Large Terrestrial Carnivores Research Articles

Rehabilitating tigers for range expansion: lessons from the Russian Far East

AbstractEmpty but suitable habitat exists for many of the world's terrestrial large carnivores, yet reintroductions are often considered difficult. In the Russian Far East, orphaned Amur tiger (Panthera tigris altaica) cubs were brought into captivity but prepared for re‐release into the wild. We addressed 2 questions after reintroduction: 1) were individuals raised in captivity capable of killing prey at a rate sufficient to survive, and 2) did individuals avoid use of domestic animals as a primary source of food? We collected data on hunting behavior of 6 orphaned tigers re‐released into their indigenous range, and compared kill composition, kill rate, and consumption rate to individuals studied within the existing range (Sikhote‐Alin) of Amur tigers. Prey composition of rehabilitated tigers varied from that of the Sikhote‐Alin tigers, but composition of major food groups was nearly identical. Kill rate of rehabilitated tigers was higher and prey size was smaller than that of Sikhote‐Alin tigers, but consumption rates were nearly identical. One young male tiger depredated domestic animals, but other individuals only rarely preyed on dogs or cattle they encountered in forests. We documented high survival, reproduction, and recruitment of re‐released individuals. These results indicate that tigers held in captivity during the majority of their early lives can survive in the wild, so long as exposure to humans is kept to a minimum and individuals learn to hunt wild prey before release. Results provide a potential framework for reintroductions of tigers and other large felids across the globe.

Large carnivore management at odds: Science or prejudice?

Large terrestrial carnivores are now widely recognized as essential components of ecosystems. However, the management of large carnivores varies greatly at national and international scales, and some management decision processes do not seem to be informed by scientific evidence. We discuss the ongoing debate on wolf management in Europe, the recent development of wolf management in Spain, and some controversial issues affecting the management of several large carnivores in North America. In Europe, the level of wolf protection may be reduced by the European Commission without robust scientific evidence. In Spain, the debate over wolf conservation continues in the courts, rather than on the basis of scientific arguments, and in several North American areas, intensive management killing has continued for decades, despite its failure to meet intended goals. Overall, we argue that decision-making processes for reducing wolf protection at the international level are less restrictive than those for increasing it, and that such processes would be more defensible if they were scientifically informed and if they applied the precautionary principle. This issue applies to wildlife management of several species on different continents and urges agencies to make responsible decisions that typically affect transboundary populations.

A global assessment of large terrestrial carnivore kill rates.

Through killing and instilling fear in their prey, large terrestrial carnivores shape the structure and function of ecosystems globally. Most large carnivore species have experienced severe range and population declines due to human activities, and many are now threatened with extinction. Consequently, the impacts of these predators on food webs have been diminished or lost completely from many ecosystems. Kill rates provide a fundamental metric for understanding large carnivore ecology and assessing and comparing predation within and across ecological communities. Our systematic review of large terrestrial mammalian carnivore kill rates reveals significant positive geographic (North America, Europe, and Africa) and taxonomic (grey wolf Canis lupus, puma Puma concolor, lion Panthera leo, and Eurasian lynx Lynx lynx) bias, with most studies apparently motivated by human-carnivore conflict over access to ungulate prey and wildlife management objectives. Our current understanding of the behaviour and functional roles of many large carnivore species and populations thus remains limited. By synthesising and comparing kill rates, we show that solitary carnivores (e.g. brown bears Ursus arctos and most felids) exhibit higher per capita kill rates than social carnivores. However, ungulate predation by bears is typically limited to predation of neonates during a short period. Lower per capita kill rates by social carnivores suggests group living significantly reduces energetic demands, or, alternatively, that group-living carnivores defend and consume a greater proportion of large prey carcasses, or may acquire more food through other means (e.g. scavenging, kleptoparasitism) than solitary hunters. Kill and consumption rates for Canidae - measured as kilograms of prey per kilogram of carnivore per day - are positively correlated with body mass, consistent with increasing energy costs associated with a cursorial hunting strategy. By contrast, ambush predators such as felids show an opposite trend, and thus the potential energetic advantage of an ambush hunting strategy for carnivores as body mass increases. Additionally, ungulate kill rates remain relatively constant across solitary felid body sizes, indicative of energetic constraints and optimal foraging. Kill rate estimates also reveal potential insights into trophic structuring within carnivore guilds, with subordinate carnivores often killing more than their larger counterparts, which may be indicative of having to cope with food losses to scavengers and dominant competitors. Subordinate carnivores may thus serve an important role in provisioning food to other trophic levels within their respective ecosystems. Importantly, kill rates also clarify misconceptions around the predatory behaviour of carnivores (e.g. spotted hyaenas Crocuta crocuta and wolverines Gulo gulo are often considered scavengers rather than the capable hunters that they are) and thus the potential impacts of various carnivore species on their ecological communities. Despite the importance of kill rates in understanding predator-prey interactions, their utility is not widely recognised, and insufficient research limits our ability to fully appreciate and predict the consequences of modified predation regimes, justify current management actions affecting carnivores, or inform effective conservation measures. Together with other important research on predator-prey interactions, robust kill rate studies that address the research deficiencies we highlight will provide a deeper understanding of the foraging behaviours and potential ecosystem impacts of many of the world's carnivores, thus aiding effective conservation and management actions.

Continent‐wide differences in diet breadth of large terrestrial carnivores: the effect of large prey and competitors

Abstract Despite their importance for understanding consumer‐resource dynamics, the dietary responses of large terrestrial predators to variations in prey richness and competition pressure are unclear. While a greater predator selectivity along with increasing prey abundance would be expected under an optimal foraging scenario, there is some evidence that predators may broaden their diet where there is a greater resource diversity. Furthermore, the use of large prey may be limited by increasing presence of competitors. We considered three widespread large carnivores (the grey wolf Canis lupus, the puma Puma concolor and the leopard Panthera pardus), whose distribution range encompasses different continents, with different communities of prey/competitors. We expected that the potential to modulate their use of large prey according to prey richness would vary according to different levels of potential competition. We collated data from more than 240 studies of the diets of wolf, puma and leopard to model whether the relationships between the diversity of used large prey (i.e. the Large Prey Index) and prey richness was modulated by carnivore richness, in different continents. The wolf showed an increase in the Large Prey Index with prey richness across its distribution range, where it is usually the apex predator in areas from which data are available. Conversely, the leopard showed this pattern in Asia, but not in Africa, where it often coexists with a greater array of potential competitors. For the puma, the Large Prey Index increased with prey richness throughout its distribution range, except in the areas where the larger and dominant jaguar also occurred. By emphasising the complex relationships between prey richness and predator diets, our results testify to the suppressive effects of larger competitors over the use of large prey by subordinate carnivores.

Habitat accessibility and snares impact large cats and their prey in Northeast Tiger and Leopard National Park, China

Snares have become a widespread hunting technique, with their indiscriminate nature jeopardizing terrestrial large carnivores. Since the lack of reliable data on snare distribution hampers an accurate evaluation of the potential risk. Continuous winter SMART (the Spatial Monitoring and Reporting Tool) patrols have operated in the Amur tiger (Panthera tigris altaica) and Amur leopard (Panthera pardus orientalis) ranges in northeast China from 2013 to 2020 to record wildlife occurrences and remove snares. Our research aimed to assess the snares threat pose in the Amur tiger range and whether snare removal benefited roe deer (Capreolus pygargus) and wild boar (Sus scrofa) recovery. We modeled the spatial distribution of Amur tigers, Amur leopards, and prey species, comparing their distributions before and after anti-poaching measures. We also assessed the overlap between Amur tigers, Amur leopards, and snare locations. Additionally, we used the MaxEnt model to predict snare distribution, and then we analyzed the overlap of snares with species at different periods between 2013 and 2015 and 2018–2020.Our results showed that the probability of occurrence of ungulates increased significantly around roads after snares were removed. Furthermore, we found that Amur tigers and Amur leopards distribution overlapped with snare locations suggesting that snares pose a serious risk to these non-target species. The overlap between snares and species has the same trend as the growing with species distribution, and the least significant increase is in DHZ-XNC.Removing snares not only aids target game species but also protects sympatric large carnivores.

Habitat Selection Differences of Two Sympatric Large Carnivores in the Southwestern Mountains of China

Large terrestrial carnivores play a crucial role in the top–down control of terrestrial ecosystems by maintaining ecosystem stability and biodiversity. However, intense interspecific competition typically occurs among large sympatric carnivores, leading to population reduction or extinction. Spatial partitioning through divergent habitat selection mitigates such competition. In this study, we analyzed the main environmental factors influencing the habitat selection and fragmentation of suitable habitats in Xinlong County, Sichuan Province, using 410 infrared cameras from 2015 to 2023. By employing generalized linear and maximum entropy models, we developed an ensemble model to predict the suitable habitat distribution of leopards (Panthera pardus) and wolves (Canis lupus). The results revealed significant disparities in suitable habitat distributions of leopards and wolves as coexisting large carnivores. Leopards prefer understory, whereas wolves prefer high-altitude meadows. Wolves spatially avoid leopards, who secure relatively superior resources and relegate wolves to inferior habitats. Although suitable habitat patches for both species cluster intensely, habitat connectivity remains low owing to pronounced anthropogenic disturbances, which is especially evident in the higher fragmentation of wolf habitats. These results suggest that sympatric large carnivores can reduce spatial competition intensity and promote spatial partitioning by selecting divergently suitable habitats, thereby facilitating species coexistence.

Stress and reproductive hormones in hair associated with contaminant metal(loid)s of European brown bear (Ursus arctos)

Environmental contaminants like arsenic (As), cadmium (Cd), mercury (Hg) or lead (Pb) may disrupt hypothalamic–pituitary–adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes due to their endocrine toxicity potential. Resulting long-term physiological stress or adverse effects on wildlife reproduction and ontogeny may cause detrimental effects at the individual and population levels. However, data on environmental metal(loid)sʼ impact on reproductive and stress hormones in wildlife, especially large terrestrial carnivores, are scarce. Hair cortisol, progesterone and testosterone concentrations were quantified and modelled with hair As, Cd, total Hg, Pb, biological, environmental and sampling factors to test for potential effects in free-ranging brown bears (Ursus arctos) from Croatia (N = 46) and Poland (N = 27). Testosterone in males (N = 48) and females (N = 25) showed positive associations with Hg and an interaction between Cd and Pb, but a negative association with interaction between age and Pb. Higher testosterone was found in hair during its growth phase compared to quiescent phase. Body condition index was negatively associated with hair cortisol and positively associated with hair progesterone. Year and conditions of sampling were important for cortisol variation, while maturity stage for progesterone variation (lower concentrations in cubs and yearlings compared to subadult and adult bears). These findings suggest that environmental levels of Cd, Hg and Pb might influence the HPG axis in brown bears. Hair was shown to be a reliable non-invasive sample for investigating hormonal fluctuations in wildlife while addressing individual and sampling specificities.

Lead and Other Trace Element Levels in Brains of Croatian Large Terrestrial Carnivores: Influence of Biological and Ecological Factors.

Trace element pollution can adversely affect the brains of individuals and thus impact the entire population of apex predators, such as large European carnivores. We assessed exposure to prominent neurotoxicants As, Cd, Hg and Pb by measuring their brain stem levels in brown bears (n = 114), grey wolves (n = 8), Eurasian lynx (n = 3), and golden jackals (n = 2) sampled in 2015-2022 in Croatia. The highest of the non-essential elements was the Pb level in the bears' brains (median, Q1-Q3; 11.1, 7.13-24.1 μg/kg wet mass), with 4% of animals, all subadults, exceeding the established normal bovine levels (100 μg/kg wet mass). Species-specific differences were noted for Ca, Cd, Cu, Fe, Pb and Se brain levels. Female brown bears had higher As brain levels than males. Cubs and yearlings had lower brain Cd, but higher Zn, while subadults had higher Cu than adult bears. Hepatic As, Cd, Cu and Hg levels were shown to be a moderate proxy for estimating brain levels in bears (rS = 0.30-0.69). Multiple associations of As, Cd, Hg and Pb with essential elements pointed to a possible interaction and disturbance of brain Ca, Cu, Fe, Se and Zn homeostasis. Non-essential element levels in the brains of four studied species were lower than reported earlier for terrestrial meso-carnivores and humans. The age and sex of animals were highlighted as essential factors in interpreting brain element levels in ecotoxicological studies of large carnivores.

Consilient evidence affirms expansive stabilizing ligaments in the tyrannosaurid foot

Tyrannosaurid dinosaurs were ecologically unique vertebrates as the sole clade of large terrestrial carnivores (adults >400 kg) in their continent-spanning habitats. Expanded ligaments between metatarsals, inferred by gross morphology of attachment correlates, have been hypothesized to have strengthened their specialized arctometatarsus. We tested the hypothesis of ligament presence with scanning electron microscopy and histological thin sections of putative attachment sites in a third metatarsal of the tyrannosaurid Gorgosaurus libratus, compared with a thin section from the unspecialized metatarsals of the early theropod Coelophysis bauri. In the Gorgosaurus metatarsal, Sharpey´s fibers and rough, pitted surface textures consistent with ligament coalescence occur at expansive distal regions and localized rugosities are ideally located for resisting torsional loading on the foot. Sparser Sharpey’s fibers occur at expected locations in other arctometatarsus-bearing coelurosaurs. In contrast, the Coelophysis metatarsal lacked Sharpey’s fibers or rugosity at the sectioned location, acting as a definitive negative control for identifying these features in tyrannosaurids. With soft-tissue correlates confirmed as ligament entheses, we conclude that tyrannosaurids possessed distinctive and specific ligament attachments to the third metatarsal lacking in other large carnivorous dinosaurs. Histological evidence for extensive distal intermetatarsal ligaments is consistent with greater inferred agility in derived tyrannosaurid dinosaurs than in earlier lineages of large theropods.

Cannibalism in bears

Bears are the largest terrestrial carnivores, and most bear species can be characterized as opportunistic omnivores. An infrequent foraging tactic for bears is cannibalism, where a bear consumes a conspecific individual, either through scavenging or following intraspecific predation. Although several reports of cannibalism events are known, no attempt has been made so far to gather the available information to analyze for general patterns. We therefore performed a systematic literature review to understand patterns of cannibalism in bears. We documented 39 studies detailing 198 cannibalism events. We only found evidence of cannibalism in 4 of the 8 bear species, with more events reported for polar bears (Ursus maritimus; n = 107, 54.0%) than for all other species combined. Cannibalism was most frequently associated with infanticide (n = 66, 33.3%) and conspecific strife (n = 30, 15.2%), both of which were more frequent among males than females. The most common apparent reason for cannibalism among predators is to increase fitness (i.e., eating a conspecific increases nutrition, whereas killing reduces competition for resources), but is also often linked to sexually selected infanticide in bears. Cannibalism most often appears to be an opportunistic consumption of an available carcass and not directly connected with the primary cause of death. As such, cannibalism in bears may be more casual and opportunistic than a behavior that evolved as a life history strategy.

Density estimations of the Asiatic black bear: application of the random encounter model

ABSTRACT It is difficult to assess the population status of large terrestrial carnivores due to their low density. Recently adopted camera-trap techniques allow us to investigate many aspects of animal ecology and conservation and are widely used in wildlife population estimation. In this study, we applied the random encounter model (REM) to estimate the density of Asiatic black bears (Ursus thibetanus) in Shirakawa Village, Gifu Prefecture, Japan, from May to October 2018. We installed 24 sensor cameras in the study area. Movement speeds of seven global positioning system (GPS)-collared bears were tracked from 2008 to 2018. The population density of bears in Shirakawa Village was estimated to be 0.55 bears/km2. To apply the REM method to Asiatic black bears, we recommend (1) installing more than 30 or 40 sensor cameras and implementing the REM method in a period of 3 weeks before the late summer season (i.e. late August), after the completion of the hibernation period and when a closed population is easily maintained; and (2) correcting the distance moved by the target animal species when using GPS telemetry with a low fixed interval.

Environmental and anthropogenic factors synergistically affect space use of jaguars

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.

Room to roam for African lions Panthera leo: a review of the key drivers of lion habitat use and implications for conservation

Abstract Globally, large terrestrial carnivores (Carnivora) have suffered precipitous declines in population and range. Today, they must persist in increasingly isolated natural habitat patches within a human‐dominated matrix. Effective conservation aimed at supporting carnivores in such landscapes requires species‐specific understanding of habitat requirements. We present results from a review of the published literature to assess the current state of knowledge regarding habitat preferences of the African lion Panthera leo, with the aim of identifying common drivers of habitat use across contexts. Using the Web of Science, we identified 154 usable articles and extracted information relating to study topic, location, habitats described, land‐use type, and any documented habitat preferences. Only 31 studies documented evidence of habitat use, and collectively, they suggested that preferences for specific habitat types were varied and context‐specific. The importance of prey abundance and proximity to water was highlighted in multiple studies. Anthropogenic factors interfered with expected patterns of habitat use. There was evident bias in study locations: 83% of the habitat‐use studies were based in only three countries, and 70% were focussed on protected or managed areas. Our synthesis suggests that lions demonstrate behavioural plasticity in habitat use in response to anthropogenic pressures. To understand the limits of this plasticity and to manage Africa’s changing landscapes effectively for roaming lions, future research should be focussed on analysis of habitat use outside protected areas, taking into account gradients of distance to water, prey abundance, and anthropogenic risk.

Polar Bear

Polar bears (Ursus maritimus), the world’s largest terrestrial carnivores, depend more on ice than land. The author notes that “as with porridge and Goldilocks, they need ice that is not too thick and not too thin.” The beast is also known as white bear, ice bear, swimming bear, and a large variety of names used by indigenous peoples in regions around the North Pole – nanuq, tornassuk, and apitiliit, among others. Often appearing in periodical articles as “lord of the Arctic,” the polar bear is sometimes referred to as the “polarizing bear,” since some people use them to argue that humans are not a cause of climate change. Although other bears sometimes have pale coats, polar bears always have a white coat. Their size helps them tolerate cold. Fat serves as both insulation and energy storage. Their favorite foods are seals, and their efficient digestion provides for rapid weight gain. Polar bears are good swimmers but not fast enough to capture seals in water, so they do most of their hunting on ice.Polar bears have been around for at least 400,000 years. The author traces the migrations of polar bears and their interactions with humans from the Arctic to Northern Europe, Siberia, and North America, using genetics and geological studies as well as carvings and pictures on rocks and in caves. Valued as spiritual guides by Arctic indigenous people who hunted them, in some other cultures they were presented as gifts to royal monarchs, and their skins were sometimes donated to houses of worship so that the priest “should not suffer frozen feet.” In On the Origin of Species, Darwin suggested that he could imagine the possibility of natural selection producing a race of bears with large mouths and “as monstrous as a whale.” He was ridiculed for the idea and removed it from his book. Even today, there is much to be learned about polar bear evolution.A sampling of other items the reader will find in this book includes the following:Marco Polo speaking of “white bears” in an account of his Chinese travels in 1300the intelligence of the polar bear, as judged by the Inuit and the medieval Norsedescriptions of polar bear fur and the structure of its hairstechniques used to mark polar bears for countingthe story of Matthew Henson, an African American associate on Robert Peary’s North Pole exploration, who wore polar bearskin clothinga thought-provoking discussion of climate change and how polar bears are used both to support its reality and to illustrate ideas that climate change is a hoaxthe reason why polar bears, among the most highly regulated animals, are considered “vulnerable”Jacques Cartier’s ship encountering polar bears near the coast of Newfoundland and his crew eating one, believing it to be “as good as a two-year-old heifer”interesting information on polar bear anatomy, physiology, behavior, skills, reproduction, and care of offspringthe story of how Danish explorer Willem Barentsz and crew ate polar bear liver, confirming the effects of vitamin A toxicitythe places where polar bear rugs are found – under pianos, in front of fireplaces, and under beautiful womenthe reason Leonardo DiCaprio was featured with a polar bear cub on the cover of Vanity FairPolar bears are found in zoos and museums, but they also turn up in many unexpected places:in Melville’s Moby Dickin songs such as “Gus the Polar Bear from Central Park,” by Canadian rock group The Tragically Hipas a life-size copper polar bear statue created for the 2015 Paris climate summitin a Punch magazine illustration (1875) showing them as attendants to the “Queen of the Arctic”as two statues on the roof of Copenhagen City Hallin an 1879 illustration by Gustave Doré for Coleridge’s The Rime of the Ancient Marineras a steel and wire sculpture in the Tower of Londonin movies such as The Golden Compass (2007), which features Zara, a zoo-born polar bearin old advertisements for Coca-Cola and Fresh and Cold Lager Beer, “direct from the North Pole”as the mascot of the Toronto Maple LeafsPacked with fascinating information, Polar Bear is an intensely researched, delightfully written, and lavishly illustrated book that should appeal to those who would like to learn more about the life and impact of this unique mammal. Appropriate for high school, college, and adult readers, Polar Bear includes a time line, a detailed list of references, a bibliography, a list of associations and websites, and an index.

Anesthetic Management of a Brown Bear (Ursus arctos) Captive Undergoing Incisional Biopsy of a Skin Nodule

Background: The brown bear (Ursus arctos) is considered one of the largest terrestrial carnivores, native from temperate forest regions of North America, Europe and Asia. In Brazil, they are founded in captivity and their safe capture and immobilization are obtained with one effective anesthesia for management and surgical and diagnostic procedures. Some anesthetic protocols are described for these purposes, however, there is a lack for data on the anesthetic and adverse effects they have on bears when used. The aim of this case is to report the use and effects of the association of dexmedetomidine with tiletamine and zolazepam in the chemical containment of a captive adult brown bear.Case: A 33-year-old female brown bear, weighing 100 kg, belonging to the Zoobotanic Park of Teresina, Piauí, Brazil, was chemically immobilized for an incisional biopsy of a cutaneous nodule with 1.0 cm diameter in the right face region. The anesthetic protocol included 6 μg/kg of dexmedetomidine associated with 3 mg/kg of tiletamine and zolazepam, administered intramuscularly by dart into the gluteal region of the right pelvic limb. The animal showed moderate ataxia at 5 min and assumed sternal decubitus 7 min after anesthetic administration. The bear's degree of sedation was considered adequate and safe to perform the biopsy at 10 min after administration. Heart rate (47 ± 3 bpm), respiratory rate (17 ± 2 mpm) and rectal temperature (38.7 ± 0.1ºC) were monitored. The bear remained immobile and unconscious throughout the procedure, with intense muscle relaxation, bilateral eyeball rotation, absent lateral palpebral reflex and mild medial reflex and without nystagmus. Complementary sedative doses were not necessary. At the beginning of anesthetic recovery, the bear received 6 µg/kg of atipamezole, intramuscularly. After 25 min of administration of atipamezole, the animal showed signs of recovery in the level of consciousness and reactivity to external stimuli, and assumed the quadrupedal position at 60 min after reverser application.Discussion: Even in captivity, the bears behavior is unpredictable and attack can occur, causing trauma or death to people. For this, the chemical immobilization is important to keep safety of everyone. This procedure was performed using blowgun-assisted darts thrown by a staff member who had experience in using this method, who darted accurately and effectively. The latency time observed after administration of the anesthetic protocol used is similar to reported in other studies with bears that also received intramuscular dexmedetomidine and tiletamine and zolazepam and showed intense muscle relaxation and immobility. The doses used contributed to the absence of bradycardia and hypoventilation and, performing the procedure in the morning, when the temperature is milder in the city, minimized the chance of hyperthermia and thermal stress in the animal, not requiring body cooling. The use of dexmedetomidine in chemical containment protocols for short and minimally invasive procedures allows the subsequent use of its antagonist, atipamezole, contributing to a shorter recovery time, return of the animal’s degree of consciousness and lower incidence of ataxia after assuming a quadrupedal position. The anesthetic protocol used was considered efficient, providing a quick and gentle chemical containment, adequate anesthetic plan and good anesthetic recovery in an adult brown bear from captivity.Keywords:atipamezole, dexmedetomidine, wildlife.Título: Manejo anestésico de um urso pardo (Ursus arctos) cativo submetido a biópsia incisional de nódulo cutâneoDescritores: atipamezole, dexmedetomidine, animais selvagens.

Range-Wide Factors Shaping Space Use and Movements by the Neotropic's Flagship Predator: The Jaguar

Large terrestrial carnivores are have undergone some of the largest population and range reductions of any species which is of concern as they have disproportionately large effects on ecosystem dynamics and function. The jaguar is the apex predator throughout the majority of the Neotropics, however, its distribution has been reduced by >50% and throughout the majority of its distribution it survives in increasingly isolated populations. Consequently, the range-wide management of the jaguar (Panthera onca) depends upon maintaining core populations connected through multi-national, transboundary cooperation, which is dependent upon understanding the movement ecology and space use of jaguars throughout their range. Using data from 116 jaguars from 13 ecoregions and seven countries, we examined the landscape-level environmental and anthropogenic factors related to jaguar home range size and movement parameters. Range-wide and at the ecoregional scale home range size decreased with increasing net productivity and increased with increasing road density. Also, range-wide, home range size decreased with increasing forest cover and decreasing human population density. Movement within home ranges was best explained by a different set of environmental covariates. Range-wide predictions of home range size were consistent with expectations based upon available density estimates. Using large-scale collaboration and open source data we overcame typical limitations of small sample sizes and limited geographic distribution of large carnivore data to demonstrate the jaguar as a model organism and in doing so provide a mechanism to evaluate range-wide habitat quality for jaguars and an inferential modeling framework adaptable to the conservation of other large terrestrial carnivores.

Reducing the sixth mass extinction: Understanding the value of human-altered landscapes to the conservation of the world's largest terrestrial mammals

The world's large terrestrial mammalian carnivores and herbivores (henceforth, megafauna) has been severely impacted by humans worldwide. Although this impact across the globe is variable, there has been little information quantifying this impact on biodiversity. Here, we use a macroecological modeling approach to evaluate the impact of different human activities on megafauna species richness at global and biogeographical scales with respect to seven human-altered landscapes variables. At both global and biogeographical scales, we found that human accessibility, human footprint, and small livestock density, had the most negative effects on megafauna species richness, whereas large livestock density, wilderness, and natural protected areas, were more positively associated with megafauna species richness. Our results indicate that megafauna can indeed persist in human-modified landscapes, but different types of human activity can differentially influence species richness. Thus, although continued human impact such as urban, livestock and agricultural development continues to represent a threat to most megafauna, their future viability is potentially compatible with several global change factors we examined. Moreover, our findings are still consistent with the emphasis on conservation strategies that focus on habitat protection to maximize the conservation of megafaunal richness. We urge stronger national and international policy commitments inclusive of multi-use landscapes, greater anti-poaching enforcement, and the development of wildlife-friendly policy incentives for the managers of private and communal land. We also advise caution in interpreting our results, and believe local and regional scale population monitoring programs are still necessary to better facilitate coexistence with humans.

Only the largest terrestrial carnivores increase their dietary breadth with increasing prey richness

Abstract Animals should adapt their foraging habits, changing their dietary breadth in response to variation in the richness and availability of food resources. Understanding how species modify their dietary breadth according to variation in resource richness would support predictions of their responses to environmental changes that alter prey communities. We evaluated relationships between the dietary breadth of large terrestrial carnivores and the local richness of large prey (defined as the number of species). We tested alternative predictions suggested by ecological and evolutionary theories: with increasing prey richness, species would (1) show a more diverse diet, thus broadening their dietary breadth, or (2) narrow their dietary breadth, indicating specialisation on a smaller number of prey. We collated data from 505 studies of the diets of 12 species of large terrestrial mammalian carnivores to model relationships between two indices of dietary breadth and local prey richness. For the majority of species, we found no evidence for narrowing dietary breadth (i.e. increased specialisation) with increasing prey richness. Although the snow leopard and the dhole appeared to use a lower number of large prey species with increasing prey richness, larger sample sizes are needed to support this result. With increasing prey richness, the five largest carnivores (puma Puma concolor, spotted hyaena Crocuta crocuta, jaguar Panthera onca, lion Panthera leo, and tiger Panthera tigris), plus the Eurasian lynx Lynx lynx and the grey wolf Canis lupus (which are usually top predators in the areas from which data were obtained), showed greater dietary breadth and/or used a greater number of large prey species (i.e. increased generalism). We suggest that dominant large carnivores encounter little competition in expanding their dietary breadth with increasing prey richness; conversely, the dietary niche of subordinate large carnivores is limited by competition with larger, dominant predators. We suggest that, over evolutionary time, resource partitioning is more important in shaping the dietary niche of smaller, inferior competitors than the niche of dominant ones.

Animal Welfare in Predator Control: Lessons from Land and Sea. How the Management of Terrestrial and Marine Mammals Impacts Wild Animal Welfare in Human-Wildlife Conflict Scenarios in Europe.

Simple SummaryBoth marine and terrestrial mammal predators come into conflict with humans in Europe and yet their situations are rarely compared. Areas of conflict include the predation of livestock and farmed fish, and also perceived competition for wild prey (for example wolves competing with hunters for deer and seals competing with fishermen for salmon). A lethal method (shooting) and non-lethal methods of conflict reduction used for terrestrial large carnivores (e.g., bear, wolf, wolverine, lynx) and marine mammals (seals) are discussed and their potential impacts on predator welfare are considered. The importance of carrying out an animal welfare assessment when choosing a control method is emphasized along with possible assessment methods. Recommendations for future work are also made.The control of predators, on land and in the sea, is a complex topic. Both marine and terrestrial mammal predators come into conflict with humans in Europe in many ways and yet their situations are rarely compared. Areas of conflict include the predation of livestock and farmed fish, and the perceived competition for wild prey (for example wolves competing with hunters for deer and seals competing with fishermen for salmon). A lethal method (shooting) and non-lethal methods of conflict reduction (including enclosures, guarding, and aversion) used for terrestrial large carnivores (e.g., bear, wolf, wolverine, lynx) and marine mammals (seals) are discussed. Control measures tend to be species- and habitat-specific, although shooting is a widely used method. Potential impacts on predator welfare are described and welfare assessments which have been developed for other wildlife control scenarios, e.g., control of introduced species, are considered for their potential use in assessing predator control. Such assessments should be applied before control methods are chosen so that decisions prioritizing animal welfare can be made. Further work needs to be carried out to achieve appropriate and widely-accepted animal welfare assessment approaches and these should be included in predator management planning. Future research should include further sharing of approaches and information between terrestrial and marine specialists to help ensure that animal welfare is prioritized.

Ancient DNA suggests modern wolves trace their origin to a Late Pleistocene expansion from Beringia.

Grey wolves (Canis lupus) are one of the few large terrestrial carnivores that have maintained a wide geographical distribution across the Northern Hemisphere throughout the Pleistocene and Holocene. Recent genetic studies have suggested that, despite this continuous presence, major demographic changes occurred in wolf populations between the Late Pleistocene and early Holocene, and that extant wolves trace their ancestry to a single Late Pleistocene population. Both the geographical origin of this ancestral population and how it became widespread remain unknown. Here, we used a spatially and temporally explicit modelling framework to analyse a data set of 90 modern and 45 ancient mitochondrial wolf genomes from across the Northern Hemisphere, spanning the last 50,000 years. Our results suggest that contemporary wolf populations trace their ancestry to an expansion from Beringia at the end of the Last Glacial Maximum, and that this process was most likely driven by Late Pleistocene ecological fluctuations that occurred across the Northern Hemisphere. This study provides direct ancient genetic evidence that long‐range migration has played an important role in the population history of a large carnivore, and provides insight into how wolves survived the wave of megafaunal extinctions at the end of the last glaciation. Moreover, because Late Pleistocene grey wolves were the likely source from which all modern dogs trace their origins, the demographic history described in this study has fundamental implications for understanding the geographical origin of the dog.