Foraging Research Articles

No Evidence for Effects of Fitness Relevance or Sex Differences in a Virtual Hunting and Gathering Task

A computerized task could be completed by predicting the location of a moving target or by choosing several stationary targets. In a fitness-relevant condition, this task was presented to participants in terms of hunting and gathering food necessary for survival. In four experiments, there was no evidence that male and female participants differed in terms of their tendency to complete the task in these two ways. In three of the experiments, performance in the fitness-relevant condition was compared to performance in a control condition in which the task was presented as a computer game with no reference to hunting or gathering. No evidence for an effect of fitness relevance was found. These results challenge the idea that sex differences in spatial cognition are related to the sexual differentiation of foraging behavior during human history. They also suggest limitations on the role of fitness-relevant processing of information (“survival processing”) on cognitive performance.

Social Customs and Beliefs among the Kadars of Anamalai Region in Coimbatore District

The social organization of the tribes in India is very diverse and often quite complicated. This is quite natural as they come from so many different races and cultures which are at various stages of development. They have also been much influenced by the surrounding superior cultures. Among the nomadic food gathering tribes, the social structure is based mainly on the natural family. Usually several such families, united by ties of kinship, form a local group. They live together, hunt and collect together and share out among themselves what they have gathered. They have obligations towards each other, and support each other in want, sickness and old age. Social life, however, is not entirely restricted to the local groups. The local groups meet occasionally to celebrate feasts, for the arrangement of marriages and for other important matters. This paper focuses on social organization, customs and culture of the Kadars, the primitive hill tribes of Anamalai region in Coimbatore District.

Modeling scan and interscan durations in antipredator vigilance

Many prey species alternate between bouts of foraging and bouts of antipredator vigilance. Models of vigilance typically predict how much total time prey animals should allocate to vigilance but do not specify how that time should be scheduled throughout foraging. Here, we examine how the scheduling of vigilance pays off in terms of food intake and predator detection. Specifically, we study how changes in ecological factors affect the expected duration of scans to look out for predators and the duration of interscan intervals dedicated to foraging. Our framework includes factors like the risk of attack, how difficult it is to locate food and predators, and the distance to protective cover. Our individual-based model makes several predictions about scan and interscan durations, which are discussed in relation to the available empirical evidence in birds and mammals. This model of antipredator vigilance is a first step in incorporating constraints related to food gathering and the detection of predators. Adding such constraints adds a novel dimension to vigilance models and produces a variety of predictions that await empirical scrutiny.

"mus co shee": Indigenous Plant Foods and Horticultural Imperialism in the Canadian Sub-Arctic.

The 17th-century arrival of the Hudson's Bay Company in Rupert's Land disrupted Mushkegowuk (Cree) hunter-gatherer society by replacing the collection of indigenous plant foods with a British planted-food model. Within a hundred years of British contact, new foodways relied upon hunting and gardening, bringing a loss in heritage plant food knowledge. Mushkegowuk living in the sub-arctic today have minimal knowledge of edible indigenous plants. Dependence on limited local gardening or imported grocery store vegetables has affected diet, nutrition, and cultural systems. In addition to exploring plant food gathering and gardening history in the Hudson Bay Lowlands, this paper demonstrates how re-discovering lost foodway knowledge can contribute to the health and well-being of those living in the far north.

Ecology: Foraging further.

Ecology: Foraging further.

Religious Affiliation Modulates Weekly Cycles of Cropland Burning in Sub-Saharan Africa.

Vegetation burning is a common land management practice in Africa, where fire is used for hunting, livestock husbandry, pest control, food gathering, cropland fertilization, and wildfire prevention. Given such strong anthropogenic control of fire, we tested the hypotheses that fire activity displays weekly cycles, and that the week day with the fewest fires depends on regionally predominant religious affiliation. We also analyzed the effect of land use (anthrome) on weekly fire cycle significance. Fire density (fire counts.km-2) observed per week day in each region was modeled using a negative binomial regression model, with fire counts as response variable, region area as offset and a structured random effect to account for spatial dependence. Anthrome (settled, cropland, natural, rangeland), religion (Christian, Muslim, mixed) week day, and their 2-way and 3-way interactions were used as independent variables. Models were also built separately for each anthrome, relating regional fire density with week day and religious affiliation. Analysis revealed a significant interaction between religion and week day, i.e. regions with different religious affiliation (Christian, Muslim) display distinct weekly cycles of burning. However, the religion vs. week day interaction only is significant for croplands, i.e. fire activity in African croplands is significantly lower on Sunday in Christian regions and on Friday in Muslim regions. Magnitude of fire activity does not differ significantly among week days in rangelands and in natural areas, where fire use is under less strict control than in croplands. These findings can contribute towards improved specification of ignition patterns in regional/global vegetation fire models, and may lead to more accurate meteorological and chemical weather forecasting.

Cannot see you but can hear you: vocal identity recognition in microbats.

Identity recognition is one of the most critical social behaviours in a variety of animal species. Microchiropteran bats present a special use case of acoustic communication in the dark. These bats use echolocation pulses for navigating, foraging, and communicating; however, increasing evidence suggests that echolocation pulses also serve as a means of social communication. Compared with echolocation signals, communication calls in bats have rather complex structures and differ substantially by social context. Bat acoustic signals vary broadly in spectrotemporal space among individuals, sexes, colonies and species. This type of information can be gathered from families of vocalizations based on voice characteristics. In this review we summarize the current studies regarding vocal identity recognition in microbats. We also provide recommendations and directions for further work.

Seasonal pattern in food gathering of the weaver ant Oecophylla longinoda (Hymenoptera: Formicidae) in mango orchards in Benin

Prey capture and food scavenging activities of Oecophylla longinoda were monitored through regular weekly samplings during two consecutive years (2009–2010) in a large mango orchard of the Borgou Department of Benin, West Africa, a main mango production area located in the Sudan agro-ecological zone. In both years, interspecific competition with other ants occurred mainly during the dry season (January to March) resulting in increased captures of Formicinae, Myrmicinae and Ponerinae. More prey was caught during the rainy season (end April to end October) than during the rest of the year, with Diptera and Coleoptera prey peaking in May and June, respectively, along with the mango season. As insect prey quickly decreased during November to December weaver ants increasingly collected seeds and plant debris. A total of 241 species of insects were captured including 61 species (25.3%) associated with mango and a few with cashew, among which 48 mango pest species (78.7% of species associated with mango tree). Only five species (2.1%) of beneficial insects were captured. It is concluded that the presence of O. longinoda colonies is beneficial to perennial tree cropping systems such as mango and cashew.

Changes in the chemical profile of cephalic salivary glands of Scaptotrigona postica (Hymenoptera, Meliponini) workers are phase related.

Most advanced eusocial bees recruit their nest mates to food resources. Recent studies in Meliponini species have revealed that the cephalic salivary (labial) glands (CSGs) are responsible for the production of scent trail pheromones. Studies on CSGs have shown that changes occur in worker glandular cell morphology from emergence from brood combs until forager phase, which may be correlated to changes in the composition of the CSG secretion. However, the composition of the CSG secretion and the chemical changes that occur in it according to the worker's life phase or tasks performed are unknown for many species, including Scaptotrigona postica. In this study, the chemical profile of CSG secretion in S. postica workers was studied. Glands were taken from specimens that were newly emerged (NE), working in the brood comb area (CA) and foraging (FO), and were analyzed by gas chromatography-mass spectrometry. The results showed that the glandular secretion consists of oxygenated compounds of middle volatility (acids, alcohols, aldehydes, ketones, esters and ether), and their quantity varies among the different life phases, increasing as the individual moves from intra- to extra-colonial activities. The NE phase contained the smallest variety and quantity of compounds. Because of the variability of compounds, the CA workers were separated into three subgroups according to the chemical constitution of their secretion. Forager workers showed the largest quantity and variety of chemical compounds. The major compounds in forager gland secretion were 7-hexadecen-1-yl acetate and 5-tetradecen-1-yl acetate. Statistical analysis indicates that the chemical composition of glandular secretion is phase related.

EYE ON CHINA

Coin-sized Micro-needles Patch to deliver Insulin: An innovation by Shanghai University Scientists Stem Cells Help Researchers Study The Effects of Pollution on Human Health A Novel and Robust Muscle Activity Onset Detection Technique by Using an Unsupervised Electromyogram Learning Framework Early Modern Humans and Neanderthals were close bedfellows FANCD2 and REV1 Cooperate in the Protection of Nascent DNA Strands in Response to Replication Stress Spiders' Foraging Strategies Have Cascading Effects on Litter Decomposition Rates Yingli Announces Sale of 18.8 MW Solar Power Plant in the UK to NextEnergy Solar Fund China's Award Winning Desertification Control in Kubiqi Desert Earthquake Early Warning System for Nepal Mechanical Coupling Mechanism of a Mechanical Force-sensing Channel Protein Discovered by IBP Scientists Jiahui International Hospital and Brigham and Women's Hospital to Co-Develop Women's Health Center of Excellence in Shanghai Big Grain1: The ‘Mr. BIG’ for Crops to Grow Bigger by Regulating Auxin Transport in Rice When there is no Queen in the house, Asian Hive Bees Avoid Risky Foraging for Reproduction UNICEF HK joins hands with Government to help Mothers sustain Breastfeeding Fresenius Medical Care Springs into Action after Deadly Tianjin Explosion

Patch fidelity in Camponotus compressus ants foraging on honeydew secreted by treehoppers.

Camponotus compressus ants are thought to be mutualistic with plant sap-sucking insects such as aphids and treehoppers, where the ants provide protection from predation and/or help maintain hygiene, in exchange for sugar-rich honeydew secreted by sapsuckers. We studied the foraging strategies and ant-treehopper interactions among C. compressus ants and Oxyrachis tarandus tree-hoppers on the plant Bauhinia tomentosa . We found that ants show fidelity to specific patches of B. tomentosa . We also found a significant correlation between hopper number and the number of visiting ants in foraging patches. Our study raises many questions about the ant-treehopper mutualism, navigation strategies and optimal foraging in C. compressus.

A novel artificial bee colony algorithm based on modified search strategy and generalized opposition-based learning

Artificial bee colony ABC algorithm, which is inspired by the foraging behavior of honey bee swarm, is a biological-inspired optimization algorithm. It shows more effective than genetic algorithm G...

Comparative Evaluation of Wheat-roti or Rice-lentil Mixture as Supplements for Growing Asiatic Elephants (Elephas maximus)

The feeding of supplements that supply all nutrients in optimum amounts to support normal growth is of paramount importance when feeding growing elephants in captivity. This experiment evaluated wheat roti (WR) and a rice–lentil mixture (RLM) as supplements for growing semi-captive Asian elephants. Six sub-adult (7–12 years; 1327–3288 kg) elephants were split into two groups of three each. The study period was divided into two, and each group received both supplements in a switch-over design. Elephants in treatment I and II received concentrate supplements consisting of WR and RLM respectively. They were allowed to forage in the nearby forests from 0530 to 1730. Cut grasses (narkul, Arundo donox ) were offered ad lib (20% excess of previous day’s intake) to each animal from 1730 to 0530 when they were in their enclosures. As animals were in enclosures during the night, faeces of each individual elephant could be collected separately, and elephants had no access to one another’s feeds. Faeces voided during foraging were collected in full, representative samples of forages consumed were taken and intake during foraging was measured indirectly using lignin as a marker. Intake of cut grasses and forages were similar between the treatments. Apparent digestibility of CP was higher (P<0.05) in treatment II. Apparent digestibility of other nutrients was comparable in both the treatments. Intake of zinc was higher in treatment II. Intake, excretion and absorption of Ca, Co, and Cu did not differ between the treatments. Absorption of P and Fe was higher (P<0.05) in treatment II. Blood metabolites, serum enzymes activities and concentration of serum minerals were similar among the treatments. The relative population of total bacteria was numerically increased in treatment II. The results of this experiment demonstrate that RLM may be better supplement for growing elephants than WR.

Social biology of Augochlora (Augochlora) phoemonoe (Hymenoptera, Halictidae) reared in laboratory nests

Fil: Dalmazzo, Maria de Los Milagros. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Departamento de Ciencias Naturales. Catedra de Entomologia; Argentina

Effects of some insecticidal chemicals under laboratory condition on honeybees [Apis mellifera L. (Hymenoptera: Apidae)] that forage on onion flowers

In Ethiopia, Apis mellifera L. are the most important honeybees to produce diverse bee products. In addition, bees also improve crop yields through their active and efficient pollination. However, they have been killed due to the misuse of various insecticides. For this reason this study was proposed to determine in the laboratory the level of toxicity of some insecticides used widely on honeybees foraging on onion flowers. Adult A. mellifera bandasii honeybees 21 to 24 days old were collected at the Adami Tullu Agricultural Research Center (ATARC) apiary. Easy to clean and well-ventilated 15 x 10 x 15 cm cages were used for feeding, contact and fumigation tests. Six insecticides: deltamethrin 2.5 EC, diazinon 60 EC, endosulfan 35 EC, lambda-cyhalothrin 5 EC, malathion 50 EC and profenofos 750 EC, were evaluated in the laboratory at the rates suggested for onion field spraying. Each treatment was replicated three times and arranged in a completely randomized design. All of the insecticides in the contact and feeding tests were toxic to honeybees and caused mortality within a few hours after exposure. In the fumigation test, profenofos did not cause honeybee mortality until the third hour, but the remaining insecticides caused varying mortality within 24 h. Key words: Insecticides, toxicity, honeybee, bee products and crop yields.

Adaptation to drought in arid and semi-arid environments: Case of the Zambezi Valley, Zimbabwe.

Small-scale rain-fed agriculture is the main livelihood in arid to semi-arid regions of sub-Saharan Africa. The area is characterised by erratic rainfall and frequent droughts, making the capacity for coping with temporal water shortages essential for smallholder farmers. Focusing on the Zambezi Valley, Zimbabwe, this study investigates the impact of drought on food security and the strategies used by smallholder farmers to cope with drought. We used meteorological data and interviews to examine the rainfall variability in the study area and the drought-coping mechanisms employed by smallholder famers respectively. The results show that there are various strategies used by smallholder farmers to cope with the impact of drought. These strategies include drought-tolerant crop production, crop variety diversification, purchasing cereals through asset sales, non-governmental organisations’ food aid and gathering wild fruit. However, consecutive droughts have resulted in high food insecurity and depletion of household assets during droughts. Smallholder farmers in the valley have also resorted to a number of measures taken before, during and after the drought. Still, these strategies are not robust enough to cope with this uncertainty.

Diverse mechanisms of feeding and movement in Cyclorrhaphan larvae (Diptera)

Direct observation, filmed behaviour and morphological analysis were used to investigate mechanisms of larval feeding and movement in 20 species of Cyclorrhapha (Diptera). Feeding mechanisms refer to techniques of gathering food close to the pharynx entrance prior to sucking it in. A total of 12 mechanisms were recorded. Contrasting mechanisms were associated with saprophagy, phytophagy, mycophagy and zoophagy. Larvae had role-specific, compartmentalised bodies. The rear compartment grips substrates enabling the front ones to scan for food by sweeping from side to side or up and down. The front compartments extend or lunge to gather food or grip substrates during locomotion. Lower cyclorrhaphans had more disparate mechanisms than higher cyclorrhaphans. In the latter, the size, shape and movements of the thorax, pseudocephalon and head skeleton are diverse. Influences on this diversity are food quality and access conditions at development sites. Movement capabilities and functions were established for many components.

Diet dependent olfactory response and predation rate of Neoseiulus californicus (Acari: Phytoseiidae) in the presence of Frankliniella occidentalis and Tetranychus urticae

Responses of female predatory mite, Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) with different diet experiences were examined in a Y-tube olfactometer. The odor sources were clean air vs. clean bean leaves, clean air vs. Tetranychus urticae (Koch) (Acari: Tetranychidae) infested bean leaves, and T. urticae infested bean leaves vs. clean bean leaves. Female predatory mites that fed on T. urticae as their previous diet for three generations, preferred clean leaves, spider mite infested leaves and again spider mite infested leaves over the alternative odor sources. When N. californicus was fed on T. urticae plus pollen, a significant movement was recorded towards clean leaves rather than clean air, but no significant preference was observed in two other olfactory experiments. Feeding on pollen alone, thrips first instar alone and thrips first instar plus pollen, the predators did not make a significant preference towards the arms in any of the olfactory experiments. Comparing the mean foraging time and predation rate of N. californicus when their prey ( T. urticae ) were experienced in a direct contact with Frankliniella occidentalis with predators whose prey had previousely received signals due to thrips ( F. occidentalis ) presence, we recorded a significantly higher foraging time and consumed prey in the patches where thrips were removed. According to our results, N. californicus is capable of detecting its prey and patches with heterospecific ( F. occidentalis ) and conspecific predators through its diet-based-understanding of chemical cues. Explanations for the olfactory response and foraging behavior of N. californicus are discussed.

Hunting &amp; Foraging

Hunting &amp; Foraging

Foraging for Farmers?

Neue Studien betonen hinsichtlich der Neolithisierung Nordwesteuropas ein Mosaik verschiedener Prozesse. Dennoch scheint es möglich, einheitliche Merkmale zu identifizieren, die die Entwicklung der Landwirtschaft überregional beeinflussten. Der folgende Beitrag hebt die Bedeutung evolutionärer Prozesse für die Neolithisierung hervor, dies mit einem Fokus auf die südlichen Niederlande. Jene Regionen zeichnen sich durch vielfältige Biome aus, in denen die Übernahme der Landwirtschaft auf unterschiedlichem Wege erfolgte. Analysiert werden dabei sich jeweils ergebende Vorteile für die körperliche Verfasstheit der beteiligten Akteure durch die Kombination von Nahrungssuche und Landwirtschaft.Die Autoren vermuten, dass die Ernährungsstrategien der Menschen von den vielfältigen Substraten unterschiedlich beeinflußt wurden, und dies sich darüber hinaus auch zwischen den Geschlechtern erkennen läßt. Bezüglich der Frage, ob und wie neolithische Innovationen übernommen wurden, werden daher für Männer und Frauen unterschiedliche Strategien sichtbar, die verfügbaren Resourcen jeweils „optimal“ zu nutzen.Les études récentes ont souligné le caractère en mosaïque du processus de néolithisation dans le nordouest de l’Europe. Il est cependant possible d’identifier à travers les différentes régions certains objectifs majeurs qui ont influencé l’adoption de l’agriculture. Nous modélisons l’importance des processus évolutionnaires à la base de la néolithisation. Nous nous concentrons sur la partie méridionale des Pays-Bas, où l’agriculture a été adoptée suivant des trajectoires bien distincts dans différents biomes. Nous analysons cette transition selon les avantages physiques que la cueillette et l’agriculture ont pu apporter aux acteurs concernés. Nous proposons que divers substrats offrent différents avantages concernant l’adoption de l’agriculture et suggérons que ces avantages variaient selon les sexes, c’est-à-dire que les stratégies « optimales » par rapport à l’adoption et du mode d’adoption des innovations néolithiques différaient entre hommes et femmes.Recent studies emphasise the mosaic character of the process of neolithisation in north-western Europe. However, some overarching motives influencing the uptake of farming can be identified across regions. We model the importance of evolutionary processes underlying neolithisation. We focus on the southern part of the Low Countries, where the uptake of agriculture follows distinct trajectories in different biomes. We analyse the transition in terms of fitness benefits that foraging and agriculture bestow on the actors involved. We suggest that different substrates offer different fitness benefits with regard to the uptake of farming and that these benefits differed between the sexes, leading to differing “optimal” strategies for males and females regarding whether and how to adopt Neolithic innovations.