RESUMO
Variation in coat color is a prominent feature in carnivores, thought to be shaped by environmental factors. As new traits could allow populations to occupy novel niches and habitats, color polymorphism may be maintained by balancing selection. Consequently, color polymorphic species may speciate more rapidly and can give rise to monomorphic daughter species. We thus predicted that, within the Carnivora, (i) speciation rate is higher in polymorphic lineages, (ii) divergence between color polymorphic lineages is more recent, and (iii) within closely related groups, polymorphic lineages are ancestral and monomorphic lineages derived. We also tested whether accelerated speciation rates relate to niche breadth, measured by the number of occupied habitats and range size. We collected data of 48 polymorphic and 192 monomorphic carnivore species, and assessed speciation rates using phylogenetic comparative methods. We found that polymorphic carnivores had higher speciation rates (λ1 = 0.29, SD = 0.13) than monomorphic species (λ0 = 0.053, SD = 0.044). Hidden and quantitative state speciation and extinction models inferred that color polymorphism was the main contributing factor, and that niche breadth was not of influence. Therefore, other selective forces than spatial niche segregation, such as predator-prey coevolution, may contribute to color polymorphism in wild carnivores.
Assuntos
Carnívoros , Especiação Genética , Filogenia , Animais , Carnívoros/genética , Carnívoros/classificação , Ecossistema , Polimorfismo Genético , Pigmentação/genéticaRESUMO
A central objective of historical biogeography is to understand where clades originated and how they moved across space and over time. However, given the dynamic history of ecosystem changes in response to climate change and geological events, the manifold long-distance dispersals over evolutionary timescales, and regional and global extinctions, it remains uncertain how reliable inferences based solely on extant taxa can be achieved. Using a novel species-level phylogeny of all known extant and extinct species of the mammalian order Carnivora and related extinct groups, we show that far more precise and accurate ancestral areas can be estimated by fully integrating extinct species into the analyses, rather than solely relying on extant species or identifying ancestral areas only based on the geography of the oldest fossils. Through a series of simulations, we further show that this conclusion is robust under realistic scenarios in which the unknown extinct taxa represent a biased subset of all extinct species. Our results highlight the importance of integrating fossil taxa into a phylogenetic framework to further improve our understanding of historical biogeography and reveal the dynamic dispersal and diversification history of carnivores.
Assuntos
Carnívoros , Extinção Biológica , Fósseis , Filogenia , Filogeografia , Animais , Carnívoros/classificação , Evolução BiológicaRESUMO
The sabertooth morphology stands as a classic case of convergence, manifesting recurrently across various vertebrate groups, prominently within two carnivorans clades: felids and nimravids. Nonetheless, the evolutionary mechanisms driving these recurring phenotypes remain insufficiently understood, lacking a robust phylogenetic and spatiotemporal framework. We reconstruct the tempo and mode of craniomandibular evolution of Felidae and Nimravidae and evaluate the strength of the dichotomy between conical and saber-toothed species, as well as within saber-toothed morphotypes. To do so, we investigate morphological variation, convergence, phenotypic integration, and evolutionary rates, employing a comprehensive dataset of nearly 200 3D models encompassing mandibles and crania from both extinct and extant feline-like carnivorans, spanning their entire evolutionary timeline. Our results reject the hypothesis of a distinctive sabertooth morphology, revealing instead a continuous spectrum of feline-like phenotypes in both the cranium and mandible, with sporadic instances of unequivocal convergence. Disparity peaked at the end of the Miocene and is usually higher in clades containing taxa with extreme sabertoothed adaptations. We show that taxa with saberteeth exhibit a lower degree of craniomandibular integration, allowing to exhibit a greater range of phenotypes. Those same groups usually show a burst of morphological evolutionary rate at the beginning of their evolutionary history. Consequently, we propose that a reduced degree of integration coupled with rapid evolutionary rates emerge as key components in the development of a sabertooth morphology in multiple clades.
Assuntos
Evolução Biológica , Fósseis , Mandíbula , Filogenia , Crânio , Animais , Mandíbula/anatomia & histologia , Crânio/anatomia & histologia , Fósseis/anatomia & histologia , Carnívoros/anatomia & histologia , Carnívoros/classificação , Felidae/anatomia & histologia , Felidae/classificação , FenótipoRESUMO
Modes of mammalian reproduction are diverse and not always conserved among related species. Progesterone is universally required to supports pregnancy but sites of synthesis and metabolic pathways vary widely. The steroid metabolome of mid-to late gestation was characterized, focusing on 5α-reduced pregnanes in species representing the Perissodactyla, Cetartiodactyla and Carnivora using mass spectrometry. Metabolomes and steroidogenic enzyme ortholog sequences were used in heirarchial analyses. Steroid metabolite profiles were similar within orders, whales within cetartiodactyls for instance, but with notable exceptions such as rhinoceros clustering with goats, and tapirs with pigs. Steroidogenic enzyme sequence clustering reflected expected evolutionary relationships but once again with exceptions. Human sequences (expected outgroups) clustered with perissodactyl CYP11A1, CYP17A1 and SRD5A1 gene orthologues, forming outgroups only for HSD17B1 and SRD5A2. Spotted hyena CYP19A1 clustered within the Perissodactyla, between rhinoceros and equid orthologues, whereas CYP17A1 clustered within the Carnivora. This variability highlights the random adoption of divergent physiological strategies as pregnancy evolved among genetically similar species.
Assuntos
Artiodáctilos/genética , Carnívoros/genética , Enzimas/genética , Metabolômica/métodos , Perissodáctilos/genética , Esteroides/química , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , Animais , Artiodáctilos/classificação , Artiodáctilos/metabolismo , Carnívoros/classificação , Carnívoros/metabolismo , Cromatografia Líquida , Sistema Enzimático do Citocromo P-450/genética , Estradiol Desidrogenases/genética , Feminino , Perissodáctilos/classificação , Perissodáctilos/metabolismo , Filogenia , Gravidez , Reprodução , Especificidade da Espécie , Suínos , Espectrometria de Massas em TandemRESUMO
In species that live in sympatry, some dimensions of their ecological niche can overlap, but coexistence is possible thanks to segregation strategies, being the differential use of space and time one of the most frequent. Through a pioneer study in North-West Africa based on a camera-trapping survey, we studied ecology features of a carnivores' community in the Middle Atlas Mountains, Morocco. We focused on how species shared (or not) the territory and their activity patterns. Camera trapping detected five carnivorous species: African golden wolf (Canis lupaster), red fox (Vulpes vulpes), domestic dog (Canis lupus familiaris), genet (Genetta genetta) and African wildcat (Felis lybica lybica). Generalized Linear Models confirmed different habitat selection patterns between these species. The presence of a small protected area or prey availability apparently were not determinant factors in the abundance of these species. Spatial segregation patterns were observed between the red fox with the domestic dog and between the red fox with the genet. Kernel density estimates showed strong temporal segregation of red fox and African golden wolf with regard to domestic dog, and suggested avoidance mechanisms for the triad red fox, genet and African golden wolf. Despite the influence of interspecific competition in the assembly of the community, human pressure was apparently the most relevant factor related with the spatio-temporal segregation in this territory.
Assuntos
Distribuição Animal , Carnívoros/fisiologia , Ecossistema , Animais , Carnívoros/classificação , Marrocos , Especificidade da EspécieRESUMO
The order Carnivora, which currently includes 296 species classified into 16 families, is distributed across all continents. The phylogeny and the timing of diversification of members of the order are still a matter of debate. Here, complete mitochondrial genomes were analysed to reconstruct the phylogenetic relationships and to estimate divergence times among species of Carnivora. We assembled 51 new mitogenomes from 13 families, and aligned them with available mitogenomes by selecting only those showing more than 1% of nucleotide divergence and excluding those suspected to be of low-quality or from misidentified taxa. Our final alignment included 220 taxa representing 2,442 mitogenomes. Our analyses led to a robust resolution of suprafamilial and intrafamilial relationships. We identified 21 fossil calibration points to estimate a molecular timescale for carnivorans. According to our divergence time estimates, crown carnivorans appeared during or just after the Early Eocene Climatic Optimum; all major groups of Caniformia (Cynoidea/Arctoidea; Ursidae; Musteloidea/Pinnipedia) diverged from each other during the Eocene, while all major groups of Feliformia (Nandiniidae; Feloidea; Viverroidea) diversified more recently during the Oligocene, with a basal divergence of Nandinia at the Eocene/Oligocene transition; intrafamilial divergences occurred during the Miocene, except for the Procyonidae, as Potos separated from other genera during the Oligocene.
Assuntos
Carnívoros/classificação , Carnívoros/genética , Genoma Mitocondrial/genética , Animais , Evolução Biológica , DNA Mitocondrial/genética , Evolução Molecular , Fósseis , Variação Genética/genética , Filogenia , Análise de Sequência de DNA/métodosRESUMO
Gut microbiota plays a critical role in host physiology and health. The coevolution between the host and its gut microbes facilitates animal adaptation to its specific ecological niche. Multiple factors such as host diet and phylogeny modulate the structure and function of gut microbiota. However, the relative contribution of each factor in shaping the structure of gut microbiota remains unclear. The giant (Ailuropoda melanoleuca) and red (Ailurus styani) pandas belong to different families of order Carnivora. They have evolved as obligate bamboo-feeders and can be used as a model system for studying the gut microbiome convergent evolution. Here, we compare the structure and function of gut microbiota of the two pandas with their carnivorous relatives using 16S rRNA and metagenome sequencing. We found that both panda species share more similarities in their gut microbiota structure with each other than each species shares with its carnivorous relatives. This indicates that the specialized herbivorous diet rather than host phylogeny is the dominant driver of gut microbiome convergence within Arctoidea. Metagenomic analysis revealed that the symbiotic gut microbiota of both pandas possesses a high level of starch and sucrose metabolism and vitamin B12 biosynthesis. These findings suggest a diet-driven convergence of gut microbiomes and provide new insight into host-microbiota coevolution of these endangered species.
Assuntos
Ailuridae/genética , Carnívoros/genética , Dieta , Evolução Molecular , Microbioma Gastrointestinal/genética , Variação Genética , Ursidae/genética , Ailuridae/classificação , Ailuridae/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Bambusa/fisiologia , Carnívoros/classificação , Carnívoros/microbiologia , Fezes/microbiologia , Comportamento Alimentar/fisiologia , Metagenômica/métodos , Filogenia , RNA Ribossômico 16S/genética , Especificidade da Espécie , Ursidae/classificação , Ursidae/microbiologiaRESUMO
Humans profoundly impact landscapes, ecosystems, and animal behavior. In many cases, animals living near humans become tolerant of them and reduce antipredator responses. Yet, we still lack an understanding of the underlying evolutionary dynamics behind these shifts in traits that affect animal survival. Here, we used a phylogenetic meta-analysis to determine how the mean and variability in antipredator responses change as a function of the number of generations spent in contact with humans under 3 different contexts: urbanization, captivity, and domestication. We found that any contact with humans leads to a rapid reduction in mean antipredator responses as expected. Notably, the variance among individuals over time observed a short-term increase followed by a gradual decrease, significant for domesticated animals. This implies that intense human contact immediately releases animals from predation pressure and then imposes strong anthropogenic selection on traits. In addition, our results reveal that the loss of antipredator traits due to urbanization is similar to that of domestication but occurs 3 times more slowly. Furthermore, the rapid disappearance of antipredator traits was associated with 2 main life-history traits: foraging guild and whether the species was solitary or gregarious (i.e., group-living). For domesticated animals, this decrease in antipredator behavior was stronger for herbivores than for omnivores or carnivores and for solitary than for gregarious species. By contrast, the decrease in antipredator traits was stronger for gregarious, urbanized species, although this result is based mostly on birds. Our study offers 2 major insights on evolution in the Anthropocene: (1) changes in traits occur rapidly even under unintentional human "interventions" (i.e., urbanization) and (2) there are similarities between the selection pressures exerted by domestication and by urbanization. In all, such changes could affect animal survival in a predator-rich world, but through understanding evolutionary dynamics, we can better predict when and how exposure to humans modify these fitness-related traits.
Assuntos
Comportamento Animal/fisiologia , Evolução Biológica , Carnívoros/fisiologia , Atividades Humanas , Comportamento Predatório/fisiologia , Animais , Carnívoros/classificação , Domesticação , Ecossistema , Atividades Humanas/tendências , Humanos , Características de História de Vida , Fenótipo , Urbanização/tendênciasRESUMO
The top trophic level in many terrestrial food webs is typically occupied by mammalian carnivores (Order Carnivora) that broadly affect and shape ecosystems through trophic cascades. Their inter-specific interactions can further complicate effects on community dynamics as a consequence of intra-guild competition. The capacity for competitive mammalian carnivores to segregate their hunting and activity regimes is in major part a function of their similarity, in terms of body-size and dietary niche; termed the 'niche variation hypothesis'. In this study, we used camera-trapping to investigate intra-guild interactions and spatio-temporal partitioning among five mesocarnivores, the golden jackal (Canis aureus), European badger (Meles meles), red fox (Vulpes vulpes), European wildcat (Felis sylvestris) and stone marten (Martes foina), in the Stara Planina Mountains, Bulgaria. We collected a total of 444 images of golden jackals, 236 images of European badgers, 200 images of red foxes, 171 images of stone martens, and 145 images of European wildcats, from 6612 camera-days across fifteen camera-trapping stations. With respect to body size, the three smaller species (fox, wildcat and marten) were active in different time periods than the two larger competitors (jackal and badger) through both the warm and cold season. The more similar the trophic niche between species pairs (particularly relating to rodent consumption), the greater the spatio-temporal partitioning we observed within the pair; however, this adapted to seasonal dietary shifts. In conclusion, spatial and temporal (fine-scale and seasonal) niche partitioning appeared to reduce encounter probabilities and competition and may act to facilitate sympatric coexistence among this regional mesocarnivore guild.
Assuntos
Distribuição Animal , Carnívoros/classificação , Ecossistema , Animais , Bulgária , Carnívoros/fisiologia , Comportamento AlimentarRESUMO
Phylogenetic comparative methods use tree topology, branch lengths, and models of phenotypic change to take into account nonindependence in statistical analysis. However, these methods normally assume that trees and models are known without error. Approaches relying on evolutionary regimes also assume specific distributions of character states across a tree, which often result from ancestral state reconstructions that are subject to uncertainty. Several methods have been proposed to deal with some of these sources of uncertainty, but approaches accounting for all of them are less common. Here, we show how Bayesian statistics facilitates this task while relaxing the homogeneous rate assumption of the well-known phylogenetic generalized least squares (PGLS) framework. This Bayesian formulation allows uncertainty about phylogeny, evolutionary regimes, or other statistical parameters to be taken into account for studies as simple as testing for coevolution in two traits or as complex as testing whether bursts of phenotypic change are associated with evolutionary shifts in intertrait correlations. A mixture of validation approaches indicates that the approach has good inferential properties and predictive performance. We provide suggestions for implementation and show its usefulness by exploring the coevolution of ankle posture and forefoot proportions in Carnivora.
Assuntos
Evolução Biológica , Carnívoros , Pé/fisiologia , Fenótipo , Filogenia , Postura , Animais , Tornozelo/fisiologia , Teorema de Bayes , Carnívoros/classificação , Análise dos Mínimos Quadrados , Características de História de VidaRESUMO
Discrete morphological data have been widely used to study species evolution, but the use of quantitative (or continuous) morphological characters is less common. Here, we implement a Bayesian method to estimate species divergence times using quantitative characters. Quantitative character evolution is modeled using Brownian diffusion with character correlation and character variation within populations. Through simulations, we demonstrate that ignoring the population variation (or population "noise") and the correlation among characters leads to biased estimates of divergence times and rate, especially if the correlation and population noise are high. We apply our new method to the analysis of quantitative characters (cranium landmarks) and molecular data from carnivoran mammals. Our results show that time estimates are affected by whether the correlations and population noise are accounted for or ignored in the analysis. The estimates are also affected by the type of data analyzed, with analyses of morphological characters only, molecular data only, or a combination of both; showing noticeable differences among the time estimates. Rate variation of morphological characters among the carnivoran species appears to be very high, with Bayesian model selection indicating that the independent-rates model fits the morphological data better than the autocorrelated-rates model. We suggest that using morphological continuous characters, together with molecular data, can bring a new perspective to the study of species evolution. Our new model is implemented in the MCMCtree computer program for Bayesian inference of divergence times.
Assuntos
Biodiversidade , Carnívoros/classificação , Classificação/métodos , Filogenia , Animais , Teorema de Bayes , Carnívoros/anatomia & histologia , Modelos BiológicosRESUMO
Attention directed at different species by society and science is particularly relevant within the field of conservation, as societal preferences will strongly impact support for conservation initiatives and their success. Here, we assess the association between societal and research interests in four charismatic and threatened species groups, derived from a range of different online sources and social media platforms as well as scientific publications. We found a high level of concordance between scientific and societal taxonomic attention, which was consistent among assessed species groups and media sources. Results indicate that research is apparently not as disconnected from the interests of society as it is often reproached, and that societal support for current research objectives should be adequate. While the high degree of similarity between scientific and societal interest is both striking and satisfying, the dissimilarities are also interesting, as new scientific findings may constitute a constant source of novel interest for the society. In that respect, additional efforts will be necessary to draw scientific and societal focus towards less charismatic species that are in urgent need of research and conservation attention.
Assuntos
Biodiversidade , Classificação/métodos , Conservação dos Recursos Naturais/métodos , Espécies em Perigo de Extinção , Animais , Caniformia/classificação , Carnívoros/classificação , Cetáceos/classificação , Primatas/classificação , Aves Predatórias/classificaçãoRESUMO
Resumen Las interacciones interespecíficas entre especies de mesocarnívoros tropicales han sido poco estudiadas, a pesar de tener implicaciones importantes en la supervivencia, estructura, demografía, y distribución de estas especies. En este estudio se analizaron las interacciones espacio-temporales de tres mesocarnívoros simpátricos que se encuentran en el límite Noreste de su distribución geográfica en México, con el objetivo de determinar si estas especies coexisten o compiten. Con un periodo de muestreo de enero 2015 a diciembre 2016 y con un total de 26 estaciones de trampeo equipadas con dos trampas-cámara puestas frente a frente y ubicadas en caminos y veredas dentro de los diferentes tipos de vegetación que presenta la Reserva de la Biosfera El Cielo, se determinó el patrón de actividad y uso de hábitat de L. wiedii (margay), L. pardalis (ocelote) y P. yagouaroundi (yaguarundi). Las fotografías independientes de cada especie se agruparon en tres categorías temporales (día, noche y crepúsculo) y en seis categorías espaciales (tipo de vegetación) para el uso del hábitat; Bosque de Encino, Bosque de Pino Encino, Bosque de Encino Pino, Bosque Mesófilo de Montaña, Selva Baja Caducifolia y Selva Mediana. El solapamiento entre especies (o interacciones) temporales y espaciales se obtuvieron con el índice de Czekanowski y el índice de Pianka, respectivamente. Estos índices son simétricos y toman valores de cero a uno, donde los resultados cercanos a cero indican que no hay solapamiento entre especies y los valores cercanos o con valor de uno indican solapamiento. Se obtuvieron un total de 379 fotografías independientes, de las cuales 239 correspondieron al margay, 118 a ocelote y 22 para el yaguarundi. Se documentó que el margay y el ocelote fueron nocturnos, más del 80 % de sus registros se presentaron en esta categoría y fueron también los que mostraron un solapamiento temporal alto (0.85), en contraste, el yaguarundi fue una especie con actividad totalmente diurna, lo que muestra que probablemente coexiste con las otras dos especies. El yaguarundi utilizó tipos de hábitat similares al ocelote y al margay (con un solapamiento de 0.81 y 0.72, respectivamente), mientras que el solapamiento espacial entre el margay y el ocelote fue intermedio (0.53), debido a que utilizaron distintos tipos de hábitat en la mayoría de los casos. Los resultados indican que no hay competencia interespecífica entre las especies de mesocarnívoros tropicales de este estudio, esto probablemente se debe a las interacciones antagonistas que exhiben entre ellos ya sea en el eje temporal o espacial. Estas estrategias pueden favorecer positivamente a las poblaciones de estos mesocarnívoros, los cuales se caracterizan por tener un comportamiento territorial alto.
Abstract Interspecific interactions among tropical mesocarnivorous species and other mammalian trophic guilds have been poorly studied, despite they have important implications in the survival, structure, demography, and distribution of these species. In this study we analyzed spatio-temporal interactions of three sympatric mesocarnivores that are located in the Northeastern limit of their geographic distribution in Mexico, with the objective of analyzing if these species coexist or compete in the axis of the temporal and spatial niche. With a sampling period from January 2015 to December 2016 and 26 camera-trapping stations (with in a set of two camera traps opposite to each other) and located along roads and animal trails, we determined the activity pattern and habitat use of L. wiedii (margay), L. pardalis (ocelote) y P. yagouaroundi (yaguarundi). All independent photographs of each species were grouped into three temporal categories (day, night and twilight) and six habitat categories; Oak Forest, Oak-Pine Forest, Cloud Forest, Pine-Oak Forest, Tropical Deciduous Forest and Medium Forest. Temporal and spatial overlap between species (i.e. interactions) was obtained with the Czekanowski index and the Pianka index, respectively. These indices are symmetrical and take values from zero to one, where the results close to zero indicate that there is no overlap between species and values close to one indicate overlap. We obtained a total of 379 independent photographs, of which 239 corresponded to margay, 118 to ocelot and 22 to yaguarundi. Margay and ocelot were nocturnal, with 75 % of their records in this category showing a high temporal overlap (0.85); whereas yaguarundi was fully diurnal, suggesting it may be able to coexist with the other two species (margay and ocelot). Moreover, the yaguarundi used habitat similar to ocelot and margay (with high spatial overlap of 0.81 and 0.72, respectively), while the spatial overlap between the margay and ocelot was intermediate (0.53), since they used in most cases different habitat types. Our results suggest that there is no interspecific competition among these tropical mesocarnivorous species, probably due to antagonistic interactions among them on the temporal and spatial axis. These strategies may positively favor populations of mesocarnivores, which are characterized by having a high territorial behavior. Rev. Biol. Trop. 66(3): 996-1008. Epub 2018 September 01.
Assuntos
Carnívoros/classificação , Felidae/crescimento & desenvolvimento , Panthera/crescimento & desenvolvimento , Ração Animal/análise , MéxicoRESUMO
Compensation programs are used globally to increase tolerance for and help offset economic loss caused by large carnivores. Compensation program funding comes from a variety of sources, and in Wyoming and Idaho, USA and Alberta, Canada this includes revenue from hunting and fishing license sales. We review the patterns of livestock depredation and compensation costs of Alberta's predator-compensation program, and compare Alberta's program to compensation programs in neighboring Canadian and American jurisdictions. Current compensation costs in Alberta are well below historic levels, but have been rapidly increasing in recent years due to an increase in depredation events coupled with increased cattle prices. That increase has caused push back from Alberta's hunting and fishing community that finances the compensation program, although less than 3.6% of Alberta's license levy dollars are used for predator compensation. Hunting effort in Alberta is highest on the same privately owned lands with livestock depredation problems, suggesting that private lands support habitats for hunted ungulate species as well as carnivores. Although compensation programs do not prevent depredation events themselves, compensation programs effectively can support the maintenance of wildlife habitats on private lands.
Assuntos
Animais Selvagens/crescimento & desenvolvimento , Carnívoros/crescimento & desenvolvimento , Compensação e Reparação , Conservação dos Recursos Naturais/métodos , Programas Governamentais/economia , Gado/crescimento & desenvolvimento , Alberta , Animais , Animais Selvagens/classificação , Carnívoros/classificação , Bovinos , Conservação dos Recursos Naturais/economia , Ecossistema , Humanos , Gado/classificaçãoRESUMO
Adaptive radiation is hypothesized to be a primary mechanism that drives the remarkable species diversity and morphological disparity across the Tree of Life. Tests for adaptive radiation in extant taxa are traditionally estimated from calibrated molecular phylogenies with little input from extinct taxa. With 85 putative species in 33 genera and over 400 described extinct species, the carnivoran superfamily Musteloidea is a prime candidate to investigate patterns of adaptive radiation using both extant- and fossil-based macroevolutionary methods. The species diversity and equally impressive ecological and phenotypic diversity found across Musteloidea is often attributed to two adaptive radiations coinciding with two major climate events, the Eocene-Oligocene transition and the Mid-Miocene Climate Transition. Here, we compiled a novel time-scaled phylogeny for 88% of extant musteloids and used it as a framework for testing the predictions of adaptive radiation hypotheses with respect to rates of lineage diversification and phenotypic evolution. Contrary to expectations, we found no evidence for rapid bursts of lineage diversification at the origin of Musteloidea, and further analyses of lineage diversification rates using molecular and fossil-based methods did not find associations between rates of lineage diversification and the Eocene-Oligocene transition or Mid-Miocene Climate Transition as previously hypothesized. Rather, we found support for decoupled diversification dynamics driven by increased clade carrying capacity in the branches leading to a subclade of elongate mustelids. Supporting decoupled diversification dynamics between the subclade of elongate mustelids and the ancestral musteloid regime is our finding of increased rates of body length evolution, but not body mass evolution, within the decoupled mustelid subclade. The lack of correspondence in rates of body mass and length evolution suggest that phenotypic evolutionary rates under a single morphological metric, even one as influential as mass, may not capture the evolution of diversity in clades that exhibit elongate body shapes. The discordance in evolutionary rates between body length and body mass along with evidence of decoupled diversification dynamics suggests that body elongation might be an innovation for the exploitation of novel Mid-Miocene resources, resulting in the radiation of some musteloids.
Assuntos
Tamanho Corporal , Carnívoros/classificação , Fósseis , Filogenia , Animais , Biodiversidade , Carnívoros/anatomia & histologia , Carnívoros/genética , Especiação GenéticaRESUMO
BACKGROUND: The red fox Vulpes vulpes is the most common mesocarnivore in Europe and with a wide geographical distribution and a high density in most terrestrial habitats of the continent. It is fast urbanising species, which can harbor high numbers of different tick species, depending on the region. Here we present the results of a large-scale study, trying to disentangle the intricate relationship between environmental factors and the species composition of ectoparasites in red foxes. The samples were collected in Transylvania (Romania), a region with a diverse geography and high biodiversity. The dead foxes (collected primarily through the National Surveillance Rabies Program) were examined carefully for the presence of ticks. RESULTS: Ticks (n = 4578) were found on 158 foxes (out of 293 examined; 53.9%). Four species were identified: Dermacentor marginatus, Ixodes canisuga, I. hexagonus and I. ricinus. The most common tick species was I. hexagonus (mean prevalence 37.5%, mean intensity 32.2), followed by I. ricinus (15.0%; 4.86), I. canisuga (4.8%; 7.71) and D. marginatus (3.7%; 3.45). Co-occurrence of two or more tick species on the same host was relatively common (12.6%), the most common co-occurrence being I. hexagonus - I. ricinus. For D. marginatus and I. canisuga the highest prevalence was recorded in lowlands, for I. hexagonus in hilly areas, while for I. ricinus in mountains. CONCLUSIONS: Altitude influenced the intensity of parasitism, with highest intensity observed for all Ixodes species in hilly areas. Dermacentor marginatus occurred only in lowlands, I. canisuga in lowlands and hilly areas while the other two species occurred in all of the regions studied. Foxes from lower altitudes had the most tick species associated, with most incidences of co-parasitism also recorded here. Land use affected tick-species composition, with the presence of D. marginatus strongly associated with the extension of arable areas and lack of forests. The presence of I. hexagonus was determined only by the extent of arable lands. As foxes are frontrunners of wildlife urbanization process, with a continuous increase of their numbers in urban areas, the knowledge of their ticks' ecology (and the pathogens vectored by these) is of utmost importance.
Assuntos
Carnívoros/parasitologia , Raposas/parasitologia , Infestações por Carrapato/veterinária , Carrapatos/fisiologia , Altitude , Distribuição Animal , Animais , Carnívoros/classificação , Carnívoros/fisiologia , Raposas/classificação , Raposas/fisiologia , Carrapatos/classificaçãoRESUMO
Extant Feliformia species are one of the most diverse radiations of Carnivora (~123 species). Despite substantial recent interest in their conservation, diversification, and systematic study, no previous phylogeny contains a comprehensive species set, and no biogeography of this group is available. Here, we present a phylogenetic estimate for Feliformia with a comprehensive species set and establish a historical biogeography based on mitochondrial DNA. Both the Bayesian and maximum likelihood phylogeny for Feliformia are elucidated in our analyses and are strongly consistent with many groups recognized in previous studies. The mitochondrial phylogenetic relationships of Felidae were for the first time successfully reconstructed in our analyses with strong supported. When divergence times and dispersal/vicariance histories were compared with historical sea level changes, four dispersal and six vicariance events were identified. These vicariance events were closely related with global sea level changes. The transgression of sea into the lowland plains between Eurasia and Africa may have caused the vicariance in these regions. A fall in the sea level during late Miocene to Pliocene produced the Bering strait land bridge, which assisted the migration of American Feliformia ancestors from Asia to North America. In contrast with the 'sweepstakes hypothesis', our results suggest that the climate cooling during 30-27 Ma assisted Feliformia migration from the African mainland to Madagascar by creating a short-lived ice bridge across the Mozambique Channel. Lineages-through-time plots revealed a large increase in lineages since the Mid-Miocene. During the Mid-Miocene Climatic Optimum, the ecosystems and population of Feliformia rapidly expanded. Subsequent climate cooling catalyzed immigration, speciation, and the extinction of Feliformia.
Assuntos
Carnívoros/genética , DNA Mitocondrial/genética , Animais , Teorema de Bayes , Carnívoros/classificação , Funções Verossimilhança , FilogeniaRESUMO
Obtaining reliable estimates of the structure of carnivore communities is of paramount importance because of their ecological roles, ecosystem services and impact on biodiversity conservation, but they are still scarce. This information is key for carnivore management: to build support for and acceptance of management decisions and policies it is crucial that those decisions are based on robust and high quality information. Here, we combined camera and live-trapping surveys, as well as telemetry data, with spatially-explicit Bayesian models to show the usefulness of an integrated multi-method and multi-model approach to monitor carnivore community structures. Our methods account for imperfect detection and effectively deal with species with non-recognizable individuals. In our Mediterranean study system, the terrestrial carnivore community was dominated by red foxes (0.410 individuals/km2); Egyptian mongooses, feral cats and stone martens were similarly abundant (0.252, 0.249 and 0.240 individuals/km2, respectively), whereas badgers and common genets were the least common (0.130 and 0.087 individuals/km2, respectively). The precision of density estimates improved by incorporating multiple covariates, device operation, and accounting for the removal of individuals. The approach presented here has substantial implications for decision-making since it allows, for instance, the evaluation, in a standard and comparable way, of community responses to interventions.
Assuntos
Animais Selvagens/classificação , Animais Selvagens/crescimento & desenvolvimento , Biota , Carnívoros/classificação , Carnívoros/crescimento & desenvolvimento , Animais , Região do Mediterrâneo , Densidade DemográficaRESUMO
Biological diversity of ixodid tick fauna of the North Caucasus is analyzed. On the whole, 38 tick species are represented in the fauna of the North Caucasus. Their distribution within the region, biotopic features, and host-parasite relationships of different stages of ontogenesis are considered.
Assuntos
Interações Hospedeiro-Parasita , Ixodidae/fisiologia , Filogenia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterinária , Animais , Biodiversidade , Aves/classificação , Aves/parasitologia , Carnívoros/classificação , Carnívoros/parasitologia , Ouriços/classificação , Ouriços/parasitologia , Especificidade de Hospedeiro , Humanos , Ixodidae/classificação , Lagomorpha/classificação , Lagomorpha/parasitologia , Roedores/classificação , Roedores/parasitologia , Ruminantes/classificação , Ruminantes/parasitologia , Federação Russa/epidemiologia , Especificidade da Espécie , Infestações por Carrapato/parasitologiaRESUMO
Mercury (Hg), lead (Pb) and cadmium (Cd) are involved in mammalian brain damage. However, little is known about Pb and Cd brain levels in wildlife that reflect the geochemical background. The aims of the study include the estimation of Hg, Pb and Cd concentrations, and the determination of relationships between these elements in the brains of 94 mesocarnivores. Road-killed or hunted animals were obtained from north-western Poland near the Polish-German border. The investigation covered the native Eurasian otter Lutra lutra, badger Meles meles, pine marten Martes martes, beech marten M. foina, European polecat Mustela putorius, red fox Vulpes vulpes, and alien species: feral and ranch American mink Neovison vison, raccoon Procyon lotor and raccoon dog Nyctereutes procyonoides. Depending on the diet and environmental pollution, the carnivore brains accumulated toxic metals in varying amounts. The highest median Hg levels (in mg/kg dry weight, dw) were found in the piscivorous Eurasian otter and feral mink (2.44 and 3.96), Pb in the omnivorous raccoon (0.47), while Cd in minks (~0.06). We indicated that Pb-based ammunition is a significant source of the element in scavengers from hunting area, and we also found a significant correlation between Pb and Cd levels in the fox brain. Finally, this study is the first to suggest background levels for brain Pb and Cd in mesocarnivores (<0.50 and <0.04 mg/kg dw, respectively).