Giving-up Densities Research Articles

Does sentinel presence improve foraging success? A study in a cooperative breeder

Abstract In various cooperative breeding species, a group member often sentinels from a prominent position that enables early detection of approaching predators, and then utters alarm calls to which the other group members react immediately. We tested in the cooperatively breeding Arabian babbler (Argya squamiceps), whether in the presence of a sentinel the other group members forage for longer or more effectively. In natural observations, in different distances from shelter and in different group sizes, we found no effect of sentinel presence on foraging time. Likewise, in a giving-up density (GUD) experiment with artificial food patches containing mealworms in each of 3 different distances from shelter, fewer mealworms were consumed further from shelter, but irrespective of whether a sentinel was present or not during foraging. While foragers react to a sentinel’s alarm calls when a predator approaches, our findings indicate that Arabian babbler foragers do not improve their foraging efficiency due to the sentinel’s presence. Combined with previous studies on the Arabian babbler, these findings reinforce the conclusion that in this species the sentinel is “selfish” and benefits from early detection of predators. These results contrast with those from other cooperative breeders in which sentinels utter calming calls and foraging efficiency increases when sentinels are present. We, therefore, suggest that similar sentinel behavior may serve different sentinel systems and functions in different cooperative breeders.

Adaptive responses to habitat change: Theory and tests with field experiments.

Habitat loss and change are often implicated as the primary causes of species extinction. Although any population can be instantly imperiled by catastrophe, most habitat loss occurs gradually, thus enabling affected individuals an adaptive advantage to occupy the best of their dwindling opportunities. I demonstrate how to infer the advantage between two habitats for any density and frequency-dependent strategy of habitat selection. I explore the concept of an Adaptive Dispersal Strategy Landscape to reveal the Evolutionarily Stable Strategy separately for ideal-free and ideal preemptive habitat selectors. Both solutions reveal an initially counterintuitive expectation that individuals living at high density gain insufficient adaptive advantage to disperse from a deteriorating habitat. Adaptive dispersal is constrained at high density because habitats of better quality are fully occupied. I test the theory with measures of movement and foraging in crossover experiments on a seminatural population of meadow voles. The experiment allowed the voles to choose among patches and between enclosures in which I differentially manipulated food and shelter. Although photographs from an infrared camera documented voles venturing from one habitat to the other, none became resident. Voles preferentially foraged in the richer of the two enclosures, even when I reversed treatments, and they foraged more in patches protected by mulched straw. The adaptive advantage of dispersal using a surrogate fitness proxy based on the voles' giving-up densities mirrored that generated by theory. The convergence between theory and experiment yields much-needed insight into our ability to test, predict, and hopefully resolve, the ecological, evolutionary, and conservation consequences of habitat loss.

No evidence that Mycoplasma infection causes cognitive impairment during foraging in Allenby’s gerbil (Gerbillus andersoni allenbyi)

Abstract Pathogens can impose substantial ecological costs on infected individuals, including reduced cognition, foraging ability, and predator avoidance. In a prior experiment, gerbils infected with Mycoplasma haemomuris-like bacteria had higher giving up densities, despite spending more time foraging, and were more likely to be killed by predators. One hypothesis to explain this is that infected gerbils suffer from cognitive impairment that reduces their ability to forage efficiently, causing them to spend more time foraging and placing themselves at higher risk of predation. We tested this hypothesis by comparing the ability of gerbils uninfected, acutely infected, or chronically infected with Mycoplasma to equalize giving up densities (GUDs) in seed patches with different initial abundances and detect micropatches within seed patches in a semi-natural vivarium enclosure. We predicted that uninfected gerbils would equalize GUDs and detect micropatches better than infected gerbils. Contrary to our predictions, infected gerbils performed equally well as uninfected gerbils on both tasks. These experiments did not support the hypothesis that cognitive impairment explains past results regarding Mycoplasma and gerbil foraging.

Mosquitoes do not influence Cotton Mouse (Peromyscus gossypinus) giving-up densities

Abstract It is commonly recognized that predation and the risk of predation can have profound effects on behaviors and population ecology of prey. Comparatively, little attention has been paid to the trade-offs hosts make to manage the risk of parasitism, but there is evidence that hosts make behavioral trade-offs to avoid parasitism in ways that resemble those made by prey animals under the risk of predation. Mosquitoes are common hematophagous ectoparasites which parasitize a wide range of vertebrates, resulting in blood loss, distraction, and disease transmission. Many hosts engage in defensive behaviors to repel or kill mosquitoes and these behaviors likely come at the expense of activities such as foraging and vigilance for predators. We placed a mosquito attractant (BG-Sweetscent) and repellant (allethrin) near artificial foraging patches in areas where mosquitoes were common and measured the amount of grain left after a night of foraging (giving-up density) to investigate whether mosquitoes influenced Cotton Mouse (Peromyscus gossypinus) foraging. We predicted that in patches with mosquito attractants, mosquito harassment would cause mice to engage in defensive behaviors which would distract or deter them from foraging, resulting in less grain consumption relative to control patches. Conversely, we predicted that in mosquito-repellent patches, mice would experience less harassment, resulting in more grain consumption. Indoor arena trials found no evidence that the mosquito treatments influenced cotton mouse behavior in the absence of mosquitoes. However, we found no evidence that mosquito treatments affected giving-up densities.

Foraging Behavior Response of Small Mammals to Different Burn Severities

Wildfires cause profound challenges for animals to overcome due to their reliance on vegetation. This study addresses the impact of three levels of forest burn severity (unburned, low, and high burn severity) on the foraging behavior of small mammals in the Pinaleño Mountains (AZ, USA) using the giving up density (GUD) experiment approach. Overall, burn severity affected the foraging behavior of small mammals that spent less time foraging in high burn severity patches. Vegetation characteristics influenced GUD differently based on the level of burn severity. Higher canopy cover was perceived as areas with a higher predation risk (higher GUD) in unburned and low burn severity patches, while cover provided by logs and shrubs decreased the GUD (increased foraging). This suggests a complicated interaction between horizontal (logs, grass, shrub cover) and vertical vegetation cover in relation to burn severity. Fires affected the foraging behavior of the small mammals but did not impact all species in the same way. Generalists, such as Peromyscus sp. and Tamias dorsalis, seemed to forage across all burn severities, while specialist species, such as tree squirrels, tended to avoid the high burn severity patches. Clarifying the complex impacts of fires on small mammals’ foraging behaviors contributes to our understanding of the intricate interactions, at micro-habitat levels, between vegetation structure and the behavioral responses of animals and it can help managers to plan actions to reduce the negative impacts of wildfires.

So many choices, so little time: Food preference and movement vary with the landscape of fear.

Spatial and temporal variation in perceived predation risk is an important determinant of movement and foraging activity of animals. Foraging in this landscape of fear, individuals need to decide where and when to move, and what resources to choose. Foraging theory predicts the outcome of these decisions based on energetic trade-offs, but complex interactions between perceived predation risk and preferences of foragers for certain functional traits of their resources are rarely considered. Here, we studied the interactive effects of perceived predation risk on food trait preferences and foraging behavior in bank voles (Myodes glareolus) in experimental landscapes. Individuals (n = 19) were subjected for periods of 24 h to two extreme, risk-uniform landscapes (either risky or safe), containing 25 discrete food patches, filled with seeds of four plant species in even amounts. Seeds varied in functional traits: size, nutrients, and shape. We evaluated whether and how risk modifies forager preference for functional traits. We also investigated whether perceived risk and distance from shelter affected giving-up density (GUD), time in patches, and number of patch visits. In safe landscapes, individuals increased time spent in patches, lowered GUD and visited distant patches more often compared to risky landscapes. Individuals preferred bigger seeds independent of risk, but in the safe treatment they preferred fat-rich over carb-rich seeds. Thus, higher densities of resource levels remained in risky landscapes, while in safe landscapes resource density was lower and less diverse due to selective foraging. Our results suggest that the interaction of perceived risk and dietary preference adds an additional layer to the cascading effects of a landscape of fear which affects biodiversity at resource level.

Integrating Measures of Fecal Glucocorticoid Metabolites and Giving-Up Densities to Assess Adrenocortical Activity and Well-Being in Zoo-Housed Three-Banded Armadillos (Tolypeutes matacus).

To monitor adrenocortical activity in zoo-housed species, we propose using physiological and behavioral indicators that are non-invasive and practical to implement. We explore this model in the southern three-banded armadillo (Tolypeutes matacus; armadillo), which is a near-threatened species commonly found in zoos. We aimed to (1) deploy food patches to quantify foraging behavior (via giving-up densities, GUDs); (2) determine the effects of food patch and environmental modifications on individuals' GUDs and adrenocortical activity (via fecal glucocorticoid metabolites, FGMs); and (3) examine the relationship between GUDs and FGMs. Three males and four females received food patches under varying experimental conditions at the Lincoln Park Zoo (Chicago, IL, USA). Fecal samples were collected before, during, and after foraging experiments to examine FGMs. Armadillos did not respond to patch modifications but did forage more when given increased cover. Individual mean FGMs and GUDs were highly variable, and individuals had consistent FGM and GUD ranks across experiments. FGMs and GUDs did not vary across the experiments nor did they relate to each other. Armadillos and species with a limited behavioral repertoire (i.e., constant movement) can benefit from this multi-trait model to determine the effect of environmental modifications on individuals and provide meaningful information about adrenocortical activity.

Ineffectiveness of plastic mesh for protecting artificial freshwater turtle nests from red fox (Vulpes vulpes) predation

AbstractInvasive mammalian predators are efficient at driving native animal declines. The red fox (Vulpes vulpes) kills millions of endemic reptiles in Australia each year. In areas of south‐eastern Australia, the eastern long‐necked turtle (Chelodina longicollis) and Murray River turtle (Emydura macquarii) have declined by more than 50%. High rates of nest predation by foxes limit the recruitment of young turtles in these populations, but previous methods of fox control have been ineffective at protecting turtle nests. Here, we tested the effectiveness of plastic mesh for protecting artificial turtle nests from predation by foxes, in the mid‐Murray catchment, Victoria. We also tested whether protecting a large number of artificial nests in a given area encourages foxes to give up foraging following predictions from giving‐up density theory. We made a series of plots, each containing 32 artificial turtle nests. In each plot, we covered a percentage (0%, 25%, 50%, 81% or 100%) of the nests with either 1 or 2 sheets of plastic mesh. We used remote cameras to photograph and identify any predator that attacked nests in the plots. The cameras also allowed us to estimate the amount of time a fox was visible on each plot, as a metric of how much effort foxes expended on protected nests. Nest survival rate was not increased by either 1 or 2 sheets of mesh, and increasing the number of protected nests on a plot did not reveal a giving‐up density (GUD) value for fox foraging behaviour. Our study demonstrates that plastic mesh is not effective for protecting artificial turtle nests from foxes in this region.

Combined effects of light pollution and vegetation height on behavior and body weight in a nocturnal rodent

At a global scale, organisms are under threat due to various kinds of environmental changes, such as artificial light at night (ALAN), noise, climatic change and vegetation destruction. Usually, these changes co-vary in time and space and may take effect simultaneously. Although impacts of ALAN on biological processes have been well documented, our knowledge on the combined effects of ALAN and other environmental changes on animals remains limited. In this study, we conducted field experiments in semi-natural enclosures to explore the combined effects of ALAN and vegetation height on foraging behavior, vigilance, activity patterns and body weight in dwarf striped hamsters (Cricetulus barabensis), a nocturnal rodent widely distributed in East Asia. We find that ALAN and vegetation height affected different aspects of behavior. ALAN negatively affected search speed and positively affected handling speed, while vegetation height negatively affected giving-up density and positively affected body weight. ALAN and vegetation height also additively shaped total time spent in a food patch. No significant interactive effect of ALAN and vegetation height was detected. C. barabensis exposed to ALAN and short vegetation suffered a significant loss in body weight, and possessed a much narrower temporal niche (i.e. initiated activity later but became inactive earlier) than those under other combinations of treatments. The observed behavioral responses to ALAN and changes in vegetation height may bring fitness consequences, as well as further changes in structure and functioning of local ecosystems.

Small Mammals Perceive Most Fruits of Invasive Plants as Low-Quality Forage in a Pennsylvanian Forest and Meadow

Invasive plants often drastically alter food webs. Small-mammal assemblages may be greatly impacted by invasive plants, which often provide cover from predators. In addition, a less-studied potential impact is the possibility that small mammals use invasive plants as a food resource. We quantified small mammal giving-up densities (GUDs) by offering fruits of 5 common invasive shrubs and 1 native shrub in adjacent meadow and forest habitats in Pennsylvania. The study ran for two 48-hour sessions in November in 2 consecutive years with different combinations of shrub fruits available to small mammals within buckets that also contained Panicum miliaceum (Proso Millet), and sand. While some degree of differences in foraging activity could be accredited to annual variation, significant differences in GUDs among fruit species and between habitats were detected. The fruits of the invasive shrubs Berberis thunbergia (Japanese Barberry), Ligustrum vulgare (Eurasian Privet), and Rhodotypos scandens (Jetbead) did not appear to be significantly foraged on by small mammals in either habitat. However, the woody liana Celastrus orbiculatus (Oriental Bittersweet) was readily consumed in both the forest and meadow. Fruits of the invasive shrub Eleagnus umbellata (Autumn Olive) was favored but only in meadow habitat, while fruits of the native shrub Lindera benzoin (Spicebush) were moderately foraged in the forest. Through this experiment, we were able to conclude that most woody plants included in this study offer fruits with limited perceived benefit. However, Oriental Bittersweet and Autumn Olive may represent important exceptions that could be influencing small-mammal foraging patterns in northeastern forest and meadow ecosystems.

Vegetation cover and food availability shapes the foraging activity of rodent pests in and around maize fields

Evidence-based information for smallholder farmers on where and when to conduct rodent management is vital given that most are resource poor and depend on agriculture for food and income. However, there is scarce information on how the foraging activity of rodent pests changes over agricultural cropping seasons. We used the concepts of giving-up-density (GUD) and landscape of fear to monitor how the foraging activity of rodent pests changes in and around maize (Zea mays) fields over the cropping season. We tested the hypothesis that the foraging activity of rodent pests will be influenced by vegetation cover, perceived predation risk and food availability. Mastomys natalensis was the dominant species in all maize fields (n = 3, 87.05 % of the total captures). We observed that the foraging activity of rodents was influenced by vegetation cover and food availability. During the germination stage, rodent activity in the natural habitat and along the border was higher than inside the maize fields. During land preparation, planting, weeding, maize tasselling, maturity, and post-harvest stages, there was no difference in the foraging activity in and around the maize fields. During the harvest stage, the foraging activity was higher in the maize fields than along the border and in the natural habitat. These results can be used to guide smallholder farmers where and when to focus rodent control measures during different stages of the cropping season. An additional approach would be to develop strategies that could potentially increase rodent fear perceptions in cropping landscapes.

Using activity densities as an alternative approach to measuring ungulate giving-up densities in the presence of non-target species

Using activity densities as an alternative approach to measuring ungulate giving-up densities in the presence of non-target species

Forager-mediated cascading effects on food resource species diversity.

Perceived predation risk varies in space and time. Foraging in this landscape of fear alters forager-resource interactions via cascading nonconsumptive effects. Estimating these indirect effects is difficult in natural systems. Here, we applied a novel measure to quantify the diversity at giving-up density that allows to test how spatial variation in perceived predation risk modifies the diversity of multispecies resources at local and regional spatial levels. Furthermore, we evaluated whether the nonconsumptive effects on resource species diversity can be explained by the preferences of foragers for specific functional traits and by the forager species richness. We exposed rodents of a natural community to artificial food patches, each containing an initial multispecies resource community of eight species (10 items each) mixed in sand. We sampled 35 landscapes, each containing seven patches in a spatial array, to disentangle effects at local (patch) and landscape levels. We used vegetation height as a proxy for perceived predation risk. After a period of three nights, we counted how many and which resource species were left in each patch to measure giving-up density and resource diversity at the local level (alpha diversity) and the regional level (gamma diversity and beta diversity). Furthermore, we used wildlife cameras to identify foragers and assess their species richness. With increasing vegetation height, i.e., decreasing perceived predation risk, giving-up density, and local alpha and regional gamma diversity decreased, and patches became less similar within a landscape (beta diversity increased). Foragers consumed more of the bigger and most caloric resources. The higher the forager species richness, the lower the giving-up density, and alpha and gamma diversity. Overall, spatial variation of perceived predation risk of foragers had measurable cascading effects on local and regional resource species biodiversity, independent of the forager species. Thus, nonconsumptive predation effects modify forager-resource interactions and might act as an equalizing mechanism for species coexistence.

College squirrels gone wild? Using Sciurus carolinensis behavior to assess the ecosystem value of urban green spaces

Predicted rapid increases in urbanization in the face of accelerating biodiversity loss underscores the need for urban development that promotes, rather than displaces, native plants and animals. One approach for increasing urban biodiversity is through the development of “green infrastructure”. Although research has explored urban-rural gradients and the overall value of urban green infrastructure, few studies have investigated the habitat value for wildlife of different types of urban greenspace. Here, we use a well-established metric in ecology, giving up-densities (GUDs), to compare foraging costs for a common urban wildlife species, the eastern gray squirrel (Sciurus carolinensis), among three green infrastructure categories: municipal parks, college campuses, and residential yards. We found that GUDs for gray squirrels did not differ significantly among location categories after controlling for proximity to roads, but proximity to roads was associated with significantly higher GUDs in all locations. In an explicit test, we also found that both proximity to roads and traffic volume were associated with higher GUDs. We also found that maximum distance from roads was significantly higher for campuses and parks than for residential yards, indicating a greater proportion of the area of campuses and parks is “away from roads” compared to residential yards. Our results indicate that vehicle traffic may contribute significantly to an “urban landscape of fear” for gray squirrels and suggest that campus and park configurations that reduce road effects could improve habitat quality for squirrels and possibly other animals.

Prey responses to predation risk under chronic road noise

AbstractAnthropogenic noise has dramatically increased over the past decades with potentially significant impacts on wildlife and their community interactions. Using giving‐up densities (GUDs) paired with camera traps, we examined the concurrent influence of chronic road noise and predation risk on free‐living small mammals. Specifically, we looked for differences in foraging and vigilance behavior during various noise treatments. We found that small mammals significantly reduced food intake when exposed to predation risk; however, concurrent exposure to road noise eliminated this effect; small mammals increased food intake when exposed to road noise and risk compared to risk alone. Furthermore, road noise reduced the number of visits and time spent at foraging trays while it increased vigilance behavior of small mammals in risky situations, meaning they were able to increase their foraging efficiency. Mice also ate less when moon illumination was greater; however, this had no effect on our overall results. This is one of the first studies to concurrently examine the effects of road noise and predation risk on free‐living prey. It shows the complex responses of prey exposed to chronic noise conditions as they attempt to gain reliable information about predation risk and respond appropriately. We highlight the potential consequences road noise may have on the survival of prey as it interferes with their appropriate risk responses.

Small Prey Animal Foraging Behaviors in Landscapes of Fear: Effects of Predator Presence and Human Activity Along an Urban Disturbance Gradient

Urban environments provide the only or best habitats that are left for wildlife in many areas, promoting increased interest in urban conservation and a need to understand how wildlife cope with urban stressors, such as altered predator activity and human disturbance. Here, we used filmed giving-up density experiments to investigate behavioral coping responses of foraging small prey animals at three sites (close, mid, and far) along an urban disturbance gradient. Our study design included “natural” and experimentally added stressor cues of predators and/or human disturbance. We observed small mammal foraging behaviors, particularly: the common brushtail possum (Trichosurus vulpecula), northern brown bandicoot (Isoodon macrourus), brown antechinus (Antechinus stuartii), black rat (Rattus rattus), and brown rat (Rattus norvegicus), and to a lesser degree several species of native birds. We found that at the close urban-edge environment, coping responses to human disturbances were most pronounced, and predator cues from the red fox (Vulpes vulpes) were perceived as least risky. However, at the mid environment, red fox cues were perceived as most risky, especially when combined with human disturbance. At the far environment, domestic cat (Felis catus) cues were perceived as most risky, again when combined with human disturbance. Impacts from the combined stressors of predator and human disturbance cues appeared to be additive, with higher risk being perceived with increasing distance from urban build-up. Behavioral adjustments were observed to be the primary response to stressors by small prey animals in the close environment. In the mid environment, slight temporal shifts in activity across the night were more evident. In the far environment, habitat components were likely being used differently as the primary coping response to stressors. As mostly the same species were observed along the disturbance gradient, our results suggest a level of response plasticity that is calibrated to the level of exposure to a stressor and the stressor type. To maximize conservation outcomes in urban habitats, we therefore propose that management should be sensitive to the level and history of human disturbance, as this affects the coping responses of wildlife that remain.

Welcome to the Dark Side: Partial Nighttime Illumination Affects Night-and Daytime Foraging Behavior of a Small Mammal

Differences in natural light conditions caused by changes in moonlight are known to affect perceived predation risk in many nocturnal prey species. As artificial light at night (ALAN) is steadily increasing in space and intensity, it has the potential to change movement and foraging behavior of many species as it might increase perceived predation risk and mask natural light cycles. We investigated if partial nighttime illumination leads to changes in foraging behavior during the night and the subsequent day in a small mammal and whether these changes are related to animal personalities. We subjected bank voles to partial nighttime illumination in a foraging landscape under laboratory conditions and in large grassland enclosures under near natural conditions. We measured giving-up density of food in illuminated and dark artificial seed patches and video recorded the movement of animals. While animals reduced number of visits to illuminated seed patches at night, they increased visits to these patches at the following day compared to dark seed patches. Overall, bold individuals had lower giving-up densities than shy individuals but this difference increased at day in formerly illuminated seed patches. Small mammals thus showed carry-over effects on daytime foraging behavior due to ALAN, i.e., nocturnal illumination has the potential to affect intra- and interspecific interactions during both night and day with possible changes in personality structure within populations and altered predator-prey dynamics.

Small Prey Animal Habitat Use in Landscapes of Fear: Effects of Predator Presence and Human Activity Along an Urban Disturbance Gradient

Human activity can impose additional stressors to wildlife, both directly and indirectly, including through the introduction of predators and influences on native predators. As urban and adjacent environments are becoming increasingly valuable habitat for wildlife, it is important to understand how susceptible taxa, like small prey animals, persist in urban environments under such additional stressors. Here, in order to determine how small prey animals’ foraging patterns change in response to habitat components and distances to predators and human disturbances, we used filmed giving-up density (GUD) trials under natural conditions along an urban disturbance gradient. We then ran further GUD trials with the addition of experimentally introduced stressors of: the odors of domestic cat (Felis catus)/red fox (Vulpes vulpes) as predator cues, light and sound as human disturbance cues, and their combinations. Small mammals were mostly observed foraging in the GUD trials, and to a lesser degree birds. Animals responded to proximity to predators and human disturbances when foraging under natural conditions, and used habitat components differently based on these distances. Along the urban disturbance gradient situation-specific responses were evident and differed under natural conditions compared to additional stressor conditions. The combined predator with human disturbance treatments resulted in responses of higher perceived risk at environments further from houses. Animals at the urban-edge environment foraged more across the whole site under the additional stressor conditions, but under natural conditions perceived less risk when foraging near predators and further from human disturbance (houses). Contrastingly, at the environments further from houses, foraging near human disturbance (paths/roads) when close to a predator was perceived as lower risk, but when foraging under introduced stressor conditions these disturbances were perceived as high risk. We propose that sensory and behavioral mechanisms, and stress exposure best explain our findings. Our results indicate that habitat components could be managed to reduce the impacts of high predation pressure and human activity in disturbed environments.

Top-down effects of foraging decisions on local, landscape and regional biodiversity of resources (DivGUD).

Foraging by consumers acts as a biotic filtering mechanism for biodiversity at the trophic level of resources. Variation in foraging behaviour has cascading effects on abundance, diversity, and functional trait composition of the community of resource species. Here we propose diversity at giving-up density (DivGUD), i.e. when foragers quit exploiting a patch, as a novel concept and simple measure quantifying cascading effects at multiple spatial scales. In experimental landscapes with an assemblage of plant seeds, patch residency of wild rodents decreased local α-DivGUD (via elevated mortality of species with large seeds) and regional γ-DivGUD, while dissimilarity among patches in a landscape (ß-DivGUD) increased. By linking theories of adaptive foraging behaviour with community ecology, DivGUD allows to investigate cascading indirect predation effects, e.g. the ecology-of-fear framework, feedbacks between functional trait composition of resource species and consumer communities, and effects of inter-individual differences among foragers on the biodiversity of resource communities.

Perceived risk structures the space use of competing carnivores

Abstract Competition structures ecological communities. In carnivorans, competitive interactions are disproportionately costly to subordinate carnivores who must account for the risk of interspecific killing when foraging. Accordingly, missed opportunity costs for meso-carnivores imposed by risk can benefit the smallest-bodied competitors. However, the extent to which the risk perpetuates into spatial partitioning in hierarchically structured communities remains unknown. To determine how risk-avoidance behaviors shape the space-use of carnivore communities, we studied a simple community of carnivores in northern Patagonia, Argentina: pumas (Puma concolor; an apex carnivore), culpeo foxes (Lycalopex culpaeus; a meso-carnivore), and chilla foxes (Lycalopex griseus; a small carnivore). We used multi-species occupancy models to quantify the space use within the carnivore community and giving-up densities to understand the behaviors that structure space use. Notably, we applied an analytical framework that tests whether the actual or perceived risk of predation most strongly influences the space use of subordinate carnivores although accounting for their foraging and vigilance behaviors. We found that there was a dominance hierarchy from the apex carnivore through the meso-carnivore to the subordinate small carnivore, which was reflected in space. Although both meso- and small carnivores exhibited similar predator avoidance behavioral responses to apex carnivores, the habitat associations of apex carnivores only altered meso-carnivore space use. The biases in risk management we observed for meso-carnivores likely translates into stable co-existence of this community of competing carnivores. We believe our analytical framework can be extended to other communities to quantify the spatial-behavioral tradeoffs of risk.