Effects of food quality, diet preference and water on patch use by Nubian ibex

Measuring patch use of a forager can reveal not only its cost and benefits from foraging, but also the importance of environmental factors and the significance of energy, nutrients and predation risk to its fitness. In order to assess the effects of various variables that may affect the foraging behavior of free-ranging Nubian ibex in the Negev Desert, Israel, giving-up densities (GUD) in artificial food patches were measured following Kotler et al. In particular, we tested the effects of food quality and water availability on Nubian ibex foraging behavior. To do so, we (1) tested whether the tannic acid content of food affected diet preferences, (2) assayed their diet selection strategy, (3) tested if the foraging decisions of the Nubian ibex were affected by the availability of water and (4) determined the nutritional relationship between food resources and water. Nubian ibex had lower GUDs and used resources patches more intensively where water was available, the food quality was higher and the location was closer to the escape terrain. Nubian ibex showed an expanding specialist diet selection when exploiting resource patches with a mix of items that differ in quality. Overall, food and water were complementary resources for Nubian ibex, and tannins reduced food quality. These factors help to determine patch foraging behavior decisions in Nubian ibex and contribute to habitat quality.     

相关风险因子对高原鼠兔摄食行为的影响

研究了捕食风险环境中集和洞口距离对高原鼠兔摄食行为的影响。结果表明,集群数量的增加不仅降低了警觉行为,同时也减少了摄食行为,在高风险环境中,集群为1时的取食行为强度最大,低风险环境中,为0时最大,警觉行为主要出现在距洞口2m的范围内,其行为强度与洞口踪影职责负相关,当洞口距离大于3m时,风险处理区的高原鼠兔几乎无警觉行为出现,且该处理区的取食区域几乎压缩的洞口旁,研究结果表明,在捕食风险环境中,高原鼠兔摄食行为与集群和洞口距离之间具有复杂的关系,其行为决策反映了降低风险与摄取食物间的权衡,行为目标是在降低捕食风险的同时尽可能地取食食物。     

The fear diet: Risk,refuge, and biological control by omnivorous weed seed predators

Weed seed biocontrol by omnivorous mice and insects can limit weed seedbanks, but this ecosystem service can be difficult to predict given the broad diet breadth of seed predators and their potential for intraguild predation. Seed foraging behavior is further modified by fluctuating cues of predation risk from higher trophic levels and the availability of refuge habitat. Uncertainty about whether co-occurring insects and mice additively contribute to weed biocontrol or interfere with each other via intraguild predation limits our ability to recommend habitat management strategies that reliably promote seed destruction. Using seed removal assays, fluorescent powder tracking, and stable isotope analyses, we assessed effects of a predation risk cue (moonlight) on mouse foraging patterns in a patchwork of vegetated and exposed plots in a cultivated field. Mouse foraging activity decreased on exposed ground during the full moon, compared to dark nights, yet foraging movements were unaffected by moon cycle within refuge patches. Weed seed consumption was more than three times higher in cover than exposed soil, and 78% of that difference was attributable to invertebrate granivores. Mice and invertebrate granivores both exhibited higher foraging activity in cover, indicating co-occurrence of intraguild predators and prey. However, stable isotope analyses of fecal samples revealed that mice captured in refuge habitats fed at slightly lower trophic levels than those in exposed habitats (suggesting minimal intraguild predation in refuge habitat), and mouse diet was unaffected by moonlight. Despite increased availability of invertebrate prey in cover patches, mice do not appear to preferentially exploit prey when avoiding their own predators or interfere with weed seed predation. Therefore, functional redundancy of mice and invertebrate seed predators in cover crops and other refuge habitats may strengthen and stabilize weed seed biocontrol.     

Spatially heterogeneous refugia and predation risk in intertidal salt marshes

The effect of habitat structure on interactions between predators and prey may vary spatially. In estuarine salt marshes, heterogeneity in refuge quality derives from spatial variation in vegetation structure and in tidal inundation. We investigated whether predation by blue crabs on periwinkle snails was influenced by distance from the seaward edge of the salt marsh and by characteristics of the primary habitat structure, smooth cordgrass ( Spartina alterniflora ). Spartina may provide refuge for snails and interfere with foraging by crabs. Furthermore, predation risk should decline with distance from the seaward edge because landward regions require more travel time for crabs during tidal inundation. We investigated these processes using a comparative survey of snails and habitat traits, an experiment that assessed the crab population and measured predation risk, and a size-structured model that estimated encounter rates. Taken together, these approaches indicated that predation risk for snails was lower where Spartina was present and was lower in a landward direction. Furthermore, Spartina architecture and distance from the seaward edge interacted. The strength of the predation gradient between seaward and landward regions of the marsh was greater where Spartina was tall or dense. These predation gradients emerge because vegetation and distance inland decrease encounter rates between crabs and snails. This study suggests that habitat modification, a process not uncommon in salt marshes, may have consequences for interactions among intertidal fauna.     

Dynamics of herbivores and resources on a landscape with interspersed resources and refuges

A tradeoff between energy gain from foraging and safety from predation in refuges is a common situation for many herbivores that are vulnerable to predation while foraging. This tradeoff affects the population dynamics of the plant–herbivore–predator interaction. A new functional response is derived based on the Holling type 2 functional response and the assumption that the herbivore can forage at a rate that maximizes its fitness. The predation rate on the herbivore is assumed to be proportional to the product of the time that the herbivore spends foraging and a risk factor that reflects the habitat complexity; where greater complexity means greater interspersion of high food quality habitat and refuge habitat, which increases the amount of the edge zone between refuge and foraging areas, making foraging safer. The snowshoe hare is chosen as an example to demonstrate the resulting dynamics of an herbivore that has been intensely studied and that undergoes well-known cycling. Two models are studied in which the optimal foraging by hares is assumed, a vegetation–hare–generalist predator model and a vegetation–hare–specialist predator model. In both cases, the results suggest that the cycling of the snowshoe hare population will be greatly moderated by optimal foraging in a habitat consisting of interspersed high quality foraging habitat and refuge habitat. However, there are also large differences in the dynamics produced by the two models as a function of predation pressure.     

Predator detection and avoidance by starlings under differing scenarios of predation risk

Practically all animals must find food while avoiding predators.An individual's perception of predation risk may depend on manyfactors, such as distance to refuge and group size, but it isunclear whether individuals respond to different factors ina similar manner. We tested whether flocks of foraging starlingsresponded in the same way to an increased perception of predationrisk by assessing three factors: (1) neighbor distances, (2)habitat obstruction, and (3) recent exposure to a predator.We found that in all three scenarios of increased risk, starlingsreduced their interscan intervals (food-searching bouts), whichincreased the frequency of their vigilance periods. We thenexamined how one of these factors, habitat obstruction, affectedescape speed by simulating an attack with a model predator.Starlings were slower to respond in visually obstructed habitats(long grass swards) and slower when they had their head downin obstructed habitats than when they had their head down inopen habitats. In addition, reaction times were quicker whenstarlings could employ their peripheral fields of vision. Ourresults demonstrate that different sources of increased riskcan generate similar behavioral responses within a species.The degree of visibility in the physical and social environmentaffects both the actual and perceived risk of predation.     

Foraging Patch Selection in Winter: A Balance between Predation Risk and Thermoregulation Benefit

In winter, foraging activity is intended to optimize food search while minimizing both thermoregulation costs and predation risk. Here we quantify the relative importance of thermoregulation and predation in foraging patch selection of woodland birds wintering in a Mediterranean montane forest. Specifically, we account for thermoregulation benefits related to temperature, and predation risk associated with both illumination of the feeding patch and distance to the nearest refuge provided by vegetation. We measured the amount of time that 38 marked individual birds belonging to five small passerine species spent foraging at artificial feeders. Feeders were located in forest patches that vary in distance to protective cover and exposure to sun radiation; temperature and illumination were registered locally by data loggers. Our results support the influence of both thermoregulation benefits and predation costs on feeding patch choice. The influence of distance to refuge (negative relationship) was nearly three times higher than that of temperature (positive relationship) in determining total foraging time spent at a patch. Light intensity had a negligible and no significant effect. This pattern was generalizable among species and individuals within species, and highlights the preponderance of latent predation risk over thermoregulation benefits on foraging decisions of birds wintering in temperate Mediterranean forests.     

Habitat and patch use by hyraxes: there’s no place like home?

Models of central place foraging predict that animals should forage more thoroughly in resource patches located closer to the central place. Travel time, cost of transporting food back to the central place, and exposure to predators should all act to increase foraging costs with increasing distance from the refuge. We examined habitat and patch use in rock hyraxes ( Procavia capensis ) inhabiting a group of kopjes in a semiarid savanna, Augrabies Falls National Park, South Africa. We tested the prediction of more intense patch use closer to the central place by measuring giving-up densities (GUDs) in experimental resource patches set at four different distances from the kopje and in two microhabitats differing in cover. Surprisingly, hyraxes had their lowest GUDs at intermediate distances from the kopje. These unexpected results suggest that the sentinel behaviour of hyraxes alters the probability of detection of predators for animals foraging away from the kopje.     

Effects of habitat edges on American lobster abundance and survival

Habitat edges frequently possess distinct ecological conditions that affect interactions such as competition and predation. Within a species' preferred habitat, the structural complexity and resource availability of adjacent habitats may influence the effect of edges on ecological processes. In nearshore waters of New England, American lobsters (Homarus americanus) inhabit fragmented cobble reefs that often are bordered by unvegetated sediment and occasionally by seagrass. We determined whether proximity to cobble patch edges, microhabitat characteristics within cobble habitat, and the type of habitat adjacent to cobble patches (seagrass or unvegetated sediment) influence the density and survival of juvenile and adult American lobsters in Narragansett Bay, Rhode Island, USA. We surveyed naturally occurring cobble patches and artificial cobble reefs to determine how the odds of finding lobsters varied with distance from the edge and habitat type. Additionally, we tethered lobsters at different distances from the edge inside and outside of cobble patches to determine how lobster relative survival varied with edge proximity and habitat type. In cobble habitat, the odds of finding large lobsters (adolescents and adults > 40 mm carapace length (CL)) were highest near patch edges regardless of adjacent habitat type, whereas smaller lobsters (e.g. emergent juveniles 15-25 mm CL) were more abundant in patch interiors when seagrass bordered cobble patches. The odds of finding lobsters also increased with the relative amount of cobble cover within patches. In predation experiments, lobster relative survival after 6 h was lowest outside of cobble and increased toward cobble patch interiors, but after 24 h this trend disappeared or reversed. Seagrass appeared to offer greater refuge for lobsters than did unvegetated sediment. Our results suggest that proximity to patch edges influences lobster distribution and survival, and that edge effects on lobsters vary with life history phase and with the type of habitat adjacent to cobble patches.     

Vigilance and its complex synchrony in the red-necked pademelon, Thylogale thetis

Several adaptive functions, including gaining information fromother group members and detecting predators, are generally ascribedto vigilance in groups of animals subject to predation. Moststudies of the effects of neighbors on vigilance have focusedon individual vigilance. We investigated the effects of neighborson vigilance in wild red-necked pademelons Thylogale thetisforaging at night in nonpersistent aggregations in a clearingin rain forest. Neither the total number of pademelons in theclearing nor the numbers at various distances around focal individualsaffected the individual vigilance of focal animals. However,focal animals’ individual vigilance did change with thedistance to their nearest neighbor and also with distance tocover. Pairs of individuals closer than 10 m apart tended tosynchronize their bouts of individual vigilance and foraging.The degree of synchrony within pairs increased with both distanceto cover and the total number of pademelons foraging in thearea and decreased with increasing distance to the pair's nearestneighbor but did not vary with the distance separating the membersof the pair. Thus, despite their individual vigilance beingunaffected by the number of other pademelons in the feedingaggregation, pademelons were nonetheless sensitive to the presenceof conspecifics and adjusted their behavior in relation to theirseparation from neighbors. Thus, some vigilance benefits maybe obtained from the presence of conspecifics even in speciesthat aggregate only temporarily on food patches without formingmore permanent social groups.     

Indirect risk effects reduce feeding efficiency of ducks during spring

Indirect risk effects of predators on prey behavior can have more of an impact on prey populations than direct consumptive effects. Predation risk can elicit more vigilance behavior in prey, reducing the amount of time available for other activities, such as foraging, which could potentially reduce foraging efficiency. Understanding the conditions associated with predation risk and the specific effects predation risk have on prey behavior is important because it has direct influences on the profitability of food items found under various conditions and states of the forager. The goals of this study were to assess how ducks perceived predation risk in various habitat types and how strongly perceived risk versus energetic demand affected foraging behavior. We manipulated food abundance in different wetland types in Illinois, USA to reduce confounding between food abundance and vegetation structure. We conducted focal‐animal behavioral samples on five duck species in treatment and control plots and used generalized linear mixed‐effects models to compare the effects of vegetation structure versus other factors on the intensity with which ducks fed and the duration of feeding stints. Mallards fed more intensively and, along with blue‐winged teal, used longer feeding stints in open habitats, consistent with the hypothesis that limited visibility was perceived to have a greater predation risk than unlimited visibility. The species temporally nearest to nesting, wood ducks, were willing to take more risks for a greater food reward, consistent with an increase in a marginal value of energy as they approached nesting. Our results indicate that some duck species value energy differently based on the surrounding vegetation structure and density. Furthermore, increases in the marginal value of energy can be more influential than perceived risk in shaping foraging behavior patterns. Based on these findings, we conclude that the value of various food items is not solely determined by energy contained in the item but by conditions in which it is found and the state of the forager.     

Foraging patterns of voles at heterogeneous avian and uniform mustelid predation risk

Temporal variation of antipredatory behavior and a uniform distribution of predation risk over refuges and foraging sites may create foraging patterns different from those anticipated from risk in heterogenous habitats. We studied the temporal variation in foraging behavior of voles exposed to uniform mustelid predation risk and heterogeneous avian predation risk of different levels induced by vegetation types in eight outdoor enclosures (0.25 ha). We manipulated mustelid predation risk with weasel presence or absence and avian predation risk by reducing or providing local cover at experimental food patches. Foraging at food patches was monitored by collecting giving-up densities at artificial food patches, overall activity was automatically monitored, and mortality of voles was monitored by live-trapping and radiotracking. Voles depleted the food to lower levels in the sheltered patches than in the exposed ones. In enclosures with higher avian predation risk caused by lower vegetation height, trays were depleted to lower levels. Unexpectedly, voles foraged in more trays and depleted trays to lower levels in the presence of weasels than in the absence. Weasels match their prey's body size and locomotive abilities and therefore increase predation risk uniformly over both foraging sites and refuge sites that can both be entered by the predator. This reduces the costs of missing opportunities other than foraging. Voles changed their foraging strategy accordingly by specializing on the experimental food patches with predictable returns and probably reduced their foraging in the matrix of natural food source with unpredictable returns and high risk to encounter the weasel. Moreover, after 1 day of weasel presence, voles shifted their main foraging activities to avoid the diurnal weasel. This behavior facilitated bird predation, probably by nocturnal owls, and more voles were killed by birds than by weasels. Food patch use of voles in weasel enclosures increased with time. Voles had to balance the previously missed feeding opportunities by progressively concentrating on artificial food patches.     

Behavioural Response of Juvenile Bluegill Sunfish to Variation in Predation Risk and Food Level

The behavioural response of juvenile bluegill sunfish (Lepomis macrochirus) to predation risk when selecting between patches of artificial vegetation differing in food and stem density was investigated. Bluegill foraging activity was significantly affected by all three factors. Regardless of patch stem density or risk of predation bluegills preferred patches with the highest prey number. During each trial bluegill foraging activity was clearly divided into a between- and within-patch component. In the presence of a predator bluegills reduced their between-patch foraging activity by an equivalent amount regardless of patch stem density or food level, apparently showing a risk-adjusting behavioural response to predation risk. Within patches, however, foraging activity was affected by both food level and patch stem density. When foraging in a patch offering a refuge from predation, the presence of a predator had no effect on bluegill foraging activity within this patch. However, if foraging in a patch with only limited refuge potential, bluegill foraging activity was reduced significantly in the presence of a predator. Further, this reduction was significantly greater if the patch contained a low versus a high food level, indicating a risk-balancing response to predation with respect to within-patch foraging activity. Both these responses differ from the risk-avoidance response to predation demonstrated by juvenile bluegills when selecting among habitats. Therefore, our results demonstrate the flexibility of juvenile bluegill foraging behaviour.     

The effect of group size on vigilance in Ruddy Turnstones Arenaria interpres varies with foraging habitat

Foraging birds can manage time spent vigilant for predators by forming groups of various sizes. However, group size alone will not always reliably determine the optimal level of vigilance. For example, variation in predation risk or food quality between patches may also be influential. In a field setting, we assessed how simultaneous variation in predation risk and intake rate affects the relationship between vigilance and group size in foraging Ruddy Turnstones Arenaria interpres. We compared vigilance, measured as the number of ‘head‐ups’ per unit time, in habitat types that differed greatly in prey energy content and proximity to cover from which predators could launch surprise attacks. Habitats closer to predator cover provided foragers with much higher potential net energy intake rates than habitats further from cover. Foragers formed larger and denser flocks on habitats closer to cover. Individual vigilance of foragers in all habitats declined with increasing flock size and increased with flock density. However, vigilance by foragers on habitats closer to cover was always higher for a given flock size than vigilance by foragers on habitats further from cover, and habitat remained an important predictor of vigilance in models including a range of potential confounding variables. Our results suggest that foraging Ruddy Turnstones can simultaneously assess information on group size and the general likelihood of predator attack when determining their vigilance contribution.     

Risk management in optimal foragers: the effect of sightlines and predator type on patch use,time allocation,and vigilance in gerbils

In the foraging game between gerbils and their predators, gerbils manage risk of predation using the tools of time allocation (where, when and for how long to forage) and vigilance. The optimal level of a forager's vigilance should be affected by its encounter rate with predators and the effectiveness of its vigilance in reducing mortality risk. The physical structure of the environment can alter the effectiveness of its vigilance and therefore alter its foraging behaviour. We tested this for gerbils at risk of predation from barn owls or foxes in a large vivarium. In particular, we reduced the effectiveness of vigilance by placing obstructions around feeding trays that blocked sight lines along either the vertical (vigilance directed against owls) or horizontal axis (vigilance directed against foxes), thereby changing the physical structure of the environment. In addition, we manipulated the presence of foxes and owls. In general, gerbils harvested fewer seeds, allocated less time to foraging in dangerous patches, and used more vigilance while foraging where and when risks were higher (i.e. in the presence of predators and in bright moonlight). Vertical and horizontal sightline treatments interacted synergistically to further raise perceived risk. These results imply that blocking sight lines reduces the effectiveness of vigilance, causing gerbils to use it less. Moreover, in the presence of a predator, the gerbils’ response to the blocked sightlines was more severe – harvesting less food and spending less time and vigilance – in the patches with the increased risk. This was especially so in the presence of the predator that was expected to most benefit from blocking that particular type of sight line: cover that blocked vertical sight lines was riskiest in the presence of owls, and cover that blocked horizontal sight lines was riskiest in the presence of foxes. These results strongly indicate the importance of sightlines and landscape features such as bushes in the risk management and forging decisions of gerbils, demonstrating that bush cover provides mixed blessing to gerbils by providing cover, but making vigilance ineffective.     

The effect of sward height and drainage on Common Starlings Sturnus vulgaris and Northern Lapwings Vanellus vanellus foraging in grassland habitats

Agricultural change is often cited as a causal factor in the decline of the UK's farmland birds because bird declines have mirrored changes in agricultural practices. Although much is known about the mechanisms driving population declines on arable systems, mechanisms in grassland systems are relatively poorly studied, despite receiving a similar degree of intensification. Agricultural intensification may affect bird declines by reducing food abundance or accessibility, forager mobility or predation risk. Here we examine experimentally the effects of sward height on the foraging behaviour of adult Common Starlings Sturnus vulgaris , and the effects of sward height and drainage on the behaviour of Northern Lapwing Vanellus vanellus chicks. Both species are declining across the UK and both forage in farmed grassland habitats, but they differ in their foraging methods because Starlings probe for soil invertebrates whereas Lapwing chicks glean prey from surfaces. Overall, after controlling for prey abundance, short swards were found to be more productive for both species. Prey capture rate within foraging bouts did not differ with sward height for Starlings, but Starlings spent more time foraging on short swards and captured 33.2% more prey. Starlings walked more steps on short swards. Lapwing chick foraging rates declined as sward height increased. Soil moisture was not found to be a predictor of Lapwing chick foraging rates within the observed range. Our results suggest that short swards are a more profitable foraging habitat for soil and surface invertebrate feeders. Short swards may facilitate surface prey detection, improve forager mobility and increase foraging time by altering vigilance patterns. Provision of short swards in areas where these are lacking could be simple method of improving foraging habitats for grassland birds.     

Detecting predators and locating competitors while foraging: an experimental study of a medium-sized herbivore in an African savanna

Vigilance allows individuals to escape from predators, but it also reduces time for other activities which determine fitness, in particular resource acquisition. The principles determining how prey trade time between the detection of predators and food acquisition are not fully understood, particularly in herbivores because of many potential confounding factors (such as group size), and the ability of these animals to be vigilant while handling food. We designed a fertilization experiment to manipulate the quality of resources, and compared awareness (distinguishing apprehensive foraging and vigilance) of wild impalas (Aepyceros melampus) foraging on patches of different grass height and quality in a wilderness area with a full community of predators. While handling food, these animals can allocate time to other functions. The impalas were aware of their environment less often when on good food patches and when the grass was short. The animals spent more time in apprehensive foraging when grass was tall, and no other variable affected apprehensive behavior. The probability of exhibiting a vigilance posture decreased with group size. The interaction between grass height and patch enrichment also affected the time spent in vigilance, suggesting that resource quality was the main driver when visibility is good, and the risk of predation the main driver when the risk is high. We discuss various possible mechanisms underlying the perception of predation risk: foraging strategy, opportunities for scrounging, and inter-individual interference. Overall, this experiment shows that improving patch quality modifies the trade-off between vigilance and foraging in favor of feeding, but vigilance remains ultimately driven by the visibility of predators by foragers within their feeding patches.     

Testing predictions of foraging theory for a sit-and-wait forager, Anolis gingivinus

Research in foraging theory has been dominated by studies ofactive foragers choosing among patches and among prey withina patch. Studies of central-place foraging have mainly focusedon loading decisions of an animal provisioning a central place.The problem faced by a sit-and-wait forager that encountersprey at a distance has received little attention. In this studywe tested foraging theory predictions for such foragers, Anolisgingivinus females in the West Indies island of Anguilla. Wepresented lizards with antlion larvae at various distances.Experiment 1 showed that an individual's probability of pursuingprey decreases with the prey's distance and is best describedby a sigmoidal function (which may be as steep as a step function).This function's inflection point defines a cutoff distance.Experiment 3 tested how cutoff distance changes as a functionof prey size. Cutoff distances were greater for larger prey,as predicted for an energy-maximizing forager. Experiments 2and 4 tested how cutoff distance changes as a function of preyabundance. As predicted, cutoff distance were greater at a sitewhere prey abundance was lower. Furthermore, cutoff distancesdecreased immediately following prey augmentation and returnedto previous values within one day of ending augmentation. Thus,moles' foraging behavior is a dynamic process, consistent withthe qualitative predictions of foraging theory. We attributethe success of this study in supporting fundamental foragingtheory predictions to the lizards exhibiting natural behaviorunder field conditions and to particular advantages of studyingsit-and-wait foragers.     

Foraging behaviour and dispersion of eastern grey kangaroos (Macropus giganteus) in an ideal free framework

Ideal free distribution (IFD) theory predicts that animals in competitive situations should distribute themselves among available habitat patches according to the density of conspecifics and its regulatory effect on resources. To investigate the applicability of IFD models to free-ranging herbivores, we quantified the dispersion and foraging behaviour of eastern grey kangaroos Macropus giganteus among habitat patches of differing suitability, within and outside a reservoir catchment in southern Victoria, Australia. Kangaroo densities within the catchment had a regulatory effect on resource density, while surrounding farmland maintained a higher standing crop despite higher densities of competitors. This difference was slight in autumn, however, when the system was apparently close to equilibrium. Gross bite rates of individuals foraging in farmland were lower than for individuals foraging within the catchment, and vigilance behaviour occurred more frequently in farmland habitat than any other, decreasing time devoted to feeding. Interference competition occurred in only 1.9% of focal samples, although competitive differences based on phenotype were observed. Although resource gains by individual kangaroos are likely to be influenced by other factors, including resource dynamics, predation risk and phenotypic differences, IFD theory provides a valuable analytical framework for this herbivore foraging system.     

Spatial and temporal scaling in habitat utilization by klipspringers (Oreotragus oreotragus) determined using giving‐up densities

An animal's pattern of habitat use can reveal how different parts of its environment vary in quality based on the costs (such as predation risk) and benefits (such as food intake) of using each habitat. We studied klipspringer habitat use in Augrabies Falls National Park, South Africa using giving‐up densities (GUDs; the amount of food remaining in a resource patch following exploitation) in experimental food patches. We tested hypotheses related to how salient habitat variables might influence klipspringers' perceptions of foraging costs. At small spatial scales (3–4 m), klipspringer GUDs did not vary with cover and open microhabitats, or with the four cardinal aspects (shading) around shrubs. Adding water adjacent to food patches did not influence GUDs, showing that water is not a limiting complementary resource to food. Generally, klipspringers do not appear to be physiologically constrained. There was no difference in GUDs between four daily time periods, or between summer and winter; however, a significant interaction effect of time‐of‐day with season resulted from GUDs during the midday time period in winter being significantly higher (perceived value lower) than during the same time period in summer. At moderate spatial scales (10–60 m), klipspringer GUDs increased with distance from rocks because of increased predation risk. Based on GUDs collected at the largest scale (two 4.41‐ha grids), klipspringers preferred foraging at greater distances from drainage lines and on pebble and cobble substrates. Overall, this study has shown the efficacy of measuring GUDs to determine klipspringers' habitat utilization while foraging.