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1.
Conserv Biol ; 38(1): e14197, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37811741

RESUMO

Hybridization is an important evolutionary force with a principal role in the origin of new species, known as hybrid speciation. However, ongoing hybridization can create hybrid swamping, in which parental genomes are completely lost. This can become a biodiversity threat if it involves species that have adapted to certain environmental conditions and occur nowhere else. Because conservation scientists commonly have a negative attitude toward hybrids, it is important to improve understanding of the influence of interspecific gene flow on the persistence of species. We reviewed the literature on species hybridization to build a list of all known cases in the order Carnivora. To examine the relative impact, we also noted level of introgression, whether fertile offspring were produced, and whether there was mention of negative or positive evolutionary effects (hybrid speciation and swamping). To evaluate the conservation implications of hybrids, we developed a decision-making tree with which to determine which actions should be taken to manage hybrid species. We found 53 hybrids involving 68 unique taxa, which is roughly 23% of all carnivore species. They mainly involved monophyletic (83%) and sympatric species (75%). For 2 species, the outcome of the assessment was to eliminate or restrict the hybrids: Ethiopian wolf (Canis simensis) and Scottish wildcat (Felis silvestris silvestris). Both species hybridize with their domestic conspecifics. For all other cases, we suggest hybrids be protected in the same manner as native species. We found no evidence of genomic extinction in Carnivora. To the contrary, some species appear to be of hybrid origin, such as the Asiatic black bear (Ursus thibetanus) and African golden wolf (Canis lupaster). Other positive outcomes of hybridization are novel genetic diversity, adaptation to extreme environments, and increased reproductive fitness. These outcomes are particularly valuable for counterbalancing genetic drift and enabling adaptive introgression in a human-dominated world.


La especiación por hibridación es una fuerza evolutiva importante con un papel principal en el origen de una nueva especie. Sin embargo, la hibridación continua puede generar un estancamiento híbrido en el que se pierden por completo los genomas parentales. Esto puede convertirse en una amenaza para la biodiversidad si involucra a una especie que se ha adaptado a ciertas condiciones ambientales y sólo se encuentra en un lugar. Ya que los científicos de la conservación suelen tener una actitud negativa hacia los híbridos, es importante incrementar el entendimiento de la influencia que tiene el flujo interespecífico sobre la persistencia de las especies. Revisamos la literatura sobre la hibridación de especies para generar una lista de todos los casos conocidos en el orden Carnívora. También observamos el nivel de introgresión, si se produjo descendencia fértil y si hubo mención de los efectos evolutivos positivos o negativos (especiación híbrida y estancamiento) para analizar el impacto relativo. Desarrollamos un árbol de decisión con el cual determinar cuáles acciones deberían tomarse en el manejo de las especies híbridas para evaluar las implicaciones que tienen los híbridos para la conservación. Encontramos 53 híbridos de 68 taxones únicos, lo que representa aproximadamente el 23% de todos los carnívoros. Estos híbridos incluyen principalmente a especies monofiléticas (83%) y simpátricas (75%). Para dos especies, los resultados del análisis fueron la eliminación o restricción de los híbridos: el lobo etíope (Canis simensis) y el lince escocés (Felis silvestris silvestris). Ambas especies hibridan con sus coespecíficos domésticos. Para todos los demás casos sugerimos que se proteja a los híbridos de la misma manera que a las especies nativas. No encontramos evidencias de una extinción genómica en el orden Carnívora. Al contrario, algunas especies parecen tener un origen híbrido, como el oso negro asiático (Ursus thibetanus) y el lobo dorado africano (Canis lupaster). Otros resultados positivos de la hibridación son la diversidad genética novedosa, la adaptación a ambientes extremos y el incremento en la adaptabilidad reproductiva. Estos resultados son de valor particular para contrarrestar la deriva génica y permitir la introgresión adaptativa en un mundo dominado por humanos. Evaluación de la especiación y estancamiento en carnívoros silvestres con una estrategia de árbol de decisión.


Assuntos
Ursidae , Lobos , Animais , Humanos , Conservação dos Recursos Naturais , Evolução Biológica , Hibridização Genética , Ursidae/genética , Árvores de Decisões
2.
Sci Rep ; 13(1): 22574, 2023 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-38114536

RESUMO

The Carpathian Mountains have been constantly inhabited by grey wolves and present one of the largest distribution areas in Europe, comprising between 2300 and 2700 individuals in Romania. To date, however, relatively little is known about the Romanian wolf population. We aimed to provide a first assessment of genetic diversity, population structure and wolf-dog hybridisation based on 444 mostly non-invasively collected samples in the Eastern Romanian Carpathians. Pack reconstruction and analysis of population genetic parameters were performed with mitochondrial DNA control-region sequencing and microsatellite genotyping. We found relatively high levels of genetic diversity, which is similar to values found in previous studies on Carpathian wolves from Poland and Slovakia, as well as to the long-lasting Dinaric-Balkan wolf population. We found no significant population structure in our study region, suggesting effective dispersal and admixture. Analysis of wolf-dog hybridisation using a Single Nucleotide Polymorphism panel optimised for hybrid detection revealed low rates of admixture between wolves and domestic dogs. Our results provide evidence for the existence of a genetically viable wolf population in the Romanian Carpathians. The genetic data obtained in this study may serve as valuable baseline information for the elaboration of monitoring standards and management plans for wolves in Romania.


Assuntos
Genética Populacional , Lobos , Animais , Lobos/genética , Romênia , Europa (Continente) , Variação Genética
3.
PLoS One ; 18(9): e0290547, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37703235

RESUMO

Social learning is highly adaptive in transmitting essential information between individuals in many species. While several mechanisms have been observed, less is known about how much animals can remember. However, results on observational spatial memory among caching species, i.e. a form of social learning allowing individuals to remember and pilfer food caches made by others, suggest that this ability correlates with their social organization. Both wolves and their domesticated form, dogs, are social species known to make food caches, and previous studies have shown that they both can use observational spatial memory abilities to find hidden food. In order to test how much socially transmitted information wolves and dogs can remember, we tested both species in a task requiring them to find 4, 6 or 8 caches after they observed a human hiding food items, or after a control condition where they could not observe the hiding. We found that both wolves and dogs retrieved more caches and were more efficient for the first few caches if they observed the hiding than in the control condition, suggesting that they did not simply rely on scent to find the rewards. Interestingly, wolves outperformed dogs irrespective of whether the caching could be observed or not. We suggest that this result is due to a difference in motivation/persistence between wolves and dogs rather than observational spatial memory.


Assuntos
Lobos , Animais , Cães , Alimentos , Rememoração Mental , Motivação , Memória Espacial
4.
J Radiol Prot ; 43(1)2023 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-36731127

RESUMO

Radon-222 (222Rn) and its decay products are the primary sources of a population's exposure to background ionizing radiation. Radon decay products are the leading cause of lung cancer for non-smokers and the second leading cause of lung cancer after smoking for smokers. A community-driven long-term radon survey was completed in 232 residential homes in different subdivisions of Whitehorse, the capital of the Yukon, during the heating season from November to April in 2016-2017 and in 2017-2018. Radon concentrations were measured in living rooms and bedrooms on ground floors. The arithmetic and geometric means of indoor radon activity concentrations in different subdivisions of Whitehorse ranged from 52 ± 0.6 Bq m-3and 37 ± 2.3 Bq m-3in the Downtown area of Whitehorse to 993.0 ± 55.0 Bq m-3and 726.2 ± 2.4 Bq m-3in Wolf Creek. Underlying geology and glacial surfaces may partly explain these variations of indoor radon concentrations in subdivisions of Whitehorse. A total of 78 homes (34.0%) had radon concentrations higher than 100 Bq m-3, 47 homes (20.5%) had concentrations higher than 200 Bq m-3and 33 homes (14.4%) had concentrations higher than 300 Bq m-3. The indoor radon contribution to the annual effective inhalation dose to residents ranged from 3.0 mSv in the Downtown area to 51.0 mSv in Wolf Creek. The estimated annual average dose to adults in Whitehorse, Yukon, is higher than the world's average annual effective dose of 1.3 mSv due to the inhalation of indoor radon. The annual radon inhalation effective dose was assessed using radon measurements taken during winter; hence the assessed dose may be overestimated. Cost-efficient mitigation methods are available to reduce radon in existing buildings and to prevent radon entry into new buildings.


Assuntos
Poluentes Radioativos do Ar , Poluição do Ar em Ambientes Fechados , Monitoramento de Radiação , Radônio , Lobos , Animais , Poluição do Ar em Ambientes Fechados/análise , Radônio/análise , Poluentes Radioativos do Ar/análise , Canadá , Habitação , Monitoramento de Radiação/métodos
5.
Sci Total Environ ; 838(Pt 2): 156171, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35613645

RESUMO

Mercury has become a ubiquitous hazardous element even ending up in pristine areas such as the Arctic, where it biomagnifies and leaves especially top predators vulnerable to potential health effects. Here we investigate total mercury (THg) concentrations and dietary proxies for trophic position and habitat foraging (δ15N and δ13C, respectively) in fur of 30 Arctic wolves collected during 1869-1998 in the Canadian High Arctic and Greenland. Fur THg concentrations (mean ± SD) of 1.46 ± 1.39 µg g -1 dry weight are within the range of earlier reported values for other Arctic terrestrial species. Based on putative thresholds for Hg-mediated toxic health effects, the studied Arctic wolves have most likely not been at compromised health. Dietary proxies show high dietary plasticity among Arctic wolves deriving nutrition from both marine and terrestrial food sources at various trophic positions. Variability in THg concentrations seem to be related to the wolves' trophic position rather than to different carbon sources or regional differences (East Greenland, the Foxe Basin and Baffin Bay area, respectively). Although the present study remains limited due to the scarce, yet unique historic study material and small sample size, it provides novel information on temporal and spatial variation in Hg pollution of remote Arctic species.


Assuntos
Mercúrio , Poluentes Químicos da Água , Lobos , Animais , Regiões Árticas , Canadá , Monitoramento Ambiental , Cadeia Alimentar , Groenlândia , Mercúrio/análise , Poluentes Químicos da Água/análise
6.
Proc Biol Sci ; 289(1966): 20212512, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-35016539

RESUMO

Ecologists have long sought to understand space use and mechanisms underlying patterns observed in nature. We developed an optimality landscape and mechanistic territory model to understand mechanisms driving space use and compared model predictions to empirical reality. We demonstrate our approach using grey wolves (Canis lupus). In the model, simulated animals selected territories to economically acquire resources by selecting patches with greatest value, accounting for benefits, costs and trade-offs of defending and using space on the optimality landscape. Our approach successfully predicted and explained first- and second-order space use of wolves, including the population's distribution, territories of individual packs, and influences of prey density, competitor density, human-caused mortality risk and seasonality. It accomplished this using simple behavioural rules and limited data to inform the optimality landscape. Results contribute evidence that economical territory selection is a mechanistic bridge between space use and animal distribution on the landscape. This approach and resulting gains in knowledge enable predicting effects of a wide range of environmental conditions, contributing to both basic ecological understanding of natural systems and conservation. We expect this approach will demonstrate applicability across diverse habitats and species, and that its foundation can help continue to advance understanding of spatial behaviour.


Assuntos
Carnívoros , Lobos , Animais , Ecossistema , Territorialidade
7.
Artigo em Alemão | MEDLINE | ID: mdl-34666366

RESUMO

OBJECTIVE: Since 2000 the wolf population is reestablishing itself in Germany. In consequence to increasing numbers, livestock damage caused by wolves is on the rise, with horses likewise being affected. The aim of the study was to provide an overview of this challenge and its possible solutions. MATERIAL AND METHODS: Based on a literature research, data on the wolf population in Germany, wolf-related damage as well as possibilities and limitations of herd protection for horses were evaluated. An online survey addressed to horse owners/keepers served to determine the actual and/or perceived threat posed by wolves and the resulting effects on horse husbandry. RESULTS: The literature search showed a continuous increase of the wolf population in recent years as well as a significant increase of wolf-caused livestock damage in general especially since 2016; although horses were rarely affected. Half of the 574 evaluated questionnaires were from Brandenburg and Lower Saxony. The greatest influence on the individual risk assessment concerning their own horses by the growing wolf population was the horse owners' knowledge of wolf attacks in their own county. Especially the aspects of keeping young horses as well as pasture keeping played a significant role. 64 % of respondents indicated that they had not changed their horse management practices despite the increasing wolf population. Only 8 of 576 horse owners had reported officially confirmed wolf attacks and 30 respondents had not reported a suspected wolf damage to official agencies. More than half of the respondents who had contact with a wolf advisor described the cooperation as either not or only slightly purposeful. CONCLUSION AND CLINICAL RELEVANCE: The number of officially confirmed wolf attacks on horses is low. These numbers could be objectified by a routinely performed genetic test in case of corresponding suspicion. Despite the awareness of an increasing danger of horses by wolves, horse owners mostly do not undertake prophylactic protection measures. The communication between responsible authorities for wolf monitoring and horse owners seems to be in need of improvement.


Assuntos
Doenças dos Cavalos , Lobos , Criação de Animais Domésticos , Animais , Alemanha , Conhecimentos, Atitudes e Prática em Saúde , Cavalos , Medição de Risco , Inquéritos e Questionários
8.
J Hered ; 112(5): 458-468, 2021 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-34132805

RESUMO

In North American gray wolves, black coat color is dominantly inherited via a 3 base pair coding deletion in the canine beta defensin 3 (CBD103) gene. This 3 base pair deletion, called the KB allele, was introduced through hybridization with dogs and subsequently underwent a selective sweep that increased its frequency in wild wolves. Despite apparent positive selection, KBB wolves have lower fitness than wolves with the KyB genotype, even though the 2 genotypes show no observable differences in black coat color. Thus, the KB allele is thought to have pleiotropic effects on as-yet unknown phenotypes. Given the role of skin-expressed CBD103 in innate immunity, we hypothesized that the KB allele influences the keratinocyte gene expression response to TLR3 pathway stimulation and/or infection by canine distemper virus (CDV). To test this hypothesis, we developed a panel of primary epidermal keratinocyte cell cultures from 24 wild North American gray wolves of both Kyy and KyB genotypes. In addition, we generated an immortalized Kyy line and used CRISPR/Cas9 editing to produce a KyB line on the same genetic background. We assessed the transcriptome-wide responses of wolf keratinocytes to the TLR3 agonist polyinosinic:polycytidylic acid (polyI:C), and to live CDV. K locus genotype did not predict the transcriptional response to either challenge, suggesting that variation in the gene expression response does not explain pleiotropic effects of the KB allele on fitness. This study supports the feasibility of using cell culture methods to investigate the phenotypic effects of naturally occurring genetic variation in wild mammals.


Assuntos
Vírus da Cinomose Canina , Lobos , Alelos , Animais , Vírus da Cinomose Canina/genética , Cães , Expressão Gênica , Receptor 3 Toll-Like/genética , Lobos/genética
9.
Proc Natl Acad Sci U S A ; 118(22)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34031245

RESUMO

Recent studies uncover cascading ecological effects resulting from removing and reintroducing predators into a landscape, but little is known about effects on human lives and property. We quantify the effects of restoring wolf populations by evaluating their influence on deer-vehicle collisions (DVCs) in Wisconsin. We show that, for the average county, wolf entry reduced DVCs by 24%, yielding an economic benefit that is 63 times greater than the costs of verified wolf predation on livestock. Most of the reduction is due to a behavioral response of deer to wolves rather than through a deer population decline from wolf predation. This finding supports ecological research emphasizing the role of predators in creating a "landscape of fear." It suggests wolves control economic damages from overabundant deer in ways that human deer hunters cannot.


Assuntos
Conservação dos Recursos Naturais , Comportamento Predatório , Segurança , Meios de Transporte , Lobos/fisiologia , Animais , Cervos , Ecossistema , Densidade Demográfica , Estados Unidos
10.
Proc Biol Sci ; 288(1946): 20210108, 2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33653139

RESUMO

As an outcome of natural selection, animals are probably adapted to select territories economically by maximizing benefits and minimizing costs of territory ownership. Theory and empirical precedent indicate that a primary benefit of many territories is exclusive access to food resources, and primary costs of defending and using space are associated with competition, travel and mortality risk. A recently developed mechanistic model for economical territory selection provided numerous empirically testable predictions. We tested these predictions using location data from grey wolves (Canis lupus) in Montana, USA. As predicted, territories were smaller in areas with greater densities of prey, competitors and low-use roads, and for groups of greater size. Territory size increased before decreasing curvilinearly with greater terrain ruggedness and harvest mortalities. Our study provides evidence for the economical selection of territories as a causal mechanism underlying ecological patterns observed in a cooperative carnivore. Results demonstrate how a wide range of environmental and social conditions will influence economical behaviour and resulting space use. We expect similar responses would be observed in numerous territorial species. A mechanistic approach enables understanding how and why animals select particular territories. This knowledge can be used to enhance conservation efforts and more successfully predict effects of conservation actions.


Assuntos
Carnívoros , Lobos , Animais , Montana , Seleção Genética , Territorialidade
12.
Biol Rev Camb Philos Soc ; 95(3): 782-801, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32043747

RESUMO

Human-driven species annihilations loom as a major crisis. However the recovery of deer and wolf populations in many parts of the northern hemisphere has resulted in conflicts and controversies rather than in relief. Both species interact in complex ways with their environment, each other, and humans. We review these interactions in the context of the ecological and human costs and benefits associated with these species. We integrate scattered information to widen our perspective on the nature and perception of these costs and benefits and how they link to each other and ongoing controversies regarding how we manage deer and wolf populations. After revisiting the ecological roles deer and wolves play in contemporary ecosystems, we explore how they interact, directly and indirectly, with human groups including farmers, foresters, shepherds, and hunters. Interactions with deer and wolves generate various axes of tension, posing both ecological and sociological challenges. Resolving these tensions and conflicts requires that we address key questions using integrative approaches: what are the ecological consequences of deer and wolf recovery? How do they influence each other? What are the social and socio-ecological consequences of large deer populations and wolf presence? Finally, what key obstacles must be overcome to allow deer, wolves and people to coexist? Reviewing contemporary ecological and sociological results suggests insights and ways to improve our understanding and resolve long-standing challenges to coexistence. We should begin by agreeing to enhance aggregate benefits while minimizing the collective costs we incur by interacting with deer and wolves. We should also view these species, and ourselves, as parts of integrated ecosystems subject to long-term dynamics. If co-existence is our goal, we need deer and wolves to persevere in ways that are compatible with human interests. Our human interests, however, should be inclusive and fairly value all the costs and benefits deer and wolves entail including their intrinsic value. Shifts in human attitudes and cultural learning that are already occurring will reshape our ecological interactions with deer and wolves.


Assuntos
Cervos/fisiologia , Interação Humano-Animal , Lobos/fisiologia , Agricultura/economia , Animais , Análise Custo-Benefício , Europa (Continente)/epidemiologia , Agricultura Florestal/economia , Humanos , América do Norte/epidemiologia , Comportamento Predatório/fisiologia , Segurança/economia , Doenças Transmitidas por Carrapatos/economia , Doenças Transmitidas por Carrapatos/epidemiologia , Doença de Emaciação Crônica/economia , Doença de Emaciação Crônica/epidemiologia
14.
Oecologia ; 187(3): 573-583, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29654482

RESUMO

Where direct killing is rare and niche overlap low, sympatric carnivores may appear to coexist without conflict. Interference interactions, harassment and injury from larger carnivores may still pose a risk to smaller mesopredators. Foraging theory suggests that animals should adjust their behaviour accordingly to optimise foraging efficiency and overall fitness, trading off harvest rate with costs to fitness. The foraging behaviour of red foxes, Vulpes vulpes, was studied with automated cameras and a repeated measures giving-up density (GUD) experiment where olfactory risk cues were manipulated. In Plitvice Lakes National Park, Croatia, red foxes increased GUDs by 34% and quitting harvest rates by 29% in response to wolf urine. In addition to leaving more food behind, foxes also responded to wolf urine by spending less time visiting food patches each day and altering their behaviour in order to compensate for the increased risk when foraging from patches. Thus, red foxes utilised olfaction to assess risk and experienced foraging costs due to the presence of a cue from gray wolves, Canis lupus. This study identifies behavioural mechanisms which may enable competing predators to coexist, and highlights the potential for additional ecosystem service pathways arising from the behaviour of large carnivores. Given the vulnerability of large carnivores to anthropogenic disturbance, a growing human population and intensifying resource consumption, it becomes increasingly important to understand ecological processes so that land can be managed appropriately.


Assuntos
Comportamento Predatório , Lobos , Animais , Ecossistema , Medo , Raposas , Humanos
15.
Conserv Biol ; 31(6): 1247-1256, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28440021

RESUMO

Human-wildlife conflict is a major conservation challenge, and compensation for wildlife damage is a widely used economic tool to mitigate this conflict. The effectiveness of this management tool is widely debated. The relative importance of factors associated with compensation success is unclear, and little is known about global geographic or taxonomic differences in the application of compensation programs. We reviewed research on wildlife-damage compensation to determine geographic and taxonomic gaps, analyze patterns of positive and negative comments related to compensation, and assess the relative magnitude of global compensation payments. We analyzed 288 publications referencing wildlife compensation and identified 138 unique compensation programs. These publications reported US$222 million (adjusted for inflation) spent on compensation in 50 countries since 1980. Europeans published the most articles, and compensation funding was highest in Europe, where depredation by wolves and bears was the most frequently compensated damage. Authors of the publications we reviewed made twice as many negative comments as positive comments about compensation. Three-quarters of the negative comments related to program administration. Conversely, three-quarters of the positive comments related to program outcomes. The 3 most common suggestions to improve compensation programs included requiring claimants to employ damage-prevention practices, such as improving livestock husbandry or fencing of crops to receive compensation (n = 25, 15%); modifying ex post compensation schemes to some form of outcome-based performance payment (n = 21, 12%); and altering programs to make compensation payments more quickly (n = 14, 8%). We suggest that further understanding of the strengths and weaknesses of compensation as a conflict-mitigation tool will require more systematic evaluation of the factors driving these opinions and that differentiating process and outcomes and understanding linkages between them will result in more fruitful analyses and ultimately more effective conflict mitigation.


Assuntos
Animais Selvagens , Conservação dos Recursos Naturais/economia , Comportamento Predatório , Ursidae , Lobos , Agricultura/economia , Agricultura/estatística & dados numéricos , Animais , Conservação dos Recursos Naturais/estatística & dados numéricos , Europa (Continente) , Humanos
16.
Sci Rep ; 7: 42475, 2017 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-28195213

RESUMO

Understanding the dynamics of wolf-dog hybridization and delineating evidence-based conservation strategies requires information on the spatial extent of wolf-dog hybridization in real-time, which remains largely unknown. We collected 332 wolf-like scats over ca. 5,000km2 in the NW Iberian Peninsula to evaluate wolf-dog hybridization at population level in a single breeding/pup-rearing season. Mitochondrial DNA (MtDNA) and 18 ancestry informative markers were used for species and individual identification, and to detect wolf-dog hybrids. Genetic relatedness was assessed between hybrids and wolves. We identified 130 genotypes, including 67 wolves and 7 hybrids. Three of the hybrids were backcrosses to dog whereas the others were backcrosses to wolf, the latter accounting for a 5.6% rate of introgression into the wolf population. Our results show a previously undocumented scenario of multiple and widespread wolf-dog hybridization events at the population level. However, there is a clear maintenance of wolf genetic identity, as evidenced by the sharp genetic identification of pure individuals, suggesting the resilience of wolf populations to a small amount of hybridization. We consider that real-time population level assessments of hybridization provide a new perspective into the debate on wolf conservation, with particular focus on current management guidelines applied in wolf-dog hybridization events.


Assuntos
Cruzamento , Hibridização Genética , Animais , Teorema de Bayes , Biodiversidade , DNA Mitocondrial , Cães , Variação Genética , Genótipo , Geografia , Lobos
17.
Artigo em Inglês | MEDLINE | ID: mdl-29292356

RESUMO

Playback experiments have proved to be a useful tool to investigate the extent to which wild animals understand numerical concepts and the factors that play into their decisions to respond to different numbers of vocalizing conspecifics. In particular, playback experiments have broadened our understanding of the cognitive abilities of historically understudied species that are challenging to test in the traditional laboratory, such as members of the Order Carnivora. Additionally, playback experiments allow us to assess the importance of numerical information versus other ecologically important variables when animals are making adaptive decisions in their natural habitats. Here, we begin by reviewing what we know about quantity discrimination in carnivores from studies conducted in captivity. We then review a series of playback experiments conducted with wild social carnivores, including African lions, spotted hyenas and wolves, which demonstrate that these animals can assess the number of conspecifics calling and respond based on numerical advantage. We discuss how the wild studies complement those conducted in captivity and allow us to gain insights into why wild animals may not always respond based solely on differences in quantity. We then consider the key roles that individual discrimination and cross-modal recognition play in the ability of animals to assess the number of conspecifics vocalizing nearby. Finally, we explore new directions for future research in this area, highlighting in particular the need for further work on the cognitive basis of numerical assessment skills and experimental paradigms that can be effective in both captive and wild settings.This article is part of a discussion meeting issue 'The origins of numerical abilities'.


Assuntos
Carnívoros/psicologia , Compreensão , Inteligência , Comportamento Social , Animais , Hyaenidae/psicologia , Leões/psicologia , Lobos/psicologia
18.
Environ Manage ; 59(2): 175-188, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27796488

RESUMO

This paper utilizes economic valuation to offer a new perspective on livestock rancher-predator conflicts. While most studies have considered losses to the species directly involved, i.e., cattle and wolves (Canis lupus), we take into account other species that are threatened by efforts to protect livestock. In this case, vultures (Gyps fulvus) and gazelles (Gazella gazella), both endangered species, are either poisoned (vultures) or suffer from habitat fragmentation (gazelles) in the Upper Galilee region in Israel. Since the ecological value of these species is unobserved in the marketplace, we use the contingent valuation method to quantify the loss incurred from damage to protected species: wolves, vultures and gazelles. This method uses surveys of a representative sample from the population to generate estimates for use and non-use values of animals and other components of the natural environment. These value estimates are then used to compare between different measures that address the problem: either protect cattle herds by building anti-wolf fences and taking other protective measures, or compensating ranchers for their losses from wolf depredations. Our analysis suggests that while it is optimal from the ranchers' point of view to invest in protective measures such as fences, dogs and guards against wolves, it is not in society's best interest. A cost-benefit analysis taking into account all the ecological values finds a higher net benefit to society from a relatively small amount of protection, coupled with compensation to the farmers for depredations.


Assuntos
Conservação dos Recursos Naturais/métodos , Ecossistema , Espécies em Perigo de Extinção , Falconiformes/crescimento & desenvolvimento , Gado/crescimento & desenvolvimento , Lobos/crescimento & desenvolvimento , Animais , Bovinos , Conservação dos Recursos Naturais/economia , Análise Custo-Benefício , Espécies em Perigo de Extinção/tendências , Israel , Dinâmica Populacional , Comportamento Predatório
19.
Ecology ; 97(8): 1938-1948, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27859195

RESUMO

Parasites, by definition, extract energy from their hosts and thus affect trophic and food web dynamics even when the parasite may have limited effects on host population size. We studied the energetic costs of mange (Sarcoptes scabiei) in wolves (Canis lupus) using thermal cameras to estimate heat losses associated with compromised insulation during the winter. We combined the field data of known, naturally infected wolves with a data set on captive wolves with shaved patches of fur as a positive control to simulate mange-induced hair loss. We predict that during the winter in Montana, more severe mange infection increases heat loss by around 5.2-12 MJ per night (1,240-2,850 kcal, or a 65-78% increase) for small and large wolves, respectively, accounting for wind effects. To maintain body temperature would require a significant proportion of a healthy wolf's total daily energy demands (18-22 MJ/day). We also predict how these thermal costs may increase in colder climates by comparing our predictions in Bozeman, Montana to those from a place with lower ambient temperatures (Fairbanks, Alaska). Contrary to our expectations, the 14°C differential between these regions was not as important as the potential differences in wind speed. These large increases in energetic demands can be mitigated by either increasing consumption rates or decreasing other energy demands. Data from GPS-collared wolves indicated that healthy wolves move, on average, 17 km per day, which was reduced by 1.5, 1.8, and 6.5 km for light, medium, and severe hair loss. In addition, the wolf with the most hair loss was less active at night and more active during the day, which is the converse of the movement patterns of healthy wolves. At the individual level, mange infections create significant energy demands and altered behavioral patterns, this may have cascading effects on prey consumption rates, food web dynamics, predator-prey interactions, and scavenger communities.


Assuntos
Monitoramento Ambiental/métodos , Infestações por Ácaros/epidemiologia , Termografia/métodos , Lobos/parasitologia , Alaska , Animais , Ecologia , Montana , Comportamento Predatório
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