Fragmentation and low density as major conservation challenges for the southernmost populations of the European wildcat

Toxoplasma gondii exposure in wildlife in Spain: Is there any predictable threat for humans and domestic animals?

Toxoplasmosis is a parasitic zoonosis of key importance in veterinary and public health. This article summarizes the available data (from 2000 to 2023) of exposition to Toxoplasma gondii in wildlife species in Spain based on a systematic bibliographic search, as well as further analysis of its potential relationship with environmental variables, biodiversity, anthropogenic impact on the habitat, and the reported human cases of toxoplasmosis. The overall seroprevalence of T. gondii in carnivorous mammals, birds, ungulate and lagomorph species in Spain was estimated at 69.3 %, 36.4 %, 18.4 %, and 16.2 %, respectively. Among the studies considered, great heterogeneity was observed both between and within taxonomic groups [Cohen's d > 0.8; X2 = 1039.10, df = 4 (p < 0.01) I2 = 97 %, r2 = 1.88, (p < 0.001)] and between and within bioregions [Cohen's d > 0.5; X2 = 368.59, df = 4 (p < 0.01)]. The results of a generalized linear model explaining T. gondii seroprevalence in wild animals suggest the influence of abiotic variables [wetland (p < 0.001), unvegetated (p < 0.001), isothermality (p < 0.001), and mean temperature during wettest quarter (p < 0.05)] and number of intermediate host species as positively associated with increased exposure of wildlife to T. gondii (p < 0.01). Toxoplasma gondii DNA was detected in both wild birds and wild mammals (range: 0.0-51.2 %) mainly from north-centre, northeast, and central-west of Spain. Regarding hospitalisation rates due to toxoplasmosis in humans, some abiotic variables [permanent crops (p < 0.05) and mean temperature during wettest quarter (p < 0.05)] showed a positive association. Despite certain limitations, this research evidences a substantial gap of knowledge on the implication of wildlife in the life cycle of T. gondii in Spain. This lack of knowledge is particularly evident in areas where the human-livestock-wildlife interface overlaps, preventing us from accurately determining its true distribution in different habitats, as well as its potential direct or indirect implications on public and veterinary health.

The wildcat (Felis s. silvestris) in the Mediterranean forest: sighting through photo-trapping and non-invasive hair collection for genetic purposes

The European wildcat (Felis silvestris silvestris) is a mesocarnivore species widely distributed in Europe, from Eastern Europe to Portugal and from Scotland to Italy. Recent biogeographical studies of wildcat populations have endeavoured to assess in detail the various issues that pose a threat to this species, including hybridization with domestic cats. The use of non-invasive sampling methods supported by photo-trapping and some attractants has made it possible to gather genetic material for the detection of native wildcats in locally threatened populations, some of which live in the Iberian Peninsula. Testimonies of naturalists, hunters and farm workers led our team to choose specific areas in two large territories of Mediterranean forests where the presence of wildcats has been historically attested: the Almonte River basin and the Sierra de San Pedro Mountains. Between 2014 and 2018, non-invasive hair sampling was performed using valerian (Valeriana officinalis) as an attractant and supported by photo-trapping to guarantee the collection of genuine biological material (hair samples). The hair samples were genetically assessed by sequencing the nuclear gene IRBP (interphotoreceptor retinoid-binding protein) and the mtDNA gene ND4 (NADH dehydrogenase subunit 4). Despite the low density of wildcats, this combined protocol proved to be an applicable tool for detecting the presence of elusive wildcats and other mesocarnivore species in this remote region of southern Europe. In addition, non-invasive hair trapping contributes to the collection of genetic material from current wildcat populations. This procedure could enhance future management actions focused on collecting quality individualized biological material.

Assessing Changes in the Distribution Patterns of the European Wildcat in Hungary

The European wildcat (Felis silvestris Schreber, 1777) is an endangered and elusive carnivore that is slowly recovering in Central Europe after persecution and a decline in its distribution over the past two centuries, and specific conservation plans are needed in most of its range. Knowledge of the continent-wide distribution and status of this species is still poor. Using an online questionnaire, we evaluated the nationwide distribution of wildcats across three time periods (2004, 2014, and 2022) in Hungary. The species' reported occurrence was analyzed according to binominal logistic regression using the percent cover of land cover categories as explanatory variables. We found that the spatial cover of broad-leaved forest was positively associated with the occurrence of wildcats, and the analysis revealed a positive trend in the larger 2004-2022 time frame. We also recorded that although wildcats have disappeared from areas of the central, southern, and western parts of Hungary, regions in the eastern, northern, and south-western areas appear to retain stable populations.

Thelazia callipaeda as a potential new threat to european wildcats: insights from an eco-epidemiological study

Global warming and displacement of vectors and wild and domestic hosts by humans greatly change host-parasite interactions and parasite transmission rates. Thelazia callipaeda Railliet and Henry, 1910 (Spirurida: Thelaziidae) is a zoonotic parasite rapidly colonizing Europe from its Asian native range. This nematode is vectored by Phortica flies and may cause ocular disorders, such as keratitis and corneal ulcers, in wild mammals, dogs, cats and humans. With the aim of detecting possible threats for the European wildcat (Felis silvestris) in one of its last Mediterranean strongholds, we initiated in 2017 a long-term monitoring program in Sierra Arana (southeastern Spain), which includes exploring its epidemiological and spatial relationships with domestic cats (Felis catus). During routine medical check-ups, we detected ocular nematodes in 3 of 17 (17.6%) wildcats and 1 of 23 (4.3%) domestic cats tested, confirmed to be T. callipaeda by microscopic and molecular analyses. This nematode species was first detected in the study area in 2021. To our knowledge, this is the first case of infection in wildcats in Spain. Through telemetry, we detected little spatial overlap between the home ranges of wildcats and domestic cats, which seems to be sufficient to facilitate the inter-specific transmission of T. callipaeda. Our findings suggest that this pathogen could be a new threat to the wildcat, a locally endangered wild felid. Further eco-epidemiological monitoring and sanitary control of domestic cats will be strongly needed, especially given the ongoing global warming scenario.

Prevalence of Toxoplasma gondii in Endangered Wild Felines (Felis silvestris and Lynx pardinus) in Spain

The wildcat (Felis silvestris) and the Iberian lynx (Lynx pardinus) are important species in Spain, considered as near-threatened and endangered, respectively. Both can be infected by Toxoplasma gondii, a parasite that can cause morbidity and mortality in transplacentally-infected or immunocompromised mammals. The data on the prevalence of this parasite in wild populations of these species in Spain are outdated. The objective of this study was to update information and evaluate the role of these felines in parasite epidemiology and the potential impact of the parasite on their conservation. Blood and fecal samples were collected from captured animals, as well as the tongue, diaphragm, and spleen, from animals killed in road accidents in central Spain. An indirect fluorescent antibody test (IFAT) was used to detect parasite antibodies in serum, microscopy and molecular analysis were used to detect oocysts in feces, and molecular analysis was used to determine the existence of tissue cysts. Seroprevalence was 85% in wildcats and 45% in lynx, and parasite DNA was detected in the feces of one wildcat and in tissue samples from 10 wildcats and 11 Iberian lynxes. These results highlight the epidemiological importance and high risk of T. gondii infection in animals and humans in the studied areas. Considering feline susceptibility to infection, monitoring programs are needed to assess the health status of wild felines.

Applications of non-intrusive methods to study the sand cat: a field study in the Sahara Desert

Surveys based on indirect signs and camera trapping are two non-invasive methods extensively used for monitoring elusive mammals. Both approaches can be useful to obtain key information on wildlife in remote areas, since they may allow for the logistically viable design of optimal field frameworks. The sand cat (Felis margarita) is a feline that inhabits the Sahara Desert, the Arabian Peninsula, and western Asian deserts. Its basic ecology is poorly known and the status and impacts of threats are difficult to assess. Some local population declines have been detected, and more research is needed. Based on field surveys carried out in the Atlantic Sahara, we have evaluated the applications of both methods to study this species. Our results show that (a) camera trapping provided reliable data on several key aspects of its ecology, (b) walking surveys to collect feces for molecular data failed completely, and (c) for footprints, identification problems and the marked effects of the absence of optimal substrates and the prevalence of wind are relevant handicaps. Beyond this evaluation, we provide for the first time some key aspects of the ecology of sand cats in the Sahara Desert, including habitat selection, density, diel activity, and predator–prey relationships.

Eurasian lynx density and habitat use in one of Europe’s strongholds, the Romanian Carpathians

The Eurasian lynx (Lynx lynx) faces population declines in the western part of its range, and its ecological requirements are poorly understood in the eastern part of its range. The Romanian Carpathians harbor an intact large carnivore community, in which lynx co-occur with bears (Ursus arctos), wolves (Canis lupus), and humans (Homo sapiens), with which they potentially compete for ungulate prey. We provide a science-based estimate of lynx density and habitat use, combining non-invasive monitoring techniques (camera trapping) with spatially explicit capture-recapture models (SECR) in the Southern Carpathians of Romania. We sampled 59 and 76 trap stations during two monitoring sessions (winter and autumn), identified at least 30 individuals, from which we reconstructed encounter histories for 23 individuals. SECR modeling resulted in similar density estimates between winter and autumn (1.6 ± 0.39 SE and 1.7 ± 0.38 SE lynx/100 km2, respectively), but the cumulative number of lynx detected reached the asymptote faster during autumn, suggesting that monitoring prior to the mating season is preferable. Density varied within and across sessions with topography (slope), percent forest cover, and landscape heterogeneity (i.e., agricultural mosaic). Density hotspots shifted between low-altitude agricultural mosaic during winter and more rugged, mid-altitude forest stands during autumn. Estimated densities of lynx in the Romanian Carpathians are higher than those reported in the Alps or Slovak Carpathians, highlighting the importance of this population as a source both for natural recolonization and recent reintroduction programs. When used in an SECR framework, camera trapping is an efficient method for assessing spatial and temporal variation in lynx population density in the remote Romanian Carpathians. We recommend this methodology for improving lynx population estimates and to monitor lynx population trends nationwide.

Spatial Ecology and Diel Activity of European Wildcat (Felis silvestris) in a Protected Lowland Area in Northern Greece

Simple Summary

The European wildcat is a species of conservation concern protected across its range in Europe, where it occurs in five discontinuous populations. The Balkan population has received little attention, making it difficult to assess whether the ecological traits reported for other populations apply also to this population. This hampers the development of targeted conservation measures. The present study reports the first findings on the spatial ecology and daily activity pattern of wildcats in a human modified landscape in Greece, using cutting edge data loggers attached to wildcat collars. In Greece, wildcat home range sizes are within the range of those reported for other populations. Male wildcats are active primarily at night and near dawn and dusk, as is typical for the species. However, the activity of some females varied from this pattern in late spring, in ways expected for wildcats, caring for offspring at a den. Overall, our findings help fill the ecological knowledge gap of the species in Greece and suggest that lowland agricultural areas with patches of natural habitats may have a significant role in the future conservation of the species.

Abstract

The Balkan populations of the European wildcat are among the least studied. This study reports the first findings on the spatial ecology and activity pattern of the wildcat in Greece and compares them to those of better studied northern populations. We fitted five wildcats (two males, three females) with collars containing GPS and accelerometer loggers (E-obs 1A) and collected data from fall to early summer. All animals moved within a mosaic of lowland agricultural fields, woodland patches, riparian forests and wetlands near the banks of a lake. The trapping rate was the highest reported for the species. The home range sizes, estimated using Brownian bridge movement models, ranged from 0.94 to 3.08 km² for females and from 1.22 to 4.43 km² for males. Based on overall dynamic body acceleration (ODBA) values estimated from the accelerometer data, the diel activity of male wildcats followed the species’ typical nocturnal pattern with crepuscular peaks. Female activity varied seasonally, at times being cathemeral. We found only weak effects of environmental variables on wildcat activity, and no significant difference in the activity in open versus forested areas. Our findings suggest that human modified landscapes can play a significant role in the conservation of this typically forest-associated species.

Abundance and use pattern of wildcats of ancient human-modified cattle pastures in northern Iberian Peninsula

The wildcat is typically found in low densities. Here, we estimated wildcat abundance in cattle pastures interspersed between forests in northern Iberian Peninsula, and their patterns of intra-annual and daily use. We censused wildcats three times daily (morning, afternoon, and night) from a car during 4 years in summer season. We also carried out four monthly tracks (two in the morning and two in the afternoon) for a complete year. Overall, we recorded 191 wildcats in pastures and 5 on the road in forest zones. Thirteen different individual wildcats were identified during the summer censuses, but only 29.9% of the wildcats observed (n = 196) could be assigned to an individual wildcat. The number of wildcats sighted decreased especially during the last year, when sightings were 52–67% lower than in previous years. Wildcats were seen significantly more during the morning and night censuses than during the afternoon ones. Estimated annual summer densities in pasture areas ranged between 0.11 and 0.46 sightings/km2. Throughout the year, wildcats were observed 5.9 times more during summer-autumn than during winter-spring, and they could be observed in any time of the day, but more often close to dusk. It is noteworthy that the ancient human-transformed landscapes for cattle pastures could be an important habitat for wildcats in northern Iberian Peninsula, and conserving these areas should be important to maintaining wildcat populations.

First Description of Sarcoptic Mange in a Free-Ranging European Wildcat (Felis silvestris silvestris) from Spain

Simple Summary

Sarcoptic mange caused by the mite Sarcoptes scabiei is a worldwide-distributed skin infestation with a wide range of hosts, among them several species within the Felidae family. Sarcoptes scabiei was diagnosed in a dead adult female European wildcat (Felis silvestris silvestris) from Spain. This is the first description of Sarcoptes scabiei in a European wildcat. Since this is a species of conservation concern due to its critical demography in the southernmost population of the Iberian Peninsula, the impacts of infectious diseases, including sarcoptic mange, should be considered during disease surveillance programs of the species’ populations.

Abstract

Sarcoptic mange caused by the mite Sarcoptes scabiei is a worldwide-distributed skin infestation with a wide range of hosts, among them several species within the Felidae family. Sarcoptes scabiei was diagnosed in a dead adult female European wildcat (Felis silvestris silvestris) from Spain, based on histological evaluation of skin biopsies and identification of the arthropod from skin scrapings and molecular methods. This is the first description of Sarcoptes scabiei in a European wildcat. Due to its critical demography in the southernmost population of the Iberian Peninsula, the impacts of infectious diseases, including sarcoptic mange, as a new potential threat should be considered during disease surveillance programs of the species’ populations.

Do all roads lead to resistance? State road density is the main impediment to gene flow in a flagship species inhabiting a severely fragmented anthropogenic landscape

AIM

Connectivity conservation is ideally based on empirical information on how landscape heterogeneity influences species-specific movement and gene flow. Here, we present the first large-scale evaluation of landscape impacts on genetic connectivity in the European wildcat (Felis silvestris), a flagship and umbrella species for connectivity conservation across Europe.

LOCATION

The study was carried out in the core area of the distributional range of wildcats in Germany, covering about 186,000 km2 of a densely populated and highly fragmented landscape.

METHODS

We used data of 975 wildcats genotyped at 14 microsatellites and an individual-based landscape genetic framework to assess the importance of twelve landscape variables for explaining observed genetic connectivity. For this, we optimized landscape resistance surfaces for all variables and compared their relative impacts using multiple regression on distance matrices and commonality analysis.

RESULTS

Genetic connectivity was best explained by a synergistic combination of six landscape variables and isolation by distance. Of these variables, road density had by far the strongest individual impact followed by synergistic effects of agricultural lands and settlements. Subsequent analyses involving different road types revealed that the strong effect of road density was largely due to state roads, while highways and federal roads had a much smaller, and county roads only a negligible impact.

MAIN CONCLUSIONS

Our results highlight that landscape-wide genetic connectivity in wildcats across Germany is strongly shaped by the density of roads and in particular state roads, with higher densities providing larger resistance to successful dispersal. These findings have important implications for conservation planning, as measures to mitigate fragmentation effects of roads (e.g., over- or underpasses) often focus on large, federally managed transportation infrastructures. While these major roads exert local barrier effects, other road types can be more influential on overall connectivity, as they are more abundant and more widespread across the landscape.

Spatial capture-recapture with multiple noninvasive marks: An application to camera-trapping data of the European wildcat (Felis silvestris) using R package multimark

In Switzerland, the European wildcat (Felis silvestris), a native felid, is protected by national law. In recent decades, the wildcat has slowly returned to much of its original range and may have even expanded into new areas that were not known to be occupied before. For the implementation of efficient conservation actions, reliable information about the status and trend of population size and density is crucial. But so far, only one reliable estimate of density in Switzerland was produced in the northern Swiss Jura Mountains. Wildcats are relatively rare and elusive, but camera trapping has proven to be an effective method for monitoring felids. We developed and tested a monitoring protocol using camera trapping in the northern Jura Mountains (cantons of Bern and Jura) in an area of 100 km2. During 60 days, we obtained 105 pictures of phenotypical wildcats of which 98 were suitable for individual identification. We identified 13 individuals from both sides and, additionally, 5 single right-sided flanks and 3 single left-sided flanks that could not be matched to unique individuals. We analyzed the camera-trap data using the R package multimark, which has been extended to include a novel spatial capture-recapture model for encounter histories that include multiple "noninvasive" marks, such as bilaterally asymmetrical left- and right-sided flanks, that can be difficult (or impossible) to reliably match to individuals. Here, we present this model in detail for the first time. Based on a "semi-complete" data likelihood, the model is less computationally demanding than Bayesian alternatives that rely on a data-augmented complete data likelihood. The spatially explicit capture-recapture model estimated a wildcat density (95% credible interval) of 26 (17-36) per 100 km2 suitable habitat. Our integrated model produced higher abundance and density estimates with improved precision compared to single-sided analyses, suggesting spatially explicit capture-recapture methods with multiple "noninvasive" marks can improve our ability to monitor wildcat population status.