1. Within the broad field of optimal foraging, it is increasingly acknowledged that animals often face digestive constraints rather than constraints on rates of food collection. This therefore calls for a formalization of how animals could optimize food absorption rates. 2. Here we generate predictions from a simple graphical optimal ...

Temporal variation of antipredatory behavior and a uniform distribution of predation risk over refuges and foraging sites may create foraging patterns different from those anticipated from risk in heterogenous habitats. We studied the temporal variation in foraging behavior of voles exposed to uniform mustelid predation risk and heterogeneous avian predation ...

Ants belong to the most important groups of arthropods, inhabiting and commonly dominating most terrestrial habitats, especially tropical rainforests. Their highly collective behavior enables exploitation of various resources and is viewed as a key factor for their evolutionary success. Accordingly, a great variety of life strategies evolved in this group ...

It has been suggested that affiliated social relations may facilitate information transfer between individuals. We here tested this rarely examined hypothesis with juvenile and adult jackdaws (Corvus monedula) in three stimulus enhancement tasks, both in a non-food context (experiment 1) and in a food context (experiments 2 and 3). We ...

Collective foraging in group living animal populations displaying behavioral polymorphism is considered. Using mathematical modeling it is shown that symmetric, spatially homogeneous (food sources are used equally) and asymmetric, spatially inhomogeneous (only one food source is used) regimes can coexist, as a result of differential amplification of choice depending on ...

Experimental manipulation of foraging costs per food reward can be used to study the plasticity of physiological systems involved in energy metabolism. This approach is useful for understanding adaptations to natural variation in food availability. Earlier studies have shown that animals foraging on a fixed reward schedule decrease energy intake ...

The intensification of agricultural practices has been identified as the main cause of population decline in farmland birds since the 1960s in both Europe and North America. Although the links between species richness or abundance and various components of agricultural intensification are well established, the mechanisms underlying these trends have ...

The status of many Gyps vulture populations are of acute conservation concern as several show marked and rapid decline. Vultures rely heavily on cues from conspecifics to locate carcasses via local enhancement. A simulation model is developed to explore the roles vulture and carcass densities play in this system, where ...

This study links summer foraging and scatter-hoarding to winter larder-hoarding and winter survival in yellow pine chipmunks (Tamias amoenus) by comparing patterns of time allocation and winter larder contents in 2 years with very different levels of resource availability. In 2003, seed production and the number of trees and shrubs ...

The honeybee (Apis mellifera) waggle dance is one of the most intriguing animal communication signals. A dancing bee communicates the location of a profitable food source and its odour. Followers may often experience situations in which dancers indicate an unfamiliar location but carry the scent of a flower species the ...

Distinguishing nest-mates from non-nest-mates underlies key animal behaviours, such as territoriality, altruism and the evolution of sociality. Despite its importance, there is very little empirical support for such a mechanism in nature. Here we provide data that the nest-mate recognition mechanism in an ant is based on a colony-specific Z9-alkene ...

Many ant species have morphologically distinct worker sub-castes. This presumably increases colony efficiency and is thought to be optimized by natural selection. Optimality arguments are, however, often lacking in detail. In ants, the benefits of having workers in a range of sizes have rarely been explained mechanistically. In Atta leafcutter ...

Observational spatial memory (OSM) refers to the ability of remembering food caches made by other individuals, enabling observers to find and pilfer the others' caches. Within birds, OSM has only been demonstrated in corvids, with more social species such as Mexican jays (Aphelocoma ultramarine) showing a higher accuracy of finding ...

Here we investigate the counting ability in honeybees by training them to receive a food reward after they have passed a specific number of landmarks. The distance to the food reward is varied frequently and randomly, whilst keeping the number of intervening landmarks constant. Thus, the bees cannot identify the ...

Trade-offs between locomotor performance and load-carrying in animals are well-established and often result from requisite life processes including reproduction and feeding. Osmoregulation, another necessary process, may involve storage of fluid in the urinary bladder of some species. The purpose of this study was to determine whether storage of urine in ...

The foraging efficiencies of four sympatric southern African seed-eating birds, namely Bronze Mannikin <i>Spermestes cucullatus</i>, Cape Sparrow <i>Passer melanurus</i>, Southern Red Bishop <i>Euplectes orix</i> and Thick-billed Weaver <i>Amblyospiza albifrons</i>, and a domesticated species, the Bengalese Finch <i>Lonchura domestica</i>, were measured and compared using giving-up densities (the amount of food remaining ...

The colonies of ants, bees, wasps and termites, the social insects, consist of large numbers of closely related individuals; circumstances ideal for contagious diseases. Antimicrobial assays of these animals have demonstrated a wide variety of chemical defenses against both bacteria and fungi that can be broadly classified as either external ...

The ability to orient and navigate in space is essential for all animals whose home range is organized around a central point. Because of their small home range compared to vertebrates, central place foraging insects such as ants have for a long time provided a choice model for the study ...

Most small-colony termites live confined within a single piece of wood on which they feed and do not possess permanent workers: Tasks are done by developmentally flexible immatures (pseudergates). By contrast, large-colony termites possess a specialized (true) worker caste and forage outside their nest for food. To shed light on ...

Despite the widespread impacts invasive species can have in introduced populations, little is known about competitive mechanisms and dominance hierarchies between invaders and similar taxa in their native range. This study examines interactions between the red imported fire ant, Solenopsis invicta, and other above-ground foraging ants in two habitats in ...

Top-down effects of predators on prey behavior and population dynamics have been extensively studied. However, some populations of very large herbivores appear to be regulated primarily from the bottom up. Given the importance of food resources to these large herbivores, it is reasonable to expect that forage heterogeneity (variation in ...

Recent work has demonstrated considerable benefits of intracolonial genetic diversity for the productivity of honeybee colonies: single-patriline colonies have depressed foraging rates, smaller food stores and slower weight gain relative to multiple-patriline colonies. We explored whether differences in the use of foraging-related communication behaviour (waggle dances and shaking signals) underlie ...

Foraging mode has molded the evolution of many aspects of lizard biology. From a basic sit-and-wait sprinting feeding strategy, several lizard groups have evolved a wide foraging strategy, slowly moving through the environment using their highly developed chemosensory systems to locate prey. We studied locomotor performance, whole-body mechanics and gaits ...

Resource selection plasticity and behavioral dominance may influence the ability of a species to respond to changes in resource availability, particularly if dominant species have highly specialized resource requirements. We examined the response of several dominant and subordinate cavity-nesting species to a reduction in the availability of an essential resource ...

Predator mobbing is a widespread phenomenon in many taxa but the evolution of cooperative mobbing as an adaptive behavior is still subject to debate. Here, we report evidence for cooperative predator defense in a nocturnal solitarily foraging primate, the gray mouse lemur (Microcebus murinus). Several mouse lemurs mobbed a snake ...

Patterns of faunal exploitation play a central role in debates concerning the behavioral modernity of Middle Stone Age (MSA) peoples. MSA foragers have been portrayed as less effective hunters than their Later Stone Age (LSA) successors on the basis of relative species abundances from ungulate assemblages in southern Africa. Specifically, ...

Since the seminal work of Lindauer and Kerr (1958), many stingless bees have been known to effectively recruit nestmates to food sources. Recent research clarified properties of several signals and cues used by stingless bees when exploiting food sources. Thus, the main source of the trail pheromone in Trigona are ...

The critically endangered Juan Fernández firecrown (Sephanoides fernandensis) is restricted to only one island in the world, Isla Robinsonson Crusoe, Juan Fernández Archipelago, Chile. The presence of exotic taxa, in the form of competitors or food resources, frequently have significant effects on the foraging strategies employed by local endemics. We ...

Ethanol occurs in fleshy fruit as a result of sugar fermentation by both microorganisms and the plant itself; its concentration [EtOH] increases as fruit ripens. At low concentrations, ethanol is a nutrient, whereas at high concentrations, it is toxic. We hypothesized that the effects of ethanol on the foraging behavior ...

In eusocial Hymenoptera, queen control over workers is probably inseparable from the mechanism of queen recognition. In primitively eusocial bumblebees (Bombus), worker reproduction is controlled not only by the presence or absence of a dominant queen but also by other dominant workers. Furthermore, it was shown that the queen dominance ...

In stingless bees, recruitment of hive bees to food sources involves thoracic vibrations by foragers during trophallaxis. The temporal pattern of these vibrations correlates with the sugar concentration of the collected food. One possible pathway for transferring such information to nestmates is through airborne sound. In the present study, we ...

The pollination of Cypripedium plectrochilum Franch. was studied in the Huanglong Nature Reserve, Sichuan, China. Although large bees (Bombus, Apis), small bees (Ceratina, Lasioglossum), ants (Formica sp.), true flies (Diptera) and a butterfly were all found to visit the flowers, only small bees, including three Lasioglossum spp. (L. viridiclaucum, L. ...

Caching behavior frequently occurs within a social context that may include heterospecific cache pilferers. All else equal, the value of cacheable food should decline as the probability of cache recovering declines. We manipulated gray squirrels' (Sciurus carolinensis) estimate of the probability of cache recovery using experimental playbacks of the vocalizations ...

We explore the variability that animals display in their movement choices as they forage in a finite-sized food patch with a uniform food distribution, and present a framework for how these choices may be adjusted to optimize foraging efficiency. Inspired by experimental studies of the zooplankton Daphnia, we model foraging ...

Movement in Caenorhabditis elegans is the result of sensory cues creating stimulatory and inhibitory output from sensory neurons. Four interneurons (AIA, AIB, AIY, and AIZ) are the primary recipients of this information that is further processed en route to motor neurons and muscle contraction. C. elegans has >1,000 G protein-coupled ...

Evolution of complex cognition in animals has been linked to complex social behaviour. One of the costs of sociality is increased competition for food which may be reduced by food caching, but cache theft may undermine the benefits of caching. In birds, sophisticated food-caching-related cognition has been demonstrated only for ...

Caste polyethism has been recorded in some termite species, however the foraging behavior of subterranean termites remains poorly known. Heterotermes tenuis Hagen (Isoptera: Rhinotermitidae) is a subterranean termite that is native to Brazil and is an agricultural and urban pest. The aim of this study was to investigate which caste ...

A variety of anthropoids travel efficiently from one food source to another, although there is disagreement over how this is accomplished over large-scale space. Mental maps, for example, require that animals internally represent space, geometrically locate landmarks, use true distance and direction, and generate novel shortcuts to resources. Alternately, topological ...

BACKGROUND: This paper presents the Enawene-Nawe Society's traditional knowledge about stingless bees. The Enawene-Nawe are an Aruak speaking people, indigenous to the Meridian Amazon. Specifically, they live in the Jurema River hydrological basin, located in the northwestern region of the Mato Grosso state. METHODS: The stingless bees were sampled from ...

The competitive regime faced by individuals is fundamental to modelling the evolution of social organization. In this paper, we assess the relative importance of contest and scramble food competition on the social dynamics of a provisioned semi-free-ranging Cebus apella group (n = 18). Individuals competed directly for provisioned and clumped ...

Ants and termites are the most abundant animals on earth. Their ecological success is attributed to their social life. They live in colonies consisting of few reproducing individuals, while the large majority of colony members (workers/soldiers) forego reproduction at least temporarilly. Despite their apparent resemblance in social organisation, both groups ...

A honeybee informs her nestmates of the location of a flower she has visited by a unique behavior called a "waggle dance." On a vertical comb, the direction of the waggle run relative to gravity indicates the direction to the food source relative to the sun in the field, and ...

The honeybee waggle dance, through which foragers advertise the existence and location of a food source to their hive mates, is acknowledged as the only known form of symbolic communication in an invertebrate. However, the suggestion, that different species of honeybee might possess distinct 'dialects' of the waggle dance, remains ...

Foraging behaviour is an essential ecological process linking different trophic levels. A central assumption of foraging theory is that food selection maximises the fitness of the consumer. It remains unknown, however, whether animals use innate or learned behaviour to discriminate food rewards. While many studies demonstrated that previous experience is ...

Declines in bumble bee species in the past 60 years are well documented in Europe, where they are driven primarily by habitat loss and declines in floral abundance and diversity resulting from agricultural intensification. Impacts of habitat degradation and fragmentation are likely to be compounded by the social nature of ...

To understand the foraging strategies of free-ranging diving animals, time series information on both foraging effort and foraging success is essential. Theory suggests that wing stroke frequency for aerial flight should be higher in heavier birds. Based on this premise, we developed a new methodology using animal-borne accelerometers to estimate ...

Audience effects are increasingly recognized as an important aspect of intraspecific communication. Yet despite the common occurrence of interspecific interactions and considerable evidence that individuals respond to the calls of heterospecifics, empirical evidence for interspecific audience effects on signalling behaviour is lacking. Here we present evidence of an interspecific audience ...

Recruitment to food or nest sites is well known in ants; the recruiting ants lay a chemical trail that other ants follow to the target site, or they walk with other ants to the target site. Here we report that a different process determines foraging direction in the harvester ant ...

The ants that live in the swollen thorns (domatia) of Acacia drepanolobium are staple foods for patas monkeys (Erythrocebus patas). To obtain a better understanding of these insects as resources for patas monkeys, we sampled the contents of 1,051 swollen thorns (ant domatia) over a 22-month period from December 1999 ...

The hymenopteran tarsus is equipped with claws and a movable adhesive pad (arolium). Even though both organs are specialised for substrates of different roughness, they are moved by the same muscle, the claw flexor. Here we show that despite this seemingly unfavourable design, the use of arolium and claws can ...