A feral cat is a domesticated cat that has returned to the wild, or the descendants of such an animal. It is distinguished from a stray cat, which is a pet cat that has been lost or abandoned, while feral cats have never been socialized. The offspring of a stray cat can be considered feral if born in the wild. In many parts of the world, feral cats are the offspring of unaltered domestic cats.
- 1 Behavior of feral cats
- 2 History
- 3 Diet and predators
- 4 Effects on wildlife
- 5 Disease prevalence
- 6 Colonies
- 7 See also
- 8 References
- 9 External links
Behavior of feral cats
Feral versus stray
The term "feral" is sometimes used to refer to an animal that does not appear friendly when approached by humans, but the term can apply to any domesticated animal without human contact. Hissing and growling are self-defence behaviours, which, over time, may change as the animal (whether "feral" or "stray") begins to trust humans that provide food, water, and care.
Feral cats that are born and living outdoors, without any human contact or care, have been shown to be adoptable and can be tamed by humans, provided they are removed from a wild environment before truly feral behaviours are established. Such behaviours are established while it is still a kitten being raised by its mother.
Life span and survival
Feral cats in managed colonies can live long lives. A number of cats in managed colonies in the U.K. died of old age.:522 In the U.S., the last cat in a managed colony in Washington, D.C. died at age 17, and Zorro, the last cat of a colony at the Merrimack River in Newburyport, Massachusetts, died in 2009 at age 16.
A long-term study of a trap-neuter-return (TNR) program in Central Florida found that despite widespread concern about the welfare of free-roaming cats, 83% of the cats studied had been present for over six years, with almost half first observed as adults of unknown age. These time spans compared favourably to the average lifespan of 7.1 years for pet cats reported in a 1984 study,:45 and to the finding that only 42% of the pet cat population in the U.S. is more than 5 years old.:1358
Without human assistance, feral kittens are expected to have a high death rate.:45
Adult feral cats without human assistance have been found in surprisingly good condition. In Florida, a study of feral cats admitted to a trap-neuter-return program concluded that "euthanasia for debilitated cats for humane reasons is rarely necessary". A further study of over 100,000 community cats (feral and stray) admitted to TNR programs in diverse locations of the U.S. resulted in the same 0.4% rate of euthanasia for debilitating conditions. Rates of feline leukemia virus infection and feline immunodeficiency virus antibodies in feral cats studied in North Carolina and Florida were similar to those of owned cats. The body condition of feral cats entering a TNR program in Florida was described as "generally lean but not emaciated". However, many community cats had suffered from parasites such as fleas and ear mites before entering TNR programs.
Control and management
Trap-neuter-return (TNR) involves trapping feral cats, spaying or neutering them, and then returning them to the place where there were originally trapped, where ongoing care is provided by caregivers. When neutered, the cats receive vaccinations against rabies, and attention to other medical needs, such as dental care and flea treatments.:115 TNR programs are prevalent in several countries, including England, Italy, Canada and the United States, supported by many local and state governments. Various long-term studies have shown that TNR is effective in stopping reproduction and reducing the population over time. TNR results in fewer complaints, as nuisance behaviors diminish following neutering,:16 and the quality of life of the cats is improved.:1359 The practice is reported to save money:294 and garner more public support and better morale than efforts that involve killing cats.:297:49
The International Companion Animal Management Coalition advocates for TNR as a humane method of controlling feral cat populations. In the U.S., the practice is endorsed by the Humane Society of the United States and the National Animal Control Association. While the United States Department of Defense does not formally advocate TNR, it provides information to military installations on how to implement TNR programs, with the main message that population control programs must be humane.
During the Age of Discovery, ships released rabbits onto islands to provide a future food source for other travelers. They eventually multiplied out of control and cats were introduced to keep their numbers, and that of mice and rats, down. The cats tended to favor local species as they were ecologically naive and easier to hunt. Their numbers, too, increased dramatically and soon they colonised many areas and were seen as pests. Cats were introduced to Tasmania in 1804 and had become feral by the 1840s. Feral cats were reported on mainland Australia around Sydney in 1820. It has been suggested that feral cats could have been introduced accidentally to the north-western coast in the 17th century from the wrecks of Dutch ships; alternatively, they could have arrived earlier, possibly around the fifteenth century, via mariners from Indonesia.
Diet and predators
Feral cats living in managed colonies are fed kibble and/or wet food by volunteers.
Domestic and feral cats have generally been found to eat a very broad range of vertebrate and invertebrate prey. Preferred prey usually are small mammals, birds and lizards, especially those with body weights under 100g. Feral cats in Australia prey on a variety of wildlife. In arid and semi-arid environments they eat mostly introduced European rabbits and house mice. In arid environments where rabbits do not occur, native rodents are taken. In forests and urbanised areas, they eat mostly native marsupials, birds and reptiles. On Macaronesian islands, cats prey mainly on introduced mammals but also on birds and reptiles.
Feral cats may be apex predators in some local ecosystems. In others, they may be preyed on by feral dogs, dingoes, coyotes, wolves, bears, cougars, leopards, bobcats, lynx, hyenas, fishers, crocodiles, snakes, foxes and birds of prey.
Effects on wildlife
Mice and rats
For thousands of years, cats have been known for their ability to hunt mice and rats and keep their populations under control. This ability is understood as the reason cats became domesticated.:68 The relationship was more of convenience (or mutualistic) than dependence: "Cats killed mice and rats, and humans provided lots of mice and rats to kill since mice and rats lived in human settlements.":68 A 2014 study examining 5,300 years of cat remains in an agricultural village of Quanhucun, China, provides early evidence of this dynamic, where cats protected grain stores by eating rodents.
If they are well-fed, farm cats are more dependable as effective ratters, as they are less likely to stray or hunt further afield.:110 Cats are wary of adult rats, given their size,:111 but are particularly adept at hunting young rats.:110
In 2002, feral cats introduced to a flower market in Los Angeles, California, were noted to have helped lower rat populations. In Chicago's 47th Ward, feral cats were introduced in 2012 to help the city deal with the rat problem there.
Efforts to eradicate feral cats in Ventura, California, were noted in 2002 to have resulted in increasing numbers of rats, which were being monitored for health problems such as bubonic plague.
A 2013 study by Scott R. Loss and others of the Smithsonian Conservation Biology Institute and the US Fish and Wildlife Service suggested that free-ranging domestic cats (mostly unowned) are the top human-caused threat to wildlife in the United States, killing an estimated 1.3 to 4 billion birds and 6.3 to 22.3 billion mammals annually. These figures were much higher than previous estimates for the U.S.:2 Unspecified species of birds native to the U.S. and mammals including mice, shrews, voles, squirrels and rabbits were considered most likely to be preyed upon by cats.:4
Advocates for feral cats counter that Loss's study and earlier related studies have inflated estimates of wildlife killed by cats in the U.S., based on unscientific research that extrapolates from tiny samples and projects them onto whole nations. One reviewer stated that Loss's study was filled with "numerous major ﬂaws in the statistical arguments made" that in his view made it "unacceptable for publication".:1 It was unclear how predation rates were obtained, and then "applying these estimates to all cats across the country is highly questionable.":3 Extrapolation was also misused when "Based on a small sample of cats over three summer months in one speciﬁc geographic area, the authors see ﬁt to extrapolate this predation rate to all cats at all times of the year in all geographic regions in the United States.":3
Perhaps the first U.S. study that pointed to predation by cats on wildlife as a concern was ornithologist Edward Howe Forbush's 1916 report for the Massachusetts State Board of Agriculture, The Domestic Cat: Bird Killer, Mouser and Destroyer of Wildlife: Means of Utilizing and Controlling It.
U.K. biologist and cat behaviour expert Roger Tabor states that "studies from all around the world have found that cats catch relatively few birds compared to small mammals.":135 The Royal Society for the Protection of Birds states that there is no scientific evidence that cat predation "is having any impact on bird populations UK-wide." Moreover, city cats have smaller ranges; in his research, Tabor found "the average annual catch of the average London cat to be two items instead of the fourteen of a village cat.":135 Tabor comments about some of the challenges of stalking birds for cats: "From the cat's point of view not only do birds not play fair by flying and having eyes that can see beyond the back of their heads, but they can positively cheat by using loud alarm calls and throw the cat's chances of catching any others.":123
Island settings pose particular challenges for wildlife. A 2001 study identified cats alone as responsible for the plight of some island bird species, such as the Townsend's shearwater, socorro dove, and the Marquesan ground dove.:400 The same study identified the greatest cause of endangerment of birds as habitat loss and degradation, with at least 52% of endangered birds affected,:399 while introduced species on islands, such as domestic cats, rats and mustelids,:403 affected only 6% of endangered birds.:399 Other studies caution that removing domestic cats from islands can have unintended consequences, as increasing rat populations can put native bird and mammal species at risk.
Feral cats in Australia have been linked to the decline and extinction of various native animals. They have been shown to cause a significant impact on ground nesting birds and small native mammals. Feral cats have also hampered any attempts to re-introduce threatened species back into areas where they have become extinct as the cats have hunted and killed the newly released animals. Numerous Australian environmentalists claim the feral cat has been an ecological disaster in Australia, inhabiting most ecosystems except dense rainforest, and being implicated in the extinction of several marsupial and placental mammal species.
The fauna of New Zealand has evolved in isolation for millions of years without the presence of mammals (apart from a few bat species). Consequently, birds dominated the niches occupied by mammals and many became flightless. The introduction of mammals after settlement by Māori from about the 12th century had a huge effect on the indigenous biodiversity. European explorers and settlers brought cats on their ships and the presence of feral cats were recorded from the latter decades of the 19th century. It is estimated that feral cats have been responsible for the extinction of six endemic bird species and over 70 localised subspecies as well as depleting bird and lizard species.
In the U.K., The Royal Society for the Protection of Birds states that there is no scientific evidence that cat predation "is having any impact on bird populations UK-wide. This may be surprising, but many millions of birds die naturally every year, mainly through starvation, disease, or other forms of predation. There is evidence that cats tend to take weak or sickly birds ... Those bird species that have undergone the most serious population declines in the UK (such as skylarks, tree sparrows and corn buntings) rarely encounter cats, so cats cannot be causing their declines. Research shows that these declines are usually caused by habitat change or loss, particularly on farmland." This evidence is despite the common practice in the U.K. of allowing owned cats access to the outdoors, which is recommended to prevent feline obesity (p. 138) and behavior problems and other health problems arising from confinement stress (p. 121).
Consequences of introduction
Many islands host ecologically naive animal species; that is, animals that do not have predator responses for dealing with predators such as cats. Feral cats introduced to such islands have had a devastating impact on these islands' biodiversity. They have been implicated in the extinction of several species and local extinctions, such as the hutias from the Caribbean, the Guadalupe Storm Petrel from Pacific Mexico, the Stephens Island wren; in a statistical study, they were a significant cause for the extinction of 40% of the species studied. Moors and Atkinson wrote, in 1984, "No other alien predator has had such a universally damaging effect."
Feral cats, along with rabbits, some sea birds, and sheep, form the entire large animal population of the remote Kerguelen Islands in the southern Indian Ocean. Although exotic mammals form the bulk of their diet, cats' impact on seabirds is very important.
Because of the damage cats cause in islands and some ecosystems, many conservationists working in the field of island restoration have worked to remove feral cats. (Island restoration involves the removal of introduced species and reintroducing native species.) As of 2004, 48 islands have had their feral cat populations eradicated, including New Zealand's network of offshore island bird reserves and Australia's Macquarie Island. Larger projects have also been undertaken, including their complete removal from Ascension Island. The cats, introduced in the 19th century, caused a collapse in populations of nesting seabirds. The project to remove them from the island began in 2002, and the island was cleared of cats by 2004. Since then, seven species of seabird that had not nested on the island for 100 years have returned.
In some cases, the removal of cats had unintended consequences. An example is Macquarie Island , where the removal of cats caused an explosion in the number of rabbits, rats, and mice that harm native seabirds even if the eradication was positioned within an integrated pest management framework. The removal of the rats and rabbits was scheduled for 2007 and it could take up to seven years and cost $24 million.
Hybridisation with wild felids
Feral cats have interbred with wildcats to various extents throughout the world, the first reported case occurring more than 200 years ago. The significance of hybridisation is disputed. Some old books suggested that the wildcat was a separate species to the domestic cat, but modern genetic analysis has shown that the domestic cat is a domesticated version of the near eastern wildcat (Felis sylvestra lybica), which is of the same species as the European Wildcat (Felis sylvestris sylvestris). In some locations, high levels of hybridisation have led to difficulties in distinguishing a "true" wildcat from feral domestic and domestic hybrid cats, which can complicate conservation efforts. Some researchers argue that "pure" wildcats do not exist anymore, but others dispute this. One study in Scotland suggests that while "true" Scottish wildcats are unlikely to exist, the current wildcat population is distinct enough from domestic cats to be worth protecting. In addition to Scotland, wildcat populations notable gene introgression exist also in Italy, Hungary, Spain and Portugal. For a discussion of this issue see The Encyclopedia of Mammals, OUP, pages 656–657.
Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are among the most common infectious diseases of cats. FeLV and FIV belong to the retroviridae family, and both cause immunosuppression in cats. Research has shown that the prevalence of these viruses among feral cat populations is low and is similar to prevalence rates for owned cats in the United States.
A feral cat colony is a population of feral cats. The term is used primarily when a noticeable population of feral cats live together in a specific location and use a common food source. The term is not typically applied to solitary cats passing through an area. A clowder can range from 3–25 cats. Their locations vary, some hiding in alleyways or in large parks.
Members consist of adult females, their young, and some adult males. Unneutered males in a clowder fight each other for territory and for females. Some will be driven out to find another place to live.
Feral cats who have been trapped in many warm areas where fleas exist are usually found to have a large number of fleas, making them anemic. Both the fleas, and the food source, if limited to garbage and rodents, cause the cats to have intestinal microorganisms (such as coccidia or giardia) and other parasites (commonly known as roundworms, tapeworms, and hookworms), which lead to diarrhea and subsequent dehydration. They also can have ear mites, ringworm, and upper respiratory infections. Others are wounded in mating-fights and die from the infected wounds. Still others eventually contract feline immunodeficiency virus or feline leukemia due to the constant transmission of blood and bodily fluids via fighting and sexual activity.
While all of these illnesses are quite treatable, human intervention is necessary to prevent them from becoming fatal.
- Holton, Louise (June 2007). "Wild Things? An Introduction To Feral Cats". Bandaras News. Retrieved 21 November 2010.
- Feral Cat Coalition / Ray Savage (November 2009). "Taming Feral Kittens".
- "Cat Behavior 101 – Everything you Need to Know About Cat Behaviour". Cats.about.com. 19 November 2011. Retrieved 10 December 2011.
- "How to Turn a Stray Cat Into a Pet – Page 1". Petplace.com. Retrieved 10 December 2011.
- Jenny Remfry, Feral Cats in the United Kingdom (JAVMA Vol. 208, No. 4, Feb. 15, 1996, pp. 520-523), at p. 522, available online at pp. 24-27 of "AVMA Animal Welfare Forum: The welfare of cats", Nov. 3, 1995.
- "Trap-Neuter-Return Effectively Stabilizes and Reduces Feral Cat Populations: Washington, D.C. Cat Colony Stabilized and Eventually Reduced to Zero", Alley Cat Allies, accessed August 18, 2014.
- "Trap-Neuter-Return Effectively Stabilizes and Reduces Feral Cat Populations: Trap-Neuter-Return Humanely Stabilized and Reduced in Size the Merrimack River Colony", Alley Cat Allies, accessed August 18, 2014; an earlier article in the LA Times was written when Zorro was the last remaining living cat: "Advocates report success with trap, neuter, return approach to stray cats", Los Angeles Times, Sept. 29, 2009.
- "Evaluation of the effect of a long-term trap-neuter-return and adoption program on a free-roaming cat population", Julie K. Levy et al., JAVMA, Vol. 222, No. 1, January 1, 2003, pp. 42-46.
- "Humane strategies for controlling feral cat populations", Julie K. Levy et al., JAVMA, Vol 225, No. 9, November 1, 2004, pp. 1354-1360, at p. 1356.
- "Characteristics of free-roaming cats evaluated in a trap-neuter-return program", Karen C. Scott et al., J Am Vet Med Assoc, 2002. 221(8): p. 1136-8, at p. 1138.
- "Population Characteristics of Feral Cats Admitted to Seven Trap-Neuter-Return Programs in the United States", Jennifer L. Wallace et al., Journal of Feline Medicine And Surgery 8 (2006) pp. 279-284, at p. 282.
- "Prevalence of feline leukemia virus infection and serum antibodies against feline immunodeficiency virus in unowned free-roaming cats", Irene T. Lee et al., JAVMA, Vol 220, No. 5, pp. 620-622, March 1, 2002.
- "Body Condition of Feral Cats and the Effect of Neutering", Karen C. Scott et al., Journal of Applied Animal Welfare Science (2002), 5(3), pp. 203–213, at p. 212.
- "How to Help Feral Cats: A step-by-step guide to Trap-Neuter-Return", Alley Cat Allies, 2009, updated 2002, accessed June 19, 2014.
- Bryan Kortis et al., Neighbourhood Cats TNR Handbook: The Guide to Trap-Neuter-Return for the Feral Cat Caretaker, Neighbourhood Cats, 2nd. edition, 2013.
- "Management of feral domestic cats in the urban environment of Rome (Italy)", Eugenia Natoli et al., Preventive Veterinary Medicine (2006), doi:10.1016/j.prevetmed.2006.06.005
- "Feral Cat Organizations", HSUS, Oct. 21, 2009, archived at link; accessed Oct. 11, 2014.
- Hughes KL, Slater MR; Slater (2002). "Implementation of a feral cat management program on a university campus". Journal of Applied Animal Welfare Science 5 (1): 15–28. doi:10.1207/S15327604JAWS0501_2. PMID 12738586.
- "Implementation of a Feral Cat Management Program on a University Campus", Kathy L. Hughes et al., Journal of Applied Animal Welfare Science, 5(1), 2002, pp. 15-28.
- "Feral Cats: An Overview", Margaret R. Slater and Stephanie Shain (2005), in D.J. Salem & A.N. Rowan (Eds.), The state of the Animals III: 2005 (pp. 43–53). Washington, D.C.: Humane Society Press.
- "Humane Cat Population Management Guidance", International Companion Animal Management Coalition, accessed July 19, 2014.
- "HSUS Position Statement: Trap-Neuter-Return (TNR) Humane Society of United States, March 20, 2006.
- "Taking a Broader View of Cats in the Community", Animal Sheltering, Sept./Oct. 2008.
- Kozaryn, Linda D. "Cat Herding on the Military Range-"Trap, Neuter, Return," Cat Lovers Urge". United States Department of Defense. Retrieved 21 November 2010.
- Kozaryn, Linda D. "Cat Herding on the Military Range-DoD Advocates Humane Cat Control". United States Department of Defense. Retrieved 21 November 2010.
- Hamilton, Jill (30 July 2007). "Blair and the stray cats of Jerusalem". JPost.com. Retrieved 25 August 2009.
- Abbott, Ian; Department of Environment and Conservation (2008). "Origin and spread of the cat, Felis catus, on mainland Australia: re-examination of the current conceptual model with additional information". Conservation Science Western Australia Journal (7). Retrieved 11 February 2013.
- Dickman, Chris (May 1996). Overview of the Impacts of Feral Cats on Australian Native Fauna. The Director of National Parks and Wildlife – Australian Nature Conservation Agency – Institute of Wildlife Research. ISBN 0-642-21379-8. Retrieved 11 February 2013.
- Cat diet on Macaronesia (Atlantic Ocean). petsaspests.blogspot.com.es (28 March 2013).
- Temple Grandin and Catherine Johnson, Animals Make Us Human: Creating the Best Life for Animals, 2009, Mariner Books, ISBN 9780151014897.
- "Ancient Chinese cat bones shake up domestication theory", The Guardian, Dec. 17, 2013.
- "Earliest evidence for commensal processes of cat domestication", Yaowu Hu et al., Proceedings of the National Academy of Sciences, Vol. 11, No. 1, Jan. 7, 2014.
- Roger Tabor, The Wild Life of the Domestic Cat (1983: Arrow Books), ISBN 0099312107.
- "Up, Down, In and Out in Beverly Hills: Rats", Charlie LeDuff, The New York Times, Sept. 17, 2002.
- "North Side’s 47th Ward Using Feral Cats To Catch Rats", CBS Chicago, June 28, 2012.
- "With the Cats Away, Beachfront Rodents Have a Field Day", Jessica Blanchard, Los Angeles Times, Sept. 9, 2002.
- "The impact of free-ranging domestic cats on wildlife of the United States", Loss et al., Nature Communications 4, article 1396, 29 January 2013.
- Morelle, Rebecca (29 January 2013). "Cats killing billions of animals in the US". BBC News. Retrieved 12 February 2013.
- "Setting the Record Straight", Alley Cat Allies, links to fact sheets and articles critiquing several studies.
- "A review of the statistical methods employed in the article 'The impact of free-ranging domestic cats on wildlife of the United States'", Gregory J. Matthews, prepared for Alley Cat Allies, March 4, 2013.
- Edward Howe Forbush, "The Domestic Cat: Bird Killer, Mouser and Destroyer of Wildlife: Means of Utilizing and Controlling It", Commonwealth of Massachussetts, State Board of Agriculture, Economic Biology Bulletin 42, 1916.
- Roger Tabor, Understanding Cat Behavior (2003: David & Charles Ltd.), ISBN 9780715315897.
- "Are cats causing bird declines?" The Royal Society for the Protection of Birds, accessed June 23, 2014.
- Collar, N. J. (2001). Endangered Birds 2. New York: Academic Press. p. 400. in Encyclopedia of Biodiversity
- "Cats protecting birds revisited.", M. Fan et al., Bull. Math Biol. September 2005, 67(5), pp. 1081-106.
- "Island mammal extinctions are determined by interactive effects of life history, island biogeography and mesopredator suppression", Emily Hanna et al., Global Ecology and Biogeography, Vol 23, Issue 4, 11 August 2013.
- "Feral cats help some endangered mammals survive, report says", Gerald Popkin, The Sydney Morning Herald, August 29, 2013.
- The Threat Of FeralCats. Environment.nsw.gov.au (28 October 2011). Retrieved on 5 May 2013.
- Robley, A. Reddiex, B. Arthur T. Pech R. Forsyth, D. (Sep 2004). "Interactions between feral cats, foxes, native carnivores, and rabbits in Australia". CSIRO Sustainable Ecosystems / Arthur Rylah Institute for Environmental Research. Retrieved 12 February 2013.
- King, Carolyn (1984) Immigrant Killers. Auckland: Oxford University Press. ISBN 0-19-558121-0
- Eason, Charles T.; Morgan, David R. and Clapperton, B. Kay (1992). Toxic bait and baiting strategies for feral cats. University of Nebraska – Lincoln: Proceedings of the Fifteenth Vertebrate Pest Conference 1992.
- "In the UK, the vast majority of pet cats have free access to the outside world, or are at least allowed to go outside unsupervised for large parts of the day." "A world of difference - How cat ownership in America differs to the UK", Pets4Homes, accessed September 1, 2014.
- Moors, P.J.; Atkinson, I.A.E. (1984). "Predation on seabirds by introduced animals, and factors affecting its severity" in Status and Conservation of the World's Seabirds. Cambridge: ICBP. ISBN 0-946888-03-5.
- Barcott, Bruce (2 December 2007). "Kill the Cat That Kills the Bird?". The New York Times.
- Pontier, D., L. Say, F. Debias, J. Bried, J. Thioulouse, T. Micol & E. Natoli (2002). "The diet of feral cats (Felis catus L.) at ﬁve sites on the Grande Terre, Kerguelen archipelago". doi:10.1007/s00300-002-0424-5 (inactive 2015-01-13).
- Nogales, Manuel; Martin, Aurelio; Tershy, Bernie R.; Donlan, C. Josh; Veitch, Dick; Puerta, Nestor; Wood, Bill; Alonso, Jesus (2004). "A review of feral cat eradication on islands". Conservation Biology 18 (2): 310. doi:10.1111/j.1523-1739.2004.00442.x.
- Cat eradication from Ascension Island
- "Up against rats, rabbits and costs". The Sydney Morning Herald. 12 April 2007.
- Fears for sub-antarctic island plagued by rabbits. ABC News (15 July 2006).
- Draper, Michelle and La Canna, Xavier (14 January 2009) Cat kill devastates Macquarie Island. Nine News
- Controversy on feral cat removal on Macquarie Island
- Macquarie Island World Heritage Area. Plan for the Eradication of Rabbits and Rodents on Macquarie Island. Parks and Wildlife Service, Tasmania. parks.tas.gov.au
- Driscoll, C. A.; Menotti-Raymond, M.; Roca, A. L.; Hupe, K.; Johnson, W. E.; Geffen, E.; Harley, E. H.; Delibes, M.; Pontier, D.; Kitchener, A. C.; Yamaguchi, N.; O'Brien, S. J.; MacDonald, D. W. (2007). "The Near Eastern Origin of Cat Domestication". Science 317 (5837): 519–523. doi:10.1126/science.1139518. PMID 17600185.
- European wildcat (Felis silvestris grampia) Arkive.org
- European wildcat species account IUCN Species Survival Commission. See also Genetic pollution)Cat Specialist Group
- Genetic diversity and introgression in the Scottish wildcat. Molecular Ecology (2001) 10: 319–336.
- Domestic gene introgression into wildcat populations in Europe
- The Encyclopedia of Mammals, OUP, ISBN 978-0-19-920608-7, pages 656–657
- Levy JK, Gale DW, Gale LA, JK; Gale, DW; Gale, LA (2003). "Evaluation of the effect of a long-term trap-neuter-return and adoption program on a free-roaming cat population" (PDF). J. Am. Vet. Med. Assoc. 222 (1): 42–6. doi:10.2460/javma.2003.222.42. PMID 12523478.
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