RESUMO
The assumption that activity and foraging are risky for prey underlies many predator-prey theories and has led to the use of predator-prey activity overlap as a proxy of predation risk. However, the simultaneous measures of prey and predator activity along with timing of predation required to test this assumption have not been available. Here, we used accelerometry data on snowshoe hares (Lepus americanus) and Canada lynx (Lynx canadensis) to determine activity patterns of prey and predators and match these to precise timing of predation. Surprisingly we found that lynx kills of hares were as likely to occur during the day when hares were inactive as at night when hares were active. We also found that activity rates of hares were not related to the chance of predation at daily and weekly scales, whereas lynx activity rates positively affected the diel pattern of lynx predation on hares and their weekly kill rates of hares. Our findings suggest that predator-prey diel activity overlap may not always be a good proxy of predation risk, and highlight a need for examining the link between predation and spatio-temporal behaviour of predator and prey to improve our understanding of how predator-prey behavioural interactions drive predation risk.
Assuntos
Lebres , Lynx , Animais , Ecossistema , Comportamento PredatórioRESUMO
Domestic and wild felids are considered suitable hosts for the parasitic mite Sarcoptes scabiei, and sarcoptic mange is reported in several felid species in the scientific literature. However, the historic classification of Sarcoptes mites into host-specific varieties does not include S. scabiei var. felis. It is unclear whether sarcoptic mange transmission in felids involves canids, other sympatric species, or exclusively felids. This study aimed to characterize the genetic structure of S. scabiei mites from domestic cats (Felis catus) and Eurasian lynx (Lynx lynx carpathicus), comparing them with Sarcoptes mites from sympatric domestic and wild carnivores. Ten Sarcoptes microsatellite markers were used to genotype 81 mites obtained from skin scrapings of 36 carnivores: 4 domestic cats, one dog (Canis lupus familiaris), 4 Eurasian lynx, 23 red foxes (Vulpes vulpes), and 4 grey wolves (Canis lupus lupus) from either Italy, Switzerland or France. Two genetic clusters of S. scabiei with a geographical distribution pattern were detected: mites from cats originating from Central Italy clustered with those from sympatric wolves. In contrast, all the other mites from Switzerland, France and Northern Italy clustered together. These results strengthen the previously advanced hypothesis that genetic variants of S. scabiei have a predominant geographic-related distribution with cryptic transmission patterns. These patterns may rely on the interactions between different hosts living in the same ecological niche rather than a simple infection among hosts belonging to the same taxon, reinforcing the idea that the S. scabiei historic classification into "var" might have little ongoing relevance.
Title: La gale sarcoptique chez les félidés : Sarcoptes scabiei var. felis existe-t-il ? Première étude moléculaire. Abstract: Les félidés domestiques et sauvages sont considérés comme des hôtes appropriés pour l'acarien parasite Sarcoptes scabiei, et la gale sarcoptique est signalée chez plusieurs espèces de félidés dans la littérature scientifique. Cependant, la classification traditionnelle des acariens du genre Sarcoptes en variétés spécifiques à l'hôte n'inclut pas S. scabiei var. felis. On ne sait pas si la transmission de la gale sarcoptique chez les félidés implique des canidés, d'autres espèces sympatriques ou exclusivement des félidés. Cette étude visait à caractériser la structure génétique des acariens S. scabiei des chats domestiques (Felis catus) et du lynx eurasien (Lynx lynx carpathicus), en les comparant aux Sarcoptes des carnivores domestiques et sauvages sympatriques. Dix marqueurs microsatellites de Sarcoptes ont été utilisés pour génotyper 81 acariens issus de grattages cutanés de 36 carnivores : 4 chats domestiques, un chien (Canis lupus familiaris), 4 lynx eurasiens, 23 renards roux (Vulpes vulpes) et 4 loups gris (Canis lupus lupus) d'Italie, de Suisse ou de France. Deux groupes génétiques de S. scabiei, qui suivent un modèle de distribution géographique, ont été détectés. Les acariens des chats originaires du centre de l'Italie se regroupent avec ceux des loups sympatriques. En revanche, tous les autres acariens de Suisse, de France et d'Italie du Nord sont groupés ensemble. Ces résultats renforcent l'hypothèse précédemment avancée selon laquelle les variants génétiques de S. scabiei ont une distribution géographique prédominante avec des schémas de transmission cryptiques. Ces modèles peuvent reposer sur les interactions entre différents hôtes vivant dans la même niche écologique plutôt que sur une simple transmission parmi des hôtes appartenant au même taxon, renforçant l'idée que la classification historique de S. scabiei en "var" a peu de pertinence.
Assuntos
Carnívoros , Felidae , Felis , Lynx , Escabiose , Lobos , Animais , Cães , Gatos , Escabiose/epidemiologia , Escabiose/veterinária , Escabiose/parasitologia , Sarcoptes scabiei/genética , Raposas/parasitologiaRESUMO
Human activity is leading to changes in the mean and variability of climatic parameters in most locations around the world. The changing mean has received considerable attention from scientists and climate policy makers. However, recent work indicates that the changing variability, that is, the amplitude and the temporal autocorrelation of deviations from the mean, may have greater and more imminent impact on ecosystems. In this paper, we demonstrate that changes in climate variability alone could drive cyclic predator-prey ecosystems to extinction via so-called phase-tipping (P-tipping), a new type of instability that occurs only from certain phases of the predator-prey cycle. We construct a mathematical model of a variable climate and couple it to two self-oscillating paradigmatic predator-prey models. Most importantly, we combine realistic parameter values for the Canada lynx and snowshoe hare with actual climate data from the boreal forest. In this way, we demonstrate that critically important species in the boreal forest have increased likelihood of P-tipping to extinction under predicted changes in climate variability, and are most vulnerable during stages of the cycle when the predator population is near its maximum. Furthermore, our analysis reveals that stochastic resonance is the underlying mechanism for the increased likelihood of P-tipping to extinction.
Assuntos
Lebres , Lynx , Animais , Humanos , Ecossistema , Dinâmica Populacional , Modelos Teóricos , Comportamento PredatórioRESUMO
Mesopredators abundance is often limited by top-order predators and also by key food resources. However, the contribution of these bidirectional forces to structure carnivore community is still unclear. Here, we studied how the presence and absence of an apex predator which is currently recovering its former distribution range, the Iberian lynx (Lynx pardinus), determined the absolute abundance and fine-scale spatiotemporal avoidance mechanisms of two sympatric mesocarnivores (stone marten Martes foina and common genet Genetta genetta) with different dietary plasticity. We hypothesized that the lynx causes a mesopredator suppression and subordinate predators develop segregation strategies in respect to their trophic niche breadth. We placed 120 camera-traps in Southern Spain for 8 months in two consecutive years to estimate mesocarnivore abundances by using SCR Bayesian models, prey availability and assess spatio-temporal patterns. We found that the lynx reduced mesocarnivore abundance up to 10 times. Stone marten, a mesopredator with a broad food resources spectrum, showed a total spatial exclusion with the apex predator. Meanwhile, fine-scale avoidance mechanisms allowed the genet to persist in low density inside lynx territories, probably taking advantage of high availability of its preferred prey. Thus, the strength of these top-down and bottom-up effects was rather species-specific. Given the recent recovery of large carnivore populations worldwide, variation in suppression levels on different mesopredator species could modify ecosystem functions provided by the carnivore community in contrasting ways.
Assuntos
Carnívoros , Lynx , Mustelidae , Animais , Ecossistema , Cadeia Alimentar , Viverridae , Teorema de Bayes , Dinâmica Populacional , Comportamento PredatórioRESUMO
Highly pathogenic avian influenza (HPAI) has caused widespread mortality in both wild and domestic birds in Europe during 2020-2022. Virus types H5N8 and H5N1 have dominated the epidemic. Isolated spill-over infections in mammals started to emerge as the epidemic continued. In autumn 2021, HPAI H5N1 caused a series of mass mortality events in farmed and released pheasants (Phasianus colchicus) in a restricted area in southern Finland. Later, in the same area, an otter (Lutra lutra), two red foxes (Vulpes vulpes) and a lynx (Lynx lynx) were found moribund or dead and infected with H5N1 HPAI virus. Phylogenetically, H5N1 strains from pheasants and mammals clustered together. Molecular analyses of the four mammalian virus strains revealed mutations in the PB2 gene segment (PB2-E627K and PB2-D701N) that are known to facilitate viral replication in mammals. This study revealed that avian influenza cases in mammals were spatially and temporally connected with avian mass mortalities suggesting increased infection pressure from birds to mammals.
Assuntos
Galliformes , Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A , Influenza Aviária , Lynx , Lontras , Animais , Influenza Aviária/epidemiologia , Virus da Influenza A Subtipo H5N1/genética , Finlândia/epidemiologia , Vírus da Influenza A/genética , RaposasRESUMO
PURPOSE: Reporting on the first implementation of a proton dedicated commercial device (IBA Sphinx/Lynx) for daily Quality Assurance (QA) of scanned proton and carbon ion beams. METHODS: Daily QA trendlines over more than 3 years for protons and more than 2 years for carbon ions have been acquired. Key daily QA parameters were reviewed, namely the spot size and position, beam range, Bragg peak width, coincidence (between beam and imaging system isocenters), homogeneity and dose. RESULTS: The performance of the QA equipment for protons and carbon ions was evaluated. Daily QA trendlines allowed us to detect machine performance drifts and changes. The definition of tolerances and action levels is provided and compared with levels used in the literature. CONCLUSION: The device has been successfully implemented for routine daily QA activities in a dual particle therapy facility for more than 2 years. It improved the efficiency of daily QA and provides a comprehensive QA process.
Assuntos
Lynx , Terapia com Prótons , Humanos , Animais , Prótons , Terapia com Prótons/métodos , Íons , Carbono , RadiometriaRESUMO
Polyomaviruses are oncogenic viruses that are generally thought to have co-evolved with their hosts. While primate and rodent polyomaviruses are increasingly well-studied, less is known about polyomaviruses that infect other mammals. In an effort to gain insight into polyomaviruses associated with carnivores, we surveyed fecal samples collected in the USA from bobcats (Lynx rufus), pumas (Puma concolor), Canada lynxes (Lynx canadensis), and grizzly bears (Ursus arctos). Using a viral metagenomic approach, we identified six novel polyomavirus genomes. Surprisingly, four of the six genomes showed a phylogenetic relationship to polyomaviruses found in prey animals. These included a putative rabbit polyomavirus from a bobcat fecal sample and two possible deer-trophic polyomaviruses from Canada lynx feces. One polyomavirus found in a grizzly bear sample was found to be phylogenetically distant from previously identified polyomaviruses. Further analysis of the grizzly bear fecal sample showed that it contained anelloviruses that are known to infect pigs, suggesting that the bear might have preyed on a wild or domestic pig. Interestingly, a polyomavirus genome identified in a puma fecal sample was found to be closely related both to raccoon polyomavirus 1 and to Lyon-IARC polyomavirus, the latter of which was originally identified in human saliva and skin swab specimens but has since been found in samples from domestic cats (Felis catus).
Assuntos
Cervos , Lynx , Polyomavirus , Puma , Ursidae , Coelhos , Animais , Gatos , Humanos , Suínos , Polyomavirus/genética , Filogenia , FezesRESUMO
Viruses in the family Circoviridae have small circular single-stranded DNA (ssDNA) genomes. Circoviruses are known to infect a wide variety of animals, with notable disease pathology in psittacine (psittacine beak and feather disease) and porcine (postweaning multisystemic wasting syndrome) species. There is still a dearth of research investigating circoviruses associated with felid species. In six fecal samples collected from bobcats (Lynx rufus) in California from 2010 to 2011, we identified six viruses belonging to the genera Circovirus (n = 1) and Cyclovirus (n = 5), using a high-throughput-sequencing-based approach. Of these, the virus in the genus Circovirus represents a new species, as it shares only 54-60% genome-wide sequence identity with the other members of this genus. The five viruses in the genus Cyclovirus represent three new species, sharing <73% genome-wide sequence identity with all other cycloviruses. Three of the cycloviruses belong to a single putative species and were obtained from the feces of three individual bobcats, sharing 95.7-99.9% sequence identity, whereas the other two unique cycloviruses were identified in a single fecal sample. At present, it is unknown whether the identified viruses infect bobcats, their prey, or their gut parasites.
Assuntos
Circoviridae , Circovirus , Lynx , Animais , Suínos , Circoviridae/genética , Circovirus/genética , California , Fezes , DNA de Cadeia Simples , Filogenia , Genoma ViralRESUMO
Cytauxzoon felis is a hematoprotozoan parasite with a complex life cycle involving a tick-vector and a mammalian host. The mammalian hosts are all felidae but in the bobcat reservoir host, the parasite typically causes only a brief, self-resolving illness followed by a prolonged subclinical infection. In domestic cats, however, infection often leads to an acute febrile illness characterized by severe morbidity and mortality. Diagnosis is based on microscopic identification of parasites or molecular testing. Treatment for ill cats is expensive, difficult, and often unsuccessful. Prevention is quite possible and depends on avoidance of feeding by vector ticks.
Assuntos
Doenças do Gato , Lynx , Piroplasmida , Infecções Protozoárias em Animais , Carrapatos , Animais , Gatos , Infecções Protozoárias em Animais/diagnóstico , Infecções Protozoárias em Animais/parasitologia , Reservatórios de Doenças/parasitologia , Reservatórios de Doenças/veterinária , Lynx/parasitologia , Carrapatos/parasitologia , Doenças do Gato/diagnóstico , Doenças do Gato/terapiaRESUMO
Wind speed can have multifaceted effects on organisms including altering thermoregulation, locomotion, and sensory reception. While forest cover can substantially reduce wind speed at ground level, it is not known if animals living in forests show any behavioural responses to changes in wind speed. Here, we explored how three boreal forest mammals, a predator and two prey, altered their behaviour in response to average daily wind speeds during winter. We collected accelerometer data to determine wind speed effects on activity patterns and kill rates of free-ranging red squirrels (n = 144), snowshoe hares (n = 101), and Canada lynx (n = 27) in Kluane, Yukon from 2015 to 2018. All 3 species responded to increasing wind speeds by changing the time they were active, but effects were strongest in hares, which reduced daily activity by 25%, and lynx, which increased daily activity by 25%. Lynx also increased the number of feeding events by 40% on windy days. These results highlight that wind speed is an important abiotic variable that can affect behaviour, even in forested environments.
Assuntos
Lebres , Lynx , Sciuridae , Vento , Animais , Ecossistema , Lebres/fisiologia , Lynx/fisiologia , Comportamento Predatório/fisiologia , Sciuridae/fisiologia , TaigaRESUMO
Understanding habitat selection of top predators is critical to predict their impacts on ecological communities and interactions with humans, particularly in recovering populations. We analyzed habitat selection in a recovering population of bobcats (Lynx rufus) in south-central Indiana using a Random Forest model. We predicted that bobcats would select forest habitat and forest edges but avoid agriculture to maximize encounters with prey species. We also predicted that bobcats would avoid developed areas and roads to minimize potential antagonistic interactions with humans. Results partially supported our predictions and were consistent with bobcats in the early stages of population expansion. Bobcats exhibited elevated use near forest edges, thresholds of avoidance near agriculture, and thresholds of selection for low and intermediate habitat heterogeneity. Bobcats exhibited peak probability of use 1-3 km from major roads, >800 m from minor roads, and <1km from developed areas, suggesting tradeoffs in reward for high-quality hunting areas and mortality risk. Our Random Forest model highlighted complex non-linear patterns and revealed that most shifts in habitat use occurred within 1 km of the edge of each habitat type. These results largely supported previous studies in the Midwest and across North America but also produced refinements of bobcat habitat use in our system, particularly at habitat boundaries. Refined models of habitat selection by carnivores enable improved prediction of the most suitable habitat for recovering populations and provides useful information for conservation.
Assuntos
Lynx , Animais , Ecossistema , Humanos , Indiana , América do NorteRESUMO
Despite recent local reintroductions of the Eurasian lynx Lynx lynx in central and north-eastern Poland, the increase in its population was not followed by its westward expansion. To address this problem and restore the lynx population in north-western Poland, 61 captive-born individuals of Baltic population origin were released in the province of Western Pomerania in 2019-2021. Prior to their release, all the animals underwent an adaptation training phase. They were then set free according to a hard-release protocol and subsequently monitored by means of GPS telemetry. In order to assess the short-term reintroduction success, the survival and causes of death of the released individuals were studied as a function of sex, age, training time, and release time and place. The overall survival rate was 71.15%, the median survival time 202 days. Most mortality, due to environmental factors, i.e. scabies (> 200 days) or traffic collisions (< 200 days), was recorded during the first 300 days following release. Age, year of release and training time were significantly related to survival, indicating that the older the lynx was when released, the better its survival changes. In contrast, the longer the training time, the poorer were the chances of survival. There was no evidence of any effect of sex, month of release or place of release. Based on these results, recommendations were made for the planning of further releases and measures to manage the restored population.
Assuntos
Lynx , Animais , Polônia/epidemiologiaRESUMO
Hepatitis E virus (HEV) is an emerging zoonotic pathogen in Europe. In the Iberian Peninsula, wild boar (Sus scrofa) is considered the main wildlife reservoir of HEV. This wild ungulate shares habitat and resources with other potential HEV carriers in Iberian Mediterranean ecosystems, although information about the role of such sympatric species in the HEV epidemiological cycle is still very limited. The aims of the present large-scale, long-term study were: (1) to determine the seroprevalence and prevalence of HEV in both free-living and captive populations of the Iberian lynx (Lynx pardinus), the most endangered felid in the world; (2) to determine potential risk factors associated with HEV exposure in this species and (3) to evaluate the dynamics of seropositivity in longitudinally sampled animals during the study period. Between 2010 and 2021, serum samples from 275 Iberian lynxes were collected in free-ranging and captive populations across the Iberian Peninsula. Forty-four of the 275 lynxes were also longitudinally sampled during the study period. A double-antigen sandwich ELISA was used to test for the presence of antibodies against HEV. A subset of seropositive samples was analysed by Western blot (WB) assay to confirm exposure to HEV. In addition, serum, liver and/or faecal samples from 367 individuals were tested for orthohepevirus RNA by RT-PCR. A total of 50 (18.2%; 95% CI: 14.1-23.2) of the 275 animals analysed had anti-HEV antibodies by ELISA. Exposure to HEV was confirmed by WB in most of the ELISA-positive Iberian lynxes analysed. Significantly higher seroprevalence was found in captive (33.6%) compared to free-ranging (7.4%) individuals. Within captive population, the GEE model identified 'age' (senile, adult and subadult) as risk a factor potentially associated with HEV exposure in the Iberian lynx. Thirteen (29.5%) of 44 longitudinally surveyed individuals seroconverted against HEV during the study period. HEV RNA was detected in the faeces of one (1/364; 0.3%; 95% CI: 0.0-0.8) free-ranging adult animal sampled in 2021. Phylogenetic analysis showed that the sequenced strain belongs to HEV-3f subtype and shared a high nucleotide sequence identity (97-99.6%) with human HEV-3f sequences from Spain and France. To the best of the authors' knowledge, this is the first survey study on HEV in the Iberian lynx and the first molecular report of HEV-A infection in free-ranging felines. Our results indicate high exposure to HEV-3 in Iberian lynx populations, particularly those kept in captivity. The serological results suggest widespread but not homogeneous circulation of HEV in Iberian lynx populations. Further studies are required to assess the epidemiological role of this endangered species as a potential spillover host of HEV.
Assuntos
Doenças do Gato , Vírus da Hepatite E , Hepatite E , Lynx , Animais , Gatos , Ecossistema , Hepatite E/epidemiologia , Hepatite E/veterinária , Vírus da Hepatite E/genética , Humanos , Filogenia , RNA , Estudos Soroepidemiológicos , Espanha/epidemiologiaRESUMO
The bobcat (Lynx rufus) is a medium-sized carnivore well adapted to various environments and an indicator species for landscape connectivity. It is one of the 4 species within the extant Lynx genus in the family Felidae. Because of its broad geographic distribution and central role in food webs, the bobcat is important for conservation. Here we present a high-quality de novo genome assembly of a male bobcat located in Mendocino County, CA, as part of the California Conservation Genomics Project (CCGP). The assembly was generated using the standard CCGP pipeline from a combination of Omni-C and HiFi technologies. The primary assembly comprises 76 scaffolds spanning 2.4 Gb, represented by a scaffold N50 of 142 Mb, a contig N50 of 66.2 Mb, and a BUSCO completeness score of 95.90%. The bobcat genome will be an important resource for the effective management and conservation of this species and comparative genomics exploration.
Assuntos
Felidae , Lynx , Animais , Masculino , Lynx/genéticaRESUMO
Biodiversity is dramatically declining worldwide due to the complex processes that include interactions among threats. Studies investigating how multiple drivers (inter)act to influence spatio-temporal shifts in species distribution ranges, which are among the most anticipated changes in biodiversity in the future, are still scarce in the scientific literature, particularly at meaningful conservation planning scales. We used species occurrence data for eight terrestrial Mediterranean carnivores at a regional scale of southern Spain to: 1) estimate environmental favourability to each species during two periods (1960s and present); 2) predict current favourability assuming the same environment-species relationships as the ones observed in the 1960s (expected favourability); and 3) analyse single and interactive effects of human persecution, presence of protected areas, and prey richness on favourability changes (present vs. expected) for each carnivore species. We found that, with a few exceptions, environmentally favourable areas for carnivore occurrence were more widely distributed in the past than today and, for most species, favourability tended to increase inside protected areas, with low frequency of poisoning events and high prey richness. Notwithstanding, for rare species such as Iberian grey wolf (Canis lupus signatus) and Iberian lynx (Lynx pardinus), interactions among drivers were the most important predictors of favourability changes, underpinned by a compensatory role of protected areas in the face of continued human persecution. We emphasize the role of protected areas in abating the effects of biodiversity threats and claim that scientific studies based on analyses of single-effect drivers that omit driver interactions may misinform conservation planning and require revision.
Assuntos
Carnívoros , Lynx , Lobos , Animais , Biodiversidade , Conservação dos Recursos Naturais , ChumboAssuntos
Lynx , Paraplegia Espástica Hereditária , Animais , Corpo Caloso/diagnóstico por imagem , Análise Mutacional de DNA , Humanos , Lynx/genética , Imageamento por Ressonância Magnética , Mutação/genética , Linhagem , Proteínas/genética , Paraplegia Espástica Hereditária/diagnóstico por imagem , Paraplegia Espástica Hereditária/genéticaRESUMO
BACKGROUND: The population of wild felids is large and stable in Romania with many carnivore habitats being protected. Felids can be infected with a wide variety of cardio-pulmonary nematodes and can act as reservoirs of infection for domestic cats. The aim of this study was to evaluate the distribution and species diversity of cardio-pulmonary nematodes in wild felids from Romania. METHODS: A total of 54 wild felids (7 Lynx lynx and 47 Felis silvestris) were legally collected from different locations in Romania and analysed by complete parasitological necropsy. The entire respiratory tract was longitudinally opened and checked for the presence of nematodes. Detected nematodes were collected and morphologically identified to species level. RESULTS: Two Eurasian lynxes and 29 European wildcats were positive for cardio-pulmonary nematodes. Eurasian lynxes were infected with two species of cardio-pulmonary nematodes, Eucoleus aerophilus and Troglostrongylus brevior, while in wildcats the dominant parasite was E. aerophilus (34.0%) followed by Angiostrongylus chabaudi (23.4%) and T. brevior (14.9%). Dirofilaria immitis and Aelurostrongylus abstrusus were each detected in two wildcats (4.3%). CONCLUSIONS: The present study expanded the epidemiological knowledge on felid cardiopulmonary nematodes in Romania. We confirmed the presence of A. abstrusus in wildcats and a patent infection with T. brevior in Eurasian lynx.
Assuntos
Angiostrongylus , Felidae , Lynx , Metastrongyloidea , Infecções por Strongylida , Animais , Gatos , Felidae/parasitologia , Romênia/epidemiologia , Infecções por Strongylida/epidemiologia , Infecções por Strongylida/parasitologia , Infecções por Strongylida/veterináriaRESUMO
BACKGROUND: Relative to temperate regions, little is known about bobcats (Lynx rufus) in the Sonoran Desert portion of their range, in part due to the difficulty of sampling an elusive carnivore in harsh desert environments. Here, we quantify habitat selection and evaluate diet of bobcats at Kofa National Wildlife Refuge, Arizona, USA, using multiple sampling techniques including GPS telemetry, camera traps, and DNA metabarcoding. RESULTS: Home ranges during the hot season were smaller than during the cool season. Camera trapping failed to yield a high enough detection rate to identify habitat occupancy trends but third-order resource selection from GPS-collar data showed a preference for higher elevations and rugged terrain at lower elevations. Diet composition consisted of a diverse range of available small prey items, including a higher frequency of avian prey than previously observed in bobcats. CONCLUSIONS: Desert bobcats in our study maintained smaller home ranges and primarily consumed smaller prey than their more northern relatives. This study illustrates the benefit of employing multiple, complementary sampling methods to understand the ecology of elusive species.
Assuntos
Lynx , Animais , Animais Selvagens , Ecologia , Ecossistema , Temperatura Alta , Lynx/genéticaRESUMO
Apex predators play key roles in food webs and their recovery can trigger trophic cascades in some ecosystems. Intra-guild competition can reduce the abundances of smaller predators and perceived predation risk can alter their foraging behaviour thereby limiting seed dispersal by frugivorous carnivores. However, little is known about how plant-frugivore mutualisms could be disturbed in the presence of larger predators. We evaluated the top-down effect of the regional superpredator, the Iberian lynx Lynx pardinus, on the number of visits and fruits consumed by medium-sized frugivorous carnivores, as well as the foraging behaviour of identified individuals, by examining the consumption likelihood and the foraging time. We carried out a field experiment in which we placed Iberian pear Pyrus bourgaeana fruits beneath fruiting trees and monitored pear removal by frugivorous carnivores, both inside and outside lynx ranges. Using camera traps, we recorded the presence of the red fox Vulpes vulpes, the Eurasian badger Meles meles and the stone marten Martes foina, as well as the number of fruits they consumed and their time spent foraging. Red fox was the most frequent fruit consumer carnivore. We found there were fewer visits and less fruit consumed by foxes inside lynx ranges, but lynx presence did not seem to affect badgers. We did not observe any stone marten visits inside lynx territories. The foraging behaviour of red foxes was also altered inside lynx ranges whereby foxes were less efficient, consuming less fruit per unit of time and having shorter visits. Local availability of fruit resources, forest coverage and individual personality also were important variables to understand visitation and foraging in a landscape of fear. Our results show a potential trophic cascade from apex predators to primary producers. The presence of lynx can reduce frugivorous carnivore numbers and induce shifts in their feeding behaviour that may modify the seed dispersal patterns with likely consequences for the demography of many fleshy-fruited plant species. We conclude that knowledge of the ecological interactions making up trophic webs is an asset to design effective conservation strategies, particularly in rewilding programs.
Los depredadores ápice juegan papeles clave en las cadenas tróficas y su recuperación puede dar lugar a cascadas tróficas en algunos ecosistemas. La competición intra-gremial puede reducir las abundancias de los depredadores más pequeños y el riesgo de depredación percibido puede alterar su comportamiento de forrajeo, llegando a limitar la dispersión de semillas de los carnívoros frugívoros. Sin embargo, se sabe poco sobre cómo un mutualismo planta-animal podría ser alterado en presencia de grandes depredadores. Aquí evaluamos los efectos en cascada del superdepredador regional, el lince ibérico Lynx pardinus, sobre el número de visitas y frutos consumidos por los carnívoros frugívoros de mediano tamaño, a la vez que el comportamiento de alimentación de individuos identificados, examinando la probabilidad de consumo y el tiempo de forrajeo. Llevamos a cabo un experimento en el que colocamos frutos de piruétano Iberian pear bajo árboles productores y monitoreamos la remoción de peras por los carnívoros frugívoros, tanto dentro como fuera de territorios de lince. Mediante el uso de cámaras trampa, registramos la presencia de zorro rojo Vulpes vulpes, tejón europeo Meles meles y garduña Martes foina, además del número de frutos que consumieron y el tiempo que emplearon forrajeando. El zorro rojo fue el carnívoro consumidor de frutos más frecuente. Encontramos que había menos visitas y un menor consumo de frutos por zorros dentro de los territorios del lince, pero la presencia de lince no pareció afectar a los tejones. No registramos ninguna visita de garduña dentro de los territorios de los linces. El comportamiento de forrajeo de los zorros rojos fue también alterado dentro del rango de distribución del lince, donde los zorros fueron menos eficientes, consumieron menos frutos por unidad de tiempo y realizaron visitas más cortas. La disponibilidad local de frutos, la cobertura forestal y la personalidad individual también fueron variables importantes para entender los patrones de visita y forrajeo en un paisaje del miedo. Nuestros resultados muestran una cascada trófica potencial desde un superdepredador hasta los productores primarios. La presencia de lince puede reducir la abundancia de carnívoros frugívoros e inducir cambios en sus patrones de alimentación que pueden modificar los patrones de dispersión de semillas con probables consecuencias para la demografía de muchas especies de plantas de fruto carnoso. Concluimos que el conocimiento de las interacciones ecológicas que componen las redes tróficas es esencial para diseñar estrategias de conservación eficaces, especialmente en programas de reintroducción.
