Fear of the human 'super predator' reduces feeding time in large carnivores

Insights from a 31-year study demonstrate an inverse correlation between recreational activities and red deer fecundity, with bodyweight as a mediator

Human activity is omnipresent in our landscapes. Animals can perceive risk from humans similar to predation risk, which could affect their fitness. We assessed the influence of the relative intensity of recreational activities on the bodyweight and pregnancy rates of red deer (Cervus elaphus) between 1985 and 2015. We hypothesized that stress, as a result of recreational activities, affects the pregnancy rates of red deer directly and indirectly via a reduction in bodyweight. Furthermore, we expected non-motorized recreational activities to have a larger negative effect on both bodyweight and fecundity, compared to motorized recreational activities. The intensity of recreational activities was recorded through visual observations. We obtained pregnancy data from female red deer that were shot during the regular hunting season. Additionally, age and bodyweight were determined through a post-mortem examination. We used two Generalized-Linear-Mixed Models (GLMM) to test the effect of different types of recreation on (1) pregnancy rates and (2) bodyweight of red deer. Recreation had a direct negative correlation with the fecundity of red deer, with bodyweight, as a mediator as expected. Besides, we found a negative effect of non-motorized recreation on fecundity and bodyweight and no significant effect of motorized recreation. Our results support the concept of humans as an important stressor affecting wild animal populations at a population level and plead to regulate recreational activities in protected areas that are sensitive. The fear humans induce in large-bodied herbivores and its consequences for fitness may have strong implications for animal populations.

Social-ecological predictors of spotted hyena navigation through a shared landscape

Human-wildlife interactions are increasing in severity due to climate change and proliferating urbanization. Regions where human infrastructure and activity are rapidly densifying or newly appearing constitute novel environments in which wildlife must learn to coexist with people, thereby serving as ideal case studies with which to infer future human-wildlife interactions in shared landscapes. As a widely reviled and behaviorally plastic apex predator, the spotted hyena (Crocuta crocuta) is a model species for understanding how large carnivores navigate these human-caused 'landscapes of fear' in a changing world. Using high-resolution GPS collar data, we applied resource selection functions and step selection functions to assess spotted hyena landscape navigation and fine-scale movement decisions in relation to social-ecological features in a rapidly developing region comprising two protected areas: Lake Nakuru National Park and Soysambu Conservancy, Kenya. We then used camera trap imagery and Barrier Behavior Analysis (BaBA) to further examine hyena interactions with barriers. Our results show that environmental factors, linear infrastructure, human-carnivore conflict hotspots, and human tolerance were all important predictors for landscape-scale resource selection by hyenas, while human experience elements were less important for fine-scale hyena movement decisions. Hyena selection for these characteristics also changed seasonally and across land management types. Camera traps documented an exceptionally high number of individual spotted hyenas (234) approaching the national park fence at 16 sites during the study period, and BaBA results suggested that hyenas perceive protected area boundaries' semi-permeable electric fences as risky but may cross them out of necessity. Our findings highlight that the ability of carnivores to flexibly respond within human-caused landscapes of fear may be expressed differently depending on context, scale, and climatic factors. These results also point to the need to incorporate societal factors into multiscale analyses of wildlife movement to effectively plan for human-wildlife coexistence.

Do human-wildlife interactions predict offspring hiding strategies in peri-urban fallow deer?

Human activities can induce significant behavioural changes in wildlife. Often explored through extractive interactions (e.g. hunting) that can favour certain behavioural traits, the implications of non-extractive ones, such as wildlife feeding, remain understudied. Research shows that people tend to favour bolder individuals within populations despite their dynamics and consequences being unclear. Using fallow deer in a peri-urban environment, we studied whether mothers that show reduced fear of humans and consistently approach them for food adopt weaker anti-predator strategies by selecting less concealed fawning bedsites closer to human hotspots. This would provide the advantage of additional feeding opportunities in comparison with shyer mothers while keeping their fawns close. Our dataset encompassed 281 capture events of 172 fawns from 110 mothers across 4 years. Surprisingly, mothers that regularly accepted food from humans selected more concealed bedsites farther from human hotspots, giving their offspring better protection while also benefitting from additional food during lactation. Our results show behavioural adaptations by a subset of females and, for the first time, link the tendency to approach humans and strategies to protect offspring. Given previous findings that these begging females also deliver heavier fawns at birth, our research further investigates human-wildlife feeding interactions and their behavioural implications.

Social information modifies the associations between forest fragmentation and the abundance of a passerine bird

Habitat loss and fragmentation are the main factors driving the occurrence and abundance of species in the landscape. However, the local occurrence and abundance of species may also depend on conspecific and heterospecific social information e.g. clues of animals' presence or their voices. We investigated the impact of the interaction between different types of social information and forest fragmentation on the abundance of the song thrush, Turdus philomelos, in Central Europe. Three types of social information (attractive, repulsive, and mixed) and procedural control were broadcasted via loudspeakers in 150 forest patches that varied in size and isolation metrics. Repulsive social information (cues of presence of predator) decreased abundance of song thrush. Also, the repulsive social information changed the association between forest patch isolation, size and the abundance. Attractive social information (songs of the studied thrush) had no effect on song thrush abundance. However, the attractive social information reversed the positive correlation between habitat patch size and the abundance. Mixed social information (both repulsive and attractive) had no impact on the abundance nor interacted with habitat fragmentation. The observed effects mostly did not last to the next breeding season. Overall, our findings indicate that lands of fear and social attraction could modify the effect of habitat fragmentation on the species abundance but these effects probably are not long-lasting.

Self-Organisation of Prediction Models

Living organisms are active open systems far from thermodynamic equilibrium. The ability to behave actively corresponds to dynamical metastability: minor but supercritical internal or external effects may trigger major substantial actions such as gross mechanical motion, dissipating internally accumulated energy reserves. Gaining a selective advantage from the beneficial use of activity requires a consistent combination of sensual perception, memorised experience, statistical or causal prediction models, and the resulting favourable decisions on actions. This information processing chain originated from mere physical interaction processes prior to life, here denoted as structural information exchange. From there, the self-organised transition to symbolic information processing marks the beginning of life, evolving through the novel purposivity of trial-and-error feedback and the accumulation of symbolic information. The emergence of symbols and prediction models can be described as a ritualisation transition, a symmetry-breaking kinetic phase transition of the second kind previously known from behavioural biology. The related new symmetry is the neutrally stable arbitrariness, conventionality, or code invariance of symbols with respect to their meaning. The meaning of such symbols is given by the structural effect they ultimately unleash, directly or indirectly, by deciding on which actions to take. The early genetic code represents the first symbols. The genetically inherited symbolic information is the first prediction model for activities sufficient for survival under the condition of environmental continuity, sometimes understood as the "final causality" property of the model.

Leopard density and the ecological and anthropogenic factors influencing density in a mixed-use landscape in the Western Cape, South Africa

Large carnivores face numerous threats, including habitat loss and fragmentation, direct killing, and prey depletion, leading to significant global range and population declines. Despite such threats, leopards (Panthera pardus) persist outside protected areas throughout most of their range, occupying diverse habitat types and land uses, including peri-urban and rural areas. Understanding of leopard population dynamics in mixed-use landscapes is limited, especially in South Africa, where the majority of leopard research has focused on protected areas. We use spatially explicit capture-recapture models to estimate leopard density across a mixed-use landscape of protected areas, farmland, and urban areas in the Overberg region of the Western Cape, South Africa. Data from 86 paired camera stations provided 221 independent captures of 25 leopards at 50 camera trap stations with a population density estimate of 0.64 leopards per 100 km2 (95% CI: 0.55-0.73). Elevation, terrain ruggedness, and vegetation productivity were important drivers of leopard density in the landscape, being highest on elevated remnants of natural land outside of protected areas. These results are similar to previous research findings in other parts of the Western Cape, where high-lying natural vegetation was shown to serve as both a refuge and a corridor for leopard movement in otherwise transformed landscapes. Given the low leopard density and the prevalence of transformed land intermixed with patches of more suitable leopard habitat, prioritising and preserving connectivity for leopards is vital in this shared landscape. Ecological corridors should be developed in partnership with private landowners through an inclusive and multifaceted conservation strategy which also incorporates monitoring of and rapid mitigation of emerging threats to leopards.

Frightened of giants: fear responses to elephants approach that of predators

Animals are faced with a variety of dangers or threats, which are increasing in frequency with ongoing environmental change. While our understanding of fearfulness of such dangers is growing in the context of predation and parasitism risk, the extent to which non-trophic, interspecific dangers elicit fear in animals remains less appreciated. We provide an experimental test for fear responses of savannah ungulates to a dominant and aggressive megaherbivore, the African bush elephant (Loxodonta africana), and contrast responses to an apex predator known to elicit fear in this system. Using an automated behavioural response system, we contrast vigilance and run responses of ungulates to elephant, leopard (Panthera pardus), and control (red-chested cuckoo Cuculus solitarius) vocalizations. Overall, we find that ungulates responded to elephant calls, both in terms of an increase in run and vigilance responses relative to controls. The magnitude of most behavioural responses (four of six considered) to elephant vocalizations were not significantly different than responses to leopards. These results suggest that megaherbivores can elicit strong non-trophic fear responses by ungulates and call to broaden frameworks on fear to consider dominant species, such as megaherbivores, as key modifiers of fear-induced interactions.

Trucks versus treks: The relative influence of motorized versus nonmotorized recreation on a mammal community

Outdoor recreation is increasing rapidly on public lands, with potential consequences for wildlife communities. Recreation can induce shifts in wildlife activity and habitat use, but responses vary widely even within the same species, suggesting mitigating factors that remain poorly understood. Both the type of recreation-motorized or nonmotorized-and the distance of wildlife from human disturbance may be important in developing a general understanding of recreation impacts on wildlife and making more informed management decisions. We conducted a camera-trapping survey in the Colville National Forest (CNF) of northeastern Washington in the summers of 2019 and 2020. We collected ~11,000 trap nights of spatially extensive data on nine mid-large mammalian species, simultaneously recording the presence and activity patterns of motorized (primarily vehicles on roads) and nonmotorized (primarily hikers on trails) recreation and wildlife both along trails and roads and off trails and off roads (away from most recreation). We used diel overlap analysis, time lag analysis, and single-season single-species occupancy modeling to examine the impact of recreation on the focal species. Species temporally avoided recreationists either by shifting to more nocturnal hours or delaying return to recently used recreation sites. Most species also responded spatially by altering the use or the intensity of use of camera sites due to recreation, although both positive and negative associations with recreation were documented. Species responded to nonmotorized recreation (e.g., hikers on trails) more often than motorized recreation (e.g., vehicles on roads). Most effects of recreation extended off the trail or road, although in three instances the spatiotemporal response of species to recreation along trails/roads disappeared a short distance away from those features. Our work suggests that a better understanding of landscape-scale impacts of recreation, including fitness consequences, will require additional work to disentangle the effects of different types of recreation and estimate the effective distance at which wildlife responds. Moreover, these results suggest that quiet, nonconsumptive recreation may warrant increased attention from land managers given its potential to influence the spatiotemporal ecology of numerous species.

A vision for incorporating human mobility in the study of human-wildlife interactions

As human activities increasingly shape land- and seascapes, understanding human-wildlife interactions is imperative for preserving biodiversity. Habitats are impacted not only by static modifications, such as roads, buildings and other infrastructure, but also by the dynamic movement of people and their vehicles occurring over shorter time scales. Although there is increasing realization that both components of human activity substantially affect wildlife, capturing more dynamic processes in ecological studies has proved challenging. Here we propose a conceptual framework for developing a 'dynamic human footprint' that explicitly incorporates human mobility, providing a key link between anthropogenic stressors and ecological impacts across spatiotemporal scales. Specifically, the dynamic human footprint integrates a range of metrics to fully acknowledge the time-varying nature of human activities and to enable scale-appropriate assessments of their impacts on wildlife behaviour, demography and distributions. We review existing terrestrial and marine human-mobility data products and provide a roadmap for how these could be integrated and extended to enable more comprehensive analyses of human impacts on biodiversity in the Anthropocene.

Influence of heterospecifics on mesocarnivore behaviour at shared scavenging opportunities in the Canadian Rocky Mountains

In seasonal environments, the ability of mustelid species to acquire carrion-a dietary resource heavily depended upon-is driven by a collection local habitat characteristics and competition dynamics. In resource-scarce winter, sympatric mesocarnivores must balance energetic rewards of carrion with avoiding antagonistic interactions with conspecifics. We examined scavenging interactions among three mustelid species in the northern Canadian Rocky Mountains. Camera traps (n = 59) were baited with carrion during winter between 2006 to 2008. Spatial and temporal dimensions of scavenger behaviour (i.e., carcass use) were evaluated using a multi-model approach, which enabled us to recognize potentially adaptive behavioural mechanisms for mitigating competition at carcass sites. Best performing models indicated that carrion site use is governed by a combination of competition threats and environmental factors. A decrease in scavenging with increasing snow depth was observed across all species. Mustelids adopted a host of adaptive behavioural strategies to access shared scavenging opportunities. We found evidence that wolverine (Gulo gulo) and American marten (Martes americana) segregate in space but temporally tracked one another. Short-tailed weasel (Mustela erminea) scavenging decreased with greater site use by marten. Carcass availability across a spatially complex environment, as well as spatial-temporal avoidance strategies, can facilitate carrion resource partitioning.

Crowded mountains: Long-term effects of human outdoor recreation on a community of wild mammals monitored with systematic camera trapping

Outdoor recreation in natural areas has become an increasingly popular activity globally, yet the long-term effects on wildlife are poorly known. Reconciling human access to nature and wildlife conservation requires sound evaluations of how outdoor activities affect biodiversity in space and time. We aimed to contribute to this topic by asking whether tourism in the world-renown Dolomites, Italy, affected wild mammals in the long term, and if it elicited spatial or temporal avoidance. We detected mammals by systematic camera trapping over seven consecutive summers at 60, consistently sampled, sites, and estimated trends in occurrence at community and species levels through a dynamic community occupancy model, combined with site use intensity and an index of nocturnality. Overall, 70% of the 520 000 images obtained depicted humans, whose presence intensified over the 7-year period. Nonetheless, both community and most species-level occurrences increased. However, human activities caused a strong temporal avoidance in the whole community, especially in most disturbed sites, while spatial avoidance was observed only for bigger-sized species.

Habitat fragmentation reduces survival and drives source-sink dynamics for a large carnivore

Rigorous understanding of how environmental conditions impact population dynamics is essential for species conservation, especially in mixed-use landscapes where source-sink dynamics may be at play. Conservation of large carnivore populations in fragmented, human-dominated landscapes is critical for their long-term persistence. However, living in human-dominated landscapes comes with myriad costs, including direct anthropogenic mortality and sublethal energetic costs. How these costs impact individual fitness and population dynamics are not fully understood, partly due to the difficulty in collecting long-term demographic data for these species. Here, we analyzed an 11-year dataset on puma (Puma concolor) space use, mortality, and reproduction in the Santa Cruz Mountains, California, USA, to quantify how living in a fragmented landscape impacts individual survival and population dynamics. Long-term exposure to housing density drove mortality risk for female pumas, resulting in an 18-percentage-point reduction in annual survival for females in exurban versus remote areas. While the overall population growth rate appeared stable, reduced female survival in more developed areas resulted in source-sink dynamics across the study area, with 42.1% of the Santa Cruz Mountains exhibiting estimated population growth rates <1. Since habitat selection is often used as a proxy for habitat quality, we also assessed whether puma habitat selection predicted source and sink areas. Patterns of daytime puma habitat selection predicted source areas, while time-of-day-independent habitat selection performed less well as a proxy. These results illuminate the individual- and population-level consequences of habitat fragmentation for large carnivores, illustrating that habitat fragmentation can produce source-sink dynamics that may not be apparent from other metrics of habitat quality. Locally, conserving high-quality source habitat within the Santa Cruz Mountains is necessary to support long-term puma population persistence. More broadly, source-sink dynamics may at play for other carnivore populations in similar fragmented systems, and linking landscape conditions to population dynamics is essential for effective conservation. Caution should be used in inferring habitat quality from habitat selection alone, but these results shed light on metrics of selection that may be better or worse proxies to identify source areas for large carnivores.

Fear of large carnivores amplifies human-caused mortality for mesopredators

The challenge that large carnivores face in coexisting with humans calls into question their ability to carry out critical ecosystem functions such as mesopredator suppression outside protected areas. In this study, we examined the movements and fates of mesopredators and large carnivores across rural landscapes characterized by substantial human influences. Mesopredators shifted their movements toward areas with twofold-greater human influence in regions occupied by large carnivores, indicating that they perceived humans to be less of a threat. However, rather than shielding mesopredators, human-caused mortality was more than three times higher than large carnivore-caused mortality. Mesopredator suppression by apex predators may thus be amplified, rather than dampened, outside protected areas, because fear of large carnivores drives mesopredators into areas of even greater risk from human super predators.

Integrating traditional ecological knowledge into US public land management: Knowledge gaps and research priorities

Traditional Ecological Knowledge (TEK) is an understanding of natural systems acquired through long-term human interactions with particular landscapes. Traditional knowledge systems complement western scientific disciplines by providing a holistic assessment of ecosystem dynamics and extending the time horizon of ecological observations. Integration of TEK into land management is a key priority of numerous groups, including the United Nations and US public land management agencies; however, TEK principles have rarely been enshrined in national-level US policy or planning. We review over 20 years of TEK literature to describe key applications of TEK to ecological understanding, conservation, restoration and land management generally. By identifying knowledge gaps, we highlight research avenues to support the integration of TEK into US public land management, in order to enhance conservation approaches and participation of historically underrepresented groups, particularly American Indian Tribes, in the stewardship of ancestral lands critical to the practice of living cultural traditions.

Impacts of top predators and humans on the mammal communities of recovering temperate forest regions

Top predators are important drivers in shaping ecological community structure via top-down effects. However, the ecological consequences and mechanisms of top predator loss under accelerated human impacts have rarely been quantitatively assessed due to the limited availability of long-term community data. With increases in top predator populations in northern China over the past two decades, forests with varying densities of top predators and humans provide an opportunity to study their ecological effects on mammal communities. We hypothesized a priori of conceptual models and tested these using structural equation models (SEMs) with multi-year camera trap data, aiming to reveal the underlying independent ecological effects of top predators (tigers, bears, and leopards) and humans on mammal communities. We used random forest models and correlations among species pairs to validate results. We found that top predator reduction could be related to augmented populations of large ungulates ("large ungulate release") and mesopredators ("mesopredator release"), consistent with observations of mammal communities in other ecosystems. Additionally, top predator reduction could be related to reduced small mammal abundance. Hierarchical SEMs identified three bottom-up pathways from forest quality to human activities, large ungulates, and some small mammals, and five top-down pathways from human activities and top predators to some small mammals, large ungulates, and mesopredators. Furthermore, our results suggest that humans showed predominant top-down effects on multiple functional groups, partially replacing the role of top predators, rather than be mediated by them; effects of humans and top predators appeared largely independent. Effects of humans on top predators were non-significant. This study provides novel insights into the effects of top predators and humans as super-predators on mammal communities in forest ecosystems and presents cues of bottom-up effects that can be translated into actionable management plans for improving forest quality, thereby supporting top predator recovery and work/life activities of local people.

Large carnivores avoid humans while prioritizing prey acquisition in anthropogenic areas

Large carnivores are recovering in many landscapes where the human footprint is simultaneously growing. When carnivores encounter humans, the way they behave often changes, which may subsequently influence how they affect their prey. However, little research investigates the behavioural mechanisms underpinning carnivore response to humans. As a result, it is not clear how predator-prey interactions and their associated ecosystem processes will play out in the human-dominated areas into which carnivore populations are increasingly expanding. We hypothesized that humans would reduce predation risk for prey by disturbing carnivores or threatening their survival. Alternatively, or additionally, we hypothesized that humans would increase predation risk by providing forage resources that congregate herbivorous prey in predictable places and times. Using grey wolves Canis lupus in Jackson Hole, Wyoming, USA as a study species, we investigated 170 kill sites across a spectrum of human influences ranging from heavily restricted human activities on protected federal lands to largely unregulated activities on private lands. Then, we used conditional logistic regression to quantify how the probability of predation changed across varied types and amounts of human influences, while controlling for environmental characteristics and prey availability. Wolves primarily made kills in environmental terrain traps and where prey availability was high, but predation risk was significantly better explained with the inclusion of human influences than by environmental characteristics alone. Different human influences had different, and even converse, effects on the risk of wolf predation. For example, where prey were readily available, wolves preferentially killed animals far from motorized roads but close to unpaved trails. However, wolves responded less strongly to humans, if at all, where prey were scarce, suggesting they prioritized acquiring prey over avoiding human interactions. Overall, our work reveals that the effects of large carnivores on prey populations can vary considerably among different types of human influences, yet carnivores may not appreciably alter predatory behaviour in response to humans if prey are difficult to obtain. These results shed new light on the drivers of large carnivore behaviour in anthropogenic areas while improving understanding of predator-prey dynamics in and around the wildland-urban interface.

The effect of decreasing human activity from COVID-19 on the foraging of fallen fruit by omnivores

In 2020, a lockdown was implemented in many cities around the world to contain the COVID-19 pandemic, resulting in a significant cessation of human activity which have had a variety of impacts on wildlife. But in many cases, due to limited pre-lockdown information, and there are limited studies of how lockdowns have specifically affected behaviors. Foraging behavior is inherently linked to fitness and survival, is particularly affected by changes in temporal activity, and the influence of human disturbance on foraging behavior can be assessed quantitatively based on foraging duration and quantity. The purpose of this study was to determine whether and how the fruit-foraging behaviors of two omnivores, the Japanese badger (Meles anakuma) and the raccoon dog (Nyctereutes procyonoides), were influenced by the decrease of human activity associated with lockdowns. Specifically, by comparing to a previous study in 2019-2020, we attempted to determine (1) whether foraging behavior increases during the daytime? (2) whether the duration of foraging per visit increases? and (3) what factors animals select for in fruiting trees? The results of the initial investigation showed that the foraging behavior of both species in 2019 was almost exclusively restricted to the nighttime. But as opportunities for foraging behavior without human interference increased in 2020 due to the lockdown, both species (but especially raccoon dogs) showed substantial changes in their activity patterns to be more diurnal. The duration of foraging per visit also increased in 2020 for both species, and the selection during foraging for both species shifted from selecting trees that provided greater cover in 2019 to trees with high fruit production in 2020. Our results show how human activity directly affects the foraging behavior of wildlife in an urban landscape.

Behavioral responses to anthropogenic noise at highways vary across temporal scales

Anthropogenic noise is pervasive across the landscape and can be present at two temporal scales: acute (occurring sporadically and stochastically over the shortest time scales, e.g., milliseconds), and chronic (more persistent than instantaneous and occurring over longer timescales, e.g., minutes, days). Acute and chronic anthropogenic noise may induce a behavioral fear-mediated response in wildlife that is analogous to a prey response to predators. Understanding wildlife responses to anthropogenic noise is especially important in the case of wildlife crossing structures that provide wildlife with access to resources across busy roadways. Focusing on two species common at wildlife crossing structures, mule deer (Odocoileus hemionus) and coyotes (Canis latrans), we addressed the hypotheses that (1) acute traffic noise causes flight behavior; and (2) chronic traffic noise causes changes in a range of behaviors associated with the vigilance–foraging trade-off (vigilance, running, and foraging). We placed camera traps at entrances to ten crossing structures for a period of ∼ 2 months each throughout California, USA. Mule deer and coyotes demonstrated a flight response to acute traffic noise at entrances to crossing structures. Both species demonstrated shifts in behavioral response to chronic traffic noise within and among structures. Coyote behavior was indicative of fear, demonstrating increased vigilance at louder times within crossing structures, and switching from vigilance to running activity at louder crossings. Mule deer responded positively, increasing foraging at both spatial scales, and demonstrating decreased vigilance at louder structures, potentially using crossing structures as a Human Shield. Our results are the first to demonstrate that anthropogenic noise at crossing structures could alter wildlife passage, and that variations in fear response to anthropogenic noise exist across temporal, spatial, and amplitude scales. This dynamic response could alter natural predator-prey interactions and scale up to ecosystem-level consequences such as trophic cascades in areas with roads.

Dietary patterns of a versatile large carnivore, the puma (Puma concolor)

Large carnivores play critical roles in terrestrial ecosystems but have suffered dramatic range contractions over the past two centuries. Developing an accurate understanding of large carnivore diets is an important first step towards an improved understanding of their ecological roles and addressing the conservation challenges faced by these species.The puma is one of seven large felid species in the world and the only one native to the non-tropical regions of the New World. We conducted a meta-analysis of puma diets across the species' range in the Americas and assessed the impact of varying environmental conditions, niche roles, and human activity on puma diets. Pumas displayed remarkable dietary flexibility, consuming at least 232 different prey species, including one Critically Endangered and five Endangered species.Our meta-analysis found clear patterns in puma diets with changing habitat and environmental conditions. Pumas consumed more larger-bodied prey species with increasing distance from the equator, but consumption of medium-sized species showed the opposite trend.Puma diets varied with their realized niche; however, contrary to our expectations, puma consumption of large species did not change with their trophic position, and pumas consumed more small prey and birds as apex predators. Consumption of domestic species was negatively correlated with consumption of medium-sized wild species, a finding which underscores the importance of maintaining intact native prey assemblages.The tremendous dietary flexibility displayed by pumas represents both an opportunity and a challenge for understanding the puma's role in ecosystems and for the species' management and conservation. Future studies should explore the linkages between availability and selection of primary and other wild prey, and consequent impacts on predation of domestic species, in order to guide conservation actions and reduce conflict between pumas and people.

Functional diversity loss and change in nocturnal behavior of mammals under anthropogenic disturbance

In the Anthropocene, understanding the impacts of anthropogenic influence on biodiversity and behavior of vulnerable wildlife communities is increasingly relevant to effective conservation. However, comparative studies aimed at disentangling the concurrent effect of different types of human disturbance on multifaceted biodiversity and on activity patterns of mammals are surprisingly rare. We applied a multiregion community model to separately estimate the effects of cumulative human modification (e.g., settlement, agriculture, and transportation) and human presence (aggregated presence of dogs, people, and livestock) on species richness and functional composition of medium- and large-bodied mammals based on camera trap data collected across 45 subtropical montane forests. We divided the detected mammal species into three trophic guilds-carnivores, herbivores, and omnivores-and assessed the nocturnal shifts of each guild in response to anthropogenic activities. Overall, species richness tended to increase (β coefficient = 0.954) as human modification increased but richness decreased as human presence increased (β = -1.054). Human modification was associated with significantly lower functional diversity (mean nearest taxon distance [MNTD], β = -0.134; standardized effect sizes of MNTD, β = -0.397), community average body mass (β = -0.240), and proportion of carnivores (β = -0.580). Human presence was associated with a strongly reduced proportion of herbivores (β = -0.522), whereas proportion of omnivores significantly increased as human presence (β = 0.378) and habitat modification (β = 0.419) increased. In terms of activity patterns, omnivores (β = 12.103) and carnivores (β = 9.368) became more nocturnal in response to human modification. Our results suggest that human modification and human presence have differing effects on mammals and demonstrate that anthropogenic disturbances can lead to drastic loss of functional diversity and result in a shift to nocturnal behavior of mammals. Conservation planning should consider concurrent effects of different types of human disturbance on species richness, functional diversity, and behavior of wildlife communities.

Kill rates and associated ecological factors for an apex predator

Kill rates and functional responses are fundamental to the study of predator ecology and the understanding of predatory-prey dynamics. As the most widely distributed apex predator in the western hemisphere, pumas (Puma concolor) have been well studied, yet a synthesis of their kill rates is currently lacking. We reviewed the literature and compiled data on sex- and age-specific kill rate estimates of pumas on ungulates, and conducted analyses aimed at understanding ecological factors explaining the observed spatial variation. Kill rate studies on pumas, while numerous, were primarily conducted in Temperate Conifer Forests (< 10% of puma range), revealing a dearth of knowledge across much of their range, especially from tropical and subtropical habitats. Across studies, kill rates in ungulates/week were highest for adult females with kitten(s) (1.24 ± 0.41 ungulates/week) but did not vary significantly between adult males (0.84 ± 0.18) and solitary adult females (0.99 ± 0.26). Kill rates in kg/day differed only marginally among reproductive classes. Kill rates of adult pumas increased with ungulate density, particularly for males. Ungulate species richness had a weak negative association with adult male kill rates. Neither scavenger richness, puma density, the proportion of non-ungulate prey in the diet, nor regional human population density had a significant effect on ungulate kill rates, but additional studies and standardization would provide further insights. Our results had a strong temperate-ecosystem bias highlighting the need for further research across the diverse biomes pumas occupy to fully interpret kill rates for the species. Data from more populations would also allow for multivariate analyses providing deeper inference into the ecological and behavioural factors driving kill rates and functional responses of pumas, and apex predators in general.

“Ecology of fear” in ungulates: Opportunities for improving conservation

Because ungulates are important contributors to ecosystem function, understanding the “ecology of fear” could be important to the conservation of ecosystems. Although studying ungulate ecology of fear is common, knowledge from ungulate systems is highly contested among ecologists. Here, we review the available literature on the ecology of fear in ungulates to generalize our current knowledge and how we can leverage it for conservation. Four general focus areas emerged from the 275 papers included in our literature search (and some papers were included in multiple categories): behavioral responses to predation risk (79%), physiological responses to predation risk (15%), trophic cascades resulting from ungulate responses to predation risk (20%), and manipulation of predation risk (1%). Of papers focused on behavior, 75% were about movement and habitat selection. Studies were biased toward North America (53%), tended to be focused on elk (Cervus canadensis; 29%), and were dominated by gray wolves (40%) or humans (39%) as predators of interest. Emerging literature suggests that we can utilize predation risk for conservation with top‐down (i.e., increasing predation risk) and bottom‐up (i.e., manipulating landscape characteristics to increase risk or risk perception) approaches. It is less clear whether fear‐related changes in physiology have population‐level fitness consequences or cascading effects, which could be fruitful avenues for future research. Conflicting evidence of trait‐mediated trophic cascades might be improved with better replication across systems and accounting for confounding effects of ungulate density. Improving our understanding of mechanisms modulating the nature of trophic cascades likely is most important to ensure desirable conservation outcomes. We recommend future work embrace the complexity of natural systems by attempting to link together the focal areas of study identified herein.

Assessment of medium and large-sized mammals and their behavioral response toward anthropogenic activities in Jorgo-Wato Protected Forest, Western Ethiopia

Medium and large-sized mammals of Jorgo-Wato Protected Forest have not yet been documented though the forest established before four decades. Hence, this study aims to document medium and large mammals and the behavioral responses of selected mammals toward anthropogenic activities in the study area. The study was conducted from February 2015 to June 2016, encompassing the wet and dry seasons. Data were collected mainly through camera traps, indirect and direct evidence. The study revealed about 23 medium and large-sized mammals that belong to seven orders namely Bovidae, Carnivora, Primates, Rodentia, Tubulidentata, Lagomorpha, and Hyracoidea. Papio anubis, C. guereza, and C. aethiops were the most abundant large mammals in JWPF. Because of high anthropogenic activities, African buffalo shifted its activity period from diurnal into crepuscular and nocturnal. African buffalo traveled longer distances during the wet season (mean = 14.33 km, SD = 1.25 km) than during the dry season (mean = 9.00 km, SD = 2.16 km). This could be due to the fact that the local people were less likely to go to the forest for resource exploitation during the wet season as they are fully engaged in agricultural activities. However, low agricultural activities during the dry season allow the local people to extract resources and involve in bushmeat hunting which could limit the movement of mammals to their refugia. African buffalo preferred to rest on and adjacent to a gravel road (22.1%) in the forest, followed by on open rocky hilltops (14.7%) at night time, but rest in the bottomland thicket vegetation during the dry daytime. Regardless of high human pressure in the area, this study has revealed a good number of medium and large-sized mammals that could be used as baseline information to design a sound conservation and management action plan of large mammals and their habitat in Jorgo-Wato Protected Forest.

Prey tells, large herbivores fear the human 'super predator'

Fear of the human 'super predator' has been demonstrated to so alter the feeding behavior of large carnivores as to cause trophic cascades. It has yet to be experimentally tested if fear of humans has comparably large effects on the feeding behavior of large herbivores. We conducted a predator playback experiment exposing white-tailed deer to the vocalizations of humans, extant or locally extirpated non-human predators (coyotes, cougars, dogs, wolves), or non-predator controls (birds), at supplemental food patches to measure the relative impacts on deer feeding behavior. Deer were more than twice as likely to flee upon hearing humans than other predators, and hearing humans was matched only by hearing wolves in reducing overall feeding time gaged by visits to the food patch in the following hour. Combined with previous, site-specific research linking deer fecundity to predator abundance, this study reveals that fear of humans has the potential to induce a larger effect on ungulate reproduction than has ever been reported. By demonstrating that deer most fear the human 'super predator', our results point to the fear humans induce in large ungulates having population- and community-level impacts comparable to those caused by the fear humans induce in large carnivores.

Animal movements occurring during COVID-19 lockdown were predicted by connectivity models

Recent events related to the measures taken to control the spread of the Coronavirus (SARS-CoV-2) reduced human mobility (i.e. anthropause), potentially opening connectivity opportunities for wildlife populations. In the Italian Alps, brown bears have recovered after reintroduction within a complex anthropogenic matrix, but failed to establish a metapopulation due to reduced connectivity and human disturbance (i.e. infrastructure, land use, and human mobility). Previous work from Peters et al. (2015, Biol. Cons. 186, 123–133) predicted the main corridors and suitable hot spots for road network crossing for this population across all major roads and settlement zones, to link most suitable habitats. Bears used the identified hot spots for road network crossing over the years, but major barriers such as main motor roads were not overcome, possibly due to functional anthropogenic disturbance, specifically human mobility. By analyzing 404 bear occurrences reported to local authorities (as bear-related complaints) collected between 2016 and 2020 (March 9th - May 18th), hence including the COVID-19 related lockdown, we tested the effect of human presence on brown bears' use of space and hot spots for road network crossing. Animals occupied human-dominated spaces and approached hot spots for crossing at a higher rate during the lockdown than in previous years, suggesting that connectivity temporarily increased with reduced human mobility for this population. As a result of their increased use of hot spots, bears expanded their use of suitable areas beyond the population core area. Movement of animals across structural barriers such as roads and human settlements may therefore occur in absence of active disturbance. We also showed the value of predictive models to identify hot spots for animal barrier crossing, the knowledge of which is critical when implementing management solutions to enhance connectivity. Understanding the factors that influence immigration and emigration across metapopulations of large mammals, particularly carnivores that may compete indirectly with humans for space or directly as super-predators, is critical to ensure the long-term viability of conservation efforts for their persistence. We argue that dynamic factors such as human mobility may play a larger role than previously recognized.

Contrasting patterns of risk from human and non-human predators shape temporal activity of prey

Spatiotemporal variation in predation risk arises from interactions between landscape heterogeneity, predator densities and predator hunting mode, generating landscapes of fear for prey species that can have important effects on prey behaviour and ecosystem dynamics. As widespread apex predators, humans present a significant source of risk for hunted animal populations. Spatiotemporal patterns of risk from hunters can overlap or contrast with patterns of risk from other predators. Human infrastructure can also reshape spatial patterns of risk by facilitating or impeding hunter or predator movement, or deterring predators that are themselves wary of humans. We examined how anthropogenic and natural landscape features interact with hunting modes of rifle hunters and mountain lions Puma concolor to generate spatiotemporal patterns of risk for their primary prey. We explored the implications of human-modified landscapes of fear for Columbian black-tailed deer Odocoileus hemionus columbianus in Mendocino County, California. We used historical harvest records, hunter GPS trackers and camera trap records of mountain lions to model patterns of risk for deer. We then used camera traps to examine deer spatial and temporal activity patterns in response to this variation in risk. Hunters and mountain lions exhibited distinct, contrasting patterns of spatiotemporal activity. Risk from rifle hunters, who rely on long lines of sight, was highest in open grasslands and near roads and was confined to the daytime. Risk from mountain lions, an ambush predator, was highest in dense shrubland habitat, farther from developed areas, and during the night and crepuscular periods. Areas of human settlement provided a refuge from both hunters and mountain lions. We found no evidence that deer avoided risk in space at the scale of our observations, but deer adjusted their temporal activity patterns to reduce the risk of encounters with humans and mountain lions in areas of higher risk. Our study demonstrates that interactions between human infrastructure, habitat cover and predator hunting mode can result in distinct spatial patterns of predation risk from hunters and other predators that may lead to trade-offs for prey species. However, distinct diel activity patterns of predators may create vacant hunting domains that reduce costly trade-offs for prey. Our study highlights the importance of temporal partitioning as a mechanism of predation risk avoidance.

Temporal scale of habitat selection for large carnivores: Balancing energetics, risk and finding prey

When navigating heterogeneous landscapes, large carnivores must balance trade-offs between multiple goals, including minimizing energetic expenditure, maintaining access to hunting opportunities and avoiding potential risk from humans. The relative importance of these goals in driving carnivore movement likely changes across temporal scales, but our understanding of these dynamics remains limited. Here we quantified how drivers of movement and habitat selection changed with temporal grain for two large carnivore species living in human-dominated landscapes, providing insights into commonalities in carnivore movement strategies across regions. We used high-resolution GPS collar data and integrated step selection analyses to model movement and habitat selection for African lions Panthera leo in Laikipia, Kenya and pumas Puma concolor in the Santa Cruz Mountains of California across eight temporal grains, ranging from 5 min to 12 hr. Analyses considered landscape covariates that are related to energetics, resource acquisition and anthropogenic risk. For both species, topographic slope, which strongly influences energetic expenditure, drove habitat selection and movement patterns over fine temporal grains but was less important at longer temporal grains. In contrast, avoiding anthropogenic risk during the day, when risk was highest, was consistently important across grains, but the degree to which carnivores relaxed this avoidance at night was strongest for longer term movements. Lions and pumas modified their movement behaviour differently in response to anthropogenic features: lions sped up while near humans at fine temporal grains, while pumas slowed down in more developed areas at coarse temporal grains. Finally, pumas experienced a trade-off between energetically efficient movement and avoiding anthropogenic risk. Temporal grain is an important methodological consideration in habitat selection analyses, as drivers of both movement and habitat selection changed across temporal grain. Additionally, grain-dependent patterns can reflect meaningful behavioural processes, including how fitness-relevant goals influence behaviour over different periods of time. In applying multi-scale analysis to fine-resolution data, we showed that two large carnivore species in very different human-dominated landscapes balanced competing energetic and safety demands in largely similar ways. These commonalities suggest general strategies of landscape use across large carnivore species.

Fear of large carnivores is tied to ungulate habitat use: evidence from a bifactorial experiment

The fear large carnivores inspire in large ungulates has been argued to have cascading effects down food webs. However, a direct link between ungulate habitat use and their fear of large carnivores has not been experimentally tested. To fill this critical gap, we conducted a bi-factorial experiment in an African savanna. We removed shrub cover and broadcast large carnivore vocalizations (leopard, hyena, dog) or non-threatening control vocalizations in both experimentally cleared and shrubby control sites. We recorded the proactive (frequency of visitation) and reactive (fleeing or vigilance) responses of multiple prey (impala, warthog, nyala and bushbuck). Critically, we found a significant proactive-reactive interaction. Ungulates were 47% more likely to run after hearing a predator vocalization in shrubby control sites than experimental clearings, demonstrating that ungulates perceived less fear from large carnivores in open habitat (clearings). Consistent with this finding, ungulates visited clearings 2.4 times more often than shrubby control sites and visited shrubby control sites less often at night, when large carnivores are most active. Combined with results from previous experiments demonstrating that the disproportionate use of available habitats by large ungulates can alter ecosystem properties, our experiment provides critical evidence that the fear large carnivores inspire in large ungulates can cause trophic cascades.

Threading the needle: How humans influence predator-prey spatiotemporal interactions in a multiple-predator system

Perceived predation risk and the resulting antipredator behaviour varies across space, time and predator identity. Communities with multiple predators that interact and differ in their use of space, time of activity and hunting mode create a complex landscape for prey to avoid predation. Anthropogenic presence and disturbance have the potential to shift interactions among predators and prey and the where and when encounters occur. We examined how white-tailed deer Odocoileus virginianus fawn spatiotemporal antipredator behaviour differed along an anthropogenic disturbance gradient that had black bears Ursus americanus, coyotes Canis latrans, bobcats Lynx rufus and humans present. We quantified (a) spatial co-occurrence in species distributions, (b) temporal overlap across the diel cycle and (c) spatiotemporal associations between humans, bears, coyotes, bobcats, adult male deer and fawns. We also examined how deer vigilance behaviour changed across the anthropogenic disturbance gradient and survey duration. Anthropogenic disturbance influenced spatiotemporal co-occurrence across multiple scales, often increasing spatiotemporal overlap among species. In general, species' spatial co-occurrence was neutral or positive in anthropogenically disturbed environments. Bears and fawns, coyotes and adult male deer, and bobcats and fawns all had higher temporal overlap in the agriculture-development matrix sites. In addition, factors that influenced deer vigilance (e.g. distance to forest edge and predator relative abundance) in the agriculture-development matrix sites did not in the forest matrix site. By taking into account the different antipredator behaviours that can be detected and the different scales these behaviours might occur, we were able to gain a more comprehensive picture of how humans reduce available niche space for wildlife, creating the neutral and positive spatiotemporal associations between species that studies have been seeing in more disturbed areas.

A Framework for the Eltonian Niche of Humans

Recent research has highlighted several influential roles that humans play in ecosystems, including that of a superpredator, hyperkeystone species, and niche constructor. This work has begun to describe the Eltonian niche of humans, which encompasses humanity's cumulative ecological and evolutionary roles in trophic systems. However, we lack a unifying framework that brings together these strands of research, links them to ecoevolutionary and sociocultural theory, and identifies current research needs. In this article, we present such a framework in hope of facilitating a more holistic approach to operationalizing human roles in trophic systems across an increasingly anthropogenic biosphere. The framework underscores how humans play numerous nuanced roles in trophic systems, from top-down to bottom-up, that entail not only pernicious effects but also benefits for many nonhuman species. Such a nuanced view of the Eltonian niche of humans is important for understanding complex social–ecological system functioning and enacting effective policies and conservation measures.

Mismatch Between Risk and Response May Amplify Lethal and Non-lethal Effects of Humans on Wild Animal Populations

Human activity has rapidly transformed the planet, leading to declines of animal populations around the world through a range of direct and indirect pathways. Humans have strong numerical effects on wild animal populations, as highly efficient hunters and through unintentional impacts of human activity and development. Human disturbance also induces costly non-lethal effects by changing the behavior of risk-averse animals. Here, we suggest that the unique strength of these lethal and non-lethal effects is amplified by mismatches between the nature of risk associated with anthropogenic stimuli and the corresponding response by wild animals. We discuss the unique characteristics of cues associated with anthropogenic stimuli in the context of animal ecology and evolutionary history to explore why and when animals fail to appropriately (a) detect, (b) assess, and (c) respond to both benign and lethal stimuli. We then explore the costs of over-response to a benign stimulus (Type I error) and under-response to a lethal stimulus (Type II error), which can scale up to affect individual fitness and ultimately drive population dynamics and shape ecological interactions. Finally, we highlight avenues for future research and discuss conservation measures that can better align animal perception and response with risk to mitigate unintended consequences of human disturbance.

Effects of Human Disturbance on Terrestrial Apex Predators

The effects of human disturbance spread over virtually all ecosystems and ecological communities on Earth. In this review, we focus on the effects of human disturbance on terrestrial apex predators. We summarize their ecological role in nature and how they respond to different sources of human disturbance. Apex predators control their prey and smaller predators numerically and via behavioral changes to avoid predation risk, which in turn can affect lower trophic levels. Crucially, reducing population numbers and triggering behavioral responses are also the effects that human disturbance causes to apex predators, which may in turn influence their ecological role. Some populations continue to be at the brink of extinction, but others are partially recovering former ranges, via natural recolonization and through reintroductions. Carnivore recovery is both good news for conservation and a challenge for management, particularly when recovery occurs in human-dominated landscapes. Therefore, we conclude by discussing several management considerations that, adapted to local contexts, may favor the recovery of apex predator populations and their ecological functions in nature.

Behavioral Responses of Wild Rodents to Owl Calls in an Austral Temperate Forest

Simple Summary

Growing human populations are challenging scientists to find effective ways to control and mitigate human–wildlife conflict while preserving biodiversity. It has been reported that predator odor and calls can drive away rodents, but little is known about species-specific responses of prey. For these reasons, we compared the behavioral changes of common rodent species inhabiting the Chilean temperate forest (Abrothrix spp., the long-tailed pygmy rice rat Oligoryzomyslongicaudatus and the black rat Rattus rattus) when exposed to two different native predator calls (the austral pygmy owl Glaucidium nana and the rufous-legged owl Strix rufipes) and a control (no predator calls). Our results showed that all rodent species modified their behavior in the presence of predator calls, but the effects were species dependent. These findings point to the need to carefully study target rodent species instead of applying a general control plan for all rodent species.

Abstract

Ecologically based rodent management strategies are arising as a sustainable approach to rodent control, allowing us to preserve biodiversity while safeguarding human economic activities. Despite predator signals being known to generally repel rodents, few field-based studies have compared the behavioral effects of several predators on different prey species, especially in Neotropical ecosystems. Here, we used camera traps to study the behavior of rodent species native to the Chilean temperate forest (Abrothrix spp., long-tailed pygmy rice rat Oligoryzomys longicaudatus) and an introduced rodent (black rat Rattus rattus). Using playbacks of raptor calls, we experimentally exposed rodents to three predation risk treatments: austral pygmy owl calls (Glaucidium nana), rufous-legged owl calls (Strix rufipes) and a control treatment (absence of owl calls). We evaluated the effects of the treatments on the time allocated to three behaviors: feeding time, locomotor activity and vigilance. Moonlight and vegetation cover were also considered in the analyses, as they can modify perceived predation risk. Results showed that predator calls and environmental factors modified prey behavior depending not only on the predator species, but also on the rodent species. Consequently, owl playbacks could be regarded as a promising rodent control tool, knowing that future studies would be critical to deeply understand differences between species in order to select the most effective predator cues.