lethal top-predator control: predator manipulation experiments. Frontiers in Zoology, 11(1), 56.

Introduction: Many prey species around the world are suffering declines due to a variety of interacting causes such as land use change, climate change, invasive species and novel disease. Recent studies on the ecological roles of top-predators have suggested that lethal top-predator control by humans (typically undertaken to protect livestock or managed game from predation) is an indirect additional cause of prey declines through trophic cascade effects. Such studies have prompted calls to prohibit lethal top-predator control with the expectation that doing so will result in widespread benefits for biodiversity at all trophic levels. However, applied experiments investigating in situ responses of prey populations to contemporary top-predator management practices are few and none have previously been conducted on the eclectic suite of native and exotic mammalian, reptilian, avian and amphibian predator and prey taxa we simultaneously assess. We conducted a series of landscape-scale, multi-year, manipulative experiments at nine sites spanning five ecosystem types across the Australian continental rangelands to investigate the responses of sympatric prey populations to contemporary poison-baiting programs intended to control top-predators (dingoes) for livestock protection.
Results: Prey populations were almost always in similar or greater abundances in baited areas. Short-term prey responses to baiting were seldom apparent. Longer-term prey population trends fluctuated independently of baiting for every prey species at all sites, and divergence or convergence of prey population trends occurred rarely. Top-predator population trends fluctuated independently of baiting in all cases, and never did diverge or converge. Mesopredator population trends likewise fluctuated independently of baiting in almost all cases, but did diverge or converge in a few instances.
Conclusions: These results demonstrate that Australian populations of prey fauna at lower trophic levels are typically unaffected by top-predator control because top-predator populations are not substantially affected by contemporary control practices, thus averting a trophic cascade. We conclude that alteration of current top-predator management practices is probably unnecessary for enhancing fauna recovery in the Australian rangelands. More generally, our results suggest that theoretical and observational studies advancing the idea that lethal control of top-predators induces trophic cascades may not be as universal as previously supposed.

German hunters angered by proposed ban on shooting cats

The hunters' federation of the rural state of North Rhine-Westphalia defends the practice on environmental grounds, saying on its website that a wild cat can "kill up to 1,000 birds" a year.But a new law, due to be presented to the regional parliament before the end of the year aims to move tabbies out of their crosshairs.Environment ministry spokesman Wilhelm Deitermann said under current legislation dating from the 1930s, hunters can target cats which venture more than 200 metres (650 feet) from a house or prowl fields and the edges of forests.But the ministry, headed by ecologist Johannes Remmel, argues that the damage caused by cats "does not justify such regulation".The legal change spells good news for local felines. During the last hunting season shooters in the state killed "about 8,000 cats," Deitermann told AFP.

Read more at: http://phys.org/news/2014-10-german-hunters-angered-cats.html#jCp

ISFM guidelines on population management and welfare of unowned domestic cats

Sparkes, A. H., Bessant, C., Cope, K., Ellis, S. L., Finka, L., Halls, V., Hiestand, K., Horsford, K., Laurence, C., MacFarlaine, I., Neville, P.F., Stavisky, J. & Yeates, J. (2013). ISFM guidelines on population management and welfare of unowned domestic cats (Felis catus). Journal of feline medicine and surgery,15(9), 811-817.

Guidelines rationale: Cats are among the most commonly kept domestic pets, and coexist with humans in a variety of different circumstances. Cats are sentient beings and, as such, humans have a responsibility for cat welfare where humans and cats coexist. Because cats reproduce efficiently, measures to control populations are frequently needed, but these should be based on ethical and humane approaches.

Framework: These consensus guidelines from the International Society of Feline Medicine’s Welfare Advisory Panel provide a framework for the approach to welfare and population control measures, primarily among unowned cats and those going through a homing programme.

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.

Feral cat eradication in the presence of endemic San Nicolas Island foxes

Hanson, C. C., Jolley, W. J., Smith, G., Garcelon, D. K., Keitt, B. S., Little, A. E., & Campbell, K. J. (2014). Feral cat eradication in the presence of endemic San Nicolas Island foxes. Biological Invasions, 1-10.

Projects to eradicate invasive species from islands are a high priority for conservation. Here we describe the process used to successfully eradicate an introduced carnivore on an island where a native carnivore of similar size was also present. We primarily used padded leg-hold live trapping to capture feral cats (Felis silvestris catus). Trapped feral cats were transported off-island and housed in a permanent enclosure on the continent. We used additional methods, such as tracking dogs and spotlight hunting, to detect and remove more-difficult individuals. Project implementation caused no significant negative impacts to the endemic San Nicolas Island fox (Urocyon littoralis dickey) population. Mitigation measures included on-site veterinary resources, modified padded leg-hold live traps, conditioned trap aversion, a trap monitoring system and personnel training. To confirm eradication, we utilized camera traps and sign search data in a model to predict project success. A key part of the success of this project was the partnerships formed between NGOs, and government organizations. With support from the partnership, the use of innovative technology to improve traditional trapping methods allowed feral cats to be removed effectively in the presence of a native species occupying a similar niche. This project shows that strong partnerships, innovative methods, and use of technology can provide the conditions to eradicate invasive species when major barriers to success exist.

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.

Toxoplasmosis in White tailed deers

Ballash, G. A., Dubey, J. P., Kwok, O. C. H., Shoben, A. B., Robison, T. L., Kraft, T. J., & Dennis, P. M. 2014. Seroprevalence of Toxoplasma gondii in White-Tailed Deer (Odocoileus virginianus) and Free-Roaming Cats (Felis catus) Across a Suburban to Urban Gradient in Northeastern Ohio. EcoHealth, 1-9.

Felids serve as the definitive host of Toxoplasma gondii contaminating environments with oocysts. White-tailed deer (WTD; Odocoileus virginianus) are used as sentinel species for contaminated environments as well as a potential source for human foodborne infection with T. gondii. Here we determine the seroprevalence of T. gondii in a WTD and felid population, and examine those risk factors that increase exposure to the parasite. Serum samples from 444 WTD and 200 free-roaming cats (Felis catus) from urban and suburban reservations were tested for T. gondii antibodies using the modified agglutination test (MAT, cut-off 1:25). Antibodies to T. gondii were found in 261 (58.8%) of 444 WTD, with 164 (66.1%) of 248 from urban and 97 (49.5%) of 196 from suburban regions. Significant risk factors for seroprevalence included increasing age (P < 0.0001), reservation type (P < 0.0001), and household densities within reservation (P < 0.0001). Antibodies to T. gondii were found in 103 (51.5%) of 200 cats, with seroprevalences of 79 (51%) of 155 and 24 (53.3%) of 45 from areas surrounding urban and suburban reservations, respectively. Seroprevalence did not differ by age, gender, or reservation among the cats’ sample. Results indicate WTD are exposed by horizontal transmission, and this occurs more frequently in urban environments. The difference between urban and suburban cat densities is the most likely the reason for an increased seroprevalence in urban WTD. These data have public health implications for individuals living near or visiting urban areas where outdoor cats are abundant as well as those individuals who may consume WTD venison.

Cats seem to predate on birds with lower immunocompetence

Møller, A.P. & Erritzøe, J. 2000. Predation against birds with low immunocompetence. Oecologia. 122(4): 500–504.

Differences in the phenotypic characteristics between individuals falling prey to predators and conspecifics avoiding predation will reflect the intensity of selection on prey. If prey are generally in poor condition, we predicted that they should have an inferior health status in comparison to individuals dying for other reasons. We investigated this prediction for prey and conspecifics that did not die from predation by comparing the size of the spleen, which is an important immune defence organ reflecting one component of immunocompetence, using 18 species of passerine birds and domestic cat Felis catus predators as a model system. Prey had consistently smaller spleens than non-prey, implying that they had weak immune systems. The data set did not indicate that sex or age, month of death, body mass, body condition, liver mass, wing length or tarsus length differed significantly between prey and non-prey. Thus there was little evidence of confounding factors affecting the results. These observations indirectly suggest that disease and parasitism may play an important role in predator-prey interactions.

Mean (+SE) spleen mass (g) for birds captured by cats (Prey) and other conspecifics (Others). Numbers are sample sizes

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.

Evaluation of outdoor access of owned cats

Clancy, E.A., Moore, A.S., and Bertone, E.R. 2003. Evaluation of cat and owner characteristics and their relationships to outdoor access of owned cats. Journal of the American Veterinary Medical Association. 222(11): 1541–1545.


Objective—To examine characteristics of cats and their owners with regard to outdoor access of owned cats.

Design—Cross-sectional study.

Animals—184 owned cats admitted to a veterinary referral center for nonemergency health concerns.

Results—Cats acquired recently were less likely to be allowed outdoors than those acquired during previous years. Outdoor access was often limited during the day; few owners allowed their cats to remain outdoors at night. Cats acquired from shelters were more likely to be kept exclusively as indoor pets than those cats acquired as strays. The presence of dogs but not other cats in the household was associated with increased outdoor access. Age, health status, and onychectomy status were not significantly associated with outdoor access. Cats allowed outdoor access were more likely to have been bitten by other cats.

Conclusions and Clinical Relevance—The basis for an owner's decision to allow outdoor access appears to be multifactorial, and there may be regional differences in outdoor access of owned cats. Acquisition source is associated with outdoor access of owned cats. Availability of information regarding outdoor access of cats may influence decision making. Educational efforts targeted at specific groups of cat owners, as well as programs that acknowledge owner beliefs regarding quality of life for their cats, may help to address the health, safety, and population concerns associated with outdoor access of owned cats. (J Am Vet Med Assoc2003;222:15417–1545)

A review of feral cat control

Robertson, S. A. (2008). A review of feral cat control. Journal of Feline Medicine and Surgery, 10(4), 366-375.

Animal overpopulation including feral cats is an important global problem. There are many stakeholders involved in the feral cat debate over ‘what to do about the problem’, including those who consider them a nuisance, the public at risk from zoonotic disease, people who are concerned about the welfare of feral cats, those concerned with wildlife impacts, and the cats themselves. How best to control this population is controversial and has ranged from culling, relocation, and more recently ‘trap neuter return’ (TNR) methods. Data support the success of TNR in reducing cat populations, but to have a large impact it will have to be adopted on a far greater scale than it is currently practised. Non-surgical contraception is a realistic future goal. Because the feral cat problem was created by humans, concerted educational efforts on responsible pet ownership and the intrinsic value of animals is an integral part of a solution.

TNR program for feral cats on Prince Edward Is.

Gibson, K. L., Keizer, K., & Golding, C. (2002). A trap, neuter, and release program for feral cats on Prince Edward Island. The Canadian Veterinary Journal, 43(9), 695.

A new program to address the feral cat population on Prince Edward Island was undertaken during the spring and summer of 2001. Feral cats from specific geographic areas were trapped, sedated, and tested for feline leukemia virus and feline immunodeficiency virus. Healthy cats were neutered, dewormed, vaccinated, tattooed, and released to their area of origin. A total of 185 cats and kittens were trapped and tested during a 14-week period; 158 cats and kittens as young as 6 weeks of age were neutered and released. Twenty-three adult cats were positive for feline leukemia virus, feline immunodeficiency virus, or both, and were euthanized.

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.

Male reproductive success in the domestic cat

Pontier, D., & Natoli, E. (1996). Male reproductive success in the domestic cat (Felis catus L.): A case history. Behavioural processes, 37(1), 85-88.

The domestic cat shows a great variability in different life history traits like its social organization, ranging from a solitary life to living in large social groups depending on environmental conditions. Until now, the mating system has not been shown to vary between populations and was described as promiscuous. Here we present data on the reproductive success of a male, which clearly show that monopolization of females by males is possible in this species.

Feeding-order in an urban feral domestic cat colony

Bonanni, R., Cafazzo, S., Fantini, C., Pontier, D., & Natoli, E. (2007). Feeding-order in an urban feral domestic cat colony: relationship to dominance rank, sex and age. Animal Behaviour, 74(5), 1369-1379.

In social species, dominance relationships and access to food resources are often affected by asymmetries in resource-holding potential (RHP) between competitors of different age–sex classes with males usually being dominant and feeding first, followed by females and then juveniles. In this study we investigated how variables such as sex and age affected dominance rank and feeding order in a social group of feral domestic cats, Felis silvestris catus, a sexually dimorphic species in which males are larger than females and do not take part in parental care. Intersexual dominance relationships varied depending on the competitive context: males occupied top rank positions away from food, whereas females increased in rank at the expense of males in a feeding context. Around the age of 4–6 months, kittens were significantly more likely than adults of both sexes to be the first to feed, indicating that they received a certain level of tolerance. These results provide support for game-theory models predicting conflict outcome in favour of the smaller competitor when asymmetries in both the value of winning and in the cost of winning inappropriately may compensate for the smaller competitor's lower RHP. It is suggested that the results are not an artifact of domestication: unlike male lions, Panthera leo, which usually dominate both females and cubs at kills, male domestic cats may value the food less than females and juveniles, because they do not need to maintain constantly a peak physical condition to defend a group of females and protect offspring from infanticide.

Ecology of the feral cat on Macquarie Island

Jones, E. (1977). Ecology of the feral cat, Felis catus (L.),(Carnivora: Felidae) on Macquarie Island. Wildlife Research, 4(3), 249-262.

On Macquarie Island from December 1973 to March 1975 the diet of feral domestic cats (Felis catus) was estimated. There was rabbit (Oryctolagus cuniculus) in 82% of faeces and 71% of guts, rabbits under 600 g bodyweight, about 10 weeks old, were 81% of all rabbits eaten. There were Antarctic prion (Pachyptila desolata) and white-headed petrel (Pterodroma lessonii). Cats ate small numbers of rats, mice and wekas and scavenged on dead elephant seals and penguins, especially in winter. Availability of food in winter seemed to be an important factor limiting the population; adult population was estimated to be 250 to 500 and the area of the island is 120 km². Prion and white-headed petrel nest in burrows; there was little or no predation by cats on surface nesters such as albatross, giant petrel, southern skua or southern black-backed gull, or on live penguin.