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Rasmussen Gregory S A - - 2008
This study empirically tests two foundation ecological theories: (1) pack hunting is a driver for the evolution of sociality; and (2) species have a finite energy potential, whereby increased maintenance costs result in decreased reproductive effort. Using activity and prey data from 22 packs of African wild dogs (Lycaon pictus), ...
Cummings John L - - 2008
To address some concerns about the expansion of genetically engineered pharmaceutical and industrial crops to outdoor plantings and potential impacts on the human food supply, we determined whether commercial agriculture seeds of maize or corn Zea mays L., barley Hordeum vulgare L., safflower Carthamus tinctorius L. and rice Oryza sativa ...
Dacke M - - 2008
Although several studies have examined how honeybees gauge and report the distance and direction of a food source to their nestmates, relatively little is known about how this information is combined to obtain a representation of the position of the food source. In this study we manipulate the amount of ...
Durant Daphné - - 2009
To explain the preference of wintering greylag geese Anser anser for small Scirpus maritimus tubers (<10mm) over larger ones, our hypothesis was that the former would provide higher intake rates. This 'consumption rate hypothesis' was tested experimentally by deriving the functional responses of geese feeding on tubers of three contrasting ...
McClure Melanie - - 2008
This study reports new information on interactions between two sympatric ant species, the plant-ant Azteca alfari (Dolichoderinae) living in association with the myrmecophyte Cecropia obtusa (Cecropiaceae) and Camponotus blandus (Formicinae), a ground-nesting, arboreal-foraging species. Workers of A. alfari forage only on the foliage and the upper parts of the trunk ...
Broom Mark - - 2008
Kleptoparasitism, the stealing of food by one animal from another, is a widespread biological phenomenon. In this paper we build upon earlier models to investigate a population of conspecifics involved in foraging and, potentially, kleptoparasitism. We assume that the population is composed of four types of individuals, according to their ...
Doblas-Miranda Enrique - - 2008
Animals principally forage to try to maximize energy intake per unit of feeding time, developing different foraging strategies. Temperature effects on foraging have been observed in diverse ant species; these effects are limited to the duration of foraging or the number of foragers involved. The harvester ant Messor barbarus L. ...
Choe Dong-Hwan - - 2008
Five insecticides used by urban pest management professionals for ant control and three experimental insecticides were tested to determine whether these insecticides were horizontally transferred among individuals in colonies of Argentine ants, Linepithema humile (Mayr) (Hymenoptera: Formicidae). Ants were exposed to insecticide-treated sand for 1 min and then placed in ...
Zhang Hongmao - - 2008
Mast seeding is a common phenomenon, and has important effects on seed dispersal and hoarding by animals. At population level, the predator satiation hypothesis proposes that the satiating effect of a large amount of seeds on a relatively small number of predators benefits seed survival in mast-seeding years. However, the ...
van Gils Jan A - - 2008
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 ...
Eccard Jana A - - 2008
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 ...
Witte Volker - - 2008
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 ...
Schwab Christine - - 2008
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 ...
Nicolis S C - - 2008
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 ...
Ghilain Arnaud - - 2008
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 ...
Schubert Kristin A - - 2008
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 ...
Jackson Andrew L - - 2008
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 ...
Kuhn Kellie M - - 2008
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 ...
Martin Stephen J - - 2008
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 ...
Grüter Christoph - - 2008
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 ...
Helanterä Heikki - - 2008
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 ...
Scheid Christelle - - 2008
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 ...
Dacke Marie M ARC Centre for Excellence in Vision Science, Research School of Biological Sciences, Australian National University, P. O. Box 475, Canberra, ACT, 2601, Australia. - - 2008
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 ...
Davis Jon R - - 2008
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 ...
Soobramoney, Shernice; School of ...
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 ...
Stow Adam - - 2008
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 ...
Gerbier Grégory - - 2008
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 ...
Rupf Thomas - - 2008
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 ...
Calcaterra Luis A - - 2008
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 ...
Winnie John A JA - - 2008
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 ...
Mattila Heather R - - 2008
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 ...
McElroy Eric J - - 2008
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 ...
Aitken Kathryn E H - - 2008
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 ...
Eberle Manfred - - 2008
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 ...
Faith J Tyler - - 2008
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, ...
Barth Friedrich G - - 2008
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 ...
Wolf, Coral
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 ...
Sánchez Francisco - - 2008
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 ...
Sramkova A - - 2008
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 ...
Hrncir Michael - - 2008
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 ...
Li P - - 2008
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. ...
Schmidt Kenneth A - - 2008
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 ...
Dees Nathan D - - 2008
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 ...
Bendena William G - - 2008
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 ...
Pravosudov Vladimir V - - 2008
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 ...
Casarin Fabiana Elaine - - 2008
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 ...
Erhart Elizabeth M - - 2008
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 ...
dos Santos Gilton Mendes - - 2008
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 ...
Ferreira Renata G - - 2008
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 ...
Korb Judith - - 2008
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 ...
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