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1.
PLoS One ; 16(9): e0257878, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34587184

RESUMO

Extracellular microRNAs (miRNAs) have been proposed to function in cross-kingdom gene regulation. Among these, plant-derived miRNAs of dietary origin have been reported to survive the harsh conditions of the human digestive system, enter the circulatory system, and regulate gene expression and metabolic function. However, definitive evidence supporting the presence of plant-derived miRNAs of dietary origin in mammals has been difficult to obtain due to limited sample sizes. We have developed a bioinformatics pipeline (ePmiRNA_finder) that provides strident miRNA classification and applied it to analyze 421 small RNA sequencing data sets from 10 types of human body fluids and tissues and comparative samples from carnivores and herbivores. A total of 35 miRNAs were identified that map to plants typically found in the human diet and these miRNAs were found in at least one human blood sample and their abundance was significantly different when compared to samples from human microbiome or cow. The plant-derived miRNA profiles were body fluid/tissue-specific and highly abundant in the brain and the breast milk samples, indicating selective absorption and/or the ability to be transported across tissue/organ barriers. Our data provide conclusive evidence for the presence of plant-derived miRNAs as a consequence of dietary intake and their cross-kingdom regulatory function within human circulating system.


Assuntos
Biologia Computacional/métodos , MicroRNAs/genética , Plantas/genética , Análise de Sequência de RNA/métodos , Ração Animal/análise , Animais , Química Encefálica , Carnívoros/genética , Dieta , Feminino , Herbivoria/genética , Humanos , Leite Humano/química , Especificidade de Órgãos , RNA de Plantas/genética , Tamanho da Amostra
2.
PLoS One ; 16(9): e0256876, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34506529

RESUMO

Africa is home to some of the world's most functionally diverse guilds of large carnivores. However, they are increasingly under threat from anthropogenic pressures that may exacerbate already intense intra-guild competition. Understanding the coexistence mechanisms employed by these species in human-impacted landscapes could help shed light on some of the more subtle ways in which humans may impact wildlife populations, and inform multi-species conservation planning. We used camera trap data from Tanzania's Ruaha-Rungwa landscape to explore temporal and spatiotemporal associations between members of an intact East African large carnivore guild, and determine how these varied across gradients of anthropogenic impact and protection. All large carnivores except African wild dog (Lycaon pictus) exhibited predominantly nocturnal road-travel behaviour. Leopard (Panthera pardus) appeared to employ minor temporal avoidance of lion (Panthera leo) in all sites except those where human impacts were highest, suggesting that leopard may have been freed up from avoidance of lion in areas where the dominant competitor was less abundant, or that the need for leopard to avoid humans outweighed the need to avoid sympatric competitors. Lion appeared to modify their activity patterns to avoid humans in the most impacted areas. We also found evidence of avoidance and attraction among large carnivores: lion and spotted hyaena (Crocuta crocuta) followed leopard; leopard avoided lion; spotted hyaena followed lion; and lion avoided spotted hyaena. Our findings suggest that large carnivores in Ruaha-Rungwa employ fine-scale partitioning mechanisms to facilitate coexistence with both sympatric species and humans, and that growing human pressures may interfere with these behaviours.


Assuntos
Animais Selvagens , Carnívoros , Conservação dos Recursos Naturais/métodos , Ecossistema , Animais , Humanos , Tanzânia
3.
J Vet Diagn Invest ; 33(6): 1197-1201, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34382452

RESUMO

A 16-y-old female Sumatran tiger (Panthera tigris sumatrae) was evaluated for hyporexia. Examination revealed chronic kidney disease and a large subcutaneous axillary mass with draining tracts that contained numerous small black grains. Histologic examination revealed the presence of intralesional fungal hyphae. Persistent hyporexia and pyogranulomatous disease, as well as progressive cachexia and azotemia occurred despite treatment, and euthanasia was performed. Disseminated phaeohyphomycosis was diagnosed on postmortem examination, additionally affecting various lymph nodes, the nasal cavity, mesenteric adipose tissue, abdominal aorta, pericardium, and kidney. Fungal culture from a deep-tissue sample isolated a pure growth of Curvularia sp., a dematiaceous opportunistic fungus able to cause eumycetomas and/or phaeohyphomycosis. Phaeohyphomycosis is a rare but emerging condition, not previously reported as disseminated disease in an exotic carnivore, to our knowledge. Aggressive systemic antifungal treatment was unsuccessful, likely complicated by diagnostic challenges and concurrent renal disease. The presence of a swelling with abundant grains exiting draining tracts should direct clinicians to the diagnosis of a mycetoma, warranting early and aggressive treatment.


Assuntos
Carnívoros , Micetoma , Feoifomicose , Tigres , Animais , Feminino , Rim , Micetoma/diagnóstico , Micetoma/tratamento farmacológico , Micetoma/veterinária , Feoifomicose/diagnóstico , Feoifomicose/tratamento farmacológico , Feoifomicose/veterinária
4.
Vet Parasitol ; 297: 109545, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34389191

RESUMO

The European badger, Meles meles (Carnivora, Mustelidae) is a widespread opportunistic omnivorous mammal. Its food spectrum comprises a wide variety of plants and small animals, occasionally including rodents, such as mice or rats. Considering that rodents are known to play a key role in the life cycle of Trichinella spp., the aims of this study were to investigate the occurrence of these parasites in badgers from Romania and to identify the species. Overall, 61 badgers originating from 14 counties were examined by trichinoscopy and artificial digestion. For species determination, the positive muscle samples, and the larvae recovered from the artificial digestion were used for DNA isolation, and further processed by multiplex PCR. A single badger, originating from Sibiu County, Central Romania, was found positive for Trichinella spp. Five cysts were identified using trichinoscopy: four in the diaphragm and one in the foreleg muscles. Artificial digestion revealed an infection rate of 70 larvae/100 g of muscle. The PCR indicated the occurrence of T. britovi, which is the most commonly detected species in wild carnivores in temperate areas. Although T. britovi has previously been reported in Romania, this represents the first report of its occurrence in the European badger in the country. However, the low prevalence indicates a minor reservoir role of this species.


Assuntos
Carnívoros , Mustelidae , Doenças dos Roedores , Trichinella , Triquinelose , Animais , Camundongos , Reação em Cadeia da Polimerase Multiplex/veterinária , Ratos , Romênia/epidemiologia , Trichinella/genética , Triquinelose/epidemiologia , Triquinelose/veterinária
5.
Cell Rep ; 36(8): 109614, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34433041

RESUMO

Zoonotic pathogens, such as COVID-19, reside in animal hosts before jumping species to infect humans. The Carnivora, like mink, carry many zoonoses, yet how diversity in host immune genes across species affect pathogen carriage is poorly understood. Here, we describe a progressive evolutionary downregulation of pathogen-sensing inflammasome pathways in Carnivora. This includes the loss of nucleotide-oligomerization domain leucine-rich repeat receptors (NLRs), acquisition of a unique caspase-1/-4 effector fusion protein that processes gasdermin D pore formation without inducing rapid lytic cell death, and the formation of a caspase-8 containing inflammasome that inefficiently processes interleukin-1ß. Inflammasomes regulate gut immunity, but the carnivorous diet has antimicrobial properties that could compensate for the loss of these immune pathways. We speculate that the consequences of systemic inflammasome downregulation, however, can impair host sensing of specific pathogens such that they can reside undetected in the Carnivora.


Assuntos
Carnívoros/metabolismo , Evolução Molecular , Inflamassomos/metabolismo , Zoonoses/patologia , Animais , Caspase 1/genética , Caspase 1/metabolismo , Caspase 8/metabolismo , Caspases Iniciadoras/genética , Caspases Iniciadoras/metabolismo , Morte Celular , Linhagem Celular , Humanos , Interleucina-1beta/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas NLR/genética , Proteínas NLR/metabolismo , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Salmonella typhi/patogenicidade , Zoonoses/imunologia , Zoonoses/parasitologia
6.
Sci Rep ; 11(1): 16371, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385570

RESUMO

Deforestation and agricultural intensification have resulted in an alarming change in the global land cover over the past 300 years, posing a threat to species conservation. Dhole is a monophyletic, social canid and, being an endangered and highly forest-dependent species, is more prone to the loss of favorable habitat in the Anthropocene. We determined the genetic differentiation and demographic history of dhole across the tiger reserves of Maharashtra using the microsatellite data of 305 individuals. Simulation-based analyses revealed a 77-85% decline in the major dhole sub-populations. Protected areas have provided refuge to the historically declining dhole population resulting in clustering with strong genetic structure in the remnant dhole population. The historical population decline coincides with the extreme events in the landscape over the past 300 years. The study highlights the pattern of genetic differentiation and diversity of a highly forest-dependent species which can be associated with the loss of forest cover outside tiger reserves. It also warrants attention to develop conservation plans for the remnant surviving population of dholes in India.


Assuntos
Animais Selvagens/genética , Carnívoros/genética , Cães/genética , Variação Genética/genética , Animais , Conservação dos Recursos Naturais/métodos , Demografia/métodos , Ecossistema , Espécies em Perigo de Extinção , Florestas , Índia , Repetições de Microssatélites/genética , Tigres/genética
7.
An Acad Bras Cienc ; 93(3): e20191384, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34287456

RESUMO

Key compendia of Neotropical mammals contain conflicting information regarding the dental formulae of Brazilian carnivores. The objective of the present study was to review the dental formulae of Brazilian Canidae, Felidae, Mephitidae, Mustelidae and Procyonidae. We illustrate the dental morphology of all Brazilian genera, and report intra and interspecific tooth variation, and supernumerary teeth. We examined skulls and mandibles of 710 Brazilian terrestrial carnivores, including juvenile and adult specimens. Adults of all genera have three incisors and one canine in each quadrant. Members of the canid family have the following postcanine formula P 4/4 and M 2/3, except Speothos venaticus (M 1/2); felids have P 3/2 and M 1/1; mephitids present P 2/3 and M 1/2; mustelids show P 2-4/2-3 and M 1/2; and finally, procyonids have P 4/4 and M 2/2, except Potos flavus (P 3/3). Supernumerary teeth were found in individuals of seven genera in every family except Procyonidae. Although our results corroborate previous descriptions based on vouchered material, we detected several incongruences being replicated, possibly due to the lack of examination of museum vouchers, propagating erroneous information without critical analysis. Finally, we present a dichotomous key based on the review of dental morphology.


Assuntos
Carnívoros , Dente , Animais , Brasil , Humanos
8.
Ecol Appl ; 31(6): e02393, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34164878

RESUMO

People and wildlife are living in an increasingly urban world, replete with unprecedented human densities, sprawling built environments, and altered landscapes. Such anthropogenic pressures can affect multiple processes within an ecological community, from spatial patterns to interspecific interactions. We tested two competing hypotheses, human shields vs. human competitors, to characterize how humans affect the carnivore community using multispecies occupancy models. From 2017 to 2020, we conducted the first camera survey of city parks in Detroit, Michigan, and collected spatial occurrence data of the local native carnivore community. Our 12,106-trap night survey captured detection data for coyotes (Canis latrans), red foxes (Vulpes vulpes), raccoons (Procyon lotor), and striped skunks (Mephitis mephitis). Overall occupancy varied across species (Ψcoyote = 0.40, Ψraccoon = 0.54, Ψred fox = 0.19, Ψstriped skunk = 0.09). Contrary to expectations, humans did not significantly affect individual occupancy for these urban carnivores. However, co-occurrence between coyote and skunk increased with human activity. The observed positive spatial association between an apex and subordinate pair supports the human shield hypothesis. Our findings demonstrate how urban carnivores can exploit spatial refugia and coexist with humans in the cityscape.


Assuntos
Carnívoros , Parques Recreativos , Animais , Cidades , Coiotes , Raposas , Mephitidae , Michigan , Guaxinins
9.
Ticks Tick Borne Dis ; 12(5): 101752, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34134063

RESUMO

Anaplasma platys and Ehrlichia canis are members of the Anaplasmataceae family that cause disease in dogs and are mainly transmitted by Rhipicephalus sanguineus species group ticks. We performed a cross-sectional study on these pathogens across six bioclimatic regions of Chile, including 719 free-ranging rural dogs, 132 Andean foxes (Lycalopex culpaeus), and 82 South American gray foxes (Lycalopex griseus). Dog and fox blood samples were first screened for DNA of Anaplasmataceae followed by two Ehrlichia-specific protocols. Antibodies against Anaplasma sp. and E. canis were assessed by immunofluorescence in dogs. Ectoparasites were collected and identified, with the determination of the lineages of the Rhipicephalus sanguineus species group by molecular and phylogenetic analyses. Finally, potential risk factors for infection were investigated across the different bioclimatic regions and host species. All DNA amplicons obtained from the screening protocol corresponded to Anaplasma platys. The occurrence of both A. platys DNA and antibodies was confirmed in all six bioclimatic regions, except for regions at high altitude and/or without either R. sanguineus species group lineage present. Dogs infested with R. sanguineus ticks were significantly more prone to be infected and exposed to Anaplasma spp. Prevalence of DNA was significantly higher in juvenile (19%) than in adult dogs (9%), whereas the opposite was found for seroprevalence (19% versus 35%, respectively). Overall prevalence of A. platys DNA was higher in dogs (11%) than in foxes (4%), probably owing to markedly lower tick infestations in the foxes. Ehrlichia canis DNA was not detected in any sample, and antibodies against this pathogen were detected only in four dogs, in areas with both R. sanguineus lineages present. Free-ranging dogs in Chile could be favoring the maintenance of A. platys in all areas suitable for its tick vector. Although apparently infrequent, spillovers from dogs to foxes may be taking place and should be considered in management plans in Chile.


Assuntos
Anaplasmataceae , Carnívoros/microbiologia , Doenças do Cão , Infecções por Rickettsiaceae/veterinária , Anaplasma/genética , Anaplasma/isolamento & purificação , Anaplasmataceae/genética , Anaplasmataceae/isolamento & purificação , Anaplasmose/epidemiologia , Animais , Animais Selvagens/microbiologia , Antígenos de Bactérias/sangue , Vetores Aracnídeos/microbiologia , Chile , Estudos Transversais , Doenças do Cão/epidemiologia , Doenças do Cão/microbiologia , Cães , Ehrlichia canis/genética , Ehrlichia canis/isolamento & purificação , Ehrlichiose/epidemiologia , Raposas/microbiologia , Genes Bacterianos , Filogenia , Prevalência , RNA Ribossômico 16S/genética , Rhipicephalus sanguineus/microbiologia , Infecções por Rickettsiaceae/epidemiologia , Fatores de Risco , Estudos Soroepidemiológicos , Infestações por Carrapato/veterinária , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/veterinária
10.
Ann Agric Environ Med ; 28(2): 199-207, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34184498

RESUMO

INTRODUCTION AND OBJECTIVE: The aim was to review available data concerning the occurrence of protozoan parasites affecting carnivorous fur farm animals, such as: American mink, blue and silver foxes, and raccoon dogs. Although, many protozoan pathogens have been isolated in wild fur animals, some are still not recognised as relevant to particular fur farm animal species. Protozoans that have been isolated as causative agents of clinical cases and reported in these animals are: Cryptosporidium spp., Eimeria spp., Isospora spp., Leishmania infantum, Neospora caninum, Sarcocystis spp., and Toxoplasma gondii. Unfortunately, in most reports, neither clinical symptoms nor detailed pathogenicity and clinical pathology are satisfactory discriminated. This data is essential for preparing treatment and preventive measure protocols. Additionally, attempts to better understand the infections might be useful in the case of outbreaks. RESULTS: The results of the literature research revealed that some detected infections may have zoonotic potential, and are quite likely to be transmitted in both directions. The role of vectors, e.g. small rodents, birds, insects (sand-flies), or pets (cats and dogs), which might be involved in the transmission of various parasitic infections, is also discussed. The summarized list of protozoans involved can be used for further studies on the health and welfare aspects of fur farm animal breeding and public health issues.


Assuntos
Animais Domésticos/parasitologia , Carnívoros/parasitologia , Infecções Protozoárias em Animais/parasitologia , Animais , Humanos , Infecções por Protozoários/parasitologia , Infecções por Protozoários/transmissão , Infecções Protozoárias em Animais/transmissão , Zoonoses/parasitologia , Zoonoses/transmissão
11.
Sci Rep ; 11(1): 12979, 2021 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-34155290

RESUMO

The fear large carnivores inspire in large ungulates has been argued to have cascading effects down food webs. However, a direct link between ungulate habitat use and their fear of large carnivores has not been experimentally tested. To fill this critical gap, we conducted a bi-factorial experiment in an African savanna. We removed shrub cover and broadcast large carnivore vocalizations (leopard, hyena, dog) or non-threatening control vocalizations in both experimentally cleared and shrubby control sites. We recorded the proactive (frequency of visitation) and reactive (fleeing or vigilance) responses of multiple prey (impala, warthog, nyala and bushbuck). Critically, we found a significant proactive-reactive interaction. Ungulates were 47% more likely to run after hearing a predator vocalization in shrubby control sites than experimental clearings, demonstrating that ungulates perceived less fear from large carnivores in open habitat (clearings). Consistent with this finding, ungulates visited clearings 2.4 times more often than shrubby control sites and visited shrubby control sites less often at night, when large carnivores are most active. Combined with results from previous experiments demonstrating that the disproportionate use of available habitats by large ungulates can alter ecosystem properties, our experiment provides critical evidence that the fear large carnivores inspire in large ungulates can cause trophic cascades.


Assuntos
Comportamento Animal , Carnívoros , Ecossistema , Medo , Animais , Cadeia Alimentar , Comportamento Predatório , Vocalização Animal
12.
BMC Genomics ; 22(1): 429, 2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34107880

RESUMO

BACKGROUND: The range of body sizes in Carnivora is unparalleled in any other mammalian order-the heaviest species is 130,000 times heavier than the lightest and the longest species is 50 times longer than the shortest. However, the molecular mechanisms underlying these huge differences in body size have not been explored. RESULTS: Herein, we performed a comparative genomics analysis of 20 carnivores to explore the evolutionary basis of the order's great variations in body size. Phylogenetic generalized least squares (PGLS) revealed that 337 genes were significantly related to both head body length and body mass; these genes were defined as body size associated genes (BSAGs). Fourteen positively-related BSAGs were found to be associated with obesity, and three of these were under rapid evolution in the extremely large carnivores, suggesting that these obesity-related BSAGs might have driven the body size expansion in carnivores. Interestingly, 100 BSAGs were statistically significantly enriched in cancer control in carnivores, and 15 of which were found to be under rapid evolution in extremely large carnivores. These results suggested that large carnivores might have evolved an effective mechanism to resist cancer, which could be regarded as molecular evidence to support Peto's paradox. For small carnivores, we identified 15 rapidly evolving genes and found six genes with fixed amino acid changes that were reported to reduce body size. CONCLUSIONS: This study brings new insights into the molecular mechanisms that drove the diversifying evolution of body size in carnivores, and provides new target genes for exploring the mysteries of body size evolution in mammals.


Assuntos
Carnívoros , Neoplasias , Animais , Evolução Biológica , Tamanho Corporal/genética , Carnívoros/genética , Genômica , Filogenia
13.
J Anim Ecol ; 90(10): 2268-2276, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34013520

RESUMO

Global road networks facilitate habitat modification and are integral to human expansion. Many animals, particularly scavengers, use roads as they provide a reliable source of food, such as carrion left after vehicle collisions. Tasmania is often cited as the 'roadkill capital of Australia', with the isolated offshore islands in the Bass Strait experiencing similar, if not higher, levels of roadkill. However, native mammalian predators on the islands are extirpated, meaning the remaining scavengers are likely to experience lower interference competition. In this study, we used a naturally occurring experiment to examine how the loss of mammalian carnivores within a community impacts roadside foraging behaviour by avian scavengers. We monitored the locations of roadkill and forest ravens Corvus tasmanicus, an abundant scavenger species, on eight road transects across the Tasmanian mainland (high scavenging competition) and the Bass Strait islands (low scavenging competition). We represented raven observations as one-dimensional point patterns, using hierarchical Bayesian models to investigate the dependence of raven spatial intensity on habitat, season, distance to roadkill and route location. We found that roadkill carcasses were a strong predictor of raven presence along road networks. The effect of roadkill was amplified on roads on the Bass Strait islands, where roadside carrion was a predictor of raven presence across the entire year. In contrast, ravens were more often associated with roadkill on Tasmanian mainland roads in the autumn, when other resources were low. This suggests that in the absence of competing mammalian scavengers, ravens choose to feed on roadside carrion throughout the year, even in seasons when other resources are available. This lack of competition could be disproportionately benefiting forest ravens, leading to augmented raven populations and changes to the vertebrate community structure. Our study provides evidence that scavengers modify their behaviour in response to reduced scavenger species diversity, potentially triggering trophic shifts and highlighting the importance of conserving or reintroducing carnivores within ecosystems.


Assuntos
Carnívoros , Ecossistema , Animais , Teorema de Bayes , Cadeia Alimentar , Ilhas , Estações do Ano
14.
Sci Rep ; 11(1): 10209, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33986378

RESUMO

Competition for resources is a key question in the study of our early human evolution. From the first hominin groups, carnivores have played a fundamental role in the ecosystem. From this perspective, understanding the trophic pressure between hominins and carnivores can provide valuable insights into the context in which humans survived, interacted with their surroundings, and consequently evolved. While numerous techniques already exist for the detection of carnivore activity in archaeological and palaeontological sites, many of these techniques present important limitations. The present study builds on a number of advanced data science techniques to confront these issues, defining methods for the identification of the precise agents involved in carcass consumption and manipulation. For the purpose of this study, a large sample of 620 carnivore tooth pits is presented, including samples from bears, hyenas, jaguars, leopards, lions, wolves, foxes and African wild dogs. Using 3D modelling, geometric morphometrics, robust data modelling, and artificial intelligence algorithms, the present study obtains between 88 and 98% accuracy, with balanced overall evaluation metrics across all datasets. From this perspective, and when combined with other sources of taphonomic evidence, these results show that advanced data science techniques can be considered a valuable addition to the taphonomist's toolkit for the identification of precise carnivore agents via tooth pit morphology.


Assuntos
Ciência de Dados/métodos , Paleontologia/métodos , Dente/anatomia & histologia , Animais , Arqueologia/métodos , Inteligência Artificial , Osso e Ossos/anatomia & histologia , Carnívoros , Biologia Computacional/métodos , Fósseis , Hominidae , Humanos , Modelos Estatísticos
15.
Oecologia ; 196(1): 223-234, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33934223

RESUMO

Apex predators can shape communities via cascading top-down effects, but the degree to which such effects depend on predator life history traits is largely unknown. Within carnivore guilds, complex hierarchies of dominance facilitate coexistence, whereby subordinate species avoid dominant counterparts by partitioning space, time, or both. We investigated whether a major life history trait (hibernation) in an apex carnivore (black bears Ursus americanus) mediated its top-down effects on the spatio-temporal dynamics of three sympatric mesocarnivore species (coyotes Canis latrans, bobcats Lynx rufus, and gray foxes Urocyon cinereoargenteus) across a 15,000 km2 landscape in the western USA. We compared top-down, bottom-up, and environmental effects on these mesocarnivores using an integrated modeling approach. Black bears exerted top-down effects that varied as a function of hibernation and were stronger than bottom-up or environmental impacts. High black bear activity in summer and fall appeared to buffer the most subordinate mesocarnivore (gray foxes) from competition with dominant mesocarnivores (coyotes and bobcats), which were in turn released by black bear hibernation in winter and early spring. The mesocarnivore responses occurred in space (i.e., altered occupancy and site visitation intensity) rather than time (i.e., diel activity patterns unaffected). These results suggest that the spatio-temporal dynamics of mesocarnivores in this system were principally shaped by a spatial predator cascade of interference competition mediated by black bear hibernation. Thus, certain life history traits of apex predators might facilitate coexistence among competing species over broad time scales, with complex implications for lower trophic levels.


Assuntos
Carnívoros , Lynx , Ursidae , Animais , Clima , Raposas
16.
Proc Biol Sci ; 288(1950): 20210341, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33947240

RESUMO

Species invasions and range shifts can lead to novel host-parasite communities, but we lack general rules on which new associations are likely to form. While many studies examine parasite sharing among host species, the directionality of transmission is typically overlooked, impeding our ability to derive principles of parasite acquisition. Consequently, we analysed parasite records from the non-native ranges of 11 carnivore and ungulate species. Using boosted regression trees, we modelled parasite acquisition within each zoogeographic realm of a focal host's non-native range, using a suite of predictors characterizing the parasites themselves and the host community in which they live. We found that higher parasite prevalence among established hosts increases the likelihood of acquisition, particularly for generalist parasites. Non-native host species are also more likely to acquire parasites from established host species to which they are closely related; however, the acquisition of several parasite groups is biased to phylogenetically specialist parasites, indicating potential costs of parasite generalism. Statistical models incorporating these features provide an accurate prediction of parasite acquisition, indicating that measurable host and parasite traits can be used to estimate the likelihood of new host-parasite associations forming. This work provides general rules to help anticipate novel host-parasite associations created by climate change and other anthropogenic influences.


Assuntos
Carnívoros , Parasitos , Animais , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Fenótipo
17.
Zool Res ; 42(3): 354-361, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-33998183

RESUMO

Scientific research provides essential information for conservation of threatened species. Data deficiency due to insufficient research impedes the design of conservation plans, and research bias may mistakenly direct limited resources to low biodiversity regions or less threatened species. Here, we conducted a systematic review of published papers, grants, and graduate student training on carnivorans in China to identify species bias and research gaps. Furthermore, we collected intrinsic and extrinsic features of carnivorans, and identified features that impact research intensity using generalized linear models. We found that the amount of research on carnivorans increased markedly after 2000, but species bias existed. Bears and big cats received the greatest research attention, while most small- and medium-sized carnivorans received little attention, thus showing the 80-20 phenomenon. Species with a higher level of endemism and protection under Chinese law received more consideration. As an animal conservation icon in China, the giant panda ( Ailuropoda melanoleuca) attracted more than 50% of overall carnivoran research resources. However, the giant panda also showed spillover effects, i.e., post-doctoral graduates who studied the giant panda shifted their research focus to other species after graduation, which may help improve research on other species. Thus, to improve and strengthen Carnivora research and conservation, we suggest investing greater effort in species of less concern, training of more graduate students, and reinforcing academic exchange. If such actions are not taken, many carnivoran species will continue being data deficient and threatened.


Assuntos
Carnívoros , Pesquisa , Animais , Biodiversidade , China , Conservação dos Recursos Naturais
18.
PLoS One ; 16(4): e0250937, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33930071

RESUMO

Active predators obtain energy and nutrients from prey through complex processes in which the energy gained must exceed the energy invested in finding and ingesting the prey. In addition, the amount of energy available will vary with the prey that are selected for consumption. The muricid gastropod Acanthina monodon inhabits rocky shores, where it routinely feeds on the mytilids Semimytilus algosus and Perumytilus purpuratus. In this study, S. algosus was highly preferred by the predator (over 90% were eaten) versus P. purpuratus (only 9% were eaten) when offered a mixed diet. The energetic cost of attacking one S. algosus individual was 91 J bivalve-1 while for P. purpuratus it was slightly higher: 95 J bivalve-1. Also, whereas A. monodon required on average 19 h to consume S. algosus, successful attacks on P. purpuratus required about 32% more time (25 h). In addition, a longer resting time was needed by the predator after preying on P. purpuratus before it initiated another attack. Moreover, the active metabolic costs associated with successfully attacking the prey increased 3.2 times over the basal metabolic costs when attacking S. algosus, but only by 2.5 times when attacking P. purpuratus. The calculations associated with preying on each species showed that the energetic gain per unit time likely accounts for the predator's preference for attacking S. algosus, even though predation on both species provided net energy gains for the predator. However, as S. algosus occurs seasonally at our study site, P. purpuratus would probably also be consumed due to its constant availability throughout the whole year.


Assuntos
Carnívoros/fisiologia , Ecossistema , Cadeia Alimentar , Gastrópodes/fisiologia , Mytilidae/fisiologia , Comportamento Predatório/fisiologia , Animais , Especificidade da Espécie
19.
Environ Manage ; 68(1): 87-99, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33844062

RESUMO

Financial mechanisms to mitigate the costs of negative human-carnivore interactions are frequently promoted to support human coexistence with carnivores. Yet, evidence to support their performance in different settings is scarce. We evaluated a community-based livestock insurance program implemented as part of a broader snow leopard conservation effort in the Tost Tosonbumba Nature Reserve, South Gobi, Mongolia. We assessed program efficiency and effectiveness for snow leopard conservation using a results-based evaluation approach. Data sources included program records from 2009 to 2018, as well as surveys conducted in 2016 and 2017, which allowed us to compare key indicators across communities that participated in the insurance program and control communities. Program coverage and number of livestock insured rapidly increased over the years to reach 65% of households and close to 11,000 livestock. Participants expressed satisfaction with the program and their contributions increased over time, with an increasing proportion (reaching 64% in 2018) originating from participant premiums, suggesting strong community ownership of the program. Participants were less likely to report the intention to kill a snow leopard and reported fewer livestock losses than respondents from control communities, suggesting increased engagement in conservation efforts. These results together suggest that the insurance program achieved its expected objectives, although it is challenging to disentangle the contributions of each individual conservation intervention implemented in intervention communities. However, in the first three years of the program, snow leopard mortalities continued to be reported suggesting that additional interventions were needed to reach impact in terms of reducing retaliatory killings of large carnivores.


Assuntos
Carnívoros , Seguro , Animais , Conservação dos Recursos Naturais , Humanos , Gado , Mongólia , Comportamento Predatório
20.
BMC Genomics ; 22(1): 228, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33794768

RESUMO

BACKGROUND: The red panda (Ailurus fulgens) is a riddle of morphology, making it hard to tell whether it is an ursid, a procyonid, a mustelid, or a member of its own family. Previous genetic studies have given quite contradictory results as to its phylogenetic placement. RESULTS: A recently developed whole genome-based algorithm, the Whole Genome K-mer Signature algorithm was used to analyze the genomes of 28 species of Carnivora, including A. fulgens and several felid, ursid, mustelid, one mephitid species. This algorithm has the advantage of holistically using all the information in the genomes of these species. Being a genomics-based algorithm, it also reduces stochastic error to a minimum. Besides the whole genome, the mitochondrial DNA from 52 mustelids, mephitids, ursids, procyonids and A. fulgens were aligned to draw further phylogenetic inferences. The results from the whole genome study suggested that A. fulgens is a member of the mustelid clade (p = 9·10- 97). A. fulgens also separates from the mephitid Spilogala gracilis. The giant panda, Ailuropoda melanoleuca also clusters away from A. fulgens, together with other ursids (p = 1.2·10- 62). This could be due to the geographic isolation of A. fulgens from other mustelid species. However, results from the mitochondrial study as well as neighbor-joining methods based on the sequence identity matrix suggests that A. fulgens forms a monophyletic group. A Maximum Likelihood tree suggests that A. fulgens and Ursidae form a monophyletic group, although the bootstrap value is weak. CONCLUSIONS: The main conclusion that we can draw from this study is that on a whole genome level A. fulgens possibly belongs to the mustelid clade, and not an ursid or a mephitid. This despite the fact that previously some researchers classified A. fulgens and A. melanoleuca as relatives. Since the genotype determines the phenotype, molecular-based classification takes precedence over morphological classifications. This affirms the results of some previous studies, which studied smaller portions of the genome. However, mitochondrial analyses based on neighbor-joining and maximum likelihood methods suggest otherwise.


Assuntos
Ailuridae , Carnívoros , Ursidae , Ailuridae/genética , Animais , Carnívoros/genética , DNA Mitocondrial/genética , Filogenia , Ursidae/genética
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