Carnivore Guild Research Articles

Interspecific interactions among major carnivores in Panna Tiger Reserve: A multispecies occupancy approach

AbstractLarge carnivores play a crucial role in trophic cascades, affecting the population dynamics of both co‐predators and prey within an ecosystem. Understanding the significance of these carnivores in trophic interactions is essential for developing effective conservation and management strategies. We examined the effects of occupancy dynamics and patterns of species interactions and coexistence within the carnivore guild in the Panna Tiger Reserve in India. We collected camera trap data (two seasons, 2019) in a presence–absence framework and applied multispecies occupancy models to assess the occupancy, co‐occurrence, and interactions among species. We also examined activity overlap to understand the temporal segregation in the carnivore guild. The mean marginal occupancy was highest for leopards in winter (Ψwinter 0.92 ± 0.02, Ψsummer 0.63 ± 0.05) and hyenas in summer (Ψsummer 0.93 ± 0.03, Ψwinter 0.78 ± 0.03) and was lowest for tigers in both seasons (Ψwinter 0.62 ± 0.05, Ψsummer 0.15 ± 0.05). Co‐occurrence probability among carnivores was higher in winter than in summer, and conditional occupancy was consistently higher when other species were present. Different environmental factors influenced marginal occupancy and co‐occurrence patterns across seasons. Strong temporal overlaps were recorded between tiger–leopard (0.87–0.91) and tiger–hyena (0.78–0.79). We detected a significant spatial segregation between tigers and leopards, as they prefer different habitat types in different seasons, along with high temporal overlap. Resource availability strongly governs the association of carnivores with their habitat selection. Hyenas demonstrated higher dependency on tigers than on leopards for resources. These findings indicate that coexistence with apex‐predator species is feasible through strategic adaptation to fulfill resource requisition.

Spatial Risk Effects From Lions Compound Impacts of Prey Depletion on African Wild Dogs.

Prey depletion threatens many carnivore species across the world and can especially threaten low-density subordinate competitors, particularly if subordinates are limited to low densities by their dominant competitors. Understanding the mechanisms that drive responses of carnivore density to prey depletion is not only crucial for conservation but also elucidates the balance between top-down and bottom-up limitations within the large carnivore guild. To avoid predation, competitively subordinate African wild dogs typically avoid their dominant competitors (lions) and the prey rich areas they are associated with, but no prior research has tested whether this pattern persists in ecosystems with anthropogenically-reduced prey density, and reduced lion density as a result. We used spatial data from wild dogs and lions in the prey-depleted Greater Kafue Ecosystem to test if wild dogs continue to avoid lions (despite their low density), and consequently avoid habitats with higher densities of their dominant prey species. We found that although lion density is 3X lower than comparable ecosystems, wild dogs continue to strongly avoid lions, and consequently avoid habitats associated with their two most important prey species. Although the density of lions in the GKE is low due to prey depletion, their competitive effects on wild dogs remain strong. These effects are likely compounded by prey-base homogenization, as lions in the GKE now rely heavily on the same prey preferred by wild dogs. These results suggest that a reduction in lion density does not necessarily reduce competition, and helps explain why wild dogs decline in parallel with their dominant competitors in ecosystems suffering from anthropogenic prey depletion. Protecting prey populations within the few remaining strongholds for wild dogs is vitally important to avoid substantial population declines. Globally, understanding the impacts of prey depletion on carnivore guild dynamics should be an increasingly important area of focus for conservation.

Relative abundance of a mesocarnivore in a human-dominated, semi-arid rangeland in Namibia

Mesocarnivores fill important roles in ecological communities globally, but their distribution and abundance are often understudied. Many species have historically been regarded as vermin and subject to lethal control due to their role in livestock predation. Identifying the factors influencing mesocarnivore populations can help disentangle their relationship within ecological communities and inform conflict mitigation and conservation priorities. To help identify these factors, we used camera traps to study the community of medium and large mammals in four communal conservancies of northeastern Namibia covering the wet and dry seasons using 99 and 97 camera trap stations, respectively. We modelled black-backed jackal (Lupulella mesomelas) abundance using the robust Royle-Nichols model. Black-backed jackal were widespread, with a mean per site abundance of 2.01 (SD=0.66) in the wet season and 2.41 (SD=0.49) in the dry season. Black-backed jackal showed seasonally contrasting covariate associations, with lower abundance in areas with medium and large-sized wild prey during the wet season, and higher abundance in areas with more villages and close to African wild dog (Lycaon pictus) dens in the dry season. We identified localized hotspots of black-backed jackal abundance during the dry season, which may indicate that when resources are scarce, black-backed jackals rely on anthropogenic food sources despite an elevated risk for conflict, and on carcass remains from African wild dog kills. These findings highlight potential drivers of mesocarnivore abundance that would be obscured in a conventional occurrence modelling framework, and illustrate how local abundance may be influenced by seasonal variability, wild and anthropogenic food sources, and a likely facilitative relationship with a large carnivore. Further investigations in areas with more complex carnivore guilds and higher density of dominant predators are needed to understand black-backed jackal-African wild dog interactions and impacts on population dynamics.

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.

Different coexistence patterns between apex carnivores and mesocarnivores based on temporal, spatial, and dietary niche partitioning analysis in Qilian Mountain National Park, China.

Carnivores play key roles in maintaining ecosystem structure and function as well as ecological processes. Understanding how sympatric species coexist in natural ecosystems is a central research topic in community ecology and biodiversity conservation. In this study, we explored intra- and interspecific niche partitioning along spatial, temporal, and dietary niche partitioning between apex carnivores (wolf Canis lupus, snow leopard Panthera uncia, Eurasian lynx Lynx lynx) and mesocarnivores (Pallas's cat Otocolobus manul, red fox Vulpes vulpes, Tibetan fox Vulpes ferrilata) in Qilian Mountain National Park, China, using camera trapping data and DNA metabarcoding sequencing data. Our study showed that apex carnivore species had more overlap temporally (coefficients of interspecific overlap ranging from 0.661 to 0.900) or trophically (Pianka's index ranging from 0.458 to 0.892), mesocarnivore species had high dietary overlap with each other (Pianka's index ranging from 0.945 to 0.997), and apex carnivore and mesocarnivore species had high temporal overlap (coefficients of interspecific overlap ranging from 0.497 to 0.855). Large dietary overlap was observed between wolf and snow leopard (Pianka's index = 0.892) and Pallas's cat and Tibetan fox (Pianka's index = 0.997), suggesting the potential for increased resource competition for these species pairs. We concluded that spatial niche partitioning is likely to key driver in facilitating the coexistence of apex carnivore species, while spatial and temporal niche partitioning likely facilitate the coexistence of mesocarnivore species, and spatial and dietary niche partitioning facilitate the coexistence between apex and mesocarnivore species. Our findings consider partitioning across temporal, spatial, and dietary dimensions while examining diverse coexistence patterns of carnivore species in Qilian Mountain National Park, China. These findings will contribute substantially to current understanding of carnivore guilds and effective conservation management in fragile alpine ecosystems.

Detection rates and diel activity patterns of four understudied felids from Borneo.

Carnivore guilds are charismatic and have vital and irreplaceable roles in their native ecosystems, yet many of these species are threatened and remain understudied. Borneo is a biodiversity hotspot that hosts a rich diversity of endemic wildlife but is threatened by deforestation and habitat loss. Using cameras placed by the Smithsonian Institution in Sabah, Borneo, we assessed the detection rates and diel activity patterns of the native felid species. Across 51 camera trap sites between 2016 and 2019, felids were detected 55 times across a combined 9958 trap nights, including 20 independent detection events for Sunda leopard cats, 15 for Sunda clouded leopards, 12 for Borneo bay cats, and 5 for marbled cats, with no detections of flat-headed cats. Collectively, this demonstrates the challenge of sampling cryptic species that have declined due to habitat loss and conflict with humans. Despite this, we show that Borneo bay cats and marbled cats exhibited different diel activity patterns than Sunda cloud leopards, suggesting the smaller species use temporal displacement to avoid competition and predation. Sunda leopard cats exhibited broadly similar activity patterns to Sunda clouded leopard, potentially because the two species typically occupy different dietary and habitat niches. These results demonstrate the importance of devoting future research towards monitoring these species and understanding the mechanisms by which they co-exist.

Long-term data reveal fitness costs of anthropogenic prey depletion for a subordinate competitor, the African wild dog (Lycaon pictus).

Within carnivore guilds, dominant competitors (e.g., lions, Panthera leo) are limited primarily by the density of prey, while subordinate competitors (e.g., African wild dogs, Lycaon pictus) have been limited by the density of dominant competitors. Historically, the fitness and population density of subordinate competitors have not been tightly linked to prey density. However, populations of large herbivores have declined substantially across sub-Saharan Africa due to human impacts, and where prey depletion is severe, fitness costs for competitive subordinates may begin to outweigh the benefits of competitive release. Using long-term intensive monitoring of African wild dogs in Zambia's Luangwa Valley Ecosystem (LVE), we tested the effects of prey depletion on survival and reproduction. We hypothesized that African wild dog fitness would be lower in prey-depleted areas, despite lower lion densities. Our study area included four contiguous regions that varied in protection level, prey density, and lion density. We fit Bayesian Cormack-Jolly-Seber and closed-capture models to estimate effects on survival and population density, and generalized linear models to estimate effects on reproductive success. We found that the LVE is a stronghold for African wild dogs, with an estimated median density of 4.0 individuals/100 km2. Despite this high density, survival and reproduction differed among regions, and both components of fitness were substantially reduced in the region with the lowest prey density. Anthropogenic prey depletion is becoming an important limiting factor for African wild dogs. If prey depletion (or any other form of habitat degradation) becomes severe enough that its fitness costs outweigh the benefits of competitive release, such changes can fundamentally alter the balance between limiting factors for competitively subordinate species.

Sex and size matter: Intricate dominance relationships in an East African large carnivore guild

AbstractHuman disturbance has the potential to alter competitive interactions, favoring species better able to adapt to areas used by humans. One such species is the spotted hyena (Crocuta crocuta), which has been successful in human‐dominated areas throughout Africa. In addition, hyenas are frequently successful in kleptoparasiting prey brought down by other carnivore species (e.g., leopards [Panthera pardus]). In the Udzungwa Mountains of Tanzania, leopard density declines sharply close to human settlements, and hyenas are their only competitors. Using camera trap data and a spatio‐temporal occupancy model, we assessed the relative dominance of each species through spatial co‐occurrence, altered activity patterns and temporary site avoidance. We tested the hypothesis that hyenas gain a competitive advantage over leopards in human‐dominated areas due to their relatively higher tolerance for anthropogenic activities. We found that while hyena occupancy was best predicted by prey occupancy and not strongly affected by landscape factors associated with humans, leopards, especially male leopards, were less likely to be detected close to human settlements. Female leopards, which are smaller than males, exhibited activity shifts and temporary site avoidance in response to hyenas. In response to male leopards, hyenas shifted their activity patterns to become more active around dusk and dawn. These results suggest that while hyenas may be behaviorally dominant over female leopards, they are subordinate to male leopards. We found that male leopards and hyenas were less likely to co‐occur closer to people, especially where prey was scarce, suggesting subordinance of hyenas to male leopards may be mitigated by human disturbance. Furthermore, young male leopards shifted their activity patterns to be more diurnal in response to hyena presence, suggesting that dominance relationship between hyenas and leopards develops with age and is probably related to body size. These results indicate that human disturbance has the potential to affect the competitive relationship between leopards and hyenas in the Udzungwa Mountains, but that relationships will vary with sex and body size.

Lion lords and sharing hyaenas: Carnivore guild dynamics around elephant carcasses.

Megaherbivore carcasses represent sporadic but energetically rewarding resources for carnivores, offering a unique opportunity to study coexistence dynamics between facultative scavengers. South African fenced protected areas, such as Madikwe Game Reserve (Madikwe hereafter), host viable populations of large carnivores and high densities of elephants, Loxodonta africana. However, high carnivore densities can lead to potentially fatal interspecific encounters and increased competition, particularly around high-quality trophic resources. This study explores the temporal partitioning and co-detection strategies of carnivores at six elephant carcasses in Madikwe, aiming to understand how the increased carrion biomass available at elephant carcasses influences coexistence dynamics. Camera traps were deployed to monitor carcasses during two periods (2019 and 2020), revealing occurrences of six carnivore species. Carnivores, particularly black-backed jackals, Lupulella mesomelas, (hereafter jackal), lions, Panthera leo, and spotted hyaenas, Crocuta crocuta, comprised 56.7% of carcass observations, highlighting their pivotal roles in scavenging dynamics. Pairwise co-detection analysis demonstrated consistent association and shared peak activity periods between jackals and spotted hyaenas, indicating potential resource sharing. However, the minimal co-detection rates between lions and other carnivores highlight their resource domination. There was some evidence of temporal partitioning between carnivores, with most species exhibiting earlier peaks in nocturnal activity to avoid temporal overlap with lions. This study emphasises the importance of elephant carcasses in the diet of multiple species and coexistence techniques utilised to exploit this ephemeral resource. As fenced protected areas become crucial for conserving intact carnivore guilds globally, further research into carnivore behavioural adaptations at carcasses is recommended to shed light on their coexistence strategies.

Carnivore guild utilization of hunter‐provided food sources in boreal forest

Scavenging is an alternative foraging strategy to predation for many carnivore species, as they shift between predation and scavenging in response to changes in resource availability. The use of carrion may lead to interspecific competition and is thus influenced by a risk–reward trade‐off to balance coexistence with guild‐members, where smaller species are expected to be more vigilant due to their vulnerability to larger competitors. We used cameras to investigate the utilization of viscera from the annual moose Alces alces hunt by four sympatric carnivore species: wolf Canis lupus, wolverine Gulo gulo, red fox Vulpes vulpes and pine marten Martes martes in south–central Scandinavia, in relation to body size and habitat. Red foxes had highest probability of visiting viscera sites in both open and forested habitats. Visits by both red foxes and pine martens were longer in open habitats, while number of visits or activity did not differ between habitats. For pine martens, the probability of visiting viscera sites was twice as high in forest compared to open habitat; consequently, red foxes showed the highest overall use of viscera. Red foxes were most vigilant, especially in open habitat, whereas wolverines and pine martens spent a higher proportion of time feeding. Increased vigilance of red foxes facilitates extended resources use in open habitat, while for pine martens, the risk–reward decision occurs before leaving forest cover and entering open habitats. Viscera were not used to a large extent by wolves or wolverines. Wolves are generally less prone to scavenging and wolverines probably use other food resources, more suitable for caching. Overall, competition did not prevent use of viscera, probably due to small‐scale temporal segregation and limited use by the larger carnivores. Consequently, this pulse of human‐subsidized food resources before winter may have important implications for the smaller facultative scavengers.Keywords: carrion use, interspecific competition, pine marten, red fox, wolf, wolverine

Seasonal activity patterns of a Kalahari mammal community: Trade-offs between environmental heat load and predation pressure.

Mammals in arid zones have to trade off thermal stress, predation pressure, and time spent foraging in a complex thermal landscape. We quantified the relationship between the environmental heat load and activity of a mammal community in the hot, arid Kalahari Desert. We deployed miniature black globe thermometers within the existing Snapshot Safari camera trap grid on Tswalu Kalahari Reserve, South Africa. Using the camera traps to record species' activity throughout the 24-h cycle, we quantified changes in the activity patterns of mammal species in relation to heat loads in their local environment. We compared the heat load during which species were active between two sites with differing predator guilds, one where lion (Panthera leo) biomass dominated the carnivore guild and the other where lions were absent. In the presence of lion, prey species were generally active under significantly higher heat loads, especially during the hot and dry spring. We suggest that increased foraging under high heat loads highlights the need to meet nutritional requirements while avoiding nocturnal activity when predatory pressures are high. Such a trade-off may become increasingly costly under the hotter and drier conditions predicted to become more prevalent as a result of climate change within the arid and semi-arid regions of southern Africa.

Mesocarnivores vary in their spatiotemporal avoidance strategies at communications hubs of an apex carnivore.

Mesocarnivores face interspecific competition and risk intraguild predation when sharing resources with apex carnivores. Within a landscape, carnivores across trophic levels may use the same communication hubs, which provide a mix of risks (injury/death) and rewards (gaining information) for subordinate species. We predicted that mesocarnivores would employ different strategies to avoid apex carnivores at shared communication hubs, depending on their trophic position. To test our prediction, we examined how different subordinate carnivore species in the Santa Cruz Mountains of California, USA, manage spatial overlap with pumas (Puma concolor), both at communication hubs and across a landscape-level camera trap array. We estimated species-specific occurrence, visitation rates, temporal overlap, and Avoidance-Attraction Ratios from camera traps and tested for differences between the two types of sites. We found that mesocarnivores generally avoided pumas at communication hubs, and this became more pronounced when pumas scent-marked during their most recent visit. Coyotes (Canis latrans), the pumas' closest subordinate competitor in our system, exhibited the strongest avoidance at communication hubs. Gray foxes (Urocyon cinereoargenteus) avoided pumas the least, which may suggest possible benefits from pumas suppressing coyotes. Overall, mesocarnivores exhibited various spatiotemporal avoidance strategies at communication hubs rather than outright avoidance, likely because they benefit from information gained while 'eavesdropping' on puma activity. Variability in avoidance strategies may be due to differential predation risks, as apex carnivores often interact more aggressively with their closest competitors. Combined, our results show how apex carnivores trigger complex species interactions across the entire carnivore guild and how trophic position determines behavioral responses and subsequent space use of subordinate mesocarnivores across the landscape.

Ecological determinants of spotted hyena Crocuta crocuta occupancy in Comoé National Park, Côte d’Ivoire

Knowledge of the large carnivore guild is important in view of a possible lion reintroduction into the Comoé National Park (CNP), northern Côte d’Ivoire. We used camera trapping to assess activity patterns, habitat selection, and ecological factors influencing the occupancy of the spotted hyena Crocuta crocuta. Our results showed that the presence of leopard Panthera pardus, the only current other large carnivore and thus potential competitor, did not influence hyena occupancy. Hyena occupancy was only significantly related to Euclidian distance to nearest water point. Manly’s alpha habitat selection index values show a preference of spotted hyena for shrub savannah (αSa = 0.71), and Pianka’s overlap index showed low spatial competition with leopard (OIJ(PNC) = 0.12). Our findings showed that spotted hyena were mostly nocturnal, and generally active at the same time slots with leopard, leading to a high index of temporal overlap (OIJ(time) = 0.78). The kernel density estimation confirmed that spotted hyenas and leopard shared almost half of their activity patterns (Δ1 = 0.49 and 95% CI = 0.26–0.71). Prey diversity is high in CNP but anthropogenic threats appear to suppress population growth of prey and predators. Conservation efforts should continue to reduce pressures before contemplating a potential lion Panthera leo reintroduction.

Does restoring apex predators to food webs restore ecosystems? Large carnivores in Yellowstone as a model system

AbstractModification of food webs is a frequent cause of shifts in ecosystem states that resist reversal when the food web is restored to its original condition. We used the restoration of the large carnivore guild including gray wolves (Canis lupis), cougars (Felis concolor), and grizzly bears (Ursus arctos horribilis) to the northern range of Yellowstone National Park as a model system to understand how ecosystems might resist reconfiguration after the restoration of apex predators to the food web. The absence of wolves, cougars, and grizzly bears for nearly a century from the northern range was the primary cause of dramatic changes in riparian plant communities. Willows (Salix spp.) were suppressed in height by intense browsing by the dominant herbivore, elk (Cervus canadensis). The loss of activity by beavers (Castor canadensis) coincided with the loss of tall willows. We hypothesized that intense elk browsing interrupted the mutualism between willow and beavers: ecosystem engineering by beavers was a critical component of willow habitat and tall willows were a critical component of habitat for beavers. This interruption made riparian communities resilient to the disturbance caused by the restoration of apex predators. We hypothesized further that reductions in elk browsing attributable to reductions in elk population size were not sufficient to prevent the suppression of willow growth. To test these hypotheses, we conducted a 20‐year, factorial experiment that crossed simulated beaver dams with the exclusion of browsing. We found that willows grew to heights expected for restored communities only in the presence of dams and reduced browsing. Willows experiencing ambient conditions remained well below this expectation. We found no difference in heights or growth rates of willows in experimental controls and willows in 21 randomly chosen sites, confirming that the results of the experiment were representative of range‐wide conditions. A reorganized community of large herbivores was implicated in the suppression of willow growth. We conclude that the restoration of large carnivores to the food web failed to restore riparian plant communities on Yellowstone's northern range, supporting the hypothesis that this ecosystem is in an alternative stable state caused primarily by the extirpation of apex predators during the early 20th century.

Using photo by-catch data to reliably estimate spotted hyaena densities over time

Abstract Protected areas are becoming increasingly isolated refugia for large carnivores but remain critical for their survival. Spotted hyaenas (Crocuta crocuta) are important members of the African large carnivore guild but, like other members of the guild, routinely come into conflict with people because of their large home ranges that are not always confined to protected areas. To effectively conserve spotted hyaena populations, it is paramount to monitor their abundance through reliable and cost-effective techniques. We estimated the density of spotted hyaenas in Hluhluwe–iMfolozi Park (HiP), South Africa using camera trap images and a spatially explicit capture-recapture (SECR) framework between 2013 and 2018. We estimated an average of 18.29 ± 3.27 spotted hyaenas per 100 km2 between 2013 and 2018, with an annual estimated high of 20.83/100 km2 in 2014 and a low of 11.98/100 km2 in 2015. Our results demonstrate that camera trap by-catch data can be used for estimating spotted hyaena densities over time. We believe that given the widespread use and deployment of camera traps across Africa, collaborative efforts to use existing data to improve regional and continental estimates and population trends for spotted hyaenas should be a priority.

From meat availability to hominin and carnivore biomass: A paleosynecological approach to reconstructing predator-prey biomass ratios in the Pleistocene

Reconstructing the conditions and circumstances under which the human lineage evolved is of great interest to those disciplines related to human evolution, especially in fields such as archaeoecology and human paleoecology. A mathematical model was presented almost a decade ago aimed to reconstructing the human populations that the Pleistocene paleoecosystems could support. This model followed a paleosynecological perspective, being focused on: (i) estimating the availability of meat resources in the paleoecosystems, as these resources are vital for human survival; and (ii) measuring the level of competition for these resources among the members of the carnivore guild, including hominins. The model has been applied since then to several Pleistocene localities of Europe, with particular emphasis on the Orce and Sierra de Atapuerca sites. In this study, we use the model for estimating predator-prey biomass ratios and compare the model outputs with the values measured in present-day African ecosystems. The results obtained confirm that our paleosynecological approach provides estimates of predator-prey biomass ratios that are broadly similar to those measured in the extant ecosystems. However, our estimates tend to be slightly higher than expected, which is probably due to the weight of species that satisfy part of their nutritional requirements with resources other than the meat from large herbivores. This allows us to assume that our model performs relatively well, although it has room for methodological improvements.

An occupancy analysis of the factors affecting the presence of carnivores at the national park‐human community interface in Rwanda

AbstractPeople, livestock and carnivores are constantly interacting especially at the interface between community and protected areas. The carnivore guild category in Volcanoes National Park is important, and if well studied, could lead to additional research opportunities for improved wildlife management. We used single season occupancy models with multi‐species data, to understand the factors affecting species occurrence, detection and distribution among native carnivores of Volcanoes National Park while accounting for imperfect detection and the effects of site variables on the observed trends. Our findings showed that six native carnivores use the park edge, where the side‐striped jackal (Canis adustus) and serval (Leptailurus serval) are the most widespread with ψ = 0.904 (SE 0.051) and ψ = 0.415 (SE 0.086), respectively, followed by African golden cat (Caracal aurata) with ψ = 0.198 (SE 0.066), while the servaline genet (Genetta servalina), slender mongoose (Herpestes sanguineus) and spotted hyaena (Crocuta Crocuta) have very low probability of occupancy with ψ = 0.087 (SE 0.045), ψ = 0.044 (SE 0.032) and ψ = 0.022 (SE 0.022) respectively. In addition, there is high occurrence of feral dogs and human presence in the park edge. Overall, the occupancy of native carnivores increases as distance from settlements increase (β = 0.559 [SE 0.195]) except for hyaena and mongoose which showed a decrease in occupancy as distance to settlements increased. In general, native carnivores preferred sites located close to pasture areas, compared to areas used for agriculture and agroforestry. High overlapping activity between native carnivores and other wildlife varied greatly between species. This study provides the baseline information for the understanding of native carnivores using the park edge and insights on their interactions with other wildlife, livestock and human activities at the interface between the park and local communities. The co‐occurrence of livestock, feral dogs and humans, and native wildlife is a challenge for both wildlife conservation inside the protected area and local communities who might be negatively affected in different ways including interspecific competition, disease exposure and increased conflicts. We anticipate that some of the current livestock keeping are hindered by the challenges of having native carnivores dwelling along the park edge and community interface.

Wire-snare bushmeat poaching and the large African carnivore guild: Impacts, knowledge gaps, and field-based mitigation

Wire-snare poaching for bushmeat is increasingly recognized as a serious threat to the species comprising the large African carnivore guild (African lion, African wild dog, spotted hyena, cheetah and leopard), with impacts described primarily through prey depletion and snaring by-catch mortality or injury. However, the species-specific impacts of snaring on this guild and on intraguild dynamics are not well-understood. These guilds evolved through competition and predation and have a diverse array of behaviors, space use, movements, diet, morphology, and densities; thus, it is logical to expect snaring impacts through prey depletion and by-catch will also be variable, subtle, and complex, yet significant. Utilizing the scientific literature and ongoing, long-term research we: 1) Summarize and describe the known and potential impacts of snaring by-catch and prey depletion on specific species in the guild and on intraguild dynamics, 2) Identify knowledge gaps and propose areas of future research to better understand and address snaring threats, and 3) Describe a successful strategy collaboratively merging conservation science work with resource protection, that has been implemented across carnivore strongholds in Zambia to combat the immediate threats from snaring on large carnivore populations. Collectively, this work can help mitigate snaring impacts while longer-term community-based solutions to the bushmeat crisis are developed and implemented.

Sabretooths, giant hyenas, and hominins: Shifts in the niche of Early Pleistocene scavengers in Iberia at the Epivillafranchian-Galerian transition

The Epivillafranchian and the transition to the Galerian (1.2–0.9 Ma) was a period marked by environmental fluctuations and faunal turnover. Homo arrived into Europe around 1.4 Ma. ago, and was established in Iberia during the Epivillafranchian, as evidenced by the oldest sites with hominin fossils located in the Iberian Peninsula. The Iberian ecosystems offered a variety of trophic resources to hominins, including the opportunity to scavenge carcasses of large ungulates killed by a diverse predatory guild, especially due to the presence of two sabre-toothed cats. It has been claimed that the presence of Pachycrocuta brevirostris, a strong competitor for carrion, prevented hominins from exploiting abandoned carcasses as a reliable meat and fat resource. However, computer simulation experiments suggest that the coexistence of P. brevirostris and hominins competing for carrion was ecologically viable in the Epivillafranchian. Nevertheless, the faunal turnover of the Epivillafranchian-Galerian transition drastically changed the composition of the large carnivore fauna. The changes include the extinction of the sabre-toothed felid Megantereon, frequently considered a key provider of partially consumed carcasses, and the demise of the hyperscavenger P. brevirostris. All these changes modified the ecological scenario and the opportunities for hominins and other facultative scavengers. Computer simulation experiments using the agent-based model SCAVCOMP-ABM are used here to evaluate the viability of the coexistence of hominins and giant hyenas in the Epivillafranchian-Galerian transition. Different ecological scenarios defined by the composition of the predatory guild, ecosystem productivity, and competition pressure from other scavengers are evaluated. Results suggest that hominins and giant hyenas could coexist during the Epivillafranchian with different carnivore guilds, but a disruption of the scavenging niche likely occurred in the transition to the Galerian, coinciding with the extinction of P. brevirostris. A low ecosystem productivity during the cold intervals, maintenance of a high competition for carrion with other facultative scavengers, and a hypothetical social behaviour of the sabre-toothed cat Homotherium latidens appear as key factors to explain the changes in the scavenger guild at the Epivillafranchian-Galerian transition.

The Fox from Bajiazui (Qingyang, Central China) and an Update on Early Pleistocene Foxes from China

(1) Background: despite the fact that nowadays the genus Vulpes Frisch, 1775, is the most diverse among extant Canidae, its fossil record is utterly scarce, especially in the Asian Pliocene. The sparse nature of this record further complicates the reconstruction of the evolutionary scenario to fit these taxa with extant species. The situation seems to change slightly in the Early Pleistocene when two species are recorded: Vulpes alopecoides (Del Campana, 1913) in Europe and Vulpes chikushanensis, Young, 1930, in Asian localities. Unlike the former, which has an extensive record, the remains of the Chinese V. chikushanensis are sporadic and the validity of the taxon has also been questioned. (2) Methods: the study of the specimens from the Early Pleistocene site of Bajiazui (1.8–1.2 Ma, Qingyang, Gansu) in comparison to an extensive sample of Vulpes spp. The Pliocene–Early Pleistocene is relevant for the delimitation of fossil foxes variability; (3) Results: morphologically and morphometrically, the specimens of Bajiazui fit with the specimens of V. chikushanensis from other Chinese localities of the Early Pleistocene, e.g., Longdan (Gansu) and Huiyu (Fangshang), highlighting some difference with the latest Early Pleistocene forms of Jigushan fox; (4) Conclusions: the revision of the Asian fossil record of Vulpes is crucial in our attempt to understand and reconstruct the evolution of carnivoran guild during the late Early Pleistocene (1.8–0.8 Ma). The fox remains from Bajiazui, although fragmentary, add a valuable piece to our knowledge of V. chikushanensis, a species possibly strongly related to the extant Vulpes corsac (Linnaeus, 1768).