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Highlights • Modelled least-cost paths can be highly tortuous, mirroring some animal tracks. • Least-cost paths are scale-independent. • Least-cost paths are a vital starting point for animal trajectory analysis. Abstract Recent work has highlighted that 'energy landscapes' should affect animal movement trajectories although expected patterns are rarely quantified. We developed a model, incorporating speed, substrate, superstrate and terrain slope, to determine minimized movement costs for an energetically well-understood model animal, Homo sapiens , negotiating an urban environment, to highlight features that promote increased tortuosity and affect area use. The model showed that high differential travel power costs between adjacent areas, stemming from substantial environmental heterogeneity in the energy landscape, produced the most tortuous least-cost paths across scales. In addition, projected territory size and shape in territorial animals is likely to be affected by the details in the energy landscape. We suggest that cognisance of energy landscapes is important for understanding animal movement patterns and that energetic differences between least cost- and observed pathways might code for, and give an explicit value to, other important landscape-use factors, such as the landscape of fear, food availability or social effects. [ABSTRACT FROM AUTHOR]

Abstract The ability to produce fire at will and to maintain it for a long duration is considered one of the major advances in human evolution. The exact process by which hominins first learned to use and to create fire is still hotly debated, with some arguing for a sudden transformative event that was quickly followed by a biological and cultural dependence on fire, such as a reliance on the extra calories saved through cooking food and an external source of heat. Others suggest that the 'domestication' of fire was a long and drawn-out process, with hominins using fire when it was available on the landscape but perhaps not having the ability to produce fire until much later in human history. In this paper we propose a third option, that fire should be considered like other technologies - that is, it certainly comes with benefits but also with costs, and that hominins functioned as optimal foragers who chose to use this tool only when the costs were less than the benefits. The potential benefits of fire have been well-described in other publications. Here we discuss in detail the various kinds of costs associated with fire and how these costs could, and do, structure human fire-use behavior. We then describe a small experiment to 'put some numbers on' the potential costs of fire, by quantifying one of the most expensive costs (fuel collection) and comparing it to one of the most-praised benefits (cooking of food). The results suggest that the costs of fuel collection are very high in less-forested environments, and that excessively large amounts of cooked foods are needed to match the total costs of fuel collection and the act of cooking. Overall, the costs of fire can be quite high and must be considered when proposing models for pre-modern human adoption and regular use of fire technologies. [ABSTRACT FROM AUTHOR]

Most optimal foraging models assume that the foraging behaviour of small birds depends on a single state variable, their energy reserves in the form of stored fat. Here, we include a second state variable—the contents of the bird's gut—to investigate how a bird should optimise its gut size to minimise its long-term mortality, depending on the availability of food, the size of meal and the bird's digestive constraints. Our results show that (1) the current level of fat is never less important than gut contents in determining the bird's survival; (2) there exists a unique optimal gut size, which is determined by a trade-off between the energetic gains and costs of maintaining a large digestive system; (3) the optimal gut size increases as the bird's digestive cycle becomes slower, allowing the bird to store undigested food; (4) the critical environmental factor for determining the optimal gut size is the mass of food found in a successful foraging effort (“meal size”). We find that when the environment is harsh, it is optimal for the bird to maintain a gut that is larger than the size of a meal. However, the optimal size of the gut in rich environments exactly matches the meal size (i.e. the mass of food that the optimal gut can carry is exactly the mass of food that can be obtained in a successful foraging attempt). [ABSTRACT FROM AUTHOR]

Ecologists have long searched for a universal size-scaling constant that governs trophic interactions. Although this is an appealing theoretical concept, predator-prey size ratios (PPSRs) vary strikingly across and within natural food webs, meaning that predators deviate from their optimal prey size by consuming relatively larger or smaller prey. Here we suggest that this unexpected variation in allometric scaling of trophic interactions can be predicted by gradients of prey limitation consistent with predictions from optimal foraging theory. We analyzed 16,000 trophic interactions of 52 populations from four tropical frog species along a gradient of prey limitation. The mean of PPSR and its variance differed up to two orders of magnitude across and within food webs. Importantly, as prey availability decreased across food webs, PPSR and its variance became more size dependent. Thus, trophic interactions did not follow a fixed allometric scaling but changed predictably with the strength of prey limitation. Our results emphasize the importance of ecological contexts in arranging food webs and the need to incorporate ecological drivers of PPSR and its variance in food web and community models. [ABSTRACT FROM AUTHOR]

Successful management of forests, especially in the context of subsistence wood fuel use, can be improved by the application of theoretic models that predict patterns of use. A first step in this approach is understanding the decision rules of people using forests. While optimal foraging theory is normally applied to foraging for food, it also makes sense to apply it in the context of “foraging” for wood fuel. In this study, we applied a time allocation model of optimal foraging theory to wood gathering decisions in communities around Kakamega Forest, a mid-altitude seasonal tropical rain forest. The model predicts that the amount of wood gathered should increase with the distance to the wood source. We found that the predictions of OFT are supported, but only for adults and more strongly on a weekly scale. Based upon the results, we then discuss future improvements of the model to better understand and predict human use. [ABSTRACT FROM AUTHOR]

Converting the consumer electronic product system from a linear system to a circular one has a number of key challenges. A mismatch is observed between the rapidly changing devices entering the market and the slowly evolving voluntary design policies, regulations, and e-waste processing business strategies. Conventional electronic waste (e-waste) management systems were historically optimized to extract high-value components from large products that were relatively easy to disassemble, but the products now entering the waste stream are more often light-weight mobile devices that are typically not covered by regulations or do not contain as high a concentration of valuable metals. This article proposes that transformations in the e-waste processing system aimed at closing the material loop should look to the circular processes found in natural ecosystems, which have evolved to optimize closed loop nutrient cycling. Like species in nature, e-waste processors make decisions about where and what to “eat,” balancing a food’s quality and abundance with the energy expended in obtaining it. Adapting the concept of optimal foraging theory, we demonstrate here a conceptual framework that draws parallels between foraging behavior in the ecological and industrial world, evaluates four potential mathematical models that case be applied to the e-waste case, and demonstrate how optimal foraging decisions can guide business, design, and end of life management toward circular economy goals in the consumer electronic system. [ABSTRACT FROM AUTHOR]

Search is a universal behavior related to many types of intelligent individuals. While most studies have focused on search in two or infinite-dimensional space, it is still missing how search can be optimized in three-dimensional space. Here we study random searches on three-dimensional (3d) square lattices with periodic boundary conditions, and explore the optimal search strategy with a power-law step length distribution, p ( l ) ∼ l − μ , known as Lévy flights. We find that compared to random searches on two-dimensional (2d) lattices, the optimal exponent μ o p t on 3d lattices is relatively smaller in non-destructive case and remains similar in destructive case. We also find μ o p t decreases as the lattice length in z direction increases under high target density. Our findings may help us to understand the role of spatial dimension in search behaviors. [ABSTRACT FROM AUTHOR]

Drilling path optimization (DPO) is a crucial issue in current manufacturing systems. In this paper, an optimization algorithm named the optimal foraging algorithm (OFA) is presented based on optimal foraging theory to solve the sequencing problem when many holes must be drilled. The objective of this study is to identify the optimal sequence of drilling operations using OFA to minimize the total processing cost. Since the drilling sequence optimization problem is considered a discrete optimization problem, five operators that can address the integer-encoding vector are built for OFA; thus, a discrete version of OFA is presented. The performance of OFA is evaluated against four other baseline algorithms in solving five real-world problems. The results, including the optimal solutions, the Kruskal–Wallis test, CPU time and the evolution curves, demonstrate that OFA improves the solution by minimizing nonproductive time. OFA is verified as a feasible method for solving DPO problems. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: The use of thelytokous Wolbachia‐infected Trichogramma (parasitic wasps) has long been considered as a way to enhance the efficacy of biocontrol. However, Wolbachia can affect the host physiology. We compared decision‐making between bisexual and thelytokous Wolbachia‐infected lines of Trichogramma dendrolimi Matsumura regarding behavior toward fresh and old eggs of Corcyra cephalonica at 25 ± 1 °C and 70 ± 5% relative humidity. RESULTS: The behavioral patterns and sequences of the two lines were basically the same. The durations of various behavioral patterns and values of fitness indicators of the bisexual line on fresh eggs were generally significantly shorter and better, respectively, than on old eggs, whereas the thelytokous line behaved similarly toward the two types of eggs, and differences in most fitness indicators between fresh and old eggs were not significant. On fresh eggs, the durations of various behaviors in the bisexual line were generally significantly shorter than in the thelytokous line and the fitness indicators were generally significantly better. CONCLUSION: Wolbachia affected the fitness of T. dendrolimi negatively. The potential of the thelytokous line as a biocontrol agent would not be as good as that of the bisexual line when decision‐making only is considered. Therefore, further evaluations need to be carried out before the thelytokous line can be used in practical biocontrol. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The Transitional Zone of central Arizona is a mountainous region dissected by rivers that created barriers and drove movement between prehistoric Hohokam groups to the south and Ancestral Peoples groups to the northeast and northwest. Although never suitable for large-scale agricultural irrigation, this region provided small areas of arable land scattered across rugged terrain rich in wild foods and alboreal resources. Archaeological data recovery related to road improvement projects throughout Arizona Route 260 allowed us to examine paleobotanical and osteofaunal remains of five archaeological sites. We relate changes in diet breadth and anthropogenic land effects modeled and described using the methods of the optimal foraging theory, with modes of use modeled using concepts from the frontier theory. We found that brief intervals of prey suppression and concomitant expansion of diet breadth between low value resources coincide with intervals of prey recovery and diet amplitude contraction between low value resources and more intensive settlement. On the other hand, ranges of prey recovery and diet breadth contraction among low value resources coincide with a reduced population and seasonal, extractive, and short-term occupations. [ABSTRACT FROM AUTHOR]

Last decades saw a dramatic increase in wildlife populations within urban areas. Policymakers seek to minimize human-wildlife conflicts resulting from overabundance of species, such as wild boars ( Sus scrofa ). To this end, there is a need to understand the drivers governing infiltration of wildlife into cities. In this paper we study the availability and distribution of food resources in urban areas as driver of wild boar movement patterns. Based on the optimal foraging theory, we utilize an agent-based simulation model to investigate the ever-growing infiltration of wild boars into some cities. We apply the model to an artificial city that mimics the landscape of the city of Haifa. Manipulating food availability and relative resistance costs of different land-covers we demonstrate that infiltration of boars depends on population size of wild boars and on the amount and spatial distribution of attractors (e.g., food). Model outputs for likely sets of parameters demonstrate good correspondence to the reports of boar observations within the city of Haifa, Israel, where the porosity of the urban fabric and the connectivity of open space patches provide a trail network that makes food throughout the city accessible at a relatively low search-cost. Our results indicate that land cover and food patterns determine critically boars’ foraging movement and infiltration into the city. The proposed modeling framework provides a tool to investigate wildlife management policies that aim at reducing people-wildlife conflicts in cities. [ABSTRACT FROM AUTHOR]

Abstract: The successful conservation of Florida's alligator rests, among other things, on a recreational harvest program that provides seasonal, nontransferable hunting permits. We develop an economic hunting model adapted from evolutionary ecology to show how the incentives under Florida's program still allow for efficient behavior. Hunters can select the length for kill from a given length‐frequency distribution and pursue alligators for revenue from hide and meat. We exploit extensive data sets on harvest reports, alligator population estimates, permit costs, and annual prices for wild hides and meat across 33 alligator management units in Florida between 2000 and 2015. We show that an increase in the abundance of bulls increases the minimum length of alligator for kill, while an increase in prices and cost of foraging time pushes hunters to accept smaller alligators for harvest. Understanding the drivers of human hunting behavior is essential for effective wildlife management. Recommendations for Managers: Effective wildlife management relies on the understanding of both animal and human dynamics. Alligator population levels are actively monitored but there is limited understanding of hunter behavior. Our research shows that recreational alligator hunters in Florida respond to abundance levels of bulls, and prices and cost of foraging time by adjusting the smallest length of alligator for harvest. Management of harvest quotas should actively consider behavioral responses of hunters. [ABSTRACT FROM AUTHOR]

Being venomous should help a predator to maximize foraging gain, reduce handling time and hoard food. Shrews are a good model for study of the relationship between venomousness and optimal foraging as they have to be highly efficient foragers (because of extremely high energy requirements) and comprise a few venomous species. We hypothesized that venom facilitates shrews to overpower large prey and enables hoarding of (mainly large) prey in a comatose state. We compared hunting and hoarding behaviors of the venomous Neomys fodiens and the nonvenomous Sorex araneus, which were allowed to forage on live prey differing in body size. As we predicted, small invertebrates were immediately consumed by both shrew species, whereas larger ones were immobilized and hoarded. Smaller S. araneus hoarded proportionally more food than larger N. fodiens. Although different ways of prey immobilization were expected (venomous paralyzing by N. fodiens and mechanical damage by S. araneus), both species seemed to use mechanical immobilization. However, N. fodiens required significantly less time than S. araneus to subdue prey of proportionally similar sizes and this difference grew with the increase in prey mass. Only N. fodiens was able to overpower and kill frogs (but not larger toads). We concluded that the relatively weak venom of N. fodiens is helpful in overpowering and hoarding mainly medium-sized prey. Thus, venomousness helps N. fodiens to optimize its foraging as it reduces prey handling time, enables it to gain larger energy portions and facilitates food hoarding, which reduces foraging time. [ABSTRACT FROM AUTHOR]

Abstract: The century long publication of this journal overlapped major changes in the sciences it covers. We have been eyewitnesses to vast changes during the final third of the last century and beginning of this one, momentous enough to fundamentally alter our work separately and collectively. One (NBJ) from animal ethology, another from western North American archaeology (JOC), and a third (KH) from cultural anthropology came to longtime collaboration as evolutionary ecologists with shared focus on studying modern hunter‐gatherers to guide hypotheses about human evolution. Our findings have radically revised hypotheses each of us took for granted when we began. Our (provisional) conclusions are not the consensus among hunter‐gatherer specialists; but grateful that personal reflections are invited, we aim to explain how and why we continue to bet on them. [ABSTRACT FROM AUTHOR]

The article reports on biomass allocation decisions in sessile organisms. Topics discussed include plant exploitation strategies of local soil-nutrient patches, relative investment to primary and secondary metabolism, and filamentous fungi. Also being discussed are the growth strategies of filamentous fungi.

For a species to be able to respond to environmental change, it must either succeed in following its optimal environmental conditions or in persisting under suboptimal conditions, but we know very little about what controls these capacities. We parameterized species distribution models ( SDMs) for 135 plant species from the Algerian steppes. We interpreted low false-positive rates as reflecting a high capacity to follow optimal environmental conditions and high false-negative rates as a high capacity to persist under suboptimal environmental conditions. We also measured functional traits in the field and built a unique plant trait database for the North-African steppe. For both perennial and annual species, we explored how these two capacities can be explained by species traits and whether relevant trait values reflect species strategies or biases in SDMs. We found low false-positive rates in species with small seeds, flowers attracting specialist pollinators, and specialized distributions (among annuals and perennials), low root:shoot ratios, wide root-systems, and large leaves (perennials only) ( R 2 = .52-58). We found high false-negative rates in species with marginal environmental distribution (among annuals and perennials), small seeds, relatively deep roots, and specialized distributions (annuals) or large leaves, wide root-systems, and monocarpic life cycle (perennials) ( R 2 = .38 for annuals and 0.65 for perennials). Overall, relevant traits are rarely indicative of the possible biases of SDMs, but rather reflect the species' reproductive strategy, dispersal ability, stress tolerance, and pollination strategies. Our results suggest that wide undirected dispersal in annual species and efficient resource acquisition in perennial species favor both capacities, whereas short life spans in perennial species favor persistence in suboptimal environmental conditions and flowers attracting specialist pollinators in perennial and annual species favor following optimal environmental conditions. Species that neither follow nor persist will be at risk under future environmental change. [ABSTRACT FROM AUTHOR]

ABSTRACT Supplemental feeding, whether intentional or accidental, alters wildlife foraging behaviors and may have consequences at the population and ecosystem levels. Wildlife feeding may also cause animals to develop aggressive behaviors toward conspecifics and people. The risks to humans is potentially accrued when the species is a native predator. Food-based attraction has been implicated in the development of human-directed aggression in the dingo ( Canis lupus dingo) population on Fraser Island, Queensland, Australia. Management strategies such as education programs, prohibition of inappropriate human behaviors, and fencing of garbage dumps have been implemented to stop the (intentional or inadvertent) feeding of dingoes by people. Despite these efforts, dingoes continue to obtain human-sourced food, suggesting that other means of supplemental feeding are still available. One possible source of subsidized food is recreational fishing, which is a popular activity on the island. We conducted a quasi-experimental study during May-June 2014 of dingo foraging behaviors on the eastern beach of Fraser Island. We video-recorded the behaviors of lone and groups of dingoes when they were in the vicinity of anglers or by themselves. We hypothesized that if recreational fishing was a source of subsidies to dingoes, then there would be differences in dingo foraging behavior among the 2 groups. We found that in the absence of anglers, dingoes spent 81% of their time engaged in mobile food-related behaviors. When anglers were present, however, they spent 52% of their time sitting and resting. These results suggest that dingoes shifted from active searching to a sit and wait foraging mode upon detecting recreational anglers. We observed an event in which a dingo spent 2 hours resting near an angler, then dug up the fish remains buried by the man as soon as he had left the area. This and other anecdotal evidence support the view that the changes in dingo foraging activity detected in this study were related to increased opportunities to secure food from anglers. Recreational fishing may play an important role in the inadvertent subsidizing of dingoes on Fraser Island, although further investigations are needed before proposing and implementing additional conservation and management actions. © 2017 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Based on optimal foraging theory, we propose a metric that allows evaluating the goodness of goal systems, that is, systems comprising multiple goals with facilitative and conflicting interrelations. This optimal foraging theory takes into account expectancy and value, as well as opportunity costs, of foraging. Applying this approach to goal systems provides a single index of goodness of a goal system for goal striving. Three quasi-experimental studies (N = 277, N = 145, and N = 210) provide evidence for the usefulness of this approach for goal systems comprising between 3 to 10 goals. Results indicate that persons with a more optimized goal-system are more conscientious and open to new experience, are more likely to represent their goals in terms of means (i.e., adopt a process focus), and are more satisfied and engaged with their goals. Persons with a suboptimal goal system tend to switch their goals more often and thereby optimize their goal system. We discuss limitations as well as possible future directions of this approach. [ABSTRACT FROM AUTHOR]

The present study aimed to understand human plant resource usage strategies in the context of the Ecological Apparency Hypothesis and Optimal Foraging Theory. The relationship between plant resource knowledge and availability was tested in a rural community (Palmital) in a dry Atlantic Forest fragment in the state of Minas Gerais, Southeastern Brazil, using data from phytosociological studies and interviews. We considered both total use and separate use categories. Use Value (UV) was significantly associated with all of the analyzed ecological variables, but there was an association with relative dominance and a weak relationship with relative density. When the UVs were separately analyzed for each category, we found that some, i.e., fuel and construction, corroborate the Ecological Apparency Hypothesis, while others do not, particularly the medicinal and food categories. In addition, we found large differences with respect to the ecological variables that best correlated with UV. The data suggest that the cost/benefit relationship predicted by Optimal Foraging Theory can explain the Ecological Apparency Hypothesis when the following factors are considered: (a) resource acquisition optimization and security; (b) a higher probability of acquiring more abundant species during random collection events; and (c) differential utilization patterns (distinct requirements for a specific use) for each use category. Some implications for conservation are also discussed. [ABSTRACT FROM AUTHOR]

In July 2020, Japan undertook the first deep-sea mining test of cobalt-rich crusts on the summit of Takuyo-Daigo Seamount within their exclusive economic zone (EEZ). Seabed mining regulations are currently being developed by the International Seabed Authority (ISA) 1 ; however, a lack of experimental data has so far constrained our understanding of the associated impacts, particularly from the release of sediment plumes. 2 The area of sediment re-deposition from the crust mining test was determined using modeled data and in situ observations. To investigate biological impacts, variations in seabed megafauna (animals > 1 cm) were quantified from seabed imagery collected around the excavation site before, 1 month, and 13 months after the test in areas both inside and outside (adjacent) expected deposition. Observable responses varied across community components: densities of sessile animals were similar between deposition and adjacent areas throughout the study; mobile epifauna were less abundant only in the deposition area following disturbance; and highly mobile swimmers showed reduced densities after the test in both deposition and adjacent areas following disturbance. These results stress that monitoring of highly mobile taxa may be essential to fully assess disturbance extent and magnitude. Fish may avoid areas even outside plume deposition, possibly owing to the creation of suboptimal feeding patches resulting from deposition. Our findings suggest sufficiently large (>300 × 300 m), distant, and representative control areas are essential to optimally map deep-sea mining impacts in ferromanganese crust habitats to ensure impact assessments encompass the full range of functional components in the megabenthic community (including mobile fishes) that typically inhabit seamounts. • Japan conducted the first mining test of seamount cobalt crusts in 2020 • Communities were examined over time both inside and outside of deposition areas • Swimming predators/scavengers appeared to have the strongest response to deposition • Suboptimal feeding conditions from deposition may cause avoidance of large patches Washburn et al. quantify seabed megafauna associated with the first deep-sea mining test of cobalt-rich crusts on seamounts performed by Japan in 2020. Results stress that highly mobile taxa may be more susceptible to deep-sea disturbances than currently expected and are thus likely essential for fully assessing the extent and magnitude of mining impacts. [ABSTRACT FROM AUTHOR]

The use of optimal foraging theory in archaeology has been criticized for focusing heavily on “negative” human-environmental interactions, particularly anthropogenic resource depression, in which prey populations are reduced by foragers’ own foraging activities. In addition, some researchers have suggested the focus on resource depression is more common in the zooarchaeological literature than in the archaeobotanical literature, indicating fundamental differences in the ways zooarchaeologists and archaeobotanists approach the archaeological record. In this paper, we assess these critiques through a review of the literature between 1997 and 2017. We find that studies identifying resource depression occur at similar rates in the archaeobotanical and zooarchaeological literature. In addition, while earlier archaeological applications of optimal foraging theory did focus heavily on the identification of resource depression, the literature published between 2013 and 2017 shows a wider variety of approaches.

Background Habituation, a form of non-associative learning, has several well-defined characteristics that apply to a wide range of physiological and behavioral responses in many organisms. In classic patch time allocation models, habituation is considered to be a major mechanistic component of parasitoid behavioral strategies. However, parasitoid behavioral responses to host cues have not previously been tested for the known, specific characteristics of habituation. Methods In the laboratory, we tested whether the foraging behavior of the egg parasitoid Trissolcus basalis shows specific characteristics of habituation in response to consecutive encounters with patches of host (Nezara viridula) chemical contact cues (footprints), in particular: (i) a training interval-dependent decline in response intensity, and (ii) a training interval-dependent recovery of the response. Results As would be expected of a habituated response, wasps trained at higher frequencies decreased their behavioral response to host footprints more quickly and to a greater degree than those trained at low frequencies, and subsequently showed a more rapid, although partial, recovery of their behavioral response to host footprints. This putative habituation learning could not be blocked by cold anesthesia, ingestion of an ATPase inhibitor, or ingestion of a protein synthesis inhibitor. Discussion Our study provides support for the assumption that diminishing responses of parasitoids to chemical indicators of host presence constitutes habituation as opposed to sensory fatigue, and provides a preliminary basis for exploring the underlying mechanisms.

Herbivores must balance energy needs with avoiding risks, using various cues to assess predation risk. The American beaver (Castor canadensis) is a semi-aquatic herbivore vulnerable to predation on land by wolves (Canis lupis). We tested the use of wolf urine as a potential tool to reduce human–beaver conflicts. We used infrared cameras to monitor use of terrestrial foraging trails by beavers during food cache construction in Seney National Wildlife Refuge, Michigan, from September to November 2008. Two foraging trails at 15 colonies (30 total trails) were monitored for 1 week to establish baseline use. One trail from each colony was then treated with wolf urine, and all trails were monitored an additional week to estimate changes in trail use. Mean number of beavers detected decreased 95% on urinetreated trails and was unchanged on untreated trails. Beavers also spent 95% less time on urine-treated trails as estimated by photograph time stamps, but did not change time spent on untreated trails. Sixteen other taxa of wildlife were detected; however, avoidance of urine-treated trails was not observed in these taxa. Species richness increased with urine treatment, mostly due to increased visitation by carnivores. Beavers appear to use olfaction to assess predation risk on land. Wolf urine may be a suitable deterrent for beaver herbivory.

Snow and ice determine winter forage availability for Arctic herbivores. Winter precipitation is anticipated to increase, and icing following warm spells and rain-on-snow (ROS) are likely to become more frequent. While this may reduce herbivore survival, fecundity and population growth, we can also expect behavioural and dietary responses. Here, we tested predictions from optimal foraging theory on how changing snowpack conditions influence choice of feeding craters and diet quality in a large generalist herbivore, the wild Svalbard reindeer. Snow and ice conditions over winter 2012/13 (a ‘normal’ winter with little ROS and icing) were measured in reindeer feeding craters, in paired controls one metre away and in fixed control sites. On average, feeding craters had less snow and integrated ram hardness (IRH, the force needed to reach the ground), but not less ice, than nearby controls. However, on this fine spatial scale, reindeer tended to select for microhabitat with worse snowpack conditions up to a certain level of snow (ca. 10 cm), ice (0.5 cm) and IRH (250 kg cm) in the nearby controls, reflecting the trade-off between selection for forage abundance versus accessibility in a sparsely vegetated environment. In this lichen-free system, faecal C:N ratios increased during winter as forage accessibility was increasingly restricted by snow, possibly indicating a reduction in diet quality due to changes in diet composition. Our study suggests that snowpack depth and hardness largely determine Svalbard reindeer feeding behaviour and diet quality during the course of a winter season.

Why do people want to vote for or against content at some online communities and not at others? Social foraging theory, particularly research on insect and other animal information sharing behavior, offers a new perspective. Borrowing concepts from social foraging theory, this study proposes that four factors drive people's intention to vote online content (positively or negatively): 1) altruistic motives; 2) identification with the community; 3) information quality; and 4) knowledge self-efficacy. The research model was tested in a survey of online news communities. It found that positive voting intention was predicted by altruistic motives, community identification, and knowledge self-efficacy. Information quality is important for positive voting, but it works indirectly through fostering stronger community identification. Negative voting intention was predicted by altruistic motives and information quality. Prior research has applied foraging theory to individuals acting alone, e.g., when an individual uses Google to search for information online. This study expands the application of foraging theory to the community context where individuals provide votes to influence others in their chosen community. The findings advance our knowledge about content voting and provide implications for practitioners of voting systems. [ABSTRACT FROM PUBLISHER]

Drawing from the concepts of optimal foraging theory, this paper presents and tests the assumptions of a foraging theory of police behavior during hot spots patrols. The theory explains why, over time, officers involved in hot spots policing interventions would leave the hot spots they are assigned to police and begin working within other locations. We test what factors influence the amounts of activity that officers undertake outside of their assigned hot spots and at nearby streets using data gathered as part of the Philadelphia Foot Patrol Experiment. Officers performed more activity outside of their beats as the experiment progressed. Several theoretically relevant variables predict the level of activity that officers perform outside their beats, including the size of the target area and the amounts of crime occurring within and outside of the target area. "Dosage diffusion" might be one reason why hot spot interventions have diminishing effects over time. From an optimal foraging theory perspective, hot spots requiring police officers to constrain their actions to pre-defined areas can be perceived as counter-intuitive by the officers, especially over extended periods of time. The results of this study support the suggestion that hot spots patrols should be short-term and randomly rotated across hot spots. [ABSTRACT FROM AUTHOR]

Optimal Foraging Theory (OFT), enables understanding of foraging behaviour, which is exhibited by all of life, through the assumption that foraging behaviour maximises some currency of foraging. OFT has been relatively successful for nectar-feeding animals, with energy the primary foraging currency, and less successful for generalist herbivores and omnivores, for which foraging currencies include nutrients. It has been extended to other areas of biology, applied to human foraging, is a strong ecological theory, and 2016 marks its' 50th birthday. Human foraging has been affected by inter-related, recent and rapid developments of agriculture, animal husbandry, technology, social living and culture. Consequently, the foraging environment in which humans evolved is long gone, and our foraging may not be well adapted to current circumstances. Human foraging is therefore caught in 'evolutionary traps'. For example, as generalist omnivores we evolved a 'balanced diet', commonly represented by 'food pyramids', reflecting how often we encountered and consumed various food types during our evolutionary past. We therefore evolved preferences to collect and consume foods high in fats, oils, sugar and salt, valuable when rare, but adversely affecting our health with increasing availability. Additionally, given diverse arrays of potential food items, we should mimic foraging behaviour of others, especially those we know, admire and trust. Consequently, we are strongly affected by cultural influences, and by advertising and marketing of food types and 'fad diets', especially when promoted by movie stars, sports heroes and the like. Being omnivores, animal meat will likely remain 'on the table' indefinitely, with consumption depending on availability, plus benefits and costs, whether real or imaginary, all ingredients of the optimal foraging approach. Of course, perceived benefits of consuming animal meat are likely to be greatly influenced through what we hear or see via others. Looking ahead, 'zoology on the table' will remain contentious, OFT will be significantly developed for non-human organisms with some interest in understanding human foraging, and there will be much further research on effectiveness of advertising. No doubt, we shall continue to be deluged with messages advocating what we should eat and drink, and health issues associated with non-optimal diets will persist. [ABSTRACT FROM AUTHOR]

Humans modify their environments in ways that significantly transform the earth's ecosystems. Recent research suggests that such niche-constructing behaviors are not passive human responses to environmental variation, but instead should be seen as active and intentional management of the environment. Although such research is useful in highlighting the interactive dynamics between humans and their natural world, the niche-construction framework, as currently applied, fails to explain why people would decide to modify their environments in the first place. To help resolve this problem, we use a model of technological intensification to analyze the cost-benefit trade-offs associated with niche construction as a form of patch investment. We use this model to assess the costs and benefits of three paradigmatic cases of intentional niche construction in Western North America: the application of fire in acorn groves, the manufacture of fishing weirs, and the adoption of maize agriculture. Intensification models predict that investing in patch modification (niche construction) only provides a net benefit when the amount of resources needed crosses a critical threshold that makes the initial investment worthwhile. From this, it follows that low-cost investments, such as burning in oak groves, should be quite common, while more costly investments, such as maize agriculture, should be less common and depend on the alternatives available in the local environment. We examine how patterns of mobility, risk management, territoriality, and private property also co-evolve with the costs and benefits of niche construction. This approach illustrates that explaining niche-constructing behavior requires understanding the economic trade-offs involved in patch investment. Integrating concepts from niche construction and technological intensification models within a behavioral ecological framework provides insights into the coevolution and active feedback between adaptive behaviors and environmental change across human history. [ABSTRACT FROM AUTHOR]

Changes in species' trophic niches due to habitat degradation can affect intra- and interspecific competition, with implications for biodiversity persistence. Difficulties of measuring species' interactions in the field limit our comprehension of competition outcomes along disturbance gradients. Thus, information on how habitat degradation can destabilize food webs is scarce, hindering predictions regarding responses of multispecies systems to environmental changes. Seagrass ecosystems are undergoing degradation. We address effects of Posidonia oceanica coverage reduction on the trophic organization of a macroinvertebrate community in the Tyrrhenian Sea (Italy), hypothesizing increased trophic generalism, niche overlap among species and thus competition and decreased community stability due to degraded conditions. Census data, isotopic analysis, and Bayesian mixing models were used to quantify the trophic niches of three abundant invertebrate species, and intra- and interspecific isotopic and resource-use similarity across locations differing in seagrass coverage. This allowed the computation of (1) competition strength, with respect to each other and remaining less abundant species and (2) habitat carrying capacity. To explore effects of the spatial scale on the interactions, we considered both individual locations and the entire study area (''meadow scale'). We observed that community stability and habitat carrying capacity decreased as P. oceanica coverage declined, whereas niche width, similarity of resource use and interspecific competition strength between species increased. Competition was stronger, and stability lower, at the meadow scale than at the location scale. Indirect effects of competition and the spatial compartmentalization of species interactions increased stability. Results emphasized the importance of trophic niche modifications for understanding effects of habitat loss on biodiversity persistence. Calculation of competition coefficients based on isotopic distances is a promising tool for describing competitive interactions in real communities, potentially extendible to any subset of ecological niche axes for which specimens' positions and pairwise distances can be obtained. [ABSTRACT FROM AUTHOR]