Europe-wide biogeographical patterns in the diet of an ecologically and epidemiologically important mesopredator, the red foxVulpes vulpes: a quantitative review

Diversity and biogeographical patterns in the diet of the culpeo in South America

Here we describe the dietary patterns of the culpeo or Andean fox (Lycalopex culpaeus) on a biogeographical scale. We also analyse the influence of exotic lagomorphs on its diet and explore differences between culpeo subspecies. We selected 17 mutually comparable diet studies, which include 19 independent diet assessments. Then, we extracted and standardized the values of the different diet components from these studies and calculated the relative frequency of occurrence of the 10 main trophic groups that we found. Further, we calculated the Shannon-Wiener H' trophic diversity index. The results showed that small mammals (41%), lagomorphs (21%), invertebrates (12.4%) and large herbivores (7.3%) were the most consumed groups. A factorial analysis of all trophic groups rendered four orthogonal factors that were used as response variables in relation to a set of environmental predictors. Altitude correlated with most factors (i.e. trophic groups). Exotic lagomorphs were consumed in lowlands, in higher latitudes and in regions showing high values of the human footprint index, enriching in those areas the culpeo's trophic spectrum. There were no differences in diet between the two main culpeo subspecies analysed, L.c. culpaeus and L.c. andinus. Finally, the best explanatory models (general linear model) of trophic diversity selected, using Akaike's information criterion, showed that the most diverse diets were those composed of large herbivores, edentates, carnivorous species, birds and herptiles (i.e. reptiles and frogs). Trophic diversity was low in rainy areas where big rodents dominated the diet. Neither latitude nor altitude seemed to have an effect on the trophic diversity of the culpeos, as they were not retained by the final models.

Influence of environmental factors on the occurrence of gastrointestinal and cardiopulmonary nematodes in the red fox in the semi-arid Mediterranean areas of the Iberian Peninsula

Human-induced ecosystem fragmentation is one of the drivers causing wildlife migration from their natural habitats to urban areas, among other reasons. The red fox (Vulpes vulpes) is the most abundant wild canid in the semi-arid Mediterranean areas of the Iberian Peninsula. Water scarcity may result in areas shared by synanthropic fox populations and domestic animals becoming hotspots for parasite transmission. This study describes the gastrointestinal and cardiopulmonary nematode species affecting fox populations in these semi-arid areas and the influence of environmental variables on parasite abundance. A total of 167 foxes collected from 2015 to 2021 in the Region of Murcia (SE Spain) were analysed. Parasite abundance and spatial distribution were evaluated using environmental variables and host characteristics with a Generalised Linear Model and the Moran index. Eleven species (seven from the gastrointestinal tract and four from the cardiopulmonary tract) were described. The influence of biotic and abiotic variables was studied for Angiostrongylus vasorum, Crenosoma vulpis, Uncinaria stenocephala, Toxocara canis and Toxascaris leonina. Temperature, humidity and areas of forest or agricultural land influenced the abundance of these parasites, providing optimal conditions for free-living stages of the direct life cycle nematodes and intermediate hosts. Absolute abundance distribution maps showed defined locations for C. vulpis, T. canis and T. leonina. The results for U. stenocephala, T. canis and T. leonina were particularly important as their higher abundance levels were found close to anthropized areas, which need to be carefully evaluated to prevent transmission of these nematodes between domestic and wild canids and human health.

Nutritional ecology of a prototypical generalist predator, the red fox (Vulpes vulpes)

Generalist species, which exploit a wide range of food resources, are expected to be able to combine available resources as to attain their specific macronutrient ratio (percentage of caloric intake of protein, lipids and carbohydrates). Among mammalian predators, the red fox Vulpes vulpes is a widespread, opportunistic forager: its diet has been largely studied, outlining wide variation according to geographic and climatic factors. We aimed to check if, throughout the species' European range, diets vary widely in macronutrient composition or foxes can combine complementary foods to gain the same nutrient intake. First, we assessed fox's intake target in the framework of nutritional geometry. Secondly, we aimed to highlight the effects of unbalanced diets on fox density, which was assumed as a proxy for Darwinian fitness, as assessed in five areas of the western Italian Alps. Unexpectedly, the target macronutrient ratio of the fox (52.4% protein-, 38.7% lipid- and 8.9% carbohydrate energy) was consistent with that of hypercarnivores, such as wolves and felids, except for carbohydrate intakes in urban and rural habitats. The inverse relation between density and the deviation of observed macronutrient ratios from the intake target suggests that fox capability of surviving in a wide range of habitats may not be exempt from fitness costs and that nutrient availability should be regarded among the biotic factors affecting animal abundance and distribution.

Exposure assessment of anticoagulant rodenticides in the liver of red foxes (Vulpes vulpes) in Slovenia

The study deals with the environmental residues of anticoagulant rodenticides (ARs) in Slovenia to evaluate the toxicological risk of secondary poisoning of red foxes (Vulpes vulpes) as representatives of non-target wildlife, and in relation to the investigated use patterns of ARs and specific local parameters in Slovenia. From 2019 to 2022, 148 liver tissue samples of adult red foxes were collected from almost all state geographical regions. The samples were extracted with methanol/water (2:1, v/v), cleaned-up using a solid supported liquid-liquid extraction, and measured by liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) with reporting limits of 0.5 to 5.0 ng/g. Residues of at least one rodenticide were detected in 77.7 % of the samples. The second generation ARs of bromadiolone, brodifacoum and difenacoum were the most frequently found, appearing in 75.0, 51.4, and 18.9 % of the samples, respectively. Concentrations of pooled ARs ranged from 1.5 to 2866.5 ng/g with mean and median values of 601.4 and 350.2 ng/g, respectively. We determined bromadiolone and brodifacoum at concentrations of ≥800 ng/g in 10.8 and 10.1 % of the samples, and 1.4 and 0.7 % of the samples contained residues >2000 ng/g, respectively. These concentrations are much higher than those found in comparable studies in Europe and elsewhere in the world. Residues of ARs were detected in all monitored statistical regions of Slovenia, with higher concentrations in the eastern parts of the country. First generation ARs were found in only 9.5 % of samples, and residues were below 10 ng/g with one exception (coumatetralyl with 55 ng/g). The results of the study indicate a serious toxicological risk for red foxes in Slovenia as part of the Western Balkans, and will contribute to the growing body of knowledge about the protection of European ecosystems, as wildlife is not limited by national borders.

Identification and phylogenetic analysis of Taenia spp. parasites found in wildlife in the Emilia-Romagna region, northern Italy (2017-2022)

The recent expansion of the habitat of several wildlife species, comprising anthropized areas, is a relevant risk factor for many zoonotic diseases and should be considered in national and regional sanitary monitoring systems. We evaluated adult intestinal Taenia spp. parasites isolated from wild carnivores and cystic larval forms isolated from wild mammals analysed at the Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia-Romagna (IZSLER) as part of the regional wildlife sanitary surveillance plan. Then, we assessed parasite species through molecular analysis (multiplex PCR followed by ribosomal 12S subunit gene sequencing) in order to update the epidemiological situation on Taeniids infection in the Emilia-Romagna wildlife, reporting the prevalence of each isolated species. The most commonly isolated species was Taenia serialis, which we detected in both wolves and foxes as definitive hosts and in roe deer as intermediate host. More attention on the distribution of Taeniids in wildlife should be paid, considering their potential zoonotic role: several Taenia spp. (Taenia solium, Taenia multiceps, Taenia serialis, Taenia brauni, Taenia glomerulatus) are known for causing coenurosis in humans, with possible severe or fatal outcomes.

Neonicotinoids and pharmaceuticals in hair of the Red fox (Vulpes vulpes) from the Cavallino-Treporti peninsula, Italy

Neonicotinoids (NEOs) and active pharmaceuticals ingredients (API) are contaminants widely diffused worldwide, causing increasing concern for potential adverse effects on wildlife. However, research on these contaminants have focused on target and non-target invertebrates, while information on potential effects in terrestrial mammals is lacking. We performed preliminary non-invasive monitoring of NEOs and API in a suburban and agricultural area using hair of the Red fox. The Red fox is a widely diffused mesopredator in Europe, and its plasticity in feeding habits makes it an excellent indicator for assessing exposure to environmental contamination. We observed the presence of NEOs in many Red fox hair samples (n = 11), including imidacloprid (IMI), acetamiprid (ACE), and clothianidin (CLO). The highest quantified concentrations were 6.4 ng g^-1 dry weight (dw), 6.7 ng g^-1 dw, and 0.9 ng g^-1 dw for IMI, ACE, and CLO, respectively. The targeted APIs included non-steroidal anti-inflammatory drugs (NSAIDs) and antidepressants. APIs were less frequently detected than NEOs, and the compounds with the highest prevalence were the NSAID ketoprofen (36%), the antidepressant sertraline (36%), and its active metabolite norsertraline (27%). The presence of human pharmaceuticals such as the NSAID ibuprofen and the antidepressants sertraline, fluoxetine, and their active metabolites norsertraline and norfluoxetine suggest environmental contamination due to untreated and partially treated wastewater discharged in surface waters and soils of the study area. The detection and quantification of ketoprofen and flunixin also suggest the possible use of contaminated manure on farmland. Findings indicate that hair may be used for monitoring environmental exposure to NEOs and provide evidence that hair is a good marker of exposure for antidepressants and certain NSAIDs, including ibuprofen, ketoprofen, and flunixin.

Optimal prey for red fox cubs-An example of dual optimizing foraging strategy in foxes from a dynamic wetland habitat

The red fox (Vulpes vulpes) is the most abundant mesopredator in the Central European region. Detailed knowledge about their feeding behavior is important both from ecological and wildlife management reasons. Food choices of foxes are poorly predictable in high-biodiversity marshlands. The main aim of our study was to sample parallel the main food-type abundances in the study area and analyze the diet of fox cubs and cohabiting adults across 3 years during the period of maternal dependence of the cubs. According to the optimal foraging theory, we predicted that the cubs' diet would show higher energy content, would be more varied, and the individual prey species fed to the young would be larger. We analyzed the composition of adult fox and cub fecal samples collected separately around dens in a marshland of western Hungary, May 2014, 2017 and 2020, when the abundance values of main food sources differed. Rodents and waterfowl dominated the diet, but their relative occurrence in the samples showed yearly variations. We found that vixens follow a dual optimizing foraging strategy regarding their provisioning of the cubs and their own diet. Adult foxes optimized their diet according to the actual yearly abundances of their main food sources. Additionally, they preferred prey items that can be consumed at the site of capture (large carrion and small individual prey items). Cubs on the other hand were provisioned with optimal high-energy food, even if those in question became less abundant in that year. Vixens mostly fed to their young either larger rodents and waterfowl, or multiple small rodents at a time-these type of prey are both optimal for transportation as a single load. Providing optimal prey at an early age in a changing environment may contribute to the ecological success of the red fox.

Absence of Hepatitis E Virus (HEV) Circulation in the Most Widespread Wild Croatian Canine Species, the Red Fox (Vulpes vulpes) and Jackal (Canis aureus moreoticus)

Hepatitis E virus (HEV) can infect a wide range of domestic and wild animals, and the identification of new host species is reported successively worldwide. Nevertheless, its zoonotic potential and natural transmission, especially in wildlife remains unclear, primarily due to the discrete nature of HEV infections. Since the red fox (Vulpus vulpus) is the most widespread carnivore worldwide, and has been recognized as a potential HEV reservoir, its role as a potent host species is of increasing interest. Another wild canine species, the jackal （Canis aureus moreoticus）, is becoming more important within the same habitat as that of the red fox since its number and geographical distribution have been rapidly growing. Therefore, we have chosen these wild species to determine their potential role in the epidemiology and persistence of HEV in the wilderness. The main reason for this is the finding of HEV and a rather high HEV seroprevalence in wild boars sharing the same ecological niche as the wild canine species, as well as the risk of the spread of HEV through red foxes into the outskirts of cities, where possible indirect and even direct contact with people are not excluded. Therefore, our study aimed to investigate the possibility of natural HEV infection of free-living wild canines, by testing samples for the presence of HEV RNA and anti-HEV antibodies to gain better epidemiological knowledge of the disease. For this purpose, 692 red fox and 171 jackal muscle extracts and feces samples were tested. Neither HEV RNA nor anti-HEV antibodies were detected. Although HEV circulation was not detected in the tested samples, to our knowledge, these are the first results that include jackals as a growing and important omnivore wildlife species for the presence of HEV infection in Europe.

Temporal Response of Mesocarnivores to Human Activity and Infrastructure in Taihang Mountains, Central North China: Shifts in Activity Patterns and Their Overlap

Mesocarnivores play essential roles in terrestrial ecosystems, but anthropocentric disturbances have profoundly transformed their intraguild interactions worldwide. In this study, we explored how a guild of four mesocarnivores (red fox Vulpes vulpes, leopard cat Prionailurus bengalensis, Asian badger Meles leucurus, and hog badger Arctonyx collaris) partition their temporal niche in the temperate montane forests in North China under different human influences. We conducted a systemic camera-trapping survey on the study species in the central Taihang Mountains from 2016 to 2020. With an extensive survey effort of 111,063 camera-days from 187 camera stations, we obtained 10,035 independent detections of the four mesocarnivores and examined the activity patterns of each species under different levels of human disturbance and their overlaps. The results showed that, while the leopard cat and the badgers shifted their activity towards nocturnality, the red fox showed no significant change. The leopard cat's degree of nocturnality varied between growing and non-growing seasons, likely a response to avoid humans and other competitors. However, the activity overlaps between species pairs demonstrated no statistically significant difference, indicating a long-developed coexistence mechanism that is homogenous across the landscape. Demonstrating how mesocarnivores shift activity patterns in response to human risks while partitioning resources, this study enhances our understanding of mesocarnivore behavioral changes and interspecific interactions at human-nature interfaces.

How Should We Help Wild Animals Cope with Climate Change? The Case of the Iberian Lynx

Climate change and related shifts in weather conditions result in massive biodiversity declines and severe animal suffering. This article explores the measures that can be taken to decrease animal suffering and prevent species from going extinct. Taking the Iberian lynx as a case study, we assess the extent to which it is beneficial for animal welfare and species conservation to do nothing or reduce other threats, provide food or shelter, relocate the species via assisted migration, or bring the population into captivity. We argue that, given the Iberian lynx's non-invasive characteristics, assisted migration may be the best way to protect the species while ensuring animal welfare and protecting wildness and other ecosystem values.

Red fox (Vulpes vulpes) play an important role in the propagation of tick-borne pathogens

The red fox (Vulpes vulpes) is the most widespread free-living carnivore in the world. Over the years, foxes have been recognized as hosts for a number of tick-borne pathogens. However, their role as reservoirs for zoonotic tick-borne diseases is poorly understood. The aim of our study was to investigate tick-borne pathogens in the red fox population in the Czech Republic. Out of 117 red foxes, 110 (94.02%) individuals tested positive for the presence of at least one pathogen by the combined PCR and sequencing approach. Hepatozoon canis was the most frequently detected pathogen (n = 95; 81.2%), followed by Babesia vulpes (n = 75; 64.1%). Babesia canis was not detected in our study. Four (3.42%) red foxes were positive for Candidatus Neoehrlichia sp., 3 (2.56%) for Anaplasma phagocytophilum, and one red fox (0.85%) tested positive for the presence of Ehrlichia sp. DNA. Overall, DNA of spirochetes from the Borrelia burgdorferi s.l. complex was detected in 8.6% of the foxes and B. miyamotoi in 5.12% of the samples. As a carnivore found in all ecosystems of Central Europe, foxes obviously contribute to transmission of tick-borne pathogens such as A. phagocytophilum, B. burgdorferi s.l., and B. myiamotoi. In addition, foxes apparently harbour a community of pathogens, associated with this host in local ecological context, dominated by H. canis and B. vulpes (possibly also Candidatus Neoehrlichia sp.). These species have the potential to spread to the domestic dog population and should be included in the differential diagnosis of febrile diseases with hematologic abnormalities in dogs.

Duplication, Loss, and Evolutionary Features of Specific UDP-Glucuronosyltransferase Genes in Carnivora (Mammalia, Laurasiatheria)

UDP-glucuronosyltransferases (UGTs) are one of the most important enzymes for xenobiotic metabolism or detoxification. Through duplication and loss of genes, mammals evolved the species-specific variety of UGT isoforms. Among mammals, Carnivora is one of the orders that includes various carnivorous species, yet there is huge variation of food habitat. Recently, lower activity of UGT1A and 2B were shown in Felidae and pinnipeds, suggesting evolutional loss of these isoforms. However, comprehensive analysis for genetic or evolutional features are still missing. This study was conducted to reveal evolutional history of UGTs in Carnivoran species. We found specific gene expansion of UGT1As in Canidae, brown bear and black bear. We also found similar genetic duplication in UGT2Bs in Canidae, and some Mustelidae and Ursidae. In addition, we discovered contraction or complete loss of UGT1A7–12 in phocids, some otariids, felids, and some Mustelids. These studies indicate that even closely related species have completely different evolution of UGTs and further imply the difficulty of extrapolation of the pharmacokinetics and toxicokinetic result of experimental animals into wildlife carnivorans.

High overlap of zoonotic helminths between wild mammalian predators and rural dogs - an emerging One Health concern?

The concept of One Health emphasizes the interdependence of human, animal and environmental health and is of growing significance, in part owing to the problems related to emerging infectious diseases of wildlife origin. Wild mammalian predators are a potential risk factor for transmission of zoonotic pathogens to domesticated animals and humans. This is especially relevant in rural areas, where transmission of zoonotic pathogens can occur particularly efficiently when free-ranging dogs are present. The main aim of this study was to determine helminth infections among wild mammalian predators and evaluate the overlap between helminth faunas of wild mammals and dogs. Scat samples of predators were collected in coastal areas of Western Estonia and genetic methodology applied for the correct identification of predator species from their scat. Parasitic helminths of mammalian predators in the scat samples were analysed and compared with dog data from a previous study. High helminth prevalence (~90%) was found in dominant predator species in the area, namely the red fox (Vulpes vulpes) and golden jackal (Canis aureus). Moreover, the helminth fauna of both wild species, including potentially zoonotic helminths, overlapped largely with that of rural dogs in the same area. The results, together with the ones from earlier parasitological studies among humans in Estonia, emphasize the potential risk of pathogen transmission from wild mammalian predators to dogs and from dogs to humans, making parasitic diseases of wildlife a One Health concern.

Foxes at your front door? Habitat selection and home range estimation of suburban red foxes (Vulpes vulpes)

The red fox (Vulpes vulpes) is one of the most adaptable carnivorans, thriving in cities across the globe. We used GPS-tracking of five suburban foxes across high-density residential suburbs of Perth, Western Australia to quantify (1) their habitat selection and (2) home range area. All five foxes showed statistically significant avoidance of residential locations (p < 0.001) and preference for parkland (p < 0.001), with native vegetation reserves, golf courses, and water reserves showing disproportionately greater use. Landuse category also influenced their movements, with foxes moving quickest (i.e., commuting) in proximity to roads and slowest (i.e., foraging) when they were further from roads. Three females had core home ranges (50% autocorrelated-corrected kernel density estimate; AKDEc) averaging 37 ± 20 ha or 95% AKDEc averaging 208 ± 196 ha. One male had a 95 ha core home range and 349 ha 95% AKDEc but the other male covered an area ~ 20 times this: using a 371 ha core home range and 7,368 ha 95% AKDEc. The extensive movement patterns we describe are likely to be common for urban foxes, with half of published home range estimates for urban foxes (principally based on VHF data) excluding data for ‘lost’ individuals or animals that showed ‘excursions’. It is likely that the home range estimates for these urban exploiters have therefore been grossly underestimated to date. Further application of GPS trackers that allow remote download will vastly improve our understanding of habitat preference and exploitation of resources by urban foxes.

Interspecific coprophagia by wild red foxes: DNA metabarcoding reveals a potentially widespread form of commensalism among animals

Vertebrate animals are known to consume other species' faeces, yet the role of such coprophagy in species dynamics remains unknown, not least due to the methodological challenges of documenting it. In a large‐scale metabarcoding study of red fox and pine marten scats, we document a high occurrence of domestic dog DNA in red fox scats and investigate if it can be attributed to interspecific coprophagia. We tested whether experimental artifacts or other sources of DNA could account for dog DNA, regressed dog occurrence in the diet of fox against that of the fox’s main prey, short‐tailed field voles, and consider whether predation or scavenging could explain the presence of dog DNA. Additionally, we determined the calorific value of dog faeces through calorimetric explosion. The high occurrence of dog DNA in the diet of fox, the timing of its increase, and the negative relationship between dog and the fox's main prey, point to dog faeces as the source of DNA in fox scats. Dog faeces being highly calorific, we found that foxes, but not pine martens, regularly exploit them, seemingly as an alternative resource to fluctuating prey. Scattered accounts from the literature may suggest that interspecific coprophagia is a potentially frequent and widespread form of interaction among vertebrates. However, further work should address its prevalence in other systems and the implications for ecological communities. Tools such as metabarcoding offer a way forward.

Downtown diet: a global meta-analysis of increased urbanization on the diets of vertebrate predators

Predation is a fundamental ecological process that shapes communities and drives evolutionary dynamics. As the world rapidly urbanizes, it is critical to understand how human perturbations alter predation and meat consumption across taxa. We conducted a meta-analysis to quantify the effects of urban environments on three components of trophic ecology in predators: dietary species richness, dietary evenness and stable isotopic ratios (IRs) (δ¹³C and δ¹⁵N IR). We evaluated whether the intensity of anthropogenic pressure, using the human footprint index (HFI), explained variation in effect sizes of dietary attributes using a meta-regression. We calculated Hedges' g effect sizes from 44 studies including 11 986 samples across 40 predatory species in 39 cities globally. The direction and magnitude of effect sizes varied among predator taxa with reptilian diets exhibiting the most sensitivity to urbanization. Effect sizes revealed that predators in cities had comparable diet richness, evenness and nitrogen ratios, though carbon IRs were more enriched in cities. We found that neither the 1993 nor 2009 HFI editions explained effect size variation. Our study provides, to our knowledge, the first assessment of how urbanization has perturbed predator-prey interactions for multiple taxa at a global scale. We conclude that the functional role of predators is conserved in cities and urbanization does not inherently relax predation, despite diets broadening to include anthropogenic food sources such as sugar, wheat and corn.

Epidemiology of periodontal disease in dogs in the UK primary-care veterinary setting

Objectives

Periodontal disease is a frequent diagnosis of dogs and can have severe negative impacts on welfare. It was hypothesised that breeds with skull shapes that differ most in conformation from the moderate mesocephalic skull shape have higher odds of periodontal disease.

Materials and Methods

The cohort study included a random sample of dogs under primary veterinary care in 2016 from the VetCompass Programme database. Risk factor analysis used random effects multivariable logistic regression modelling.

Results

The study included a random sample of 22,333 dogs. The 1‐year period prevalence for diagnosis with periodontal disease was 12.52% (95% CI: 12.09 to 12.97). Eighteen breeds showed increased odds compared with crossbred dogs. Breeds with the highest odds included Toy Poodle (odds ratio 3.97, 95% confidence intervals 2.21 to 7.13), King Charles Spaniel (odds ratio 2.63, 95% confidence interval 1.50 to 4.61), Greyhound (odds ratio 2.58, 95% confidence interval 1.75 to 3.80) and Cavalier King Charles Spaniel (odds ratio 2.39, 95% confidence interval 1.85 to 3.09). Four breeds showed reduced odds compared with crossbreds. Brachycephalic breeds had 1.25 times the odds (95% confidence interval 1.11 to 1.42) of periodontal disease compared with mesocephalic breeds. Spaniel types had 1.63 times the odds (95% confidence interval 1.42 to 1.87) compared with non‐spaniel types. Increasing adult bodyweight was associated with progressively decreasing odds of periodontal disease.

Clinical Significance

The high prevalence identified in this study highlights periodontal disease as a priority welfare concern for predisposed breeds. Veterinarians can use this information to promote improved dental care in predisposed dogs, especially as these dogs age.

Intestinal system helminths of red foxes and molecular characterization Taeniid cestodes

Red foxes (Vulpes vulpes) are the most prevalent wild carnivores in the world and definitive hosts of many pathogenic parasites for humans and farm animals. These animals travel great distances in search of prey and nests, and cause contamination of large geographic areas with parasites. For this reason, monitoring the parasitic pathogens of red foxes is particularly important in terms of public and animal health. The goal of this study was to determine the intestinal helminths and molecular characterization of Taenia species of red foxes in Turkey. In this study, 103 red fox intestines obtained from 29 provinces of Turkey were examined with sedimentation and counting technique. Collected helminths were diagnosed according to their morphologic features. Additionally, further molecular analysis (PCR and DNA sequencing) was performed for the identification of Taeniid cestodes. At the end of the study, it was determined that 87.37% (90/103) of red foxes were infected with at least one helminth species. Detected helminths and their prevalence's were Mesocestoides sp. (56.31%), Joyeuxiella echinorhynchoides (33%), Taenia polyacantha (15.53%), Dipylidium caninum (0.97%), Pterygodermatites affinis (51.45%), Toxascaris leonina (45.63%), Uncinaria stenocephala (33%), Oxynema numicidum (20.38%), Toxocara canis (14.56%), Ancylostoma caninum (12.62%), and Trichuris vulpis (1.94%), respectively. Additionally, Pachysentis sp. (37.69%), Centrorhynchus sp. (0.97%) (Acantocephala), and nymphs of Linguatula serrata (20.38%) (Arthropoda) were also detected in the same intestinal samples. This is the most comprehensive study that has been conducted on the intestinal helminthes of red foxes in Turkey. To the best of our knowledge, molecular characterization of T. polyacantha and the detection of O. numicidum, A. caninum, Pachysentis sp., and Centrorhynchus sp. are the first reports in red foxes in Turkey. Our study revealed that red foxes are important hosts for many intestinal helminth species and are link between domestic and sylvatic cycles of these parasites.

Comparative analysis of the diet of members of the families Mustelidae and Canidae

The article analyzes 151 food samples of carnivoran mammals of two families. It was found that the diet includes 49 food items in the studied species of the family Canidae and 42 items in species of the family Mustelidae, of both plant and animal origin. It was revealed that plant food is an important component of the diet of predators, since the frequency of registration of these objects is 46.4%. Most often, it is the remains of cereals and plant seeds. Rodents are the main food for both families (19% in Canidae, 21% in Mustelidae). A seasonal change in diet for both families was noted. Members of the family Mustelidae consume plants more often in summer and winter, while in in spring and autumn mammals prevail in their diet when the share of juicy fruits is the lowest. Rodents are consumed throughout the year, but their largest share was noted in spring, when this family is characterized by the greatest variety of food (Shannon's index is 2.0). For members of the family Canidae, the most important component of the diet in winter is dry fruits. The number of rodents in their diet also increases in spring. The summer period is characterized by the consumption of invertebrates and the absence of animal carcasses in the diet. In autumn, the share of juicy fruits increases and during this period the diet of Canidae is the most diverse (1.9). The lowest variety of food in species of the two families was registered in summer. Competition between the studied families may increase in spring when the most important food for the representatives of both Canidae and Mustelidae is rodents. There are some sex-related trophic preferences in both families. In particular, males of the family Mustelidae consume rodents more often (68.7%), while females more often feed on plants (56.1%). As for the family Canidae, the analysis was carried out on the example of the red fox. It was found that females of this species prefer plant foods and there are no ungulates in their diet. Males consume fewer plants (41.4%) and often forage in cattle burial grounds and landfills. Accordingly, the diet of males is more diverse compared to that in females. The Shannon index is 3.3 and 2.5, respectively.

Niche partitioning between sympatric wild canids: the case of the golden jackal (Canis aureus) and the red fox (Vulpes vulpes) in north-eastern Italy

BACKGROUND

Two coexisting species with similar ecological requirements avoid or reduce competition by changing the extent of their use of a given resource. Numerous coexistence mechanisms have been proposed, but species interactions can also be aggressive; thus, generally a subordinate species modifies its realized niche to limit the probability of direct encounters with the dominant species. We studied niche partitioning between two sympatric wild canids in north-eastern Italy: the golden jackal and the red fox, which, based on competition theories, have a high potential for competition. We considered four main niche dimensions: space, habitat, time, and diet.

RESULTS

We investigated three study areas monitoring target species populations from March 2017 to November 2018 using non-invasive monitoring techniques. Red fox presence was ascertained in every study area, while golden jackal presence was not ascertained in one study area, where we collected data regarding wolf presence. Considering the two target species, we observed partial diet partitioning based on prey size, with the golden jackal mainly feeding on wild ungulates and the red fox mainly feeding on small mammals. The two canids had an extensive temporal overlap along the diel cycle, having both predominant crepuscular and nocturnal activity patterns, but marked spatial partitioning and differential use of habitats. The golden jackal proved to be specialist concerning the habitat dimension, while the red fox resulted completely generalist: the former selected less human-modified habitats and avoided intensively cultivated lands, while the latter was present in all habitats, including intensively cultivated lands.

CONCLUSIONS

The observed partitioning might be due partially to some ecological adaptations (e.g. specialist vs. generalist use of resources) and specific behaviours (e.g. cooperative vs. solitary hunting) and partially to the avoidance response of the red fox aimed at reducing the probability of direct encounters with the golden jackal.

Volatile scent chemicals in the urine of the red fox, Vulpes vulpes

The red fox is a highly adaptable mammal that has established itself world-wide in many different environments. Contributing to its success is a social structure based on chemical signalling between individuals. Urine scent marking behaviour has long been known in foxes, but there has not been a recent study of the chemical composition of fox urine. We have used solid-phase microextraction and gas chromatography-mass spectrometry to analyze the urinary volatiles in 15 free-ranging wild foxes (2 female) living in farmlands and bush in Victoria, Australia. Foxes here are routinely culled as feral pests, and the urine was collected by bladder puncture soon after death. Compounds were identified from their mass spectra and Kovats retention indices. There were 53 possible endogenous scent compounds, 10 plant-derived compounds and 5 anthropogenic xenobiotics. Among the plant chemicals were several aromatic apocarotenoids previously found in greater abundance in the fox tail gland. They reflect the dietary consumption of carotenoids, essential for optimal health. One third of all the endogenous volatiles were sulfur compounds, a highly odiferous group which included thiols, methylsulfides and polysulfides. Five of the sulfur compounds (3-isopentenyl thiol, 1- and 2-phenylethyl methyl sulfide, octanethiol and benzyl methyl sulfide) have only been found in foxes, and four others (isopentyl methyl sulfide, 3-isopentenyl methyl sulfide, and 1- and 2-phenylethane thiol) only in some canid, mink and skunk species. This indicates that they are not normal mammalian metabolites and have evolved to serve a specific role. This role is for defence in musteloids and most likely for chemical communication in canids. The total production of sulfur compounds varied greatly between foxes (median 1.2, range 0.4–32.3 μg ‘acetophenone equivalents’/mg creatinine) as did the relative abundance of different chemical types. The urinary scent chemistry may represent a highly evolved system of semiochemicals for communication between foxes.

A Mathematical Model Supporting a Hyperpredation Effect in the Apparent Competition Between Invasive Eastern Cottontail and Native European Hare

In this work a mathematical model is built in order to validate on theoretical grounds field study results on a three-species system made of two prey, of which one is native and another one invasive, together with a native predator. Specifically, our results mathematically describe the negative effect on the native European hare after the introduction of the invasive Eastern cottontail, mediated by an increased predation rate by foxes. Two nonexclusive assumptions can be made: an increase in cottontail abundance would lead to a larger fox population, magnifying their predatory impact ("hyperpredation") on hares; alternatively, cottontails attract foxes in patches where they live, which are also important resting sites for hares and consequently the increased presence of foxes results in a higher predation rates on hares. The model results support hyperpredation of increasing fox populations on native hares.

eDNA metabarcoding for biodiversity assessment, generalist predators as sampling assistants

With an accelerating negative impact of anthropogenic actions on natural ecosystems, non-invasive biodiversity assessments are becoming increasingly crucial. As a consequence, the interest in the application of environmental DNA (eDNA) survey techniques has increased. The use of eDNA extracted from faeces from generalist predators, have recently been described as "biodiversity capsules" and suggested as a complementary tool for improving current biodiversity assessments. In this study, using faecal samples from two generalist omnivore species, the Eurasian badger and the red fox, we evaluated the applicability of eDNA metabarcoding in determining dietary composition, compared to macroscopic diet identification techniques. Subsequently, we used the dietary information obtained to assess its contribution to biodiversity assessments. Compared to classic macroscopic techniques, we found that eDNA metabarcoding detected more taxa, at higher taxonomic resolution, and proved to be an important technique to verify the species identification of the predator from field collected faeces. Furthermore, we showed how dietary analyses complemented field observations in describing biodiversity by identifying consumed flora and fauna that went unnoticed during field observations. While diet analysis approaches could not substitute field observations entirely, we suggest that their integration with other methods might overcome intrinsic limitations of single techniques in future biodiversity surveys.

Estimation of the Prevalence of Antimicrobial Resistance in Badgers (Meles meles) and Foxes (Vulpes vulpes) in Northern Ireland

Antimicrobial resistant (AMR) bacteria can be shared between humans and animals, through food, water, and the environment. Wild animals are not only potential reservoirs of AMR, but are also sentinels mirroring the presence of AMR zoonotic bacteria in the environment. In Northern Ireland, little is known about levels of AMR in bacteria in wildlife, thus the current study aimed to estimate the prevalence of AMR bacteria in wildlife using wildlife species from two ongoing surveys as a proxy. Nasopharyngeal swabs and faecal samples from European badgers (Meles meles) (146 faecal samples; 118 nasal samples) and red foxes (Vulpes vulpes) (321 faecal samples; 279 nasal samples) were collected throughout Northern Ireland and were used to survey for the presence of extended spectrum beta lactamase resistant and AmpC-type beta lactamases Escherichia coli (ESBL/AmpC), Salmonella spp. (only in badgers) and methicillin resistant Staphylococcus aureus (MRSA). ESBLs were detected in 13 out of 146 badger faecal samples (8.90%) and 37 out of 321 of fox faecal samples (11.53%), all of them presenting multi-drug resistance (MDR). Fourteen out of 146 (9.59%) badger faecal samples carried Salmonella spp. [S. Agama (n = 9), S. Newport (n = 4) and S. enterica subsp. arizonae (n = 1)]. Overall, AMR was found only in the S. enterica subsp. arizonae isolate (1/14, 7.14%). No MRSA were detected in nasopharyngeal swabs from badgers (n = 118) and foxes (n = 279). This is the first attempt to explore the prevalence of AMR in the two common wildlife species in Northern Ireland. These findings are important as they can be used as a base line for further research exploring the origin of the found resistance. These results should encourage similar surveys where environmental samples are included to bring better understanding of AMR dynamics, and the impact on wildlife, domestic livestock and humans.

The role of the brown bear Ursus arctos as a legitimate megafaunal seed disperser

Megafaunal frugivores can consume large amounts of fruits whose seeds may be dispersed over long distances, thus, affecting plant regeneration processes and ecosystem functioning. We investigated the role of brown bears (Ursus arctos) as legitimate megafaunal seed dispersers. We assessed the quantity component of seed dispersal by brown bears across its entire distribution based on information about both the relative frequency of occurrence and species composition of fleshy fruits in the diet of brown bears extracted from the literature. We assessed the quality component of seed dispersal based on germination experiments for 11 fleshy-fruited plant species common in temperate and boreal regions and frequently eaten by brown bears. Across its distribution, fleshy fruits, on average, represented 24% of the bear food items and 26% of the total volume consumed. Brown bears consumed seeds from at least 101 fleshy-fruited plant species belonging to 24 families and 42 genera, of which Rubus (Rosaceae) and Vaccinium (Ericaceae) were most commonly eaten. Brown bears inhabiting Mediterranean forests relied the most on fleshy fruits and consumed the largest number of species per study area. Seeds ingested by bears germinated at higher percentages than those from whole fruits, and at similar percentages than manually depulped seeds. We conclude that brown bears are legitimate seed dispersers as they consume large quantities of seeds that remain viable after gut passage. The decline of these megafaunal frugivores may compromise seed dispersal services and plant regeneration processes.

Blessing the rains down in Africa: spatiotemporal behaviour of the crested porcupine

The assessment of habitat selection and temporal patterns of activity rhythms is paramount for wildlife conservation. Studies on behavioural ecology of wild mammals are particularly challenging in tropical areas, mostly when involving rare or elusive species. Despite being a common species in Italy, the crested porcupine Hystrix cristata is threatened of extinction throughout most of its sub-Saharan range. All available information on the ecology of this species has been collected in Italy, whereas no data is present in the scientific literature on spatiotemporal behaviour of this large rodent in Africa. In this work, we attempted to determine habitat selection and temporal patterns of activity rhythms of the crested porcupine in northern Benin and neighbouring countries, through intensive camera-trapping. We collected a total of 146 records of crested porcupine, 91 in the dry season (October-March) and 55 in the rainy season (April-September). Porcupines used most habitats in proportion to their local availability, while selecting rock outcrop formations (possibly used as shelter sites) and avoiding open areas, wetlands and gallery forests. A mostly nocturnal behaviour was confirmed throughout the year, with some diurnal activity at the start and at the end of the rainy season. The importance of rains in determining birth peak has been also showed, with juvenile individuals always observed at the start and at the end of the rainy season. Full moon always inhibited activity of this large rodent, most likely evolved as an antipredatory behaviour to limit encounters with potential predators (common leopard Panthera pardus, spotted hyaena Crocuta crocuta and honey badger Mellivora capensis) and humans. Poaching pressure towards porcupines in West Africa is strong. Porcupines are killed for the traditional medicine, for their meat and because they are widely considered as a crop pest. This assessment should therefore be used as a basic tool to design conservation plans to preserve this rodent species in its native range.

Frequency of Occurrence and Ingested Biomass of Different Prey of the Barn Owl Tyto alba in an Island Ecosystem

The Barn Owl Tyto alba is commonly reported as a non-selective predator of small mammals, and its diet has been thoroughly analyzed also to assess the small mammal assembly composition in many study areas. The aim of this work was to analyze the diet of the Barn Owl in the Elba island through the analysis of 161 pellets collected in September 2020. Undigested fragments were isolated and compared with reference collections. We confirmed that the Barn Owl is a typical predator of field mice (62% of relative frequency), with synanthropic murid rodents as the second category of prey. The frequency of consumption of shrews increased by 9% with respect to the previous work, suggesting that the natural environment of Elba island is still in a good health status. Moreover, fragments of two newborn hares were detected, increasing the knowledge on the local trophic spectrum of the Barn Owl. Finally, the skull of a Geoffroy’s Myotis Myotis emarginatus confirmed the presence of this species in Elba island after over 60 years from the first unconfirmed record. Repeated studies conducted in the same study site may provide useful information on prey population trends and local environmental status.

Identification of Hepatitis E Virus in the Feces of Red Foxes (Vulpes vulpes)

Simple Summary

Orthohepeviruses, commonly known as Hepatitis E virus (HEV), is a diverse virus group belonging to the family of Hepeviridae and is responsible for acute hepatitis in humans worldwide. These viruses show a relatively strict host specificity, e.g., rodent-related, avian-related, or even bat-related virus groups. However, similar (HEV-like) viruses have been identified in carnivores; some of them form a new genetically separated group, while others show a close evolutionary relationship with the rodent-related group, thus makes the strict host-specificity questionable and the classification of these new strains uncertain. Herein, we investigated feces of red foxes, the most widespread carnivore species worldwide, to identify the Hepatitis E virus and to ascertain their evolutionary origin via sequencing. The non-invasively collected fecal samples can provide information about the presence of viruses specific to the host and viruses derived from their prey as well. The virus we detected from our samples showed a very close relationship (91% identity) with rodent-related HEV described before from common voles, whilst a more distant relationship (85%) with fox-specific HEV strains was observed. Our results strongly support “the dietary-origin” of unclassified HEV-like strains described from various predator species.

Abstract

Orthohepeviruses (HEV) can infect a wide range of animals, showing a relatively strict host specificity; however, its zoonotic potential, natural transmission in the wildlife are less known. Several new HEV-like viruses have been identified in various animal species, including carnivores; however, the phylogenetic relationship among these viruses is poorly resolved, since some of them were known as rodent-related so far. The red fox, the most widespread carnivore worldwide, is a known reservoir of several viruses that transmit from wildlife to humans or domestic animals; they might have a defined role in the circulation of rodent-borne HEV. In this study, we performed a HEV survey by heminested RT-PCR (Reverse Transcription PCR) on red fox fecal samples to investigate the presence of HEV in red foxes living in natural conditions, and to explore the origin of the virus via phylogenetic analysis. Out of the 26 investigated samples, HEV RNA was identified in one sample. Following Sanger sequencing, the novel sequence displayed 91% identity on the nucleotide level with recently published European common vole-HEV derived from Microtus arvalis. In contrast, it shared 85% nucleotide similarity with HEV strains described previously in red foxes. Our results strongly support “the dietary-origin” of unclassified HEV-like strains described from predators that usually prey on rodents.

Individual dietary specialization in a generalist predator: A stable isotope analysis of urban and rural red foxes

Some carnivores are known to survive well in urban habitats, yet the underlying behavioral tactics are poorly understood. One likely explanation for the success in urban habitats might be that carnivores are generalist consumers. However, urban populations of carnivores could as well consist of specialist feeders. Here, we compared the isotopic specialization of red foxes in urban and rural environments, using both a population and an individual level perspective. We measured stable isotope ratios in increments of red fox whiskers and potential food sources. Our results reveal that red foxes have a broad isotopic dietary niche and a large variation in resource use. Despite this large variation, we found significant differences between the variance of the urban and rural population for δ13C as well as δ15N values, suggesting a habitat-specific foraging behavior. Although urban regions are more heterogeneous regarding land cover (based on the Shannon index) than rural regions, the dietary range of urban foxes was smaller compared with that of rural conspecifics. Moreover, the higher δ13C values and lower δ15N values of urban foxes suggest a relatively high input of anthropogenic food sources. The diet of most individuals remained largely constant over a longer period. The low intraindividual variability of urban and rural red foxes suggests a relatively constant proportion of food items consumed by individuals. Urban and rural foxes utilized a small proportion of the potentially available isotopic dietary niche as indicated by the low within-individual variation compared to the between-individual variation. We conclude that generalist fox populations consist of individual food specialists in urban and rural populations at least over those periods covered by our study.

Fox dietary ecology as a tracer of human impact on Pleistocene ecosystems

Nowadays, opportunistic small predators, such as foxes (Vulpes vulpes and Vulpes lagopus), are well known to be very adaptable to human modified ecosystems. However, the timing of the start of this phenomenon in terms of human impact on ecosystems and of the implications for foxes has hardly been studied. We hypothesize that foxes can be used as an indicator of past human impact on ecosystems, as a reflection of population densities and consequently to track back the influence of humans on the Pleistocene environment. To test this hypothesis, we used stable isotope analysis (δ¹³C, δ¹⁵N) of bone collagen extracted from faunal remains from several archaeological sites located in the Swabian Jura (southwest Germany) and covering a time range over three important cultural periods, namely the Middle Palaeolithic (older than 42,000 years ago) attributed to Neanderthals, and the early Upper Palaeolithic periods Aurignacian and Gravettian (42,000 to 30,000 years ago) attributed to modern humans. We then ran Bayesian statistic systems (SIBER, mixSIAR) to reconstruct the trophic niches and diets of Pleistocene foxes. We observed that during the Middle Palaeolithic period, when Neanderthals sparsely populated the Swabian Jura, the niches occupied by foxes suggest a natural trophic behavior. In contrast, during the early Upper Palaeolithic periods, a new trophic fox niche appeared, characterized by a restricted diet on reindeer. This trophic niche could be due to the consumption of human subsidies related to a higher human population density and the resulting higher impact on the Pleistocene environment by modern humans compared to Neanderthals. Furthermore, our study suggests that, a synanthropic commensal behavior of foxes started already in the Aurignacian, around 42,000 years ago.

Increased trophic position of black bear (Ursus americanus) at the northern fringe of its distribution range

Studies describing the diet of omnivorous species are abundant, but the drivers affecting the balance between animal and plant resources remain unclear. Among those drivers, latitude has been reported to positively correlate with the trophic position of consumers. Using stable isotope analysis, we tested the hypothesis that trophic position of black bears (Ursus americanus Pallas, 1780) is positively correlated with latitude in eastern North America. We sampled 57 bears over a 15° latitudinal gradient in Quebec, Canada, and used stable isotope analysis to assess individual trophic position and metrics of dietary niches. We found a strong positive correlation between trophic position of bears and latitude (r2 = 0.76), which persisted throughout seasons. The width of the dietary niche of bears also appeared to follow a latitudinal pattern, even though bears foraging at the southernmost part of the gradient also showed a wide dietary niche. The impact of latitude on the foraging tactic of omnivores fosters our understanding of their capability to deal with contrasting environmental conditions, especially for species whose distribution ranges are expanding due to climate change. The flexibility of black bear foraging tactic likely allows this species to expand its geographical distribution range toward northern habitats.