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We conducted the first long-term and large-scale study of demographic characteristics and reproductive behavior in a wild jaguar (Panthera onca) population. Data were collected through a combination of direct observations and camera trapping on a study area that operates both as a cattle ranch and ecotourism destination. Jaguars exhibited two birth peaks: April/May and October/November, that are the end and the beginning of the wet season in the Pantanal, respectively. The average litter size was 1.43 ± 0.65. Single cubs made up a total of 65.7% of the births, and we found a slight predominance of females (1.15:1 ratio) in litters. The mean age at independence was 17.6 ± 0.98 months, with sex-biased dispersal, with all males (n = 27) leaving the natal home range and 63.6% of females exhibiting philopatry. The interbirth intervals were 21.8 ± 3.2 months and the mean age at first parturition was 31.8 ± 4.2 months. Our results estimated a lifetime reproductive success for female jaguars of 8.13 cubs. Our observations also indicate that female jaguars can display mating behavior during cub rearing or pregnancy, representing 41.4% of the consorts and copulations recorded. We speculate that this behavior has evolved as a defense against infanticide and physical harm to the female. To our knowledge, this is the first time that such behavior is described for this species. All aggressive interactions between females involved the presence of cubs, following the offspring-defense hypothesis, that lead to territoriality among females in mammals, regardless of food availability. In the face of growing threats to this apex predator, this work unveils several aspects of its natural history, representing a baseline for comparison with future research and providing critical information for population viability analysis and conservation planning in the long term.
Este é o primeiro estudo de longo prazo e em grande escala de características demográficas e de comportamento reprodutivo em uma população selvagem de onças-pintadas (Panthera onca). Os dados foram coletados por meio de uma combinação de observações diretas e armadilhamentos fotográficos em uma área de estudo que atua tanto como fazenda de pecuária quanto como destino ecoturístico. As onças-pintadas apresentaram dois picos de nascimento: abril/maio e outubro/novembro, que são o final e o início da estação chuvosa no Pantanal, respectivamente. O tamanho médio da ninhada foi 1.43 ± 0.65. Filhotes únicos representaram um total de 65.7% dos nascimentos, e encontramos uma ligeira predominância de fêmeas (proporção 1.15:1) nas ninhadas. A idade média de independência foi de 17.6 ± 0.98 meses, com uma dispersão sexo-assimétrica, com todos os machos (n = 27) deixando a área natal e 63.6% das fêmeas apresentando filopatria. O intervalo entre ninhadas foi de 21.8 ± 3.2 meses e a idade média da primeira cria foi de 31.8 ± 4.2 meses. Nossos resultados estimaram um sucesso reprodutivo médio ao longo da vida para onças-pintadas fêmeas de 8.13 filhotes. Nossas observações também indicam que as onças-pintadas fêmeas podem apresentar comportamento de acasalamento durante a criação dos filhotes ou da gestação, representando 41.4% das cortes e cópulas registradas. Especulamos que esse comportamento tenha evoluído como uma defesa contra infanticídio e danos físicos à fêmea. Segundo nosso conhecimento, está é a primeira vez que tal comportamento é descrito para esta espécie. Todas as interações agressivas entre fêmeas envolveram a presença de filhotes, seguindo a hipótese de defesa da prole, que levam à territorialidade entre fêmeas em mamíferos, independentemente da disponibilidade de alimento. Diante das crescentes ameaças a este predador de topo, este trabalho revela vários aspectos de sua história natural, representando uma base de comparação com pesquisas futuras e fornecendo informações críticas para a análise de viabilidade populacional e planejamento de conservação em longo prazo.
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Conservation of carnivores involves finding solutions to minimize habitat loss and human-wildlife conflict. Understanding the nature of land-use economics can allow us to mitigate both threats. In the Pantanal, the two main economic activities are cattle ranching and ecotourism, each of which directly and indirectly affect the persistence of jaguars (Panthera onca). To understand how the geography of these economic activities is related to jaguar populations, we developed a jaguar distribution model (JDM), livestock density model, and ecotourism lodge density model for the Pantanal. Due to the recent wildfires within the Pantanal, we also assess the impact of burnt areas that are suitable for jaguars, cattle ranching, and tourism. Our JDM indicate that 64% of the Pantanal holds suitable habitat for jaguars. However, jaguar habitat suitability was positively correlated with ecotourism, but negatively correlated with areas most suitable for intensive cattle-ranching. This demonstrates a biome-wide scenario compatible with jaguar conservation. Of particular concern, recent wildfires overlap most suitable areas for jaguars. If wildfires become increasingly frequent, this would represent a serious threat to jaguars and many other wildlife populations. We emphasize the global importance of the Pantanal wetland ecoregion as a key stronghold for long-term jaguar conservation.
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Conservação dos Recursos Naturais/economia , Ecossistema , Panthera/fisiologia , Dinâmica Populacional , Turismo , Urbanização/tendências , Áreas Alagadas , Animais , Bovinos , GeografiaRESUMO
Large terrestrial carnivores have undergone some of the largest population declines and range reductions of any species, which is of concern as they can have large effects on ecosystem dynamics and function.1-4 The jaguar (Panthera onca) is the apex predator throughout the majority of the Neotropics; however, its distribution has been reduced by >50% and it survives in increasingly isolated populations.5 Consequently, the range-wide management of the jaguar depends upon maintaining core populations connected through multi-national, transboundary cooperation, which requires understanding the movement ecology and space use of jaguars throughout their range.6-8 Using GPS telemetry data for 111 jaguars from 13 ecoregions within the four biomes that constitute the majority of jaguar habitat, we examined the landscape-level environmental and anthropogenic factors related to jaguar home range size and movement parameters. Home range size decreased with increasing net productivity and forest cover and increased with increasing road density. Speed decreased with increasing forest cover with no sexual differences, while males had more directional movements, but tortuosity in movements was not related to any landscape factors. We demonstrated a synergistic relationship between landscape-scale environmental and anthropogenic factors and jaguars' spatial needs, which has applications to the conservation strategy for the species throughout the Neotropics. Using large-scale collaboration, we overcame limitations from small sample sizes typical in large carnivore research to provide a mechanism to evaluate habitat quality for jaguars and an inferential modeling framework adaptable to the conservation of other large terrestrial carnivores.
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Efeitos Antropogênicos , Atividade Motora , Panthera , Comportamento Espacial , Animais , Conservação dos Recursos Naturais , Ecologia , Ecossistema , MasculinoRESUMO
Top-down effects of apex predators are modulated by human impacts on community composition and species abundances. Consequently, research supporting top-down effects of apex predators occurs almost entirely within protected areas rather than the multi-use landscapes dominating modern ecosystems. Here, we developed an integrated population model to disentangle the concurrent contributions of a reintroduced apex predator, the grey wolf, human hunting and prey abundances on vital rates and abundance of a subordinate apex predator, the puma. Increasing wolf numbers had strong negative effects on puma fecundity, and subadult and adult survival. Puma survival was also influenced by density dependence. Overall, puma dynamics in our multi-use landscape were more strongly influenced by top-down forces exhibited by a reintroduced apex predator, than by human hunting or bottom-up forces (prey abundance) subsidized by humans. Quantitatively, the average annual impact of human hunting on equilibrium puma abundance was equivalent to the effects of 20 wolves. Historically, wolves may have limited pumas across North America and dictated puma scarcity in systems lacking sufficient refugia to mitigate the effects of competition.
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Ecossistema , Cadeia Alimentar , Lobos , Animais , Cervos , América do Norte , Dinâmica Populacional , Comportamento Predatório , PumaRESUMO
Camera trapping is the standard field method of monitoring cryptic, low-density mammal populations. Typically, researchers run camera surveys for 60 to 90 days and estimate density using closed population spatially explicit capture-recapture (SCR) models. The SCR models estimate density, capture probability (g0), and a scale parameter (σ) that reflects ranging behaviour. We used a year of camera data from 20 camera stations to estimate the density of male jaguars (Panthera onca) in the Cockscomb Basin Wildlife Sanctuary in Belize, using closed population SCR models. We subsampled the dataset into 276 90-day sessions and 186 180-day sessions. Estimated density fluctuated from 0.51 to 5.30 male jaguars / 100 km2 between the 90-day sessions, with comparatively robust and precise estimates for the 180-day sessions (0.73 to 3.75 male jaguars / 100 km2). We explain the variation in density estimates from the 90-day sessions in terms of temporal variation in social behaviour, specifically male competition and mating events during the three-month wet season. Density estimates from the 90-day sessions varied with σ, but not with the number of individuals detected, suggesting that variation in density was almost fully attributable to changes in estimated ranging behaviour. We found that the models overestimated σ when compared to the mean ranging distance derived from GPS tracking data from two collared individuals in the camera grid. Overestimation of σ when compared to GPS collar data was more pronounced for the 180-day sessions than the 90-day sessions. We conclude that one-off ('snap-shot') short-term, small-scale camera trap surveys do not sufficiently sample wide-ranging large carnivores. When using SCR models to estimate the density from these data, we caution against the use of poor sampling designs and/or misinterpretation of scope of inference. Although the density estimates from one-off, short-term, small-scale camera trap surveys may be statistically accurate within each short-term sampling period, the variation between density estimates from multiple sessions throughout the year illustrate that the estimates obtained should be carefully interpreted and extrapolated, because different factors, such as temporal stochasticity in behaviour of a few individuals, may have strong repercussions on density estimates. Because of temporal variation in behaviour, reliable density estimates will require larger samples of individuals and spatial recaptures than those presented in this study (mean +/- SD = 14.2 +/- 1.2 individuals, 37.7 +/- 4.7 spatial recaptures, N = 276 sessions), which are representative of, or higher than published sample sizes. To satisfy the need for larger samples, camera surveys will need to be more expansive with a higher density of stations. In the absence of this, we advocate longer sampling periods and subsampling through time as a means of understanding and describing stability or variation between density estimates.
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Monitoramento Ambiental/métodos , Panthera , Animais , Conservação dos Recursos Naturais , Coleta de Dados , Estudos Longitudinais , Densidade Demográfica , Análise EspacialRESUMO
Ecosystem engineers create physical changes in abiotic and biotic material, and through this process control the availability of resources for other species. Predators that abandon large portions of their prey may be ecosystem engineers that create habitat for carrion-dependent invertebrates that utilize carcasses during critical life-history periods. Between 04-May-2016 and 04-Oct-2016, we sampled beetle assemblages at 18 carcasses of prey killed by pumas and matching control sites in the southern Greater Yellowstone Ecosystem, USA, to measure the extent to which beetle families utilized these carcass "habitats". We used generalized linear-mixed models and linear-mixed effect models to examine changes in beetle abundance, species richness, and Simpson's Index of Diversity. We estimated kill rates and carrion production rates for individual pumas to better assess the impact of pumas on invertebrate communities. We collected 24,209 beetles representing 215 species. We identified eight beetle families that had significantly higher abundance at carcasses than control sites. Carcasses had a statistically large to very large effect (determined using Cohen's d) on beetle abundance, richness, and diversity for the initial 8 weeks of sampling. Our research revealed strong effects of an ecosystem engineer on beetle assemblages while highlighting the potential role of apex predators in creating and modifying physical habitats for carrion-dependent species. This suggests that there may be consequences for invertebrate communities where apex predators exist at reduced numbers or have been eradicated. The ecological role of invertebrates is often overlooked, yet they are essential taxa that provide critical ecological services upon which we depend.
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Besouros , Puma , Animais , Biodiversidade , Ecologia , EcossistemaRESUMO
Humans are primary drivers of declining abundances and extirpation of large carnivores worldwide. Management interventions to restore biodiversity patterns, however, include carnivore reintroductions, despite the many unresolved ecological consequences associated with such efforts. Using multistate capture-mark-recapture models, we explored age-specific survival and cause-specific mortality rates for 134 pumas (Puma concolor) monitored in the Greater Yellowstone Ecosystem during gray wolf (Canis lupus) recovery. We identified two top models explaining differences in puma survivorship, and our results suggested three management interventions (unsustainable puma hunting, reduction in a primary prey, and reintroduction of a dominant competitor) have unintentionally impacted puma survival. Specifically, puma survival across age classes was lower in the 6-month hunting season than the 6-month nonhunting season; human-caused mortality rates for juveniles and adults, and predation rates on puma kittens, were higher in the hunting season. Predation on puma kittens, and starvation rates for all pumas, also increased as managers reduced elk (Cervus elaphus) abundance in the system, highlighting direct and indirect effects of competition between recovering wolves and pumas over prey. Our results emphasize the importance of understanding the synergistic effects of existing management strategies and the recovery of large, dominant carnivores to effectively conserve subordinate, hunted carnivores in human-dominated landscapes.
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Carrion is a rich, ephemeral resource vital to biodiversity and ecosystem health. In temperate ecosystems in which cold temperatures and snowfall influence the accessibility and availability of small prey and seasonal mast crops, carrion may also be a limiting resource for mesocarnivores like red foxes (Vulpes vulpes), which are too small to predate ungulates. Using motion-triggered video cameras and generalized linear mixed models, we studied the spatial and temporal patterns of red fox scavenging at 232 mountain lion kills in the southern Greater Yellowstone Ecosystem (GYE) from 2012-2015. We found that red foxes scavenged mountain lion kills across all habitats throughout the year, however, red fox behaviors varied with season. In winter, we documented red foxes at a greater proportion of mountain lion kills (70.3% in winter vs. 48.9% in summer), and in greater numbers (1.83 foxes per kill in winter vs. 1.16 in summer). In winter, red foxes fed longer (= 102.7 ± 138.3 minutes feeding in winter vs. = 39.7 ± 74.0 in summer), and they more often scavenged while the mountain lion was nearby. We speculated that red foxes may have increased risk taking in winter due to hunger driven by resource scarcity. Our research highlighted an important ecological relationship between red foxes and mountain lions in the GYE. Mountain lions tolerate high levels of scavenging, so the frequency and intensity of red fox scavenging at their kills may not impact mountain lions, but instead facilitate the dispersion and benefits of resources created by this apex predator. Large carnivores, and mid-trophic felids like mountain lions in particular, are essential producers of carrion vital to biodiversity and ecosystem health. In turn, scavengers play critical roles in distributing these resources and increasing the heterogeneity of resources that support biodiversity and ecosystem structure, as well as ecological resilience.
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The field of movement ecology has rapidly grown during the last decade, with important advancements in tracking devices and analytical tools that have provided unprecedented insights into where, when, and why species move across a landscape. Although there has been an increasing emphasis on making animal movement data publicly available, there has also been a conspicuous dearth in the availability of such data on large carnivores. Globally, large predators are of conservation concern. However, due to their secretive behavior and low densities, obtaining movement data on apex predators is expensive and logistically challenging. Consequently, the relatively small sample sizes typical of large carnivore movement studies may limit insights into the ecology and behavior of these elusive predators. The aim of this initiative is to make available to the conservation-scientific community a dataset of 134,690 locations of jaguars (Panthera onca) collected from 117 individuals (54 males and 63 females) tracked by GPS technology. Individual jaguars were monitored in five different range countries representing a large portion of the species' distribution. This dataset may be used to answer a variety of ecological questions including but not limited to: improved models of connectivity from local to continental scales; the use of natural or human-modified landscapes by jaguars; movement behavior of jaguars in regions not represented in this dataset; intraspecific interactions; and predator-prey interactions. In making our dataset publicly available, we hope to motivate other research groups to do the same in the near future. Specifically, we aim to help inform a better understanding of jaguar movement ecology with applications towards effective decision making and maximizing long-term conservation efforts for this ecologically important species. There are no costs, copyright, or proprietary restrictions associated with this data set. When using this data set, please cite this article to recognize the effort involved in gathering and collating the data and the willingness of the authors to make it publicly available.
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Panthera , Animais , Ecologia , Feminino , Humanos , Masculino , MovimentoRESUMO
Broad scale population estimates of declining species are desired for conservation efforts. However, for many secretive species including large carnivores, such estimates are often difficult. Based on published density estimates obtained through camera trapping, presence/absence data, and globally available predictive variables derived from satellite imagery, we modelled density and occurrence of a large carnivore, the jaguar, across the species' entire range. We then combined these models in a hierarchical framework to estimate the total population. Our models indicate that potential jaguar density is best predicted by measures of primary productivity, with the highest densities in the most productive tropical habitats and a clear declining gradient with distance from the equator. Jaguar distribution, in contrast, is determined by the combined effects of human impacts and environmental factors: probability of jaguar occurrence increased with forest cover, mean temperature, and annual precipitation and declined with increases in human foot print index and human density. Probability of occurrence was also significantly higher for protected areas than outside of them. We estimated the world's jaguar population at 173,000 (95% CI: 138,000-208,000) individuals, mostly concentrated in the Amazon Basin; elsewhere, populations tend to be small and fragmented. The high number of jaguars results from the large total area still occupied (almost 9 million km2) and low human densities (< 1 person/km2) coinciding with high primary productivity in the core area of jaguar range. Our results show the importance of protected areas for jaguar persistence. We conclude that combining modelling of density and distribution can reveal ecological patterns and processes at global scales, can provide robust estimates for use in species assessments, and can guide broad-scale conservation actions.
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Panthera/fisiologia , Animais , Conservação dos Recursos Naturais , Ecossistema , Modelos Teóricos , Densidade DemográficaRESUMO
The Pantanal is the largest inland wetland in the world and is under increasing anthropogenic threats, including long-term regionally intensive gold mining practices. Gold mining activities are known to cause the release of harmful pollutants such as mercury (Hg) to the surrounding environment. Jaguars (Panthera onca (Linnaeus, 1758)) are apex predators, and therefore show great potential to accumulate Hg by biomagnification. We hypothesize that total Hg content in the fur of jaguars from two sites within the Brazilian Pantanal would be significantly different as a function of distance from active gold mining operations. The Hg content was determined by fluorescence spectrometry. The mean ± SD Hg content in jaguars from the study site influenced by gold mining (SB) was compared to jaguars sampled in the area free of gold mining activities (CA) using a one-way ANOVA. The mean Hg content in jaguars from SB (673.0 ± 916.8 µg g-1) is significantly different from jaguars sampled in CA (29.7 ± 23.3 µg g-1), p = 0.03. The maximum recorded content of Hg was 2,010.4 ± 150.5 µg g-1, highest level ever recorded in a wild animal. The data indicate that Hg is an important threat to jaguars within at-risk regions of the Pantanal.
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As technology has improved, our ability to study cryptic animal behavior has increased. Bed site selection is one such example. Among prey species, bed site selection provides thermoregulatory benefits and mitigates predation risk, and may directly influence survival. We conducted research to test whether a subordinate carnivore also selected beds with similar characteristics in an ecosystem supporting a multi-species guild of competing predators. We employed a model comparison approach in which we tested whether cougar (Puma concolor) bed site attributes supported the thermoregulatory versus the predator avoidance hypotheses, or exhibited characteristics supporting both hypotheses. Between 2012-2016, we investigated 599 cougar bed sites in the Greater Yellowstone Ecosystem and examined attributes at two scales: the landscape (second-order, n = 599) and the microsite (fourth order, n = 140). At the landscape scale, cougars selected bed sites in winter that supported both the thermoregulatory and predator avoidance hypotheses: bed sites were on steeper slopes but at lower elevations, closer to the forest edge, away from sagebrush and meadow habitat types, and on southern, eastern, and western-facing slopes. In the summer, bed attributes supported the predator avoidance hypothesis over the thermoregulation hypothesis: beds were closer to forest edges, away from sagebrush and meadow habitat classes, and on steeper slopes. At the microsite scale, cougar bed attributes in both the winter and summer supported both the predator avoidance and thermoregulatory hypotheses: they selected bed sites with high canopy cover, high vegetative concealment, and in a rugged habitat class characterized by cliff bands and talus fields. We found that just like prey species, a subordinate predator selected bed sites that facilitated both thermoregulatory and anti-predator functions. In conclusion, we believe that measuring bed site attributes may provide a novel means of measuring the use of refugia by subordinate predators, and ultimately provide new insights into the habitat requirements and energetics of subordinate carnivores.
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Cost-benefit trade-offs for individuals participating in social behaviors are the basis for current theories on the evolution of social behaviors and societies. However, research on social strategies has largely ignored solitary animals, in which we assume that rare interactions are explained by courtship or territoriality or, in special circumstances, resource distributions or kinship. We used directed network analysis of conspecific tolerance at food sources to provide evidence that a solitary carnivore, the puma (Puma concolor), exhibited adaptive social strategies similar to more social animals. Every puma in our analysis participated in the network, which featured densely connected communities delineated by territorial males. Territorial males also structured social interactions among pumas. Contrary to expectations, conspecific tolerance was best characterized by direct reciprocity, establishing a fitness benefit to individuals that participated in social behaviors. However, reciprocity operated on a longer time scale than in gregarious species. Tolerance was also explained by hierarchical reciprocity, which we defined as network triangles in which one puma (generally male) received tolerance from two others (generally females) that also tolerated each other. Hierarchical reciprocity suggested that males might be cheating females; nevertheless, we suspect that males and females used different fitness currencies. For example, females may have benefited from tolerating males through the maintenance of social niches that support breeding opportunities. Our work contributes evidence of adaptive social strategies in a solitary carnivore and support for the applicability of theories of social behavior across taxa, including solitary species in which they are rarely tested.
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Comportamento Animal , Comportamento Social , Adaptação Psicológica , Agressão , Animais , Carnivoridade , Puma , TerritorialidadeRESUMO
In this study, we estimate life history parameters and abundance for a protected jaguar population using camera-trap data from a 14-year monitoring program (2002-2015) in Belize, Central America. We investigated the dynamics of this jaguar population using 3,075 detection events of 105 individual adult jaguars. Using robust design open population models, we estimated apparent survival and temporary emigration and investigated individual heterogeneity in detection rates across years. Survival probability was high and constant among the years for both sexes (φ = 0.78), and the maximum (conservative) age recorded was 14 years. Temporary emigration rate for the population was random, but constant through time at 0.20 per year. Detection probability varied between sexes, and among years and individuals. Heterogeneity in detection took the form of a dichotomy for males: those with consistently high detection rates, and those with low, sporadic detection rates, suggesting a relatively stable population of 'residents' consistently present and a fluctuating layer of 'transients'. Female detection was always low and sporadic. On average, twice as many males than females were detected per survey, and individual detection rates were significantly higher for males. We attribute sex-based differences in detection to biases resulting from social variation in trail-walking behaviour. The number of individual females detected increased when the survey period was extended from 3 months to a full year. Due to the low detection rates of females and the variable 'transient' male subpopulation, annual abundance estimates based on 3-month surveys had low precision. To estimate survival and monitor population changes in elusive, wide-ranging, low-density species, we recommend repeated surveys over multiple years; and suggest that continuous monitoring over multiple years yields even further insight into population dynamics of elusive predator populations.
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Distribuição Animal , Animais Selvagens , Panthera , Animais , Comportamento Animal , Belize , Feminino , Masculino , Dinâmica PopulacionalRESUMO
In total, 177 of 245 terrestrial carnivores are described as solitary, and much of carnivore ecology is built on the assumptions that interactions between adult solitary carnivores are rare. We employed Global Positioning System (GPS) technology and motion-triggered cameras to test predictions of land-tenure territoriality and the resource dispersion hypothesis in a territorial carnivore, the puma Puma concolor. We documented 89 independent GPS interactions, 60% of which occurred at puma kills (n = 53), 59 camera interactions, 11 (17%) of which captured courtship behaviors, and 5 other interactions (1 F-F, 3 M-F, and 1 M-M). Mean minimum weekly contact rates were 5.5 times higher in winter, the season when elk Cervus elaphus were aggregated at lower elevations and during which puma courtship primarily occurred. In winter, contacts rates were 0.6 ± 0.3 (standard deviation (SD)) interactions/week vs. 0.1 ± 0.1 (SD) interactions/week during summer. The preponderance of interactions at food sources supported the resource dispersion hypothesis, which predicts that resource fluxes can explain temporary social behaviors that do not result in any apparent benefits for the individuals involved. Conspecific tolerance is logical when a prey is so large that the predator that killed it cannot consume it entirely, and thus, the costs of tolerating a conspecific sharing the kill are less than the potential costs associated with defending it and being injured. Puma aggregations at kills numbered as high as 9, emphasizing the need for future research on what explains tolerance among solitary carnivores.
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Mesoamerican jaguars (Panthera onca) have been extirpated from over 77% of their historic range, inhabiting fragmented landscapes at potentially reduced population sizes. Maintaining and restoring genetic diversity and connectivity across human-altered landscapes has become a major conservation priority; nonetheless large-scale genetic monitoring of natural populations is rare. This is the first regional conservation genetic study of jaguars to primarily use fecal samples collected in the wild across five Mesoamerican countries: Belize, Costa Rica, Guatemala, Honduras, and Mexico. We genotyped 445 jaguar fecal samples and examined patterns of genetic diversity and connectivity among 115 individual jaguars using data from 12 microsatellite loci. Overall, moderate levels of genetic variation were detected (NA = 4.50 ± 1.05, AR = 3.43 ± 0.22, HE = 0.59 ± 0.04), with Mexico having the lowest genetic diversity, followed by Honduras, Guatemala, Belize, and Costa Rica. Population-based gene flow measures (FST = 0.09 to 0.15, Dest = 0.09 to 0.21), principal component analysis, and Bayesian clustering applied in a hierarchical framework revealed significant genetic structure in Mesoamerican jaguars, roughly grouping individuals into four genetic clusters with varying levels of admixture. Gene flow was highest among Selva Maya jaguars (northern Guatemala and central Belize), whereas genetic differentiation among all other sampling sites was moderate. Genetic subdivision was most pronounced between Selva Maya and Honduran jaguars, suggesting limited jaguar movement between these close geographic regions and ultimately refuting the hypothesis of contemporary panmixia. To maintain a critical linkage for jaguars dispersing through the Mesoamerican landscape and ensure long-term viability of this near threatened species, we recommend continued management and maintenance of jaguar corridors. The baseline genetic data provided by this study underscores the importance of understanding levels of genetic diversity and connectivity to making informed management and conservation decisions with the goal to maintain functional connectivity across the region.
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Variação Genética , Genética Populacional , Panthera/genética , Animais , Teorema de Bayes , Conservação dos Recursos Naturais , DNA/isolamento & purificação , DNA/metabolismo , Genótipo , Desequilíbrio de Ligação , Repetições de Microssatélites/genética , Análise de Componente PrincipalRESUMO
Umbrella species are employed as conservation short-cuts for the design of reserves or reserve networks. However, empirical data on the effectiveness of umbrellas is equivocal, which has prevented more widespread application of this conservation strategy. We perform a novel, large-scale evaluation of umbrella species by assessing the potential umbrella value of a jaguar (Panthera onca) conservation network (consisting of viable populations and corridors) that extends from Mexico to Argentina. Using species richness, habitat quality, and fragmentation indices of ~1500 co-occurring mammal species, we show that jaguar populations and corridors overlap a substantial amount and percentage of high-quality habitat for co-occurring mammals and that the jaguar network performs better than random networks in protecting high-quality, interior habitat. Significantly, the effectiveness of the jaguar network as an umbrella would not have been noticeable had we focused on species richness as our sole metric of umbrella utility. Substantial inter-order variability existed, indicating the need for complementary conservation strategies for certain groups of mammals. We offer several reasons for the positive result we document, including the large spatial scale of our analysis and our focus on multiple metrics of umbrella effectiveness. Taken together, our results demonstrate that a regional, single-species conservation strategy can serve as an effective umbrella for the larger community and should help conserve viable populations and connectivity for a suite of co-occurring mammals. Current and future range-wide planning exercises for other large predators may therefore have important umbrella benefits.
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Conservação dos Recursos Naturais , Monitoramento Ambiental , Felidae/fisiologia , AnimaisRESUMO
BACKGROUND: The agents of spotted fevers in Latin America are Rickettsia rickettsii, R. parkeri, Rickettsia sp. strain Atlantic rainforest, and R. massiliae. In Continental Central America, R. rickettsii remains the only known pathogenic tick-borne rickettsia. In the present study, ticks were collected from wild mammals in natural areas of Belize. Besides providing new data of ticks from Belize, we investigated rickettsial infection in some of these ticks. Our results provide ticks harboring rickettsial agents for the first time in Central America. METHODS: Between 2010 and 2015, wild mammals were lived-trapped in the tropical broadleaf moist forests of central and southern Belize. Ticks were collected from the animals and identified to species by morphological and molecular analysis (DNA sequence of the tick mitochondrial 16S RNA gene). Some of the ticks were tested for rickettsial infection by molecular methods (DNA sequences of the rickettsial gltA and ompA genes). RESULTS: A total of 84 ticks were collected from 8 individual hosts, as follows: Amblyomma pacae from 3 Cuniculus paca; Amblyomma ovale and Amblyomma coelebs from a Nasua narica; A. ovale from an Eira Barbara; A. ovale, Amblyomma cf. oblongoguttatum, and Ixodes affinis from a Puma concolor; and A. ovale, A. coelebs, A. cf. oblongoguttatum, and I. affinis from two Panthera onca. Three rickettsial agents were detected: Rickettsia amblyommii in A. pacae, Rickettsia sp. strain Atlantic rainforest in A. ovale, and Rickettsia sp. endosymbiont in Ixodes affinis. CONCLUSIONS: The present study provides unprecedented records of ticks harboring rickettsial agents in the New World. An emerging rickettsial pathogen of South America, Rickettsia sp. strain Atlantic rainforest, is reported for the first time in Central America. Besides expanding the distribution of 3 rickettsial agents in Central America, our results highlight the possible occurrence of Rickettsia sp. strain Atlantic rainforest-caused spotted fever human cases in Belize, since its possible vector, A. ovale, is recognized as one of the most important human-biting ticks in the Neotropical region.
Assuntos
Rickettsia/classificação , Rickettsia/isolamento & purificação , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Carrapatos/classificação , Carrapatos/microbiologia , Animais , Animais Selvagens , Proteínas de Bactérias/genética , Belize/epidemiologia , Análise por Conglomerados , DNA Mitocondrial/química , DNA Mitocondrial/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Rickettsia/genética , Rickettsia rickettsii , Análise de Sequência de DNA , Carrapatos/anatomia & histologia , Carrapatos/genéticaRESUMO
There are several alternative hypotheses about the effects of territoriality, kinship and prey availability on individual carnivore distributions within populations. The first is the land-tenure hypothesis, which predicts that carnivores regulate their density through territoriality and temporal avoidance. The second is the kinship hypothesis, which predicts related individuals will be clumped within populations, and the third is the resource dispersion hypothesis, which suggests that resource richness may explain variable sociality, spatial overlap or temporary aggregations of conspecifics. Research on the socio-spatial organization of animals is essential in understanding territoriality, intra- and interspecific competition, and contact rates that influence diverse ecology, including disease transmission between conspecifics and courtship behaviours. We explored these hypotheses with data collected on a solitary carnivore, the cougar (Puma concolor), from 2005 to 2012 in the Southern Yellowstone Ecosystem, Wyoming, USA. We employed 27 annual home ranges for 13 cougars to test whether home range overlap was better explained by land tenure, kinship, resource dispersion or some combination of the three. We found support for both the land tenure and resource dispersion hypotheses, but not for kinship. Cougar sex was the primary driver explaining variation in home range overlap. Males overlapped significantly with females, whereas the remaining dyads (F-F, M-M) overlapped significantly less. In support for the resource dispersion hypothesis, hunting opportunity (the probability of a cougar killing prey in a given location) was often higher in overlapping than in non-overlapping portions of cougar home ranges. In particular, winter hunt opportunity rather than summer hunt opportunity was higher in overlapping portions of female-female and male-female home ranges. Our results may indicate that solitary carnivores are more tolerant of sharing key resources with unrelated conspecifics than previously believed, or at least during periods of high resource availability. Further, our results suggest that the resource dispersion hypothesis, which is typically applied to social species, is applicable in describing the spatial organization of solitary carnivores.
Assuntos
Comportamento de Retorno ao Território Vital , Puma/fisiologia , Animais , Ecossistema , Feminino , Masculino , Dinâmica Populacional , Estações do Ano , Territorialidade , WyomingRESUMO
BACKGROUND: Niche differentiation may betray current, ongoing competition between two sympatric species or reflect evolutionary responses to historic competition that drove species apart. The best opportunity to test whether ongoing competition contributes to niche differentiation is to test for behavioral shifts by the subordinate competitor in controlled experiments in which the abundance of the dominant competitor is manipulated. Because these circumstances are difficult to coordinate in natural settings for wide-ranging species, researchers seize opportunities presented by species reintroductions. We tested for new competition between reintroduced wolves and resident cougars in the Southern Yellowstone Ecosystem to assess whether wolves might be impacting the realized niche of sympatric cougars. RESULTS: Between2002 and 2012, a period during which wolves increased from 15 to as high as 91 in the study area, cougars significantly increased the percentage of deer and decreased the percentage of elk in their diet in summer. Our top models explaining these changes identified elk availability, defined as the number of elk per wolf each year, as the strongest predictor of changing cougar prey selection. Both elk and deer were simultaneously declining in the system, though deer more quickly than elk, and wolf numbers increased exponentially during the same time frame. Therefore,we concluded that prey availability did not explain prey switching and that competition with wolves at least partially explained cougar prey switching from elk to deer. We also recorded 5 marked cougar kittens killed by wolves and 2 more that were killed by an undetermined predator. In addition, between 2005 and 2012, 9 adult cougars and 10 cougar kittens died of starvation, which may also be in part explained by competition with wolves. CONCLUSIONS: Direct interspecific predation and shifting cougar prey selection as wolves increased in the system provided evidence for competition between recolonizing wolves and resident cougars. Through competition, recolonizing wolves have impacted the realized niche of resident cougars in the Southern Yellowstone Ecosystem (SYE), and current resident cougars may now exhibit a realized niche more reflective of an era when these species were previously sympatric in the Yellowstone Ecosystem.