Leishmania in wild and domestic canids around a Brazilian National Park

Curi, N. H. D. A., Miranda, I., & Talamoni, S. A. (2006). Serologic evidence of Leishmania infection in free-ranging wild and domestic canids around a Brazilian National Park. Memórias do Instituto Oswaldo Cruz, 101(1), 99-101.

Transmission of disease between wildlife, domestic animals, and humans is of great concern to conservation issues and public health. Here we report on the prevalence of anti-Leishmania sp. antibodies in 21 wild canids (7 Chrysocyon brachyurus, 12 Cerdocyon thous, and 2 Lycalopex vetulus) and 74 free domestic dogs (Canis familiaris) sampled around the Serra do Cipó National Park. In dogs, the apparent prevalence was 8.1% and in wild canids it was 19% (2 crab-eating foxes, C. thous, and 2 maned wolves, C. brachyurus). Management of the domestic dog population with evaluation of incidence changes in humans and wildlife, and enlightenment on the role of wild reservoirs are essential issues for future action and research.

Feral dog impact on a urban fragment of Atlantic forest in Brazil

Galetti, M. & I. Sazima. 2006 . Impacto de cães ferais em um fragmento urbano de Floresta Atlântica no sudeste do Brasil.  Natureza & Conservação 4 (1): 58-63

Os cães ferais domésticos são um dos principais predadores da vida selvagem nativa em áreas
protegidas em todo o mundo. Entretanto, o número de presas caçadas por cães ferais não é registrado
de maneira precisa. Foram encontradas, em um fragmento urbano de 250 hectares de Floresta
Atlântica na Região Sudeste do Brasil, 46 carcaças de no mínimo 12 espécies de vertebrados, caçadas
pelos cães ao longo de 44 meses. Os cães ferais não demonstraram qualquer seleção aparente em
relação às diferentes espécies de presa, matando desde veados a pequenos sapos. Os mamíferos
foram a presa mais freqüentemente encontrada (75%). Nossos dados indicam que os cães ferais têm
um grande impacto sobre a vida selvagem da Floresta Atlântica, especialmente em áreas onde os
animais silvestres precisam mover-se entre os fragmentos florestais. Os programas de erradicação,
embora controversos, são a única maneira de reduzir a predação da vida selvagem por cães ferais.

Feral dogs are one of the main predators of native wildlife inside protected areas all around the world. Nevertheless, the number of preys hunted by feral dogs has not been precisely recorded. In a 250 hectares Atlantic forest fragment in Southeast Brazil, 46 carcasses have been found from at least 12 vertebrate species, hunted by feral dogs along 44 months. Feral dogs didn't have any apparent selection related to their different preys, killing from deer to small toads. Mammals were the most frequently found preys (75%). Our data show that feral dogs have a great impact on wildlife in the Atlantic forest, especially in areas where wild animals have to move between forest fragments. Eradication programs, even if controversial, are the only way to reduce predation of wildlife by feral dogs.

Removal of feral dogs by befriending them

Morley, C. G. (2006). Removal of feral dogs Canis familiaris by befriending them, Viwa Island, Fiji. Conservation Evidence, 3(3).

On a Fijian island a decision was made to remove feral dogs Canis familiaris as they were predating
upon endangered fauna. Rather than trapping or shooting, by offering food and gradually habituating
them to people, almost all were captured unharmed and moved to the main island of Fiji. 

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

Factors affecting the presence of dogs in streets

Ibarra, L., F. Espínola, M. Echeverría. 2006. Factors related to the presence of dogsin the streets of Santiago City, Chile. Avances en Ciencias Veterinarias, 21: 21-26

In roles to know which are the factors related to the dogs in the streets and as a contribution to designing of sanitary measures for canine population surveillance and controlling, a research was carried out in 34 districts from the Metropolitan Region that conform Santiago city. The sampling unit was the street block and the specific information was obtained through direct observation of 864 city blocks from Santiago, by giving a minimum of 25 city blocks by district, randomly chosen. The street canine population characteristics, the urban structure an the habitat were registered to investigate the relationship among them.

The results show that the amount and types of dogs observed in the streets of Santiago are related to the existence of “shelter like” places and water and food sources in the urban structure of Santiago. The presence of dogs is also related to the garbage location in the street design, because the amount of dogs is significantly smaller if there are storing facilities or baskets in height that prevent the animal access to the garbage.

Ancient introductions of mammals in Mediterranean islands and their implications for conservation

Gippoliti, S., & Amori, G. (2006). Ancient introductions of mammals in the Mediterranean Basin and their implications for conservation. Mammal Review,36(1), 37-48.

1 The importance of taxonomy to the determination of conservation priorities and actions is widely accepted. It should be not surprising therefore that the taxonomic treatment of mammal species that have been subject to human actions in antiquity may well influence the contemporary assessment of conservation priorities at various levels.
2 As a result of early extinctions caused by humans and protohistoric and historic introductions, we suggest that the Mediterranean Basin and its islands are particularly prone to misdirection of efforts towards biodiversity conservation.
3 The two main risks associated with the failure to use an evolutionary and palaeoecological approach to conservation efforts are (i) an underestimation of the conservation importance of distinctive continental taxa vs. the apparent endemicity of island taxa; and (ii) a serious risk for native and endemic island species when anthropochorous mammals, especially ungulates, misguidedly become the focus of conservation actions, particularly inside protected areas.
4 Urgent measures, including refinement of mammal taxonomy, the exclusion of known anthropochorous taxa from conservation lists and implementation of protective legislation, are necessary to maintain the uniqueness and richness of the Mediterranean biodiversity hotspot.

Evolutionary basis of feeding behaviour of dogs and cats

Bradshaw, J. W. (2006). The evolutionary basis for the feeding behavior of domestic dogs (Canis familiaris) and cats (Felis catus). The Journal of nutrition,136(7), 1927S-1931S.


The dentition, sense of taste and meal patterning of domestic dogs and cats can be interpreted in terms of their descent from members of the order Carnivora. The dog is typical of its genus, Canis, in its relatively unspecialized dentition, and a taste system that is rather insensitive to salt. The preference of many dogs for large infrequent meals reflects the competitive feeding behavior of its pack-hunting ancestor, the wolf Canis lupus. However, its long history of domestication, possibly 100,000 years, has resulted in great intraspecific diversity of conformation and behavior, including feeding. Morphologically and physiologically domestic cats are highly specialized carnivores, as indicated by their dentition, nutritional requirements, and sense of taste, which is insensitive to both salt and sugars. Their preference for several small meals each day reflects a daily pattern of multiple kills of small prey items in their ancestor, the solitary territorial predator Felis silvestris. Although in the wild much of their food selection behavior must focus on what to hunt, rather than what to eat, cats do modify their food preferences based on experience. For example, the “monotony effect” reduces the perceived palatability of foods that have recently formed a large proportion of the diet, in favor of foods with contrasting sensory characteristics, thereby tending to compensate for any incipient nutritional deficiencies. Food preferences in kittens during weaning are strongly influenced by those of their mother, but can change considerably during at least the first year of life.

Mammal eradication from NZ islands

Clout, M. N., & Russell, J. C. (2006). The eradication of mammals from New Zealand islands. 127-141 In Koike, F., Clout, M.N., Kawamichi, M., De Poorter, M. and Iwatsuki, K. (eds.), Assessment and Control of Biological Invasion Risks. Shoukadoh Book Sellers, Kyoto, Japan and the World Conservation Union (IUCN), Gland, Switzerland, 2006.

Data on eradication operations against alien mammals on New Zealand islands show that there was a substantial increase in the number of successful eradications in the 1980s and 1990s. The most significant change has been in the ability to eradicate rodents from increasingly large islands (to over 11,000ha), using aerial poisoning techniques. Based on the New Zealand experience, there are good prospects for further eradications of alien mammals from islands around the world, facilitating ecological restoration and the recovery of threatened species. However, instances of reinvasion of rats (Rattus spp.) and stoats (Mustela erminea) onto previously cleared islands illustrate the importance of prevention, effective monitoring and a fuller understanding of invasion risks.

Transmission of T. gondii in an urban population of domestic cats

Afonso, E., Thulliez, P., & Gilot-Fromont, E. (2006). Transmission of Toxoplasma gondii in an urban population of domestic cats (Felis catus). International journal for parasitology, 36(13), 1373-1382.

Toxoplasma gondii is a protozoan parasite that infects humans and animal species worldwide. The relative importance of each potential transmission route in the complex life cycle of this coccidia is largely unknown, due to the lack of studies taking into account all routes simultaneously. In this study, we analyzed the transmission of T. gondii in an urban population of stray cats captured between 1993 and 2004. Analyzing prevalence, our aim was to determine which factors influence transmission in this population. Specific anti-T. gondii IgG antibodies were detected using the modified agglutination test. Firstly, we analyzed the kinetics of antibody titers in cats captured several times, using mixed linear models and correspondence analysis. We showed that antibody titers did not vary significantly with time and that titer 40 was the best threshold to separate individuals into two serological groups. Overall, prevalence was only 18.6%, thus transmission of T. gondii is infrequent in this population. As expected, a highly significant association was detected between age and presence of IgG antibodies. Prevalence was lowest in kittens aged 3–4 months, suggesting that newborn kittens may carry maternal antibodies and that vertical transmission is rare. After taking into account the effect of age, logistic regression showed that antibody carriage was related to factors that possibly related to the survival of oocysts: localization in the study site, origin of the cats, maximal temperatures and rain. Our results suggest that in this population, vertical transmission is rare, low predation limits prevalence, and oocyst survival is a determining factor in the risk of infection. We discuss the more general importance of conditions determining oocyst survival in the life cycle of T. gondii.

Introgressive hybridization between dogs and wolves in Italy

Verardi, A., Lucchini, V., & Randi, E. (2006). Detecting introgressive hybridization between free‐ranging domestic dogs and wild wolves (Canis lupus) by admixture linkage disequilibrium analysis. Molecular Ecology, 15(10), 2845-2855.

Occasional crossbreeding between free-ranging domestic dogs and wild wolves (Canis lupus) has been detected in some European countries by mitochondrial DNA sequencing and genotyping unlinked microsatellite loci. Maternal and unlinked genomic markers, however, might underestimate the extent of introgressive hybridization, and their impacts on the preservation of wild wolf gene pools. In this study, we genotyped 220 presumed Italian wolves, 85 dogs and 7 known hybrids at 16 microsatellites belonging to four different linkage groups (plus four unlinked microsatellites). Population clustering and individual assignments were performed using a Bayesian procedure implemented in structure 2.1, which models the gametic disequilibrium arising between linked loci during admixtures, aiming to trace hybridization events further back in time and infer the population of origin of chromosomal blocks. Results indicate that (i) linkage disequilibrium was higher in wolves than in dogs; (ii) 11 out of 220 wolves (5.0%) were likely admixed, a proportion that is significantly higher than one admixed genotype in 107 wolves found previously in a study using unlinked markers; (iii) posterior maximum-likelihood estimates of the recombination parameter r revealed that introgression in Italian wolves is not recent, but could have continued for the last 70 (± 20) generations, corresponding to approximately 140–210 years. Bayesian clustering showed that, despite some admixture, wolf and dog gene pools remain sharply distinct (the average proportions of membership to wolf and dog clusters were Qw = 0.95 andQd = 0.98, respectively), suggesting that hybridization was not frequent, and that introgression in nature is counteracted by behavioural or selective constraints.


Read more about canine hybidisation and gene introgression

Efficacy of an ultrasonic cat deterrent

Nelson, S. H., Evans, A. D., & Bradbury, R. B. (2006). The efficacy of an ultrasonic cat deterrent. Applied Animal Behaviour Science, 96(1), 83-91.

Ultrasound deterrents for a variety of mammals, including cats, are widely available in the commercial market, but few have been independently tested for efficacy. This study tested the efficacy of an ultrasonic cat deterrent ‘Catwatch©’, using 63 and 96 volunteer observers in two long-running (18 and 33 weeks) blind experiments. Results indicated that the device did have a moderate deterrent effect, reducing the probability of a cat intrusion into a garden by approximately 32% in the first experiment, but not in the second. The average duration of intrusions was reduced by approximately 38 and 22% in the two experiments, respectively. The magnitude of the deterrent effect appeared to increase with time, since the device was deployed. It is likely that the size of the deterrent effect could be increased by positioning the device(s) more carefully with regard to entry points to the garden that are regularly used by cats.

Acceptability of proposed cat regulations in Australia

Lilith, M., Calver, M., Styles, I., & Garkaklis, M. (2006). Protecting wildlife from predation by owned domestic cats: application of a precautionary approach to the acceptability of proposed cat regulations. Austral Ecology, 31(2), 176-189.


While it is undeniable that owned domestic cats Felis catus (Mammalia: Felidae) kill large numbers of wildlife, it is contentious if this has significant impacts on wildlife populations. Under the precautionary principle such uncertainty does not preclude measures to reduce putative risk, but action should follow consultation with stakeholders. To initiate such consultation for the City of Armadale, Western Australia, we surveyed urban and rural residents to determine their opinions regarding putative impacts of owned cats on wildlife and the acceptability of proposed regulations. Key statements accepted by 70% or more of respondents, irrespective of their residence, gender or cat ownership status, included: (i) there is a need to regulate owned domestic cats; (ii) the presence of cats in nature reserves is harmful to wildlife; (iii) cats not owned by licensed breeders should be desexed; and (iv) local councils should be empowered to restrict the maximum number of cats per household. Seventy per cent or more of owners agreed to keep their cats on their property from sunset to sunrise and to register them if these measures became compulsory. All groups except urban men also indicated 70% or greater willingness to keep their cats on their property constantly if required. However, fewer than 40% of owners supported empowering local councils to enforce cat-free zones. In this community, cat regulation excluding cat-free zones should enjoy support. Similar approaches should be effective wherever the environmental impacts of owned domestic cats are debated, because compliance with such regulations should be high.

Human attitude towards cat fecal deposition

Dabritz, H.A.,  E. R. Atwill, I.A. Gardner, M.A. Miller & P.A. Conrad. (2006) Outdoor fecal deposition by free-roaming cats and attitudes of cat owners and nonowners toward stray pets, wildlife, and water pollution. Journal of the American Veterinary Medical Association 229 (1): 74-81

Objective—To estimate cat population size, management, and outside fecal deposition and evaluate attitudes of cat owners and nonowners to stray animal control, water pollution, and wildlife protection.

Design—Cross-sectional survey.

Sample Population—294 adult residents of Cayucos, Los Osos, and Morro Bay, Calif.

Procedures—Telephone survey.

Results—The region's cat population was estimated at 7,284 owned and 2,046 feral cats, and 38% of surveyed households owned a mean of 1.9 cats/household. Forty-four percent of cats defecated outside >75% of the time. Annual fecal deposition (wet weight) by owned cats in the 3 communities was estimated to be 77.6 tonnes (76.4 tons). Cat owners were more likely to oppose cat licensing and impounding stray cats and support trap-neuter-return for stray cats and less likely to be concerned about water pollution, than were noncat owners.

Conclusions and Clinical Relevance—Feral cats represented a sizeable proportion (22%) of the free roaming cats in this area and could be contributing 30.0 tonnes (29.5 tons) of feces to the environment per year. However, feral cats are not the principal source of fecal loading because owned cats defecating outdoors contribute an estimated 77.6 tonnes (76.4 tons) or 72% of the annual outdoor fecal deposition.

Virus seroprevalence among cats in North America

Levy, J.K.,  H. M, Scott, J. L. Lachtara , P. C. Crawford. (2006) Seroprevalence of feline leukemia virus and feline immunodeficiency virus infection among cats in North America and risk factors for seropositivity. Journal of the American Veterinary Medical Association 228 (3): 371-376

Objective—To determine seroprevalence of FeLV and FIV infection among cats in North America and risk factors for seropositivity.

Design—Prospective cross-sectional survey.

Animals—18,038 cats tested at 345 veterinary clinics (n = 9,970) and 145 animal shelters (8,068) between August and November 2004.

Procedure—Cats were tested with a point-of-care ELISA for FeLV antigen and FIV antibody. A multivariable random effects logistic regression model was used to identify risk factors significantly associated with seropositivity while accounting for clinic-to-clinic (or shelter) variability.

Results—409 (2.3%) cats were seropositive for FeLV antigen, and 446 (2.5%) cats were seropositive for FIV antibody; 58 (0.3%) cats were seropositive for infection with both viruses. Multivariable analysis indicated that age, sex, health status, and cat lifestyle and source were significantly associated with risk of seropositivity, with adults more likely to be seropositive than juveniles (adjusted odds ratios [ORs], 2.5 and 2.05 for FeLV and FIV seropositivity, respectively), sexually intact adult males more likely to be seropositive than sexually intact adult females (adjusted ORs, 2.4 and 4.66), and outdoor cats that were sick at the time of testing more likely to be seropositive than healthy indoor cats (adjusted ORs, 8.89 and 11.3).

Conclusions and Clinical Relevance—Results suggest that certain characteristics, such as age, sex, health status, and lifestyle, are associated with risk of FeLV and FIV seropositivity among cats in North America. However, cats in all categories were found to be at risk for infection, and current guidelines to test all cats at the time of acquisition and again during illness should be followed.

Impacts of feral and free-ranging cats on bird species of conservation concern

Winter, L., & Wallace, G. E. (2006). Impacts of feral and free-ranging cats on bird species of conservation concern. Other Publications in Wildlife Management, 28. University of Nebraska.

This report reviews cat predation impacts on rare birds in the states of New York, New Jersey, Florida, California, and Hawaii, reviews government-authorized programs and ordinances affecting feral and freeranging cats and their management, and makes recommendations on better ways to manage cat overpopulation problems.

RECOMENDATIONS FOR CONSERVATIONISTS

Conservation groups and individuals have an important role to play in helping to educate the public on responsible pet ownership and in generating support for predator management projects. Here are some tips that can help protect birds from free-roaming cats in your community.
• Keep your own cats indoors, and walk it outside on a harness and leash, or in an outdoor enclosure. Encourage others to keep their cats indoors.
• Spay or neuter your cat at an early age before it can reproduce.
• Do not feed stray cats and never abandon a cat you can no longer care for. Instead, find a good home for your cat or take it to an animal shelter or humane society. For a shelter nearest you, see the National Shelter Directory at http://www. aspca.org.
• Work for passage of local cat ordinances that prohibit cats from roaming off their owner’s property.
• Conduct a Cats Indoors! campaign in your community. For free downloadable materials and more information, see http://www.abcbirds.org/cats.
• Support efforts of public land managers to humanely trap and remove cats from habitat managed for wildlife.
• Conduct a media campaign in your community using print and radio Public Service Announcements (PSAs) found at http://www.abcbirds.org/cats.
• Sponsor a children’s poster competition for National Keep Your Cat Indoors Day, held on the second Saturday in May. For more information see http://www.abcbirds.org/cats/NKYCID.htm.
• Print an article or PSA in your organization’s newsletter.
• Ask your state wildlife agency to print an article in their magazine and/or produce a Web page on the issue for their Web site.
• Ask your state wildlife agency to adopt the Cats Indoors! campaign and distribute brochures and other materials to the public through their visitor centers, educational programs, and displays.

Dogs in Atlantic forest fragments in Brazil

Galetti, M., & Sazima, I. (2006). Impact of feral dogs in an urban Atlantic forest fragment in southeastern Brazil. Natur. Conservation, 4, 146-151.

Feral domestic dogs are one of the main predators of native wildlife in protected areas all over the world. However, the number of prey killed by feral dogs is poorly recorded. A total of 46 carcasses of at least 12 vertebrate species killed by dogs were found along 44 months in an urban, 250 ha Atlantic forest fragment in southeastern Brazil. Feral dogs showed no apparent selection towards different species of prey, killing from small frogs to deer. Mammals were the most frequent prey found (75%). Our data indicate that feral dogs have a great impact on wildlife in the Atlantic forest, especially in areas where wildlife needs to move between forest fragments. Eradication programs, although controversial, are the only way to reduce wildlife predation by feral dogs.

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Ecology of feral cats in open forest in Australia

MOLSHER, R. L. (2006). The ecology of feral cats, Felis catus, in open forest in New South Wales: interactions with food resources and foxes. Australian Nature Conservation Agency

This report provides an overview of the impact of feral cats Felis catus on native fauna of the Pacific region, with particular reference to Australia and its island territories. In Australia, cats take a wide variety of native species of mammals, birds and reptiles, but show evident preference for young rabbits or small marsupials where these are available. Reptiles are taken primarily in and habitats, while birds often feature predominantly in the diet of cats on islands. Despite their catholic diet, population-level impacts of feral cats on native fauna have been poorly documented. There is considerable potential for competition to occur between cats and carnivorous species such as quolls and raptors, but no critical evidence has yet been adduced. There is also potential for amerisal impacts to occur, either via transmission of the pseudophyllidean tapeworm Spirometra erinacei or of the protozoan parasite Toxoplasma gondii, but evidence for deleterious effects in freeliving animals is not compelling. Direct predatory impacts have been inferred from anecdotal and historical evidence, more strongly from failed attempts to reintroduce native species to their former ranges, and most critically from the decimation of island faunas and responses of prey species following experimental removal of cats or reduction of cat numbers. Attributes of the biology of feral cats and their prey species derived from the literature review were used to develop a rank-scoring system to assess the susceptibility of native species to cat predation. Species listed federally as endangered or vulnerable were designated as being at zero, low or high risk of impact from cats according to their attribute scores, and their distributions mapped from primary sources and actual locality data. Based on the number of threatened species they contain, localities and regions within Australia were placed in order of priority for future research to clarify the precise impacts of feral cats. Although difficult and expensive to carry out, controlled and replicated field removal experiments are recommended to elucidate cat impacts in all mainland areas. Removal of cats should take place also on offshore islands and island territories, but only if pilot studies show that this will not release populations of alternative predator species such as introduced rats. If release appears likely, cats should be removed only as a component of an integrated control program that targets all relevant predators.

Exotic mammals structure Australian biota

Davey, C., A. R. E. Sinclair, R. P. Pech, A. D. Arthur, C. J. Krebs, A. E. Newsome, D. Hik, R. Molsher, & K. Allcock (2006). Do exotic vertebrates structure the biota of Australia? An experimental test in New South Wales. Ecosystems,9(6), 992-1008

From 1993 to 2001, we conducted a series of experiments in a mixed grassland–woodland system in central New South Wales (NSW) to quantify the interactions between red foxes and their prey and competitors. Foxes were removed from two areas around the perimeter of Lake Burrendong, and data were collected from these areas and a nearby untreated area before, during, and after the period of fox control. The arrival of rabbit hemorrhagic disease (RHD) in 1996 provided an opportunity to examine the interactive effects of controlling foxes and rabbits. In this landscape, typical of central NSW, (a) the fox population was not affected by a large reduction in the abundance of rabbits, or vice versa; (b) the cat population declined in areas where foxes were removed after the large RHD-induced reduction in rabbit numbers, but there was no consistent response to the removal of foxes; (c) the abundance of some macropod species increased in response only to the combined removal of rabbits and foxes; (d) there were no consistent changes in the abundances of bird species in response to the removal of either foxes or rabbits, but there were clear habitat differences in bird species richness; and (e) there was likely to be an increase in woody plant species after the large reduction in rabbit populations by RHD. We conclude that (a) long-term field experiments (more than 3 years) are required to quantify the indirect consequences of controlling foxes and rabbits, and (b) single manipulations, such as fox control or rabbit control, are not necessarily sufficient for the conservation of remnant woodland communities in southeastern Australia.

Domestic cat gene introgression into wild cat in Europe

Randi, E., Pierpaoli, M., Beaumont, M., Ragni, B., & Sforzi, A. (2001). Genetic identification of wild and domestic cats (Felis silvestris) and their hybrids using Bayesian clustering methods. Molecular Biology and Evolution, 18(9), 1679-1693.

Crossbreeding with free-ranging domestic cats is supposed to threaten the genetic integrity of wildcat populations in Europe, although the diagnostic markers to identify "pure" or "admixed" wildcats have never been clearly defined. Here we use mitochondrial (mt) DNA sequences and allelic variation at 12 microsatellite loci to genotype 128 wild and domestic cats sampled in Italy which were preclassified into three separate groups: European wildcats (Felis silvestris silvestris), Sardinian wildcats (Felis silvestris libyca), and domestic cats (Felis silvestris catus), according to their coat color patterns, collection localities, and other phenotypical traits, independently of any genetic information. For comparison, we included some captive-reared hybrids of European wild and domestic cats. Genetic variability was significantly partitioned among the three groups (mtDNA estimate of F(ST) = 0.36; microsatellite estimate of R(ST) = 0.30; P < 0.001), suggesting that morphological diversity reflects the existence of distinct gene pools. Multivariate ordination of individual genotypes and clustering of interindividual genetic distances also showed evidence of distinct cat groups, partially congruent with the morphological classification. Cluster analysis, however, did not enable hybrid cats to be identified from genetic information alone, nor were all individuals assigned to their populations. In contrast, a Bayesian admixture analysis simultaneously assigned the European wildcats, the Sardinian wildcats, and the domestic cats to different clusters, independent of any prior information, and pointed out the admixed gene composition of the hybrids, which were assigned to more than one cluster. Only one putative Sardinian wildcat was assigned to the domestic cat cluster, and one presumed European wildcat showed mixed (hybrid) ancestry in the domestic cat gene pool. Mitochondrial DNA sequences indicated that three additional presumed European wildcats might have hybrid ancestry. These four cats were sampled from the same area in the northernmost edge of the European wildcat distribution in the Italian Apennines. Admixture analyses suggest that wild and domestic cats in Italy are distinct, reproductively isolated gene pools and that introgression of domestic alleles into the wild-living population is very limited and geographically localized.

Pierpaoli, M., Birò, Z.S., Herrmann, M., Hupe, K., Fernandes, M., Ragni, B., Szemethy, L. & Randi, E. (2003). Genetic distinction of wildcat (Felis silvestris) populations in Europe, and hybridization with domestic cats in Hungary. Molecular Ecology 12: 2585-2598.

The genetic integrity and evolutionary persistence of declining wildcat populations are threatened by crossbreeding with widespread free-living domestic cats. Here we use allelic variation at 12 microsatellite loci to describe genetic variation in 336 cats sampled from nine European countries. Cats were identified as European wildcats (Felis silvestris silvestris), Sardinian wildcats (F. s. libyca) and domestic cats (F. s. catus), according to phenotypic traits, geographical locations and independently of any genetic information. Genetic variability was significantly partitioned among taxonomic groups (FST = 0.11; RST = 0.41; P < 0.001) and sampling locations (FST = 0.07; RST = 0.06; P < 0.001), suggesting that wild and domestic cats are subdivided into distinct gene pools in Europe. Multivariate and Bayesian clustering of individual genotypes also showed evidence of distinct cat groups, congruent with current taxonomy, and suggesting geographical population structuring. Admixture analyses identified cryptic hybrids among wildcats in Portugal, Italy and Bulgaria, and evidenced instances of extensive hybridization between wild and domestic cats sampled in Hungary. Cats in Hungary include a composite assemblage of variable phenotypes and genotypes, which, as previously documented in Scotland, might originate from long lasting hybridization and introgression. A number of historical, demographic and ecological conditions can lead to extensive crossbreeding between wild and domestic cats, thus threatening the genetic integrity of wildcat populations in Europe.

Lecis, R., Pierpaoli, M., Biro, Z. S., Szemethy, L., Ragni, B., Vercillo, F., & Randi, E. (2006). Bayesian analyses of admixture in wild and domestic cats (Felis silvestris) using linked microsatellite loci. Molecular Ecology, 15(1), 119-131.

Methods recently developed to infer population structure and admixture mostly use individual genotypes described by unlinked neutral markers. However, Hardy–Weinberg and linkage disequilibria among independent markers decline rapidly with admixture time, and the admixture signals could be lost in a few generations. In this study, we aimed to describe genetic admixture in 182 European wild and domestic cats (Felis silvestris), which hybridize sporadically in Italy and extensively in Hungary. Cats were genotyped at 27 microsatellites, including 21 linked loci mapping on five distinct feline linkage groups. Genotypes were analysed with structure 2.1, a Bayesian procedure designed to model admixture linkage disequilibrium, which promises to assess efficiently older admixture events using tightly linked markers. Results showed that domestic and wild cats sampled in Italy were split into two distinct clusters with average proportions of membership Q > 0.90, congruent with prior morphological identifications. In contrast, free-living cats sampled in Hungary were assigned partly to the domestic and the wild cat clusters, with Q < 0.50. Admixture analyses of individual genotypes identified, respectively, 5/61 (8%), and 16–20/65 (25–31%) hybrids among the Italian wildcats and Hungarian free-living cats. Similar results were obtained in the past using unlinked loci, although the new linked markers identified additional admixed wildcats in Italy. Linkage analyses confirm that hybridization is limited in Italian, but widespread in Hungarian wildcats, a population that is threatened by cross-breeding with free-ranging domestic cats. The total panel of 27 loci performed better than the linked loci alone in the identification of domestic and known hybrid cats, suggesting that a large number of linked plus unlinked markers can improve the results of admixture analyses. Inferred recombination events led to identify the population of origin of chromosomal segments, suggesting that admixture mapping experiments can be designed also in wild populations.


See more on domestic cat gene introgression in wildcat

TNR ineffective without awareness

Natoli, E., Maragliano, L., Cariola, G., Faini, A., Bonanni, R., Cafazzo, S., & Fantini, C. (2006). Management of feral domestic cats in the urban environment of Rome (Italy). Preventive veterinary medicine, 77(3), 180-185.

In Italy, which is rabies-free, the national Law No. 281 [Legge Nazionale 14 agosto 1991. No. 281: Legge Quadro in materia di animali di affezione e prevenzione del randagismo. Gazz. Uff. Rep. Ital. no 203 del 30 agosto 1991: p. 3] on the management of pets and on the control of feral cats has introduced the no-kill policy for this species. Thus, “trap-neuter-release” (TNR) programs have been carried out for >10 years. In this paper we present data on registered colonies and censused cats in Rome from 1991 to 2000; the results of the neutering campaign from 1991 to 2000; and a survey, on 103 cat colonies, on the effects of demographic control of urban feral-cat colonies in the city of Rome, carried out by the local Veterinary Public Services (VPS) in collaboration with the associations of cat care-takers. In 10 years almost 8000 were neutered and reintroduced in their original colony. The spay/neuter campaigns brought about a general decrease in cat number but the percentage of cat immigration (due to abandonment and spontaneous arrival) is around 21%. This suggests that all these efforts without an effective education of people to control the reproduction of house cats (as a prevention for abandonment) are a waste of money, time and energy.