Foraging Behavior

Ant colony optimization is a technique for optimization that was introduced in the early 1990's. The inspiring source of ant colony optimization is the foraging behavior of real ant colonies. This behavior is exploited in artificial ant colonies for the search of approximate solutions to discrete optimization problems, to continuous optimization problems, and to important problems in telecommunications, such as routing and load balancing. First, we deal with the biological inspiration of ant colony optimization algorithms. We show how this biological inspiration can be transfered into an algorithm for discrete optimization. Then, we outline ant colony optimization in more general terms in the context of discrete optimization, and present some of the nowadays bestperforming ant colony optimization variants. After summarizing some important theoretical results, we demonstrate how ant colony optimization can be applied to continuous optimization problems. Finally, we provide examples of an interesting recent research direction: The hybridization with more classical techniques from artificial intelligence and operations research.

1 Laboratory of Comparative Psychology and Behavioral Biology, Departments of Psychology and Zoology, Oklahoma State University, 215 N. Murray, Stillwater, OK 74078, USA 2 Uludag Universitesi, M. Kemalpasa MYO, M. Kemalpasa, Bursa 16500, Turkey 3 Northwestern ...

Humans sometimes forage or distribute the products of foraging in ways that do not maximize individual energetic return rates. As an alternative to hypotheses that rely on reciprocal altruism to counter the costs of inefficiency, we suggest that the cost itself could be recouped through signal benefit. Costly signaling theory predicts that signals can provide fitness benefits when costs are honestly linked to signaler quality, and this information is broadcast to potential mates and competitors. Here, we test some predictions of costly signaling theory against empirical data on human food acquisition and sharing patterns. We show that at least two types of marine foraging, turtle hunting and spearfishing, as practiced among the Meriam (a Melanesian people of Torres Strait, Australia) meet key criteria for costly signaling: signal traits are (1) differentially costly or beneficial in ways that are (2) honestly linked to signaler quality, and (3) designed to effectively broadcast the signal. We conclude that relatively inefficient hunting or sharing choices may be maintained in a population if they serve as costly and reliable signals designed to reveal the signaler's qualities to observers.

Movements and foraging strategies of marine predators should cope with the hierarchical spatial distribution of resources. Th erefore, in order to predict the at-sea distribution of aerial predators, it is crucial to understand the factors governing trajectory decisions at diff erent scales. Using fi rst passage time (FPT) analysis on precision tracking information (GPS-loggers data) we were able to examine the foraging strategy of Cory ' s shearwaters Calonectris diomedea and to detect the adoption of area-restricted search (ARS), measuring the scale and duration of this behaviour. Data were collected from three diff erent populations foraging in diff erent oceanographic conditions. During long excursions birds only commuted between their colony and prey patches, while on their short movements birds increased the amount of looping movements. On short trips, birds addopted ARS behaviour at an average scale of 18 km and at a second nested scale of around 2 km. When engaging in long trips, fi rst scale of ARS occurred on average at about 67 km of radii and than a second nested scale at a radii of 24 km. Overall, the diff erent populations showed foraging patterns matching the habitats exploited: a) at smaller scales of ARS, sea-surface temperature, chlorophyll-a concentration and depth infl uenced the time of residence (i.e. FPT) of birds (with variations at a population level); b) at larger scales of ARS, FPT increased within regions of higher gradients of seasurface temperature, chlorophyl-a concentration and depth. Th is study demonstrates that Cory ' s shearwaters adopt scaledependent adjustments of movement in relation to the hierarchical distribution of the environment they exploit, matching the scale and duration of ARS with the hierarchical distribution of the environmental features.

We studied the foraging behavior and marine habitats used by Laysan (Phoebastria immutabilis) and Black-footed (Phoebastria nigripes) Albatrosses, during four consecutive breeding seasons to investigate whether these marine predators changed habitat preferences, foraging distributions, or both, in accordance with natural interannual variability in the marine environment. We used satellite telemetry to track a total of 37 Laysan and 36 Black-footed Albatrosses during the incubation periods of 2002-2006 at Tern Island, Northwest Hawaiian Islands. First passage time analysis was used to determine search effort of individual albatrosses along their respective tracks, and this metric was then related to oceanographic habitat variables using linear mixed-effects regression. The majority of individuals traveled to pelagic waters of the North Pacific, with Laysan Albatrosses demonstrating a more northwesterly distribution from the breeding colony. Laysan Albatrosses traveled farther, for longer periods, and demonstrated greater interannual variability in trip characteristics than Black-footed Albatrosses. For Laysan Albatrosses, maximum trip distance was negatively correlated with body mass change during foraging and overall breeding success. There was considerable interspecific segregation of foraging habitats, and low overlap of foraging distributions between years. For all years, and both species, sea surface temperature was consistently the most important environmental variable predicting search effort of albatrosses, suggesting that both species use similar environmental cues when searching for prey. In the context of climate variability, our results suggest that Hawaiian albatrosses demonstrate flexibility in foraging strategies and track preferred marine habitats. However, adjusting foraging behavior to climatic variability may have energetic, and subsequent reproductive consequences.

Birds gather information about their environment mainly through vision by scanning their surroundings. Many prevalent models of social foraging assume that foraging and scanning are mutually exclusive. Although this assumption is valid for birds with narrow visual fields, these models have also been applied to species with wide fields. In fact, available models do not make precise predictions for birds with large visual fields, in which the head-up, head-down dichotomy is not accurate and, moreover, do not consider the effects of detection distance and limited attention. Studies of how different types of visual information are acquired as a function of body posture and of how information flows within flocks offer new insights into the costs and benefits of living in groups. Box 1. The big picture † Foraging animals use their senses to respond to food distribution and predator danger, and many forage in groups to deal appropriately with these needs. † Social foragers receive information through their own monitoring of external events and through monitoring the behaviour of their neighbours. † These different information inputs conflict with each other, and maximally efficient predator detection, food finding and neighbor monitoring are achieved by different body postures and head orientation. † Current models rarely take into account that, to infer visual targets from body postures, it is necessary to consider the organization of vision, which can vary dramatically among species. † We argue that specific features of visual systems should be incorporated into theoretical social foraging models and that doing so will change predictions and validate the use of behavioural observations as tests of functional hypotheses.

Categorizing animal populations by diet can mask important intrapopulation variation, which is crucial to understanding a species' trophic niche width. To test hypotheses related to intrapopulation variation in foraging or the presence of diet specialization, we conducted stable isotope analysis (d 13 C, d 15 N) on hair and claw samples from 51 grizzly bears (Ursus arctos) collected from 2003 to 2006 in the Mackenzie Delta region of the Canadian Arctic. We examined within-population differences in the foraging patterns of males and females and the relationship between trophic position (derived from d 15 N measurements) and individual movement. The range of d 15 N values in hair and claw (2.0-11.0%) suggested a wide niche width and cluster analyses indicated the presence of three foraging groups within the population, ranging from nearcomplete herbivory to near-complete carnivory. We found no linear relationship between home range size and trophic position when the data were continuous or when grouped by foraging behavior. However, the movement rate of females increased linearly with trophic position. We used multisource dual-isotope mixing models to determine the relative contributions of seven prey sources within each foraging group for both males and females. The mean bear dietary endpoint across all foraging groups for each sex fell toward the center of the mixing polygon, which suggested relatively well-mixed diets. The primary dietary difference across foraging groups was the proportional contribution of herbaceous foods, which decreased for both males and females from 42-76 to 0-27% and 62-81 to 0-44%, respectively. Grizzlies of the Mackenzie Delta live in extremely harsh conditions and identifying within-population diet specialization has improved our understanding of varying habitat requirements within the population.

In social foraging, scroungers take a disproportionately large share of the food found relative to their own food-searching efforts, while producers find more food than they manage to monopolize. We present a model of social foraging acknowledging the finder's advantage and foraging role asymmetries among individuals but incorporating the possibility that producers and scroungers differ in vigilance level and in vulnerability to predators. This allows simultaneous examination of both foraging benefits and anti-predatory aspects of grouping behaviour. Instead of seeking for equal payoff conditions, we first look for groups in which foraging character combinations and anti-predatory properties of producers and scroungers minimize the phenotype-specific predation hazard over food-intake rate, R i /I i , that is, fixed phenotype R i /I i minima. In the second approach, we allow individuals to change their foraging status to achieve lower R i /I i and look for combinations where it no longer pays for either producers or scroungers to change their roles, that is, evolutionarily stable group compositions, ESS. Various character combinations allow the phenotype-specific minima. In most cases, however, producers' and scroungers' minima are achievable only in different group compositions. The ESS combinations of producers and scroungers deviate widely from those combinations yielding phenotype-specific minima of R i /I i. If individuals are allowed to be flexible in adopting either a producer or a scrounger role, ESS group compositions will emerge, even though they are more expensive for both producers and scroungers in terms of R i /I i than group compositions yielding the phenotype-specific R i /I i minima.

The relationship between food flavors and postingestive feedback enables mammalian herbivores to procure nutrients and avoid toxins within ever-changing environments. We conducted four experiments with red-winged blackbirds (Agelaius phoeniceus) in captivity to determine the relative roles of color and flavor cues paired with negative postingestive feedback. We first conducted baseline tests to assess preferences for colors and flavors. All blackbirds preferred red- to blue-colored food, and they preferred umami- (l-alanine) flavored to bitter/astringent food (tannic acid). We observed no difference in consumption of salty (NaCl) vs sour (citric acid) foods during baseline tests (i.e., neutral flavors). We then conditioned experimentally naïve blackbirds with intraperitoneal injections of lithium chloride (LiCl) to avoid food treated with red and l-alanine, or red and NaCl (n=30 birds per conditioning group). Subsequent to conditioning with LiCl, three test groups were established f...

This paper proposes a model for the reoccupation of ants in a region of attraction, using evolutive partial differential diffusion-advection equations, in which the population dispersion and velocity in directions x and y are fuzzy parameters. The domain under study contains an attractive region, representing areas with high concentrations of palatable host plants with better nutritious qualities. The algorithm developed here uses information about the foraging behavior of a leaf-cutting ant colony of the Amazon region in northern Brazil. In the first model, we determined the numerical solution of the partial differential deterministic equation with constant dispersion and velocity, without incorporating uncertainties that may occur in this type of biological phenomenon. In the second model, we calculated the numerical solution of the partial differential equation, determining the dispersion at each iteration and for each triangular finite element. The dispersion was determined from a fuzzy rule-based system that depends on the number of individuals of the population and on the characteristics of the terrain. In this model, we also considered the velocity along the x and y directions as a fuzzy parameter that depends on the ant movement characteristics on the terrain in the y and x directions, respectively. The two models produced solutions consistent with ant behavior in response to the proximity of an attractive region, as stated in the papers by Shepherd (1982) [2] and Vasconcelos (1999) [3], but the fuzzy model incorporates uncertainties that do occur in the biological phenomenon under study.

Frugivores often track ripe fruit abundance closely across local areas despite the ephemeral and typically patchy distributions of this resource. We use spatial auto-and cross-correlation analyses to quantify spatial patterns of fruit abundance and avian frugivory across a 4-month period within a forested 4.05-ha study grid in Puerto Rico. Analyses focused on two tanager species, Spindalis portoricensis and Nesospingus speculiferus, and their principal food plants. Three broad questions are addressed: (1) at what spatial scales is fruit abundance and frugivory patchy; (2) at what spatial scales do frugivores respond to fruit abundance; and (3) to what extent do spatial patterns of frugivory overlap between bird species? Fruit patch size, species composition, and heterogeneity was variable among months, despite fruit patch locations remaining relatively consistent between months. Positive correlations between frugivory and fruit abundance suggested tanagers successfully tracked fruit abundance. Frugivory was, however, more localized than fruit abundance. Scales of spatial overlap in frugivory and monthly variation in the foraging locations of the two tanager species suggested that interspecific facilitation may have been important in determining bird foraging locations. In particular, S. portoricensis, a specialist frugivore, may have relied on the loud calls of the gregarious generalist, N. speculiferus, to find new foraging areas. Such a mechanism could help explain the formation of mixed species feeding flocks and highlights the potential importance of facilitation between species that share resources.

Reconstructions of foraging behavior and diet are central to our understanding of fossil hominin ecology and evolution. Current hypotheses for the evolution of the genus Homo invoke a change in foraging behavior to include higher quality foods. Recent microwear texture analyses of fossil hominin teeth have suggested that the evolution of Homo erectus may have been marked by a transition to a more variable diet. In this study, we used microwear texture analysis to examine the occlusal surface of 2 molars from Dmanisi, a 1.8 million year old fossil hominin site in the Republic of Georgia. The Dmanisi molars were characterized by a moderate degree of surface complexity (Asfc), low textural fill volume (Tfv), and a relatively low scale of maximum complexity (Smc), similar to specimens of early African H. erectus. While caution must be used in drawing conclusions from this small sample (n = 2), these results are consistent with continuity in diet as H. erectus expanded into Eurasia.

In birds, the position and extent of the region of binocular vision appears to be determined primarily by feeding ecology. Of prime importance is the degree to which vision is used for the precise control of bill position when foraging. Skimmers ( Rynchops , Rynchopidae, Charadriiformes) exhibit a unique foraging behaviour and associated structural adaptations. When foraging they fly low and straight over water with the mouth open and the mandible partially submerged. Items that are hit by the lower mandible are grasped by a rapid reflex bill closure. It is believed that this unique 'skimming' foraging technique is guided by tactile rather than visual cues. It is predicted therefore that the visual fields of skimmers will have similar topography to those of other tactile feeding birds. We determined retinal visual fields in Black Skimmers Rynchops niger using an ophthalmoscopic reflex technique. Contrary to expectation the visual fields of Black Skimmers are not like those of other tactile feeders. They show high similarity with those of birds that feed by precision-pecking. The projection of the bill tip when the mouth is closed and when open (as in skimming) falls within the frontal binocular field and there is an extensive blind area above and behind the head. We argue that this visual field topography functions to achieve accurate bill positioning with respect to the water surface when skimming and, because foraging skimmers cannot determine the identity of what they are seizing as they skim, to permit the visual identification of prey items held between the mandibles after they have been taken from the water surface. When skimming, only a small portion of the binocular field, approximately 5 ° wide and extending 5 ° above the horizontal, looks in the direction of travel. The small size of this forward-facing region of binocularity in skimmers suggests that control of locomotion in birds does not necessarily require extensive binocularity in the direction of travel.

In Experiment 1 each response on a switch delivered food to a cup, with the distance between the switch and the cup varied across conditions. The number of responses made before traveling to collect and eat the food increased with distance for rats, but not for pigeons. In Experiment 2, two switches were at different distances from a fixed food source; both pigeons and rats preferentially used the switch closest to the food source. In Experiment 3 each response on the left key increased the upcoming hopper duration by 0.5, 1.5 or 2.5 s. Completing a ratio requirement on the right key of 1, 4, 8, 16 or 32 responses then produced the food hopper for a duration that depended on the number of prior left pecks. As the ratio requirement increased on the right key, pigeons responded more on the left key and earned more food. Rats, it is concluded, have episodic foresight, whereas pigeons are not so good at forethought.

Bees need pollen for their maintenance and development. Maize tassels (Zea mays L.) produce large amounts of pollen, which are visited by several bee species. This experiment was conducted in Raj Mohini Devi College of Agriculture and Research station, Ambikapur (Chhattisgarh) in 2020 with the objective to evaluate the factors affecting the foraging behavior of bees in maize.

Periodic episodes of food scarcity may highlight the adaptive value of certain anatomical traits, particularly those that facilitate the acquisition and digestion of exigent fallback foods. To better understand the selective pressures that favored the distinctive dental and locomotor morphologies of gibbons and orangutans, we examined the foraging and ranging behavior of sympatric Hylobates albibarbis and Pongo pygmaeus wurmbii during an episode of low fruit availability at Tuanan, Kalimantan Tengah, Indonesia. We found that Hylobates ranged 0.5 km day−1 or 33% farther than did Pongo, but the overall daily ranging of both species did not vary as fruit availability decreased by as much as 50%. Among gibbons, we observed dietary switching to fallback foods; in particular, there was a progressively greater reliance on figs, liana products, and unripe fruit. Orangutans relied heavily on unripe fruit and fracture-resistant bark and pith tissues. Despite these divergent fallback patterns, the stiffness of fruit mesocarp consumed by Hylobates and Pongo did not differ. We discuss canine and molar functional morphology with respect to dietary mechanics. Next, to contextualize these results, we discuss our findings with respect to forest structure. The rain forests of Southeast Asia have been described as having open, discontinuous canopies. Such a structure may inform our understanding of the ranging behavior and distinctive locomotion of apes in the region, namely richochetal brachiation and quadrumanous clambering. Our approach of integrating behavioral ecology with physical measures of food may be a powerful tool for understanding the functional adaptations of primates. Am J Phys Anthropol 140:716–726, 2009. © 2009 Wiley-Liss, Inc.

Genetic variation in the gene foraging (for) is associated with a natural behavioral dimorphism in the fruit fly, Drosophila melanogaster. Some larvae, called 'rovers', have increased foraging locomotion compared to others, called 'sitters', and this difference is directly related to for-encoded cGMP-dependent protein kinase (PKG) activity. Here we report that larvae with mutations in the gene dgca1, which encodes a soluble guanylyl cyclase (sGC) subunit, have increases in both PKG activity and foraging locomotion. This is contrary to our original prediction that, based on the role of sGC in the synthesis of cGMP, dgca1 mutant larvae would have deficient cGMP production leading to decreased PKG activation and thus reduced larval foraging locomotion. We performed DNA microarray analyses to compare transcriptional changes induced by a dgca1 mutation in both rover and sitter wildtype genetic backgrounds. In either background, we identified many genes that are differentially transcribed, and interestingly, relatively few are affected in both backgrounds. Furthermore, several of these commonly affected genes are enhanced or suppressed in a backgrounddependent manner. Thus, genetic background has a critical influence on the molecular effects of this mutation. These findings will support future investigations of Drosophila foraging behavior.

Spiral-shaped foraging trace fossils, assigned to the graphoglyptid cf. Spirorhaphe azteca, are reported from an Early Permian intertidal flat in the Robledo Mountains of southern New Mexico, USA. Remarkably similar spiral-shaped structures are produced in modern intertidal flats by the paraonid polychaete Paraonis fulgens, and function as traps to capture mobile microorganisms migrating in the sediment in response to tides. We envisage a similar function for the Early Permian trace fossils. Previous studies have suggested that the lack of P. fulgens-type traces from ancient intertidal deposits indicates that such behavior only evolved geologically recently in such settings. However, this report demonstrates that such specialized foraging behavior was present in intertidal settings by at least the Early Permian. Graphoglyptids are typical of deep-marine settings, and characteristic of the Nereites ichnofacies. This represents their first undoubted occurrence in intertidal facies in the geological record. We postulate that the occurrence of graphoglyptids in deep-marine and intertidal settings is related to the predictability of resources. The scarcity of intertidal graphoglyptids in the geological record is most likely a preservational effect.

Highly mobile aquatic predators are known to forage in the intertidal during periods of immersion. There is limited quantitative information, however, on the extent to which these predators influence the abundance of grazing molluscs which are known to have a key role in structuring intertidal assemblages. Our preliminary video observations revealed that crabs and small fish were abundant on shores in southwest England during high-tide. We then used manipulative experiments to quantify the effect of small mobile aquatic predators on the abundance of limpets (Patella vulgata L.). On the lower shore at two moderately sheltered rocky shores three treatments were established: complete cage, partial cage (cage control) and uncaged (natural condition). The complete cages excluded all predators. The partial cage treatment allowed full access to small predators and the uncaged treatment allowed access to all predators. After two months, limpet abundance in uncaged and partial cage treatments had declined by around 50% compared to the complete cage treatment. Population structure also changed with survival of larger individuals being greater than smaller individuals in the open and partial cage treatments compared to the complete cage treatment. The effects of excluding predators were consistent at small (meters) and large spatial scales (kilometres) and hence, it would appear that the outcomes of our research are generally applicable to similar shores in the region. To explore the mechanism behind the differential effects of predators according to prey size, we compared the detachment force required to remove limpets of differing sizes from the shore. This was around four times greater for larger individuals than for smaller ones indicating that smaller limpets were more vulnerable to predation. These effects were also consistent between locations. Subsequent laboratory observations showed that the crabs Carcinus maenas (L.), Necora puber (L.) and Cancer pagurus (L.) which are locally abundant predators of limpets, had differing handling behaviour but were all highly efficient at removing limpets from substratum. Hence, shell width and attachment force appeared to be critical factors influencing the vulnerability of limpets to predation by these crabs. Limpets are known to control the abundance of macroalgae on shores in the Northeast Atlantic and so our conclusions about the role of mobile predators in regulating the abundance of these grazers are important to our broader understanding of the ecology of these shores.

A large number of South Africa's elephants can be found on small wildlife reserves. The large nutritional demands and destructive foraging behavior of elephants can threaten rare species of vegetation. If conservation management is to protect threatened species of vegetation, knowing how long elephants will stay in one area of a reserve as well as which area they will move to next could be useful. The goal of this study was to train a recurrent neural network to predict an elephant herd's next position in the Pongola Game Reserve. Accurate predictions would provide a useful tool in assessing future impact of elephant populations on different areas of the reserve. Particle swarm optimization (PSO), PSO initialized backpropagation (PSO-BP) and PSO initialized backpropagation through time (PSO-BPTT) algorithms are used to adapt the recurrent neural networks weights. The effectiveness of PSO, PSO-BP and PSO-BPTT for training a recurrent neural network for elephant migration prediction is compared and PSO-BPTT produces the most accurate predictions at the expense of more computational cost.

Aim Tracking technologies are often proposed as a method to elucidate the complex migratory life histories of migratory marine vertebrates, allowing spatially explicit threats to be identified and mitigated. We conducted a global analysis of foraging areas of adult green turtles (Chelonia mydas) subject to satellite tracking (n = 145) and the conservation designation of these areas according to International Union for Conservation of Nature criteria. Location The green turtle has a largely circumtropical distribution, with adults migrating up to thousands of kilometres between nesting beaches and foraging areas, typically in neritic seagrass or algal beds. Methods We undertook an assessment of satellite tracking projects that followed the movements of green turtles in tropical and subtropical habitats. This approach was facilitated by the use of the Satellite Tracking and Analysis Tool (http:// www.seaturtle.org) and the integration of publicly available data on Marine Protected Areas (MPAs). Results We show that turtles aggregate in designated MPAs far more than would be expected by chance when considered globally (35% of all turtles were located within MPAs) or separately by ocean basin (Atlantic 67%, Indian 34%, Mediterranean 19%, Pacific 16%). Furthermore, we show that the size, level of protection and time of establishment of MPAs affects the likelihood of MPAs containing foraging turtles, highlighting the importance of large, well-established reserves. Main conclusions Our findings constitute compelling evidence of the worldwide effectiveness of extant MPAs in circumscribing important foraging habitats for a marine megavertebrate.

Subterranean termites have highly cryptic life habits and their foraging activities are as a rule confined to below-ground level gallery systems. Mark–release–recapture (MRR) using fat-soluble histological dyes is a candidate method for the study of foraging dynamics and territories, but has not hitherto been standardized experimentally. A wide range of dye types and concentrations is reported in the literature. In this study, six potential dyes were evaluated at different concentrations for marking workers of Reticulitermes grassei (Clément) (Isoptera: Rhinotermitidae), under laboratory and simulated field conditions. Neutral red (1% wt/wt) was considered the most effective while showing acceptably low toxicity. In a subsequent field trial using dye impregnated into a wooden bait, the MMR procedure was used to map the foraging territory perimeter of a single colony. Assumptions inherent in the interpretation of MMR data are reviewed. To map the foraging territory perimeter by this method, two theoretical approaches are defined (a conservative and a non-conservative hypothesis). We show that the approach adopted may affect the estimate obtained by as much as 100%. Results are discussed in the context of the ecology and behaviour of subterranean termite colonies.

To place social insect foraging behavior within an evolutionary context, it is necessary to establish relationships between individual foraging decisions and parameters influencing colony fitness. To address this problem, we examined interactions between individual foraging behavior and pollen storage levels in the honey bee, Apis mellifera L. Colonies responded to low pollen storage conditions by increasing pollen intake rates 54% relative to high pollen storage conditions, demonstrating a direct relationship between pollen storage levels and foraging effort. Approximately 80% of the difference in pollen intake rates was accounted for by variation in individual foraging effort, via changes in foraging activity and individual pollen load size. An additional 20% resulted from changes in the proportion of the foraging population collecting pollen. Under both high and low pollen storage treatments, colonies returned pollen storage levels to pre-experimental levels within 16 days, suggesting that honey bees regulate pollen storage levels around a homeostatic set point. We also found a direct relationship between pollen storage levels and colony brood production, demonstrating the potential for cumulative changes in individual foraging decisions to affect colony fitness.

Novelty seeking refers to the tendency of humans and animals to explore novel and unfamiliar stimuli and environments. The idea that dopamine modulates novelty seeking is supported by evidence that novel stimuli excite dopamine neurons and activate brain regions receiving dopaminergic input. In addition, dopamine is shown to drive exploratory behavior in novel environments. It is not clear whether dopamine promotes novelty seeking when it is framed as the decision to explore novel options versus the exploitation of familiar options. To test this hypothesis, we administered systemic injections of saline or GBR-12909, a selective dopamine transporter (DAT) inhibitor, to monkeys and assessed their novelty seeking behavior during a probabilistic decision making task. The task involved pseudorandom introductions of novel choice options. This allowed monkeys the opportunity to explore novel options or to exploit familiar options that they had already sampled. We found that DAT blockade increased the monkeys' preference for novel options. A reinforcement learning (RL) model fit to the monkeys' choice data showed that increased novelty seeking after DAT blockade was driven by an increase in the initial value the monkeys assigned to novel options. However, blocking DAT did not modulate the rate at which the monkeys learned which cues were most predictive of reward or their tendency to exploit that knowledge. These data demonstrate that dopamine enhances novelty-driven value and imply that excessive novelty seeking-characteristic of impulsivity and behavioral addictions-might be caused by increases in dopamine, stemming from less reuptake.

Many grazing-management challenges stem from poor livestock distribution resulting in overuse of some areas and low utilization of others. Managing livestock-distribution patterns requires knowledge of pasture characteristics and animal behavior patterns. Behavioral patterns result from recognizable processes that include inherited attributes, individual and social learning systems, cue-consequence specificity, predispositions toward novel stimuli, and spatial memory. Through these behavioral mechanisms, animals form and revise preferences and aversions for specific locations in their foraging landscape. To accomplish habitat selection, domestic herbivores use sight and sound cues to seek and return to high-quality foraging locations. Nested within habitat selection are learned diet preferences and aversions by which ungulate herbivores associate taste with positive or negative postingestive feedback. The deliberate and careful modification of animal attributes and habitat characteristics could yield options for adaptive rangeland management. In this article, we describe the basic principles that underlie how animals make decisions about where to forage and how long to stay in a particular habitat. We also suggest management practices designed to modify animal behavior and alter habitat-use patterns.

Nectar robbers are birds, insects, or other flower visitors that remove nectar from flowers through a hole pierced or bitten in the corolla. This paper is a review of the effects of nectar robbers on pollinators, pollination, and fitness of the plants they rob. Charles Darwin assumed that nectar robbers had a negative impact on the plants that they visit, but research done in the last 50 years indicates that they often have a beneficial or neutral effect. Several studies document that robbers frequently pollinate the plants that they visit. Robbers may ...

Hyperactivity in anorexia nervosa is difficult to control and negatively impacts outcome. Hyperactivity is a key driving force to starvation in an animal model named activity-based anorexia (ABA). Recent research has started unraveling what mechanisms underlie this hyperactivity. Besides a general increase in locomotor activity that may be an expression of foraging behavior and involves frontal brain regions, the increased locomotor activity expressed before food is presented (food anticipatory behavior or FAA) involves hypothalamic neural circuits. Ghrelin plays a role in FAA, whereas decreased leptin signaling is involved in both aspects of increased locomotor activity. We hypothesize that increased ghrelin and decreased leptin signaling drive the activity of dopamine neurons in the ventral tegmental area. In anorexia nervosa patients, this altered activity of the dopamine system may be involved not only in hyperactivity but also in aberrant cognitive processing related to food.

Elephants (Loxodonta africana) exhibit pronounced sexual dimorphism, and in this study we test the prediction that the differences in body size and sociality are significant enough to drive divergent foraging strategies and ultimately sexual segregation. Body size influences the foraging behaviour of herbivores through the differential scaling coefficients of metabolism and gut size, with larger bodied individuals being able to tolerate greater quantities of low-quality, fibrous vegetation, whilst having lower mass-specific energy requirements. We test two distinct theories: the scramble competition hypothesis (SCH) and the forage selection hypothesis (FSH). Comprehensive behavioural data were collected from the Pongola Game Reserve and the Phinda Private Game Reserve in South Africa over a 2.5-year period. The data were analysed using sex as the independent variable. Adult females targeted a wider range of species, adopted a more selective foraging approach and exhibited greater bite rates as predicted by the body size hypothesis and the increased demands of reproductive investment (lactation and pregnancy). Males had longer feeding bouts, displayed significantly more destructive behaviour (31% of observations, 11% for females) and ingested greater quantities of forage during each feeding bout. The independent ranging behaviour of adult males enables them to have longer foraging bouts as they experience fewer social constraints than females. The SCH was rejected as a cause of sexual segregation due to the relative abundance of low quality forage, and the fact that feeding heights were similar for both males and females. However, we conclude that the differences in the foraging strategies of the sexes are sufficient to cause spatial segregation as postulated by the FSH. Sexual dimorphism and the associated behavioural differences have important implications for the management and conservation of elephant and other dimorphic species, with the sexes effectively acting as distinct “ecological species”.

The acclimation, foraging behavior, and pollination efÞciency of stingless bees of the species Nannotrigona perilampoides Cresson were evaluated in tomato (Lycopersicon esculentum Mill.) plants cultivated in two greenhouses. The greenhouses were divided into three areas of 16 m 2 , and one of the following treatments was used for pollination: stingless bees (SB), mechanical vibration (MV), and no pollination (NP). Observations were conducted once a week from 0800 to 1600 hours during 2 mo. The acclimation of the bees to the greenhouses was estimated by the number of bees that did not return to the hive (lost bees) and by comparing the population of the colonies (brood and adults). The foraging activity of the bees across the day was evaluated by comparing the number of foragers per hour. The inßuence of environmental variables on the foraging activity was also analyzed. The pollination efÞciency was compared among treatments through the percentage of fruit set, weight of individual fruit, kilograms of fruit produced per square meter, and the number of seed per fruit. The bees started foraging on the ßowers Ϸ7 d after the colonies were introduced to the greenhouse. There was a decline in the population of the colonies across the experiment, but colonies did not die out. Correlations of environmental variables with the foraging activity of the bees showed that none of them had a signiÞcant inßuence on pollen foraging. However, water collection was positively correlated with the temperature and negatively correlated with the humidity inside the greenhouse. The estimation of the pollination efÞciency per treatment showed that there were signiÞcant differences in fruit set in SB (83 Ϯ 4.2) and MV (78.5 Ϯ 6.4) compared with NP (52.6 Ϯ 7.6). However, the average weight of the fruit was similar for the three treatments (65 g). There were signiÞcant differences for seed number in SB (200 Ϯ 15.3) and MV (232 Ϯ 21.4) compared with NP (120 Ϯ 16.6). The productivity in kilograms of fruit per square meter was higher in SB (5.72 Ϯ 0.61) and MV (5.66 Ϯ 0.58 kg) compared with NP (3.34 Ϯ 0.72). The number of seed was positively correlated with the weight of the fruit. We conclude that the use of Nannotrigona testaceicornis Rondani, for pollinating greenhouse tomatoes in tropical climates, could be an alternative to the use of highly defensive African-derived Apis mellifera or non-native bumble bees (Bombus spp.). However, more research is needed to evaluate the cost/beneÞt on large-scale greenhouse pollination using N. perilampoides Cresson against other bee species and pollination methods.

Mehr als 3300 Pollenladungen und Brutzelleninhalte von insgesamt 270 Bienenarten wurden lichtund zum Teil auch rasterelektronenmikroskopisch untersucht. Dadurch können Pollen-Spezialisten (oligolektische Arten) und -Generalisten (polylektische Arten) unterschieden werden, was anhand einiger Beispiele erläutert wird. Oligolektisch sind : Andrena agilissima und Osmia brevicornis an Brassicaceae, Andrena curvungula und Melitta haemorrhoidalis an Campanula (Campanulaceae), Andrena lathyri an Vicia und Lathyrus (Fabaceae), Andrena proxima an Apiaceae, Andrena vaga an Salix (Salicaceae), Chelostoma florisomne an Ranunculus (Ranunculaceae), Osmia cerinthidis an Cerinthe (Boraginaceae), Tetralonia alticincta an Asteraceae. Als polylektisch erwiesen sich : Andrena combinata, Anthophora bimaculata und Osmia cornuta. Sowohl bei oligolektischen wie bei polylektischen Arten zeigen die Analysen alle Übergänge zwischen hoher Blütenstetigkeit und der Nutzung mehrere Pollenquellen während eines Sammelfluges. Die Ergebnisse der Pollenanalysen werden mit den oft sehr diffusen Literaturangaben über « Futterpflanzen » verglichen, die Spezialisierungen (Oligolektie) oft nicht erkennen lassen. Zur zweifelsfreien Feststellung der Oligolektie ist die Pollenanalyse ein unverzichtbares Hilfsmittel.

Mehr als 3300 Pollenladungen und Brutzelleninhalte von insgesamt 270 Bienenarten wurden lichtund zum Teil auch rasterelektronenmikroskopisch untersucht. Dadurch können Pollen-Spezialisten (oligolektische Arten) und -Generalisten (polylektische Arten) unterschieden werden, was anhand einiger Beispiele erläutert wird. Oligolektisch sind : Andrena agilissima und Osmia brevicornis an Brassicaceae, Andrena curvungula und Melitta haemorrhoidalis an Campanula (Campanulaceae), Andrena lathyri an Vicia und Lathyrus (Fabaceae), Andrena proxima an Apiaceae, Andrena vaga an Salix (Salicaceae), Chelostoma florisomne an Ranunculus (Ranunculaceae), Osmia cerinthidis an Cerinthe (Boraginaceae), Tetralonia alticincta an Asteraceae. Als polylektisch erwiesen sich : Andrena combinata, Anthophora bimaculata und Osmia cornuta. Sowohl bei oligolektischen wie bei polylektischen Arten zeigen die Analysen alle Übergänge zwischen hoher Blütenstetigkeit und der Nutzung mehrere Pollenquellen während eines Sammelfluges. Die Ergebnisse der Pollenanalysen werden mit den oft sehr diffusen Literaturangaben über « Futterpflanzen » verglichen, die Spezialisierungen (Oligolektie) oft nicht erkennen lassen. Zur zweifelsfreien Feststellung der Oligolektie ist die Pollenanalyse ein unverzichtbares Hilfsmittel.

Previous studies have proposed that seagrass habitats, by supporting diverse and abundant fish assemblages, are preferred by foraging dolphins in coastal systems. To test this hypothesis, we (1) examined the fine-scale behavior of bottlenose dolphins in relatively pristine and developed inshore sites near Clearwater Harbor, Florida, USA, and (2) used an otter trawl to sample potential fish prey in non-seagrass and seagrass habitats. In the pristine site, dolphins preferred dredged channel and spoil-island habitats, while least preferring shallow seagrass habitats. In the developed site, foraging dolphins preferred the natural channel habitat, but exhibited little further selection. Therefore, the hypothesis that dolphins prefer seagrass habitats while foraging was rejected. Feeding frequency was significantly associated with diel state, with foraging peaking at dawn and decreasing throughout the day. Dolphin group size was negatively correlated and nearest neighbor distance positively correlated with feeding frequency. Analysis of trawl data focused on the pinfish Lagodon rhomboides which dominates the diets of dolphins in west Florida. The relative abundance of pinfish was significantly greater and standard lengths significantly less in seagrass than in non-seagrass habitats. Dolphins therefore forage in non-seagrass habitats where fish prey is both larger and perhaps more available. Although seagrass habitats support greater abundance of smaller fishes, they also provide a structural refuge which obscures fishes both visually and possibly acoustically. Thus, the importance of seagrasses to the health of coastal dolphins is probably indirect, as seagrasses support fish populations on which dolphins rely.

Most herbivores are facultative generalists and include a variety of plant species and plant parts in their diet that vary in nutrient content. To counter herbivory, many plants produce secondary metabolites (PSMs) that can act as toxins or digestibility reducers. When choosing a food item, herbivores therefore face a trade-off between the nutritional benefits and the physiological and behavioural costs, or effort invested, in dealing with these anti-herbivore plant traits. PSMs also vary within a backdrop of primary plant constituents, including nutrients. This variation means that animals have the potential to choose amongst a wide array of combinations of plant primary and secondary chemistry.  Furthermore, because PSMs can interact biochemically with nutrients and with each other in the gut of herbivores, the choices that herbivores make when deciding what to eat are likely to be both complex and diverse.
The details of how PSMs and nutrients shape the behavioural foraging strategies of herbivores have been widely studied in captive animals with the focus almost always on individual components of diet and diet choice. In contrast, this thesis takes a wide and inclusive approach towards understanding the foraging behaviours of free-ranging mammalian browsers using the Swamp Wallaby (Wallabia bicolor) as a model. To achieve this, my research has four main goals: 1) to assess the importance of vegetation structure and composition in the foraging decisions of herbivores; 2) to determine whether volatile PSMs can have multiple functions in the foraging of free ranging herbivores; 3) to define how the chemical composition of food sources can alter the foraging decisions of free ranging herbivores; and 4) to elucidate if the availability of choice can affect the capacity of herbivores to deal with plant toxins.
In order to achieve these goals I used the Giving-up Density (GUD) methodological framework throughout my thesis. This is a framework for field studies that imposes an exponentially increasing harvesting cost as food is consumed at patches. The GUD framework has a series of advantages and disadvantages that became obvious during my research. Therefore, I decided to dedicate my last chapter (5) to the review and discussion of the methodology, and the construction of a comprehensive guide showing practical approaches that can be used to tackle any problems with this methodology.
For my first aim, I compared GUDs left by swamp wallabies with the vegetation characteristics (Cover, richness and diversity) of the area surrounding each feeding station. I found some support to the importance of plant community compositions in influencing the foraging decisions of this mammalian herbivore, and no evidence of structural characteristics playing any role in this process.
For my second aim, I compared the foraging response of brushtail possum (Trichosurus vulpecula) and the swamp wallaby (Wallabia bicolor) to the volatile terpene 1, 8-cineole, as a potential odour cue and a dietary toxin. I use feeding stations with food and an inedible matrix that varied in content of a volatile terpene, 1, 8-cineole. Cineole in the matrix worked as a masking odour for wallabies but not for possums, suggesting that odour may be an important foraging cue only for wallabies, and the differences between the species can be explained by the ecological niche and diet of each species. I suggested that plant volatiles can be used by herbivores as a cue that allows them to select particular plants or plants parts from a patch.
For my third aim, I tested the foraging response of free-ranging swamp wallabies to artificial foods that varied in the PSM 1, 8-cineole; primary constituents (including nitrogen and fibre); and a factorial combination of both. Swamp wallabies show an increasing GUD with higher cineole level in food, and with higher nutrient level wallabies lowered their GUD. I demonstrated that nutrients and cineole impart an interactive effect on GUD, and high nutrient food required substantially more cineole to achieve the same GUD as low nutrient food. Therefore, nutrient-rich plants may face the exacerbated problem of not only being preferred by herbivores, but of needing to produce comparatively more defence compounds to achieve the same level of protection as low nutrient plants.
For my final experimental aim, I investigated the effect of choice in the overcoming of the toxic effects of a PSM, 1, 8-cineole. I tested dietary regimens at two different concentrations of cineole. To do this, I offered swamp wallabies a choice between (i) a high protein diet (HP) and a high carbohydrates (HC) diet; (ii) a no-choice preferred diet formulated to reflect the mixture of protein and carbohydrate selected when animals had access to both HP and HC foods; and (iii) a ‘no-choice basal’ (food with no added protein or carbohydrates). Higher cineole caused an increase in GUD, however, HP:HC ratio did not change with cineole treatment. I argue that this may be a consequence of swamp wallabies relying on foraging cues, such as flavours or odours, to assess food quality, which may have been negated due to the method use to prepare these diets.
Finally, in my review of the literature of the current uses of the Giving-p Density framework (GUD), I outline the theoretical and practical benefits of the methods as well as seven issues that need consideration when applying this methodology. I suggested that the incorporation of complementary methods (such as cameras) to better understand the foraging processes involved in the GUD itself, concluding that these methods can potentially offer novel and important insights into the study of foraging behaviour.
Through the evidence I have collected, it is clear that when herbivores decide where to forage, the processes influencing these decisions are more complex than the simple additive effects of individual plant characteristics or their distribution in the landscape. By not relying on limited offers of different plants or food type, as captive trials often do, I have included the variability characteristic of naturals systems, and yet demonstrated that the influence of plant chemistry on foraging is robust. I think the approach I took has been insightful on the subject of herbivore foraging, and has offered good support to our growing understanding on this area of ecology. It is important to continue testing these hypotheses in the complex background offered in nature.

Stereotypies in captive animals have been defined as repetitive, largely invariant patterns of behavior that serve no obvious goal or function. Stereotypies are commonly attributed to boredom or stress and are typically treated by enriching captivity with distracting, appealing stimuli. These stimuli often include food presented at times other than regular feedings, and as a result, engage species-typical foraging behaviors that reduce stereotypies. The present work on captive polar bears is based on the view that stereotypies are due in part to inadequate support for the expression of species-typical foraging "loops" and can be reduced by increasing support for a more complete expression of foraging responses. We tested this view through 4 experiments that presented small samples of food and scents on several schedules, examining their effects prior to, during, and after the schedule. Most schedules reduced stereotypies and increased general activity prior to and during the schedule. These data support three conclusions: (1) individual stereotypies appear related to incomplete, repeating loops of foraging behavior; (2) providing stimuli supporting a more complete sequence of search behaviors reduces stereotypies and increases non-stereotypic activity; and (3) a descriptive, analytic approach based on how foraging behaviors relate to the captive feeding procedures can facilitate understanding of stereotypies and suggest methods to reduce them.

We present the first field study of activity budgets, diet and ranging patterns of the Sulawesi crested black macaque, Macaca nigra, one of seven macaque species endemic to Sulawesi, Indonesia. We studied three crested macaque groups, ranging in size from 50 to 97 individuals, for 18 months in the Tangkoko-DuaSudara Nature Reserve, North Sulawesi. They spent 59% of the day moving and procuring food, especially fruits, and 41% of the day resting and socializing. Their diet is composed of more than 145 species of fruit (66% of observed feeding bouts), vegetative material (2.5%), invertebrates (31.5%), and occasional vertebrate prey. Group differences were more pronounced than seasonal or diurnal differences. Specifically, the largest group moved farther during the day, moved at a faster and more uniform rate, ate less fruit, rested more, and socialized less than the smaller groups did. The largest group had the largest home range, but it included less primary forest and more disturbed habitat than the ranges of smaller groups. There are individual differences in activity budgets of adult males and females in time spent moving, resting, feeding, and socializing that may reflect differences in reproductive strategies of males versus females. The behavior of large juveniles is more similar to that of adults than to that of small juveniles. Daily movements and use of home range are correlated with diet. Macaques moved shorter distances as the proportion of time spent feeding on fruit increased, and the top four dietary items accounted for most of the variance in entry into hectare blocks of home range.

ABSTRAK
Kucing mulai dijadikan peliharaan sejak zaman mesir kuno. Pakan favorit kucing secara umum adalah ikan. Kucing peliharaaan umumnya dimanjakan dengan makanan matang dan cepat saji. Untuk dapat memakan makanan mentah yang tidak biasa dimakannya, kucing peliharaan membutuhkan proses adaptasi. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian ikan mentah terhadap perilaku kucing peliharaan. Penelitian dilakukan selama sembilan hari. Responden penelitian adalah tiga ekor kucing sebagai kucing sampel dan seekor kucing sebagai kucing kontrol. Pola perilaku kucing diperoleh melalui metode observasi disertai empat kali pengulangan untuk setiap perlakuan. Pemberian makan terdiri dari lima kombinasi perbandingan komposisi ikan matang (Ma) dan ikan mentah (Me) yaitu, 100% Ma- 0% Me, 75% Ma- 25% Me, 50% Ma- 50% Me, 25% Ma – 75% Me, 0% Ma – 100% Me. Hasil penelitian menunjukan bahwa secara umum kucing sampel menunjukan perilaku yang sebagian besar sama dengan kucing kontrol. Tetapi, seekor kucing sampel menunjukan perilaku berbeda berupa menyisakan makanannya dan pada satu waktu disusul dengan buang air kecil di atas sisa makanan. Seekor kucing sampel lain menderita diare yang dapat diasumsikan sebagai reaksi fisiologi kucing terhadap ikan mentah. Berdasarkan hasil penelitian dapat disimpulkan bahwa pemberian ikan mentah berpengaruh terhadap perilaku kucing peliharaan.
Kata Kunci : Kucing peliharaan, ikan mentah, perilaku

Social immunity, which describes how individual behaviors of group members effectively reduce disease and parasite transmission at the colony level, is an emerging field in social insect biology. An understudied, but significant behavioral disease resistance mechanism in honey bees is their collection and use of plant resins. Honey bees harvest resins with antimicrobial properties from various plant species and bring them back to the colony where they are then mixed with varying amounts of wax and utilized as propolis. Propolis is an apicultural term for the resins when used by bees within a hive. While numerous studies have investigated the chemical components of propolis that could be used to treat human diseases, there is a lack of information on the importance of propolis in regards to bee health. This review serves to provide a compilation of recent research concerning the behavior of bees in relation to resins and propolis, focusing more on the bees themselves and the potential evolutionary benefits of resin collection. Future research goals are also established in order to create a new focus within the literature on the natural history of resin use among the social insects and role that propolis plays in disease resistance. Die „soziale Immunität“ als neues Forschungsfeld bei sozialen Insekten beschreibt, wie das individuelle Verhalten von Mitgliedern einer Gruppe wirkungsvoll die Verbreitung von Krankheiten und Parasiten auf der Ebene des Sozialstaates verhindern kann. Ein bisher zwar wenig untersuchtes aber wichtiges Verhaltensmerkmal zur Krankheitsabwehr bei Honigbienen ist die Verwendung von Pflanzenharzen. Honigbienen sammeln Harze mit antimikrobiellen Eigenschaften von verschiedenen Pflanzen, mischen diese dann im Bienenvolk mit unterschiedlichen Mengen von Wachs und benutzen dies als Propolis (Abb. 1–4). Propolis ist demnach der bienenkundliche Begriff für Harze, die im Bienenstock verwendet werden. Während es zahlreiche Untersuchungen zur Verwendung bestimmter Bestandteile des Propolis zur Krankheitsbekämpfung beim Menschen gibt, sind kaum Informationen über die Bedeutung von Propolis für die Bienengesundheit vorhanden. Dieses Review ist eine Zusammenstellung neuerer Forschungsergebnisse zum Verhalten der Bienen in Bezug auf Harze und Propolis mit dem Schwerpunkt auf die möglichen evolutiven Vorteile des Harzsammelns für die Honigbienen. Die Verwendung von Harzen durch Bienenvölker (Apis mellifera) ist weit verbreitet. Während es erhebliche Unterschiede zwischen einzelnen Völkern bzgl. der Menge an gesammelten Harzen und Propolis gibt, scheinen alle — und dabei insbesondere die wildlebenden — Bienenvölker das Propolis zur Auskleidung des gesamten Stockinneren zu benutzen. Es wird angenommen, dass Propolis dazu beiträgt, die Homöostase innerhalb des Bienenstockes aufrecht zu erhalten. Konkret könnte das Propolis dabei das mikrobielle Wachstum an den Beutenwänden reduzieren, unkontrollierten Luftzug ins Beuteninnere verhindern und zusätzlich mechanische Barrieren gegenüber Eindringlingen bilden. Einige Forschungsprojekte zeigen eindeutig, dass Propolis im Bienenstock direkt gegenüber Krankheitserregern (z.B. Amerikanische Faulbrut) und Parasiten (z.B. Kleiner Beutenkäfer, Varroa destructor) wirkt. Daneben scheint es aber auch eine subtilere Wirkung über die Unterstützung des individuellen Immunsystems zu geben. Die weiteren Forschungen sollten sich auf das bessere Verständnis der Verwendung von Harzen durch Honigbienen und andere soziale Insekten konzentrieren. Dafür gibt es eine Vielzahl an Forschungsfeldern, von den pharmazeutischen Möglichkeiten des Propolis für die menschliche Gesundheit über die Mechanismen der Sammelstrategie von Propolis auf den Ebenen der Einzelbienen und des Bienenvolkes bis hin zu einer möglichen Anwendung von Propolis als Bekämpfung von Bienenkrankheiten. Schließlich ermöglichen Informationen zur Verwendung von Harzen und deren Aufnahme in den Bienenstock spannende Forschungsansätze zum Einfluss der Umwelt auf Krankheitsresistenz und soziale Immunität.