In the field of plant-herbivore interactions, a key question is to understand which plants will be consumed. From the point of view of herbivores, this question takes the form of how animals select resources. To answer it, the theory of optimal foraging provides a mathematical framework that takes into account the constraints experienced by animals, such as the availability and diversity of resources available. Historically, plant-focused researchers have framed this question slightly differently: How to explain patterns of herbivory? Hypotheses grouped under the term associational effects aim to describe how plant community characteristics influence these patterns. Results of associational effects studies, however, are variable in magnitude, in direction and are often idiosyncratic. There is a growing awareness that associational effects could be equally well explained by optimal foraging. Several studies of associational effects, however, fail to consider factors linked with herbivores' active foraging choices such as the effects of plant size. I will try to mend the gap between fields using examples of optimal foraging framework integration in studies of associational effects, mostly with mammalian herbivores, but also with invertebrates. I review the proposed mechanisms for associational effects and evaluate whether they could be explained by optimal foraging. Finally, I propose guidance on predictions and type of studies that allow us to discriminate associational effects produced by optimal foraging from other potential mechanisms. Incorporating active foraging choices and using an optimal framework could improve our understanding of associational effects and their variations. Moreover, clearly identifying herbivores as the actor in these interactions forces us to consider their abilities and behavior. It also creates links with nutritional ecology, landscape ecology, and population dynamics and has potential implications in conservation and management practices.

Understanding how herbivores adjust their foraging strategies to cope with seasonal resource fluctuations has been central to the nutritional ecology. Optimal Foraging Theory (OFT) predicts that generalists should broaden their dietary niche when high-quality resources are scarce, but empirical evidence in extreme environments remains poorly understood. We used trnL-P6 metabarcoding of fecal samples (n = 10/season) and a local reference library of 120 plant species to quantify diet composition and niche metrics of free-ranging yaks (Bos grunniens) on the Qinghai-Tibetan Plateau in June (summer) and October (autumn) 2024. Yaks shifted from a diverse, forb-dominated diet (e.g., Polygonaceae, Rosaceae) in summer to a specialized diet dominated by grasses in autumn. Although dietary richness and total niche width (TNW) decreased in autumn, phylogenetic diversity remained stable, indicating a strategic shift to distinct evolutionary lineages to ensure functional redundancy. Furthermore, food network analyses demonstrated a transformation from a flexible, modular foraging pattern in summer to a highly integrated, synchronized network in autumn. These findings suggest that under the distinct quality-quantity trade-off of high-altitude ecosystems, yaks adopt an energy-maximization strategy by minimizing search costs, aligning with the opportunity cost constraints of OFT, rather than randomly expanding their niche. This insight into selective foraging dynamics is critical for developing sustainable grazing practices that accommodate the natural adaptive behaviors of alpine herbivores.

Abstract This study examines the offence behaviours, spatial patterns, and target preferences of foraging burglars, an emerging offender typology inspired by Optimal Foraging Theory (OFT). Foraging burglars carefully balance effort, risk, and reward in target selection, much like foraging animals in the natural world. Using data from 400 crimes identified by the police as committed by foraging burglars, I use a mix of multidimensional scaling and cluster analysis to identify nine initial subtypes of foraging burglars. Using professional judgement, these are subsequently consolidated into three typologies. This approach enables the study to consider the full range of potential profiles produced by various methodological approaches before reaching a refined classification. In doing so, I identify three subtypes: Generalised Foraging Opportunists, Organised Weekend Foragers, and Specialist Foragers. These three typologies highlight diversity within foraging burglars, and differ in their prioritisation of effort, risk, and reward. Generalised Foraging Opportunists focus on fast, low-effort gains, while Organised Weekend Foragers emphasise reward, alongside careful avoidance of detection. Specialist Foragers, in contrast, invest significant effort to target high-value items such as vehicles and jewellery. These distinctions have implications for the police, strongly indicating the need for tailored interventions based on the specific typology to optimise crime prevention, reduction, and offender apprehension. Applying OFT in this way supports a “whole system” response that is especially valuable given the high potential for crime displacement among foraging burglars, who quickly modify their strategies in response to police pressure. Through this study, I advance burglary offender profiling by demonstrating how OFT can generate practically relevant typologies and, by offering evidence-based insights, directly inform how the police can counter offending through crime reduction and prevention strategies.

Optimal foraging theory (OFT) predicts that animals employ foraging strategies that maximize a particular currency, such as net energetic efficiency, to meet their nutritional demands. Two nonexclusive patterns that arise from OFT are convergence on high-quality resources and resource partitioning. Honey bees make collective decisions by integrating their individual foraging with social recruitment behaviors: returning foragers communicate the approximate vector to high-quality resources using waggle dances. Because we can eavesdrop on their communications, waggle dance decoding is a valuable tool for exploring OFT predictions as it allows us to map how honey bees use landscapes. In this study, we analyzed 8049 dances from colocalized colonies across three landscapes to investigate whether neighboring colonies forage by not partitioning patches (i.e., converging their food collection on the same patches), by partitioning at the landscape level, or by partitioning at the local level. To differentiate between these three possible scenarios, we examined three metrics: (1) interdance distances between and within colonies; (2) k-nearest neighbors; and (3) k-means clustering. We observed no difference in the distances between dances performed by bees from the same colony compared to those from different colonies. Also, we found at each of the three field sites that dances from the same colony were not more likely to appear as close neighbors to each other. Finally, k-means cluster analysis demonstrates that dance locations advertised by the same colony aggregated nonrandomly in the three sites, where dances from the same colony comprised a significant majority of dances within k-means clusters and 62% of clusters consisted entirely of dances from a single colony. Together, these results support a foraging scenario where honey bees partition their foraging, but at the local level. This strategy may help limit intercolony foraging competition.

Contrafreeloading is defined as choosing to perform work to obtain a reward, despite the presence of an identical, freely available alternative. According to standard learning and optimal foraging theories, it should not exist. Thus, any evidence of such behavior is noteworthy. We briefly review the recently introduced play hypothesis, which proposes that contrafreeloading is more likely if the action involved is viewed as play rather than work (i.e., agreeable rather than aversive). One might consequently expect species that are relatively more playful to be more likely to engage in contrafreeloading. We evaluated this possibility by testing purportedly playful umbrella cockatoos (Cacatua alba); we studied four residents of a bird sanctuary in upstate New York (Dudley, JJ, Poly, and Teddy Bear). The task involved choosing between shelled and deshelled almonds; the former choice constituting evidence of contrafreeloading. We documented contrafreeloading in a novel species and then compared our results with previously published data on the reportedly less playful Grey parrots (Psittacus erithacus). Individually, a higher percentage of cockatoos engaged in contrafreeloading on more than half the trials than did the Greys, with statistically similar levels of individual variation, but the overall amount of contrafreeloading was not statistically significantly different between the species at a group level. We discuss possible reasons for these findings. Additionally, we examine similarities in the behavioral expression of play and contrafreeloading. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Optimal Foraging Theory (OFT) integrates both the consumer and the resource, yet their simultaneous assessment is uncommon. Vultures represent an ideal model for OFT studies because carrion requires no capture effort and minimal handling, allowing them to focus primarily on food searching. Here, we combined GPS tracking of 61 Iberian griffon vultures (consumers) with photo-trapping monitoring of 49 carcasses (resources) to assess the determinants of vulture foraging and the consequences for carrion consumption in two areas with different carrion abundances. First, we determined the importance of different factors (distance to the resource, hunger and competition) in the decisions of individuals of whether to descend or not on a carcass. Second, we compared carrion consumption patterns (time of carcass discovery and consumption, and maximum number of vultures gathered around the carcass) between areas. We found that distance, rather than hunger, is the primary factor determining whether a vulture descends to a carcass. In parallel, carrion was consumed similarly in areas with different resource availabilities. These findings indicate that vultures tend to eat whenever a nearby opportunity arises, consistent with a type-I functional response.

Animal energy intake and expenditure strategies in response to environmental fluctuations have been widely studied. Optimal foraging theory (OFT) is the dominant framework in this field; however, studies addressing the OFT in endangered waterbird species are lacking. To address this gap in our knowledge, we collected behavioral data and investigated habitat variables that influence the energy intake and expenditure of the endangered Chinese merganser (Mergus squamatus ) in the Changjiang, Shuaishui, and Jianjiang Rivers in Huangshan, Anhui Province, China, from January to March 2023. The results revealed a correlation between net energy, energy intake, and energy expenditure rates. Successful foraging frequencies increased net energy intake and energy intake rates and reduced the feeding time. Furthermore, running on water, flying, diving, and average fish weight increased energy expenditure rates, whereas successful foraging frequencies, vigilance, resting, fish biomass, river width, and eye-submerging decreased energy expenditure rates. Chinese mergansers adjusted behavioral time allocations to regulate energy intake, energy expenditure, and net energy intake rates. The net energy and energy intake rates were independent of environmental factors, excluding energy expenditure rates and average fish weight, fish biomass, and river width. The behaviors influencing the energy balance were modified in response to environmental factors. However, environmental factors did not affect the energy levels through behaviors. These results elucidate the energy intake, expenditure, and balance strategies used by Chinese mergansers in response to variations in their wintering habitats. They provide valuable insights for conserving and managing habitats critical to the survival of Chinese mergansers and other waterbird species.

Optimal foraging theory (OFT) and the energy maximization hypothesis (EMH) have long been essential when examining wildlife habitat selection. At high latitudes and altitudes, animals in winter face greater limitations in availability and accessibility of forage. Here we explore the foraging behavior of wood bison (Bison bison athabascae) during winter within the Ronald Lake bison herd in northeastern Alberta, Canada, and examine the trade-offs they face due to limitations in forage abundance and availability (snow conditions), as well as the need to minimize predation risk. We used Global Positioning System (GPS) location data collected from 70 female wood bison to identify winter foraging sites and craters selected by bison to access forage beneath the snow. Within wetlands used by bison we selected 190 pairs of used (foraged) and random (available) sites to test eight a priori hypotheses explaining how bison traded-off between forage availability, accessibility, and minimizing predation risk. We found with matched-paired logistic regression that Carex atherodes was 1.21-times more likely to be selected per unit increase in ground cover, compared to 1.17-times per unit ground cover for C. aquatilis and C. utriculata. However, all Carex species showed an increase in selection when cover was > 50% cover within individual craters. While the importance of Carex was clear, forage site selection was still inversely related to snow depth. There is also a neutralizing combined effect of snow depth and Carex species ground cover which suggests that bison maximized their energy return by avoiding areas with deep snow (> 30 cm) that demanded intensive cratering, even when highly selected forage was accessible beneath. Avoidance of forage areas with deep snow demonstrates that wood bison employed a foraging strategy that considers both forage availability and environmental conditions, with snow depth being a limiting factor. We highlight the relationship between optimal foraging based on food availability and the trade-offs within an energy restrictive winter season, furthering the understanding of how large herbivores forage strategically to maximize energy intake in northern environments.

Abstract Animals searching for food must navigate complex landscapes with varying terrain, food availability, predator activity, and shelter. Where and when should they gather food? To what extent should they engage in anti-predator behaviors such as vigilance or seeking refuge if a predator is detected? Optimal foraging theory (OFT) posits that animals balance potentially conflicting goals (such as feeding versus escaping predation) by making decisions that maximize some expected utility or reward. However, OFT models have generally considered highly simplified landscapes, either ignoring spatial variability or assuming that the habitat consists of discrete, internally uniform habitat patches. As a result, OFT has largely avoided the question of how animals should move from one potential feeding area to another, or between feeding areas and refuges.We develop methods based on stochastic dynamic programming to find optimal foraging strategies, including optimal movement paths, in a continuous landscape with spatially varying predation risk. Our approach accounts for switching from foraging to escape behavior when pursued by a predator. Because contingent escape paths are considered for all visited locations, they influence the optimal foraging path even before threats are encountered. The optimal strategy thus depends on the animal’s level of hunger, the distribution of food, and the perceived threat distribution. The realized path is further influenced by actual predator encounters.We illustrate our approach with two numerical examples: the first hypothetical with two food-abundant regions accessible only via high-risk areas, the second based on empirical studies on foraging Samango monkeys,Cercopithecus albogularis schwarzi. We find that the shape of the forager’s utility function (risk-averse, risk-neutral, or with state-dependent risk sensitivity) affects not only its choices of where to feed, but also the optimal paths to and from each feeding ground.Our methods make it possible to compare properties of observed foraging trajectories with those predicted for different goal functions. Foraging trajectories can then provide additional information, along with other behavioral choices, about what quantity, if any, animals aim to optimize while foraging.

Optimal Foraging Theory (OFT) predicts that a population's trophic niche expansion should occur in periods of food scarcity as individuals begin to opportunistically exploit sub-optimal food items. However, the Niche Variation Hypothesis (NVH) posits that niche widening may result from increased among-individual differentiation due to food partitioning to avoid competition. We tested these hypotheses through a DNA metabarcoding study of the Sardinian Warbler (Curruca melanocephala) diet over a year. We used null models and the decomposition of beta diversity on among-individual dietary differentiation to infer the mechanisms driving the population's niche variation. Warblers fed frequently on berries, with a peak in late summer and, to a lesser extent, in autumn. Their diet also included a wide range of arthropods, with their prevalence varying among seasons. Consistent with OFT, the population's niche width was narrower in spring/summer when the population was strongly specialized in berries. In winter, the population's niche expanded, possibly reflecting seasonal declines in food abundance. As predicted by NVH, among-individual differentiation tended to be higher in winter, but this was mainly due to increased differences in dietary richness rather than to the partitioning of resources. Overall, our results suggest that within-individual niche does not increase in lean periods, and instead, individuals adopt either a more opportunistic or more specialized foraging strategy. Increased competition in periods of scarcity may help explain such patterns, but instead of showing increased food partitioning as expected from NVH, it may reflect OFT mechanisms on individuals with differential competitive ability to access better food resources.

The problem of rational choice by the population of a patch containing energy (nutritive) resources is considered. This problem belongs to the theory of optimal foraging, which, in turn of, studies issues related to the behavior of the population when it leaves the patch or chooses the most suitable one. In order to define the optimal patch choice for population, a variational approach, based on the idea of the Boltzmann distribution is proposed. To construct the probability distribution the utility functions are used, that take into account factors that can influence the patch choice of a population: available information about the quality of patches, the energy utility of patches, the cost of moving to the patch, the cost of information about the quality of patches. The main goal of the paper is to investigate the influence of available information about the amount of resources, contained in patches, on a decision-making process generated by the foragers while a suitable patch choosing. The optimal rationality is determined in the cases taking into account the information cost, the average energy utility of all patches, the rationality depending on the patch. The conditions under which the population, with the lack of information, select the “poor” patch, in sense of its resources, are obtained. The latter provides a theoretical justification of experimental observations, according to which a population can choose a patch with worse quality. The obtained results have a general character and may be used not only in behavioral ecology but when constructing any decision making processes.

BackgroundThe classic optimal foraging theory (OFT) predicts animals’ food patch use assuming that individuals in a population use the same strategy while foraging. However, due to the existence of animal personality, i.e. repeatable inter-individual differences and intra-individual consistency in behaviours over time and/or across contexts, individuals often exhibit different behavioural strategies, challenging the basic assumptions of the OFT. Here, we tested whether personality traits (boldness and exploration in open arena) of Japanese quail (Coturnix japonica, 38 females and 34 males) influenced their patch use in two foraging experiments with different inter-patch distances (i.e. 2 m in Experiment 1 and 3 m in Experiment 2).ResultsThe total feeding time and food intake of individuals did not differ between Experiment 1 and 2, but in both experiments, proactive (i.e. bolder and more explorative) individuals had longer feeding time and higher food intake than reactive individuals. In Experiment 1, proactive quails changed patches more frequently and had shorter mean patch residence time than reactive individuals, while the effects were not significant in Experiment 2. The quails reduced patch residence time along with feeding, and this trend was weakened in Experiment 2 which had longer inter-patch distance.ConclusionsThe above results suggest that personality traits affect animals’ patch use, while the effects might be weakened with longer inter-patch distance. Our study highlights that animal personality should be considered when investigating animals’ foraging behaviours because individuals may not adopt the same strategy as previously assumed. Furthermore, the interaction between personality traits and inter-patch distances, which is related to movement cost and capacity of information gathering, should also be considered.

The variation in niche breadth can affect how species respond to environmental and resource changes. However, there is still no clear understanding of how seasonal variability in food resources impacts the variation of individual dietary diversity, thereby affecting the dynamics of a population's dietary niche breadth. Optimal foraging theory (OFT) and the niche variation hypothesis (NVH) predict that when food resources are limited, the population niche breadth will widen or narrow due to increased within-individual dietary diversity and individual specialization or reduced within-individual dietary diversity, respectively. Here, we used DNA metabarcoding to examine the composition and seasonality of diets of the avivorous bat Ia io. Furthermore, we investigated how the dietary niches changed among seasons and how the population niche breadth changed when the availability of insect resources was reduced in autumn. We found that there was differentiation in dietary niches among seasons and a low degree of overlap, and the decrease of insect resource availability and the emergence of ecological opportunities of nocturnal migratory birds might drive dietary niche shifts toward birds in I. io. However, the population's dietary niche breadth did not broaden by increasing the within-individual dietary diversity or individual specialization, but rather became narrower by reducing dietary diversity via predation on bird resources that served as an ecological opportunity when insect resources were scarce in autumn. Our findings were consistent with the predictions of OFT, because birds as prey for bats provided extremely different resources from those of insects in size and nutritional value. Our work highlights the importance of size and quality of prey resources along with other factors (i.e., physiological, behavioral, and life-history traits) in dietary niche variation.

The late Mesolithic hunter-gatherers of what is now Denmark have long captivated archaeologists, who have meticulously studied the archaeological remains of their foraging economy since the mid-twentieth century. However, these studies – predominantly focused on subsistence – have often overlooked how individual decisions based on social and environmental settings can greatly structure foraging behaviours and, subsequently, the patterns observed in the zooarchaeological record. Perceiving hunting not just as an activity, but as a cultural practice shaping identities and social bonds, underscores the importance of considering social, symbolic and economic dimensions in Mesolithic hunting research. This study bridges this gap by integrating theoretical frameworks from human behavioural ecology (HBE), such as optimal foraging theory (OFT), costly signalling theory (CST) and notions of prestige. By doing so, it aims to elucidate the complex motivations underlying prey selection among the Ertebølle hunters. Through analysis of five sites from the Danish Ertebølle period (5400–3950 BC) using a simplified prey choice model (PCM), this research seeks to shed light on the interplay of ecological and social factors shaping hunting practices. The findings are discussed through the lens of optimal choice and prestige to examine patterns of prey selection at these archaeological sites.

Optimal foraging theory (OFT) is based on the ecological concept that organisms select behaviors that convey future fitness, and on the mathematical concept of optimization: finding the alternative that provides the best value of a fitness measure. As implemented in, for example, state-based dynamic modeling, OFT is powerful for one key problem of modern ecology: modeling behavior as a tradeoff among competing fitness elements such as growth, risk avoidance, and reproductive output. However, OFT is not useful for other modern problems such as representing feedbacks within systems of interacting, unique individuals: When we need to model foraging by each of many individuals that interact competitively or synergistically, optimization is impractical or impossible-there are no optimal behaviors. For such problems we can, however, still use the concept of future fitness to model behavior by replacing optimization with less precise (but perhaps more realistic) techniques for ranking alternatives. Instead of simplifying the systems we model until we can find optimal behavior, we can use theory based on inaccurate predictions, coarse approximations, and updating to produce good behavior in more complex and realistic contexts. This so-called state- and prediction-based theory (SPT) can, for example, produce realistic foraging decisions by each of many unique, interacting individuals when growth rates and predation risks vary over space and time. Because SPT lets us address more natural complexity and more realistic problems, it is more easily tested against more kinds of observation and more useful in management ecology. A simple foraging model illustrates how SPT readily accommodates complexities that make optimization intractable. Other models use SPT to represent contingent decisions (whether to feed or hide, in what patch) that are tradeoffs between growth and predation risk, when both growth and risk vary among hundreds of patches, vary unpredictably over time, depend on characteristics of the individuals, are subject to feedbacks from competition, and change over the daily light cycle. Modern ecology demands theory for tradeoff behaviors in complex contexts that produce feedbacks; when optimization is infeasible, we should not be afraid to use approximate fitness-seeking methods instead.

Revisiting Optimal Foraging Theory (OFT) in a Changing Amazon: Implications for Conservation and Management

Despite the omnivorous diet of most human populations, meat foraging gradually increased during the Paleolithic, in parallel with the development of hunting capacities. There is evidence of regular meat consumption by extinct hominins from 2 Ma onward, with the first occurrence prior to 3 Ma in Eastern Africa. The number of sites with cut-marked animal remains and stone tools increased after 2 Ma. In addition, toolkits became increasingly complex, and various, facilitating carcass defleshing and marrow recovery, the removal of quarters of meat to avoid carnivore competition, and allowing the emergence of cooperative (i.e., social) hunting of large herbivores. How can we assess the energy costs and benefits of meat and fat acquisition and consumption for hunter-gatherers in the past, and is it possible to accurately evaluate them? Answering this question would provide a better understanding of extinct hominin land use, food resource management, foraging strategies, and cognitive abilities related to meat and fat acquisition, processing, and consumption. According to the Optimal Foraging Theory (OFT), resources may be chosen primarily on the basis of their efficiency rank in term of calories. But, could other factors, and not only calorific return, prevail in the choice of prey, such as the acquisition of non-food products, like pelts, bone tools or ornaments, or symbolic or traditional uses? Our main goal here is to question the direct application of behavioral ecology data to archeology. For this purpose, we focus on the issue of animal meat and fat consumption in human evolution. We propose a short review of available data from energetics and ethnographic records, and provide examples of several various-sized extant animals, such as elephants, reindeer, or lagomorphs, which were some of the most common preys of Paleolithic hominins.

An agent-based model of elephant crop consumption walks using combinatorial optimization

Abstract Herbivores making space use decisions must consider the trade-off between perceived predation risk and forage quality. Herbivores, specifically snowshoe hares (Lepus americanus), must constantly navigate landscapes that vary in predation risk and food quality, providing researchers with the opportunity to explore the factors that govern their foraging decisions. Herein, we tested predictions that intersect the risk allocation hypothesis (RAH) and optimal foraging theory (OFT) in a spatially explicit ecological stoichiometry framework to assess the trade-off between predation risk and forage quality. We used individual and population estimates of snowshoe hare (n = 29) space use derived from biotelemetry across three summers. We evaluated resource forage quality for lowbush blueberry (Vaccinium angustifolium), a common and readily available forage species within our system, using carbon:nitrogen and carbon:phosphorus ratios. We used habitat complexity to proxy perceived predation risk. We analyzed how forage quality of blueberry, perceived predation risk, and their interaction impact the intensity of herbivore space use. We used generalized mixed effects models, structured to enable us to make inferences at the population and individual home range level. We did not find support for RAH and OFT. However, variation in the individual-level reactions norms in our models showed that individual hares have unique responses to forage quality and perceived predation risk. Our finding of individual-level responses indicates that there is fine-scale decision-making by hares, although we did not identify the mechanism. Our approach illustrates spatially explicit empirical support for individual behavioral responses to the food quality–predation risk trade-off.

BackgroundDiving marine predators forage in a three-dimensional environment, adjusting their horizontal and vertical movement behaviour in response to environmental conditions and the spatial distribution of prey. Expectations regarding horizontal-vertical movements are derived from optimal foraging theories, however, inconsistent empirical findings across a range of taxa suggests these behavioural assumptions are not universally applicable.MethodsHere, we examined how changes in horizontal movement trajectories corresponded with diving behaviour and marine environmental conditions for a ubiquitous Southern Ocean predator, the Adélie penguin. Integrating extensive telemetry-based movement and environmental datasets for chick-rearing Adélie penguins at Béchervaise Island, we tested the relationships between horizontal move persistence (continuous scale indicating low [‘resident’] to high [‘directed’] movement autocorrelation), vertical dive effort and environmental variables.ResultsPenguins dived continuously over the course of their foraging trips and lower horizontal move persistence corresponded with less intense foraging activity, likely indicative of resting behaviour. This challenges the traditional interpretation of horizontal-vertical movement relationships based on optimal foraging models, which assumes increased residency within an area translates to increased foraging activity. Movement was also influenced by different environmental conditions during the two stages of chick-rearing: guard and crèche. These differences highlight the strong seasonality of foraging habitat for chick-rearing Adélie penguins at Béchervaise Island.ConclusionsOur findings advance our understanding of the foraging behaviour for this marine predator and demonstrates the importance of integrating spatial location and behavioural data before inferring habitat use.