Urocyon Cinereoargenteus Research Articles

Rainforest carnivore ecology in a managed forest reserve: Differential seasonal correlates between habitat components and relative abundance

Studies of relationships between seasons and Neotropical carnivore distributions tend to focus on water and prey availability without considering other habitat components such as escape, foraging, and resting cover. Our goal was to evaluate habitat characteristics that may be important for predicting the seasonal (dry or rainy) relative abundance of four commonly captured Neotropical carnivores (i.e., jaguar [Panthera onca], puma [Puma concolor], ocelot [Leopardus pardalis], and grey fox [Urocyon cinereoargenteus]) in Chiquibul Forest Reserve in Belize, Central America. We used trail camera data and random-effect Poisson models to investigate how prey ratios (number of prey detections/total detections), cover (e.g., logs and stumps used for hiding cover from predators), vegetation structure, and environmental site characteristics (e.g., site harvest-history, slope, aspect) were related to carnivore relative abundance. Both prey ratios and vegetation structure appeared in supported models more frequently than other environmental site characteristics and were negatively correlated with carnivore relative abundance. Supported models differed for each season for all species except jaguars for which mammalian prey ratios and prey cover at sites was always negatively correlated with jaguar relative abundance. Carnivores appeared to avoid sites where vegetation created ideal escape and hiding cover for prey even though prey may be less abundant. Our data suggest that vegetation structure and composition can create conditions conducive to carnivore foraging and that these characteristics can differ by season in the tropics.

Genomic analyses of gray fox lineages suggest ancient divergence and secondary contact in the southern Great Plains.

The gray fox (Urocyon cinereoargenteus) lineage diverged from all other extant canids at their most basal node and is restricted to the Americas. Previous mitochondrial analysis from coastal populations identified deeply divergent (up to 1 Mya) eastern and western lineages that predate most intraspecific splits in carnivores. We conducted genotyping by sequencing and mitochondrial analysis on gray foxes sampled across North America to determine geographic concordance between nuclear and mitochondrial contact zones and divergence times. We also estimated the admixture within the contact zone between eastern and western gray foxes based on nuclear DNA. Both datasets confirmed that eastern and western lineages met in the southern Great Plains (i.e. Texas and Oklahoma), where they maintained high differentiation. Admixture was generally low, with the majority of admixed individuals carrying <10% ancestry from the other lineage. Divergence times confirmed a mid-Pleistocene split, similar to the mitochondrial estimates. Taken together, findings suggest gray fox lineages represent an ancient divergence event, far older than most intraspecific divergences in North American carnivores. Low admixture may reflect a relatively recent time since secondary contact (e.g. post-Pleistocene) or, alternatively, ecological or reproductive barriers between lineages. Though further research is needed to disentangle these factors, our genomic investigation suggests species-level divergence exists between eastern and western gray fox lineages.

Population Genetics of California Gray Foxes Clarify Origins of the Island Fox.

We used mitochondrial sequences and nuclear microsatellites to investigate population structure of gray foxes (Urocyon cinereoargenteus) and the evolutionary origins of the endemic island fox (Urocyon littoralis), which first appeared in the northern Channel Islands <13,000 years ago and in the southern Channel Islands <6000 years ago. It is unclear whether island foxes evolved directly from mainland gray foxes transported to the islands one or more times or from a now-extinct mainland population, already diverged from the gray fox. Our 345 mitochondrial sequences, combined with previous data, confirmed island foxes to be monophyletic, tracing to a most recent common ancestor approximately 85,000 years ago. Our rooted nuclear DNA tree additionally indicated genome-wide monophyly of island foxes relative to western gray foxes, although we detected admixture in northern island foxes from adjacent mainland gray foxes, consistent with some historical gene flow. Southern California gray foxes also bore a genetic signature of admixture and connectivity to a desert population, consistent with partial replacement by a late-Holocene range expansion. Using our outgroup analysis to root previous nuclear sequence-based trees indicated reciprocal monophyly of northern versus southern island foxes. Results were most consistent with island fox origins through multiple introductions from a now-extirpated mainland population.

Occurrence of Ancylostoma Caninum from a Gray Fox Urocyon Cinereoargenteus in Southeastern Mexico.

SummaryThe hookworm Ancylostoma caninum is a common nematode of wild and domestic canids worldwide. In Mexico, there are few records of helminths in wild canids, especially in the southeastern region. The aim of the present study was to examine the helminths from a gray fox Urocyon cinereoargenteus in southeastern Mexico. A road-killed female gray fox found in Merida, Yucatan, Mexico, was examined for helminths. Only nematodes were found in the intestine of the gray fox and identified using morphological studies and molecular analysis of 28S rRNA gene fragments. The characteristics exhibited by the nematode specimens were in accordance with descriptions of A. caninum: e. g. oral opening with a pair of prominent chitinous plates bearing three pairs of ventral teeth, lateral rays with a common trunk, dorsal ray divided into two branches with each branch terminating in three digitations. BLAST analysis of the 28S sequence showed similarity and coverage values of 99.8 % and 100 %, respectively, with a sequence of A. caninum from the domestic dog Canis familiaris in Australia. The genetic distance between the Australian specimen and the Yucatan specimen of A. caninum was 0.1 %, that is, they were only different in a single nucleotide. The gray fox examined in this study was found close to a rural community where A. caninum has been recorded from domestic dogs, which could be the source of infection. Our study increases the distribution of this nematode parasitizing the gray fox in Mexico and provides the first nucleotide sequence of A. caninum from the gray fox.

Belle Epoque or Friday Night in West Virginia, and: Depository by Natalie Homer

Reviewed by: Belle Epoque or Friday Night in West Virginia, and: Depository by Natalie Homer Natalie Homer (bio) Branches hold aloft their petalslike saucers without teacups. Rain fills them. Inside the church—old stone, red doors—dark, burnt coffee from the AA groupwends its scent through the halls. The copy machine hums,heats the bulletins as they print.Outside, a man carefully restocks the little free pantry with its peeling blue paint,its miniature glass doors.On the way home, we drive over one of the rusty steel bridges.Sometimes the river is all mist—a witch’s brew snaking through the Appalachian hills.Why are we still speaking about normal, everyday thingswith a sight like that out the window? At home, I wrap the white quilt around mewhose stiches are patterned in little doves, a nice touch.My story, like so many others’, is that I didn’t say nothough I didn’t say yesand anyway, wasn’t I lucky to be wanted at all? Now receive this blessing—I learned latethat I was not supposed to take the wafer but to cup my palms, to ask,to leave myself open and waiting. [End Page 93] Depository The most ambitious daffodils end up buried in snow.Take that to heart. The mudroom of the red brick farmhousegreets me with its unidentifiable, sweet fragrance. Inside, I run my hand along the banister’s curves,appreciate the creaks my steps make on the wood floors. In a small upstairs room, an old map of West Virginiahas a window view out on white-powdered fields, on little red berries jeweled over the bare-branched tree,rations to make it through. I’m thinking of the airy, soft fur of a gray fox,of how being desired only takes you so far— but damn if it doesn’t sometimes feellike all there is. [End Page 94] Natalie Homer Natalie Homer is the author of Under the Broom Tree (Autumn House Press, 2021). Her recent poetry has been published in River Styx, Puerto del Sol, American Literary Review, Four Way Review, Ruminate, Sou’wester, and others. She received an MFA from West Virginia University and lives in southwestern Pennsylvania. Copyright © 2022 University of Wisconsin Board of Regents

A framework to interpret co‐occurrence patterns from camera trap data: The case of the gray fox, the bobcat, and the eastern cottontail rabbit in a tropical dry habitat

AbstractIn mammals, ecological interactions are difficult to observe directly, so they are usually inferred from co‐occurrence data. Direct interpretation of co‐occurrence patterns can be complicated since they may be the result of different processes such as habitat selection. We propose a logical framework along with multispecies occupancy models, to distinguish which process or interaction of processes gives rise to co‐occurrence patterns. We also used temporal kernel density estimates to explore the overlap in diel activity patterns, and ecological knowledge of the species as a complement to explain the drivers that generate co‐occurrence. To test our framework, we analyzed three mammal species: the bobcat (Lynx rufus), the gray fox (Urocyon cinereoargenteus), and their potential prey, the eastern cottontail rabbit (Sylvilagus floridanus), in a tropical dry habitat at Tehuacán‐Cuicatlán Biosphere Reserve, Mexico. Data were collected across 67 camera trap stations that operated from February to August 2018. The best‐fitted model described the spatial interaction between U. cinereoargenteus and L. rufus with S. floridanus; in both cases, the occupancy probability of the predatory species was higher in the presence of their prey than in their absence. Additionally, the three species presented a high overlap in their temporal activity patterns. Based on the knowledge of the species' ecology and our results, we identified that trophic interactions could be an important process shaping the co‐occurrence patterns of these species. In short, our framework highlights that it is possible to discern among the processes that influence the co‐occurrence patterns for species with well‐defined ecological roles, such as in our study system.

GEOGRAPHIC SPREAD OF CANINE DISTEMPER IN WILD CARNIVORES IN MICHIGAN, USA: PATHOLOGY AND EPIDEMIOLOGY, 2008–18

Canine distemper is a widespread disease affecting both domestic and wild carnivores. This investigation of the geographic distribution, wildlife species infected, and relative prevalence rates was conducted over an 11-yr period and helps to document the disease spread, most highly infected wildlife species, and histologic lesions. Animals were collected as found dead, hunter and trapper harvested, and euthanized for displaying signs of abnormal behavior or neurologic disease. This disease appeared to spread from the Lower Peninsula of Michigan into the Upper Peninsula, was most frequently documented in raccoons (Procyon lotor), striped skunks (Mephitis mephitis), and gray fox (Urocyon cinereoargenteus), but also involved additional wildlife species. Three unique wildlife virus strains were identified. Two of these grouped within a separate subclade of the America 2 lineage. A third strain appeared to be a unique sequence type that is not associated with any existing subclade of America 2. We recommend the combined use of routine histology and immunohistochemical staining to confirm the diagnosis, and further recommend that both the lungs and spleen be collected as the optimal tissues to utilize for surveillance purposes.

Clostridium piliforme and canine distemper virus coinfection in 2 domestic dog littermates and a gray fox kit.

Concurrent Clostridium piliforme and canine distemper virus (CDV) infection was diagnosed in 2 canine littermates and 1 gray fox kit from Texas, USA. In all 3 animals, intracytoplasmic, filamentous bacteria, consistent with C. piliforme, were present along the margins of foci of hepatic necrosis. Additional histologic findings included intracytoplasmic and intranuclear inclusion bodies in bile duct and bronchial epithelial cells of the fox kit, and mild intestinal necrosis in 1 puppy. PCR assays confirmed the presence of C. piliforme in all 3 animals, CDV in both puppies, and canine parvovirus in 1 puppy. Fluorescent antibody testing confirmed the presence of CDV in the fox kit. Concurrent canine distemper and Tyzzer disease in canine littermates and the gray fox has not been reported previously, to our knowledge.

Fruits of Cyrtocarpa procera Kunth (Anacardiaceae) as resource for medium to large-sized terrestrial mammals species in a tropical dry forest

ABSTRACT The fruits of some Anacardiaceae tree species are important sources of food and water for vertebrate species in seasonal tropical forest. During a monitoring study using camera-traps in a tropical dry forest of the Tehuacán-Cuicatlán Biosphere Reserve, Mexico, we documented tree visitation and fruit consumption in the ‘Chupandillo’ Cyrtocarpa procera by medium to large-sized terrestrial mammals species. From 2012 to 2017, we established cameras-traps in front of six adult chupandillo trees during 385–499 days. A total of 4,831 photographs were obtained during a total of 2,706 days. The camera-traps recorded 12 mammals species visiting, passing in front the tree, or consuming its fruits. The white-tailed deer, cotton rabbit, collared peccary and gray fox were the species that presented the highest number of visit events, with the two ungulate species recorded visiting all of the sampled trees. These species, as well as coati, consumed fruits of this tree species from September to October. The white-tailed deer visited during the day, while the collared peccary mainly visited during the twilight-night time period. We propose that fruits of C. procera are an important resource for mammals in this region, in particular for white-tailed deer and collared peccary.

Asymmetrical intraguild interactions with coyotes, red foxes, and domestic dogs may contribute to competitive exclusion of declining gray foxes.

Species coexistence is governed by availability of resources and intraguild interactions including strategies to reduce ecological overlap. Gray foxes are dietary generalist mesopredators expected to benefit from anthropogenic disturbance, but populations have declined across the midwestern USA, including severe local extirpation rates coinciding with high coyote and domestic dog occurrence and low red fox occurrence. We used data from a large‐scale camera trap survey in southern Illinois, USA to quantify intraguild spatial and temporal interactions among the canid guild including domestic dogs. We used a two‐species co‐occurrence model to make pairwise assessments of conditional occupancy and detection rates. We also estimated temporal activity overlap among species and fit a fixed‐effects hierarchical community occupancy model with the four canid species. We partitioned the posterior distributions to compare gray fox occupancy probabilities conditional on estimated state of combinations of other species to assess support for hypothesized interactions. We found no evidence of broadscale avoidance among native canids and conclude that spatial and temporal segregation were limited by ubiquitous human disturbance. Mean guild richness was two canid species at a site and gray fox occupancy was greater when any combination of sympatric canids was also present, setting the stage for competitive exclusion over time. Domestic dogs may amplify competitive interactions by increasing canid guild size to the detriment of gray foxes. Our results suggest that while human activities can benefit some mesopredators, other species such as gray foxes may serve as bellwethers for habitat degradation with trophic downgrading and continued anthropogenic homogenization.

Listeriosis with viral coinfections in 8 gray foxes, 8 wild turkeys, and 2 young cervids in the southeastern United States.

Listeria monocytogenes is a bacterium that can cause disease in many species, including humans, livestock, and wildlife. Increased interactions via shared habitats may promote pathogen transmission among these groups. Our objectives were to evaluate the Southeastern Cooperative Wildlife Disease Study diagnostic data to characterize and compare L. monocytogenes-induced lesions and comorbidities in gray foxes and wild turkeys, and to describe cases of listeriosis in 2 cervids. From 1991-2020, 8 gray foxes, 8 wild turkeys, a neonatal elk, and a white-tailed deer fawn from several eastern states in the United States were diagnosed with listeriosis. All 8 foxes had hepatitis and/or hepatic necrosis with intralesional gram-positive bacilli, and concurrent canine distemper virus (CDV) infection; 2 of the foxes had been vaccinated recently for CDV. L. monocytogenes was cultured from the liver (6 of 8) or lung (2 of 8) of foxes. Lesions in wild turkeys included hepatocellular necrosis (3 of 8), heterophilic hepatitis (1 of 8), heterophilic granulomas (1 of 8), intrasinusoidal gram-positive bacilli without hepatic lesions (1 of 8), granulomatous dermatitis (1 of 8), and/or granulomatous myocarditis (2 of 8). Lymphoproliferative disease viral DNA was detected in 5 of 6 turkeys tested; reticuloendotheliosis viral DNA was detected in 2 of 3 turkeys tested. Both cervids had systemic listeriosis, with L. monocytogenes isolated from liver. Immunohistochemistry for Listeria spp. on select cases revealed immunolabeling in affected organs. Listeriosis was thus established as a cause of morbidity and mortality in 3 wildlife species, which often suffered from concurrent infections and likely immunosuppression.

Divergent Rabies Virus Variant of Probable Bat Origin in 2 Gray Foxes, New Mexico, USA.

In the Western Hemisphere, bat-associated rabies viruses (RABVs) have established independent transmission cycles in multiple mammal hosts, forming genetically distinct lineages. In New Mexico, USA, skunks, bats, and gray foxes are rabies reservoir hosts and represent a public health risk because of encounters with humans. During 2015 and 2019, two previously undescribed RABVs were detected in 2 gray foxes (Urocyon cinereoargenteus) in Lincoln County, New Mexico. Phylogenetic analysis of the nucleoprotein gene indicated that the isolates are a novel RABV variant. These 2 cases probably represent repeated spillover events from an unknown bat reservoir to gray foxes. Molecular analysis of rabies cases across New Mexico identified that other cross-species transmission events were the result of viral variants previously known to be enzootic to New Mexico. Despite a robust rabies public health surveillance system in the United States, advances in testing and surveillance techniques continue to identify previously unrecognized zoonotic pathogens.

Seasonal activity patterns of sympatric eastern gray squirrels (Sciurus carolinensis) and fox squirrels (Sciurus niger) in a Midwestern metropolitan region

Seasonal activity patterns of sympatric eastern gray squirrels (Sciurus carolinensis) and fox squirrels (Sciurus niger) in a Midwestern metropolitan region

Use of cenotes and the cave environment by mammals on the Yucatán Peninsula, Mexico

AbstractMammals are important sources of nutrients to cave ecosystems, and in some circumstances, caves may be an essential resource for mammals. Few studies, however, have focused on the use of caves by terrestrial mammals. The Yucatán Peninsula encompasses an extensive carbonate karst region that includes the world's largest underwater cave system. Forest in the region overlies fractured limestone bedrock, so flooded caves known regionally as cenotes represent the only reliable source of free‐standing water for much of the Peninsula's wildlife. We used camera traps at 17 cenotes on the Yucatán Peninsula to determine patterns of use by mammals. Eighteen non‐volant mammal taxa were identified using cenotes, the most commonly occurring being lowland paca (Agouti paca), opossums (Didelphis spp.), white‐nosed coati (Nasua narica), gray fox (Urocyon cinereoargenteus), tayra (Eira barbara), and gray four‐eyed opossum (Philander opossum); collectively these taxa accounted for 76% of all mammal records. We also recorded several felids using cenotes, including jaguar (Panthera onca) and puma (Puma concolor). Activity patterns at cenotes usually matched normal activity schedules, but some species were nocturnal in the forest but diurnal at cenotes. Mammals mostly accessed cenotes to drink, but a range of activities were recorded including foraging, nesting, mating, resting, and bathing. The Yucatán region has experienced continued population growth and economic development over many decades which directly threatens cenotes. Because our work has revealed that cenotes are important to the Yucatán's mammals, we believe protection of cenotes should be a central issue for regional wildlife conservation.Abstract in Spanish is available with online material.

USO DE HÁBITAT POR ZORRO GRIS (Urocyon cinereoargenteus, CARNIVORA: CANIDAE) EN UN ECOSISTEMA TROPICAL ANTROPIZADO

&lt;p&gt;&lt;strong&gt;Background. &lt;/strong&gt;Gray fox, &lt;em&gt;Urocyon cinereoargenteus&lt;/em&gt; is tolerant to habitat disturbance, but the biotic and abiotic factors that determine the selection of space in the subperennial medium forest (SMF) with different degrees of anthropization are not known, which is relevant to explain a fraction of an animal’s niche. &lt;strong&gt;Objective.&lt;/strong&gt; We described the use of habitat by the gray fox, in four habitat units in the SMF, with different degrees of anthropization. &lt;strong&gt;Methodology.&lt;/strong&gt; We classified four habitat units with vegetation structure criteria: Sugar cane-coffee plantation, Coffee plantation-forest, forest and Coffee plantation, where we evaluated parameters such as number of carnivores and potential prey and plant cover. In addition, we evaluated the altitude, temperature, precipitation and evaporation. Using indirect techniques, we obtained gray fox records in each habitat unit, which we related to biotic and abiotic parameters through a χ&lt;sup&gt;2&lt;/sup&gt; test and a partial least squares analysis; we applied a dendrogram to estimate the similarity of use of the habitats; and a response surface-based model to describe habitat use. &lt;strong&gt;Results.&lt;/strong&gt; We associated fourteen independent records of gray fox and six of them with the Coffee plantation-SMF habitat, where it was correlated with temperature. &lt;strong&gt;Implications.&lt;/strong&gt; Shrub coverage, the number of competitors and evaporation in SMF and Coffee plantation-SMF are factors correlated with a low number of gray fox records. &lt;strong&gt;Conclusion.&lt;/strong&gt; In this ecosystem anthropized by the production of coffee and sugarcane, the gray fox may be using open habitats for hunting and closed habitats to seek refuge while it is not active.&lt;/p&gt;

THE FOX AND THE ARMADILLO: AN INQUIRY INTO CLASSIC MAYA “ANIMAL” CATEGORIES

AbstractThis article investigates Classic Maya understandings of two particular animal species: the (gray) fox and the armadillo. We use these species as a point of entry into Classic Maya categorizations of the non-human animal world, examining the salient biological and physical characteristics of those animals that Classic-period artists and scribes chose to highlight. Rather than accepting the creatures depicted on painted pottery or referenced in hieroglyphic texts as generalized examples of particular kinds (i.e., simply “a fox” or “an armadillo”), however, we show how the evidence from ancient art, historical accounts, and contemporary ethnography points to an emphasis on specific beings, often named individuals, who engage in particular behaviors and relate to other entities (both human and non-human) in distinctive ways. Although this article focuses exclusively on the fox and the armadillo, those species serve as examples through which we consider the limitations of applying Western taxonomic categories to other systems of knowledge, as well as the possibilities for how we might catch glimpses of radically different ways of organizing the world.

Large-scale survey for canine vector-borne parasites in free-ranging dogs and foxes from six diverse bioclimatic regions of Chile.

Chile is a large country with a marked range of climate conditions that make it an ideal scenario for the study of vector-borne parasites (VBPs); however, knowledge about their distribution is limited to a few confined areas of this country. The presence of Hepatozoon spp., piroplasmids, Leishmania spp. and filarioids was investigated through molecular and serological methods in blood and serum samples of 764 free-ranging rural dogs, 154 Andean foxes (Lycalopex culpaeus), and 91 South American grey foxes (Lycalopex griseus) from six bioclimatic regions across Chile. Hepatozoon spp. DNA was exclusively detected in foxes (43% prevalence), including sequences closely related to Hepatozoon felis (24.1%; only Andean foxes), Hepatozoon americanum (16.2%; only grey foxes), and Hepatozoon canis (1.25%; in one grey fox). Risk factor assessment identified a higher probability of Hepatozoon infection in juvenile foxes. DNA of piroplasmids was detected in 0.7% of dogs (Babesia vogeli) but in no fox, whilst antibodies against Babesia sp. were detected in 24% of the dogs and 25% of the foxes, suggesting a wider circulation of canine piroplasmids than previously believed. A positive association between the presence of antibodies against Babesia and high Rhipicephalus sanguineus sensu lato burden was observed in dogs. Leishmania spp. DNA and antibodies were detected in 0.8% and 4.4% of the dogs, respectively. Acanthocheilonema reconditum was the only blood nematode detected (1.5% of the dogs and no fox). Differences in prevalence among bioregions were observed for some of the VBPs. These results expand our knowledge about the occurrence of vector-borne parasites in Chile, some of which are firstly reported herein. This information will facilitate the diagnosis of vector-borne diseases in domestic dogs and improve the control measures for both domestic and wild canids.

Wildlife associates of nine-banded armadillo (Dasypus novemcinctus) burrows in Arkansas.

The Nine‐banded Armadillo (Dasypus novemcinctus) is a widespread burrowing species with an expanding geographic range across the southeastern and midwestern United States. Armadillos dig numerous, large burrows within their home ranges and these burrows are likely used by a diverse suite of wildlife species as has been reported for other burrowing ecosystem engineers such as Gopher Tortoises (Gopherus polyphemus), Desert Tortoises (Gopherus agassizi), and Black‐tailed Prairie Dogs (Cynomys ludovicianus). We used motion‐triggered game cameras at 35 armadillo burrows in 4 ecoregions of Arkansas and documented 19 species of mammals, 4 species of reptile, 1 species of amphibian, and 40 species of bird interacting with burrows. Bobcat (Lynx rufus), Coyote (Canis latrans), Eastern Cottontail (Sylvilagus floridanus), Gray Fox (Urocyon cinereoargenteus), Gray Squirrel (Sciurus carolinensis), Northern Raccoon (Procyon lotor), Virginia Opossum (Didelphis virginiana), and unidentified rodents (mice and rats) were documented using burrows in all four ecoregions. We documented wildlife hunting, seeking shelter, rearing young in, and taking over and modifying armadillo burrows. The rate of use was highest in the Mississippi Alluvial Valley, a landscape dominated by agriculture, where natural refugia may be limited and rodents are abundant. Armadillo burrows are clearly visited and used by numerous wildlife species to fulfill various life stage requirements, and this list will likely expand if more attention is devoted to understanding the role of armadillos burrows. Armadillos are important ecosystem engineers, and their ecological role warrants more investigation and attention as opposed to only being viewed and managed as agricultural and garden pests.

Relationships between livestock grazing intensity and mammal predator-prey: A study case in Copo National Park in the dry Chaco forests

Extensive livestock ranching is one of the main drivers of habitat degradation in terrestrial communities in the dry Chaco forest (Argentina). Grazing intensity could differentially affect native mammals and their interactions, which could impact both, native mammal communities and livestock production systems. Here, we determined how the activity index of grey foxes Lycalopex gymnocercus and capture abundance and richness of small mammals vary along a grazing intensity gradient in a particular region of the dry Chaco forest (Copo National Park, Argentina). Track plots were used to estimate the activity index of foxes and cattle, and Sherman traps for small mammals. Fresh scats were collected to analyse the diet of foxes and to assess possible changes in predator-prey dynamics. Fruit availability and shrub density were measured in 6 plots of 2 m × 50 m. We used generalized linear mixed models, Spearman’s nonparametric rank correlation, Chi-squared test, and Spearman’s partial correlation coefficient to analyse the potential effects of grazing intensity. We found that the activity index of foxes increased (0.06 ± 0.018) while small mammal abundance (-0.08 ± 0.024) and species richness decreased (rs = -0.94) with increasing grazing intensity. However, the proportion of scats with mammalian remains decreased with increasing grazing intensity. Also, we did not find a strong partial correlation between foxes and small mammals when we controlled for grazing intensity. This suggests that the abundance and diversity of small mammals in the study area are determined more by grazing intensity than by predator-prey interactions. Grazing intensity could negatively affect small mammals, but not through changes in fruit availability or shrub density, but possibly by affecting grass cover. Consequently, foxes’ activity could increase to meet caloric intake requirements. Our results suggest that specific cattle management recommendations depend on the wildlife species that serves as a conservation target. We recommend testing whether reducing cattle load can make this productive activity compatible with wildlife conservation in dry Chaco forests.

Characterization of Salmonella spp. and E. coli Strains Isolated from Wild Carnivores in Janos Biosphere Reserve, Mexico.

Simple SummaryEmerging diseases (EIDs) represent a constant challenge in public health. With the recent emergence of new pathogens, some questions about the mechanisms and sites where they are generated have aroused interest. Natural environments could be the sites where pathogenic microorganisms find the conditions to generate new variants. It has been established that approximately 60.3% of EIDs are caused by potentially zoonotic pathogens, of which more than half are thought to have originated from wild individuals. In this aspect, carnivores can play an important role in the dynamics of various diseases, since there are species that are widely distributed, roam large areas, and can be carriers of a wide range of microorganisms, some of which are zoonotic. The results obtained in this work show that different species of wild carnivores can be carriers of atypical strains of pathogenic microorganisms, which shows that natural environments can represent important sites for the study of EIDs.Enterobacteriaceae are considered one the most important zoonotic pathogens. In this study, we analyzed the characteristics of E. coli and Salmonella spp. strains present in carnivores from Janos Biosphere Reserve, Mexico. These microorganisms had been isolated from a wide range of domestic and free-range animals, including wild carnivores. Fifty-five individuals were sampled, and the presence of Salmonella and E. coli was determined by bacteriological standard methods. Strains isolated were characterized by molecular methods and in vitro infection assays. Eight different species of carnivores were captured, including coyotes (Canis latrans), gray fox (Urocyon cinereoargenteus), desert foxes (Vulpes macrotis), striped skunks (Mephitis mephitis), hooded skunks (Mephitis macroura), lynxes (Lynx rufus), raccoons (Procyon lotor), and badgers (Taxidea taxus). Salmonella spp. and E. coli were isolated from four species of carnivores. Five Salmonella spp. strains were isolated, and their molecular characterization revealed in three of them the presence of fimbrial and virulence genes associated with cell invasion. In vitro evaluation of these strains showed their capability to invade human Hep2 cells. Sixty-one E. coli strains were isolated; different serotypes and phylogroups were observed from these strains. Additionally, the presence of virulence genes showed differently.