Cat predation on wildlife in Haute Savoie, France

Vuagnat-Kolter, M. Prédation du chat domestique, Felis catus (linnaeus, 1758) sur la faune sauvage, dans une commune péri-urbaine de Haute-Savoie (74). Le Bièvre, 22.

Le chat domestique, Felis catus (Linnaeus, 1758) est une espèce invasive, un redoutable prédateur et un animal de compagnie qui ne dépend pas de la disponibilité des proies pour survivre. Ces trois aspects associés à l’importante densité de chats font de sa prédation sur la faune sauvage, un facteur important dans le fonctionnement des écosystèmes, qui peut entraîner localement le déclin d’espèces
indigènes. La présente étude a eu lieu en Haute-Savoie dans la commune de Feigères. Toutes les proies  ramenées au domicile par 44 chats domestiques ont été identifiées sur une durée de 3 mois. Un total de 163 proies ont été tuées (86 micromammifères, 69 oiseaux, 8 reptiles) pour une moyenne de 3,7 proies par chat. Neuf espèces d’oiseaux ont été identifiées, parmi lesquelles le moineau domestique (58 %) est le plus représentée devant le merle noir (13  %). Le moineau domestique est placé en première position car il est commensal de l’homme et vit dans toutes sortes de zones modifiées par celui-ci, notamment les jardins. L’extrapolation des résultats à l’échelle de la commune montre que 2068 proies dont 878 oiseaux ont été potentiellement tuées sur trois mois entre mi-avril et mi-juillet. Le suivi télémétrique réalisé sur une durée de cinq semaines sur cinq chats, a permis de démontrer que les chats sont inactifs la majeur partie du temps (77 %) et que leurs périodes d’activité privilégiées sont l’aube et le crépuscule, lorsque les températures sont les plus basses de la journée. Le domaine vital des chats est relativement petit, ils n’effectuent pas de grandes distances et occupent principalement leur foyer ainsi que le jardin attenant à celui-ci.

The domestic cat Felix catus (Linn. 1758) is an invasive species, a formidable predator and a pet which is not dependent on the availability of prey for its survival. These three elements, plus the high density of cats, make its preying on wildlife a major factor in the functioning of ecosystems. This can lead to a decline in indigenous species locally. The present study took place in the Haute-Savoie department (France), in the commune of Feigères. All the prey brought home by 44 domestic cats were identified over a period of 3 months. There were 163 prey items in all (86 small mammals, 69 birds and 8 reptiles) for an average of 3.7 prey items per cat. 9 species of bird were identified, among which the House Sparow was the most numerous (58  %) followed by Blackbird (13  %). The House Sparrow came first because it is closely associated with man and lives in all sorts of places modified by him, notably gardens. Extrapolating the results to the scale of the commune produces 2068 prey items including 878 birds which were potentially killed over the three-month period from mid-April to mid-July. Radiotracking carried out on 5 cats over 5 weeks showed that cats are inactive most
(77  %) of the time. Their preferred periods of activity are dawn and dusk when the day temperatures are at their lowest. The cats’ territories are relatively small, not covering large distances, and mainly
occupy their homes and the adjacent gardens.

Prevalence of T. gondii depends on household effect

Fromont, E. G., Riche, B., & Rabilloud, M. (2009). Toxoplasma seroprevalence in a rural population in France: detection of a household effect. BMC infectious diseases, 9(1), 76.

Background

Toxoplasma gondii, the agent of toxoplasmosis, has a complex life cycle. In humans, the parasite may be acquired either through ingestion of contaminated meat or through oocysts present in the environment. The importance of each source of contamination varies locally according to the environment characteristics and to differences concerning human eating habits and the presence of cats; thus, the risk factors may be determined through fine-scale studies. Here, we searched for factors associated with seropositivity in the population of two adjacent villages in Lorraine region, France.

Methods
All voluntary inhabitants filled out a questionnaire and gave a blood sample. The seroprevalence was estimated globally and according to the inhabitants' ages using a cubic spline regression. A mixed logistic regression model was used to quantify the effect of individual and household factors on the probability of seropositivity.

Results

Based on serological results from 273 persons, we estimated seroprevalence to be 47% (95% confidence interval: 41 to 53%). That seroprevalence increased with age: the slope was the steepest up to the age of 40 years (OR = 2.48 per 10-year increment, 95% credibility interval: [1.29 to 5.09]), but that increase was not significant afterwards. The probability of seropositivity tended to be higher in men than in women (OR = 2.01, 95% credibility interval: [0.92 to 4.72]) and in subjects eating raw vegetables at least once a week than in the others (OR = 8.4, 95% credibility interval: [0.93 to 72.1]). These effects were close to statistical significance. The multivariable analysis highlighted a significant seroprevalence heterogeneity among households. That seroprevalence varied between 6 and 91% (5th and 95th percentile of the household seropositivity distribution).

ConclusionThe major finding is the household effect, with a strong heterogeneity of seroprevalence among households. This effect may be explained by common exposures of household members to local risk factors. Future work will quantify the link between the presence of oocysts in the soil and the seroprevalence of exposed households using a spatial analysis.

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.

Cat defecation behaviour and soil contamination by Toxoplasma gondii

Afonso, E., Lemoine, M., Poulle, M. L., Ravat, M. C., Romand, S., Thulliez, P., Villena, I., Aubert, D., Rabilloud, M., Riche, B. & Gilot-Fromont, E. (2008). Spatial distribution of soil contamination by Toxoplasma gondii in relation to cat defecation behaviour in an urban area. International journal for parasitology, 38(8), 1017-1023.

In urban areas, there may be a high local risk of zoonosis due to high densities of stray cat populations. In this study, soil contamination by oocysts of Toxoplasma gondii was searched for, and its spatial distribution was analysed in relation to defecation behaviour of cats living in a high-density population present in one area of Lyon (France). Sixteen defecation sites were first identified. Cats were then repeatedly fed with marked food and the marked faeces were searched for in the defecation sites. Of 260 markers, 72 were recovered from 24 different cats. Defecation sites were frequented by up to 15 individuals. Soil samples were also examined in order to detect the presence of T. gondii using real-time PCR. The entire study area was then sampled according to cat density and vegetation cover type. Only three of 55 samples were positive and all came from defecation sites. In a second series of observations, 16 defecation sites were sampled. Eight of 62 samples tested positive, originating in five defecation sites. Laboratory experiments using experimental seeding of soil showed that the inoculated dose that can be detected in 50% of assays equals 100–1000 oocysts/g, depending on the strain. This study shows that high concentrations of oocysts can be detected in soil samples using molecular methods and suggests that spatial distribution of contamination areas is highly heterogeneous. Positive samples were only found in some of the defecation sites, signifying that at-risk points for human and animal infection may be very localised.

Wild or feral cats in NE France

O’Brien, J., Devillard, S., Say, L., Vanthomme, H., Léger, F., Ruette, S., Pontier, D., 2009. Preserving genetic integrity in a hybridising world: are European Wildcats (Felis silvestris silvestris) in eastern France distinct from sympatric feral domestic cats? Biodiversity Conservation, 18, 2351–2360.

We investigate the genetic profile of putative European Wildcats in north-eastern France, possessing the wildcat phenotype, but sampled in an area where they are sympatric with free-roaming domestic cats and, thus, are exposed to potential hybridisation. From a sample of 209 cats, the programme STRUCTURE clearly identified two distinct genetic clusters that corresponded to European Wildcats and domestic cats. The cats from these two clusters were clearly differentiated from each other (F ST = 0.16). However, the genotypes of some individual cats were split between the two clusters, indicative of genetic admixture. Our analysis demonstrates that a genetically distinct population of cats that possess the European Wildcat phenotype persists in north-eastern France, but that there is a low, yet real, risk of hybridisation with sympatric domestic cats. These European Wildcats warrant conservation efforts to protect their genetic integrity.

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Habitat sharing of wildcat, domestic cat and hybrids

Germain, E., Benhamou, S., & Poulle, M. L. (2008). Spatio‐temporal sharing between the European wildcat, the domestic cat and their hybrids. Journal of Zoology, 276(2), 195-203.

The European wildcat Felis silvestris silvestris, which can hybridize with the domestic cat Felis catus to produce fertile hybrids, is threatened by hybridization. To identify the behavioural processes that can affect interbreeding, we investigated the spatio-temporal sharing between wildcats, domestic cats and their hybrids (defined on their genotypes) in a rural area of north-eastern France where hybridization is frequent. Wildcats' and hybrids' home ranges were larger than those of domestic cats, and they did not vary according to body mass, season and reproductive period. The three types of cats had similar daily activity rhythms but the concordance between their space use patterns was low or null. Thus, a high spatio-temporal concordance is not a prerequisite for hybridization. Rare excursions made by the cats outside of their home ranges may be at the origin of interbreeding. Moreover, hybrids may play a key role in hybridization by behaving as wildcats and by sharing at least a part of their range with them as well as with domestic cats. Behavioural barriers between them and wildcats may not exist because of their similarity in morphology and spatial behaviour.


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Distribution and spatial genetic structure of wildcat in France

Say, L., S. Devillard, F. Léger, D. Pontier & S. Ruette. 2012. Distribution and spatial genetic structure of European wildcat in France. Animal Conservation , 15 (1): 18-27

Given the problem of hybridization with domestic cats, there is a growing need to identify populations of the European wildcat Felis silvestris silvestris in order to protect the genetic integrity of this subspecies. In this paper, we use known locations of observations of wildcats or recovered carcasses to reassess the distribution of the wildcat in France and, in cases where carcasses were collected, we use both phenotypic and molecular genetic analyses to distinguish wildcats from hybrids with domestic cats. Spatially explicit multivariate analysis of wildcat' genotypes was then performed to define genetic units. Our study confirms the presence of wildcats in a large area of c. 155 000 km² , suggestive of a range of expansion, and divided into two clearly distinct and unconnected areas – the Pyrenees and the north-eastern part of France. However, European wildcat populations may be decreasing in the French Pyrenees, whereas the north-eastern part represents the main area (MA) of wildcat presence. This extension does not appear to be primarily due to hybrids, as both wildcats and hybrids were located throughout the MA. In addition, we found that genetic diversity of wildcats in the MA is remarkably high, suggesting that French populations are not threatened by a lack of genetic diversity. Furthermore, wildcats of the MA are structured into two genetically distinct populations that are contiguous and probably extend into Germany to form the largest area of wildcat presence in Europe and an area of major interest for their conservation. Our study calls for localized examination of the feasibility and usefulness of wildlife corridors to enhance connectivity between the different populations, thereby allowing sufficient levels of immigration and gene flow within the regional meta-population to ensure the long-term viability of these populations.


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