scholarly journals A New Protocol Using Artificial Seeds to Evaluate Dietary Preferences of Harvester Ants in Semi-arid Environments

Sociobiology ◽  
2018 ◽  
Vol 65 (2) ◽  
pp. 149
Author(s):  
Pedro Luna ◽  
Wesley Dáttilo
Keyword(s):  
Foraging Behavior ◽  
Resource Selection ◽  
Food Resource ◽  
Nutrient Content ◽  
Arid Environments ◽  
Harvester Ants ◽  
Artificial Seeds ◽  
Selective Predation ◽  
Resource Quality ◽  
Pogonomyrmex Barbatus

The preferences of seed intake by harvester ants (Pogonomyrmex spp.) have been debated for a long time, mainly due the lack of repeatable methods to draw clear conclusions. However, several characteristics of the food resource are well recognized as the drivers of such selective predation. For instance, resource quality (i.e., availability of carbohydrates, lipids, and proteins) is one factor that could explain the observed foraging patterns of Pogonomyrmex species. In this sense, experimental approaches using artificial resources (e.g., synthetic seeds/diaspores) have provided an useful and alternative tool to study ant’s food foraging behavior. Therefore, it is expected that the use of artificial seeds also could offer a versatile way to assess the influence of resource quality exert on the resource selection by harvester ants. On the other hand, empirical experiments involving harvester ants and artificial seeds are still rare in the literature and it is not known if such methodology is efficient with different Pogonomyrmex species. In this study carried out in a Neotropical arid environment of central Mexico, we tested a simple but fundamental question: Do harvester ants (Pogonomyrmex barbatus) predate artificial seeds with manipulated nutrient content (lipids and proteins) in the field? We found that the proportion of native seeds removed was lower than the proportion of artificial seeds removed. However, we found no difference between the removal of artificial seeds containing only lipids and the seeds containing lipids + proteins. These findings indicate that the artificial seeds synthesized by us could be an effective method to test different ecological hypothesis involving harvester ants. Moreover, our empirical experiment offers a benchmark to study the influence of resource quality on the food foraging behavior of harvester ants in Neotropical arid environments.

scholarly journals Canopy cover and anurans: nutrients are the most important predictor of growth and development

2016 ◽  
Vol 94 (3) ◽  
pp. 225-232 ◽  
Author(s):  
Freya E. Rowland ◽  
Sara K. Tuttle ◽  
María J. González ◽  
Michael J. Vanni
Keyword(s):  
Growth And Development ◽  
Large Scale ◽  
Food Resource ◽  
Canopy Cover ◽  
Resource Quality ◽  
Bottom Up ◽  
Growth And Survival ◽  
Primary Producer ◽  
Full Factorial ◽  
Potential Food

Bottom-up effects such as the availability of light and nutrients can have large impacts on primary producer quantity and quality, which is then translated into the growth and development of consumers. The use of “canopy cover” as a bottom-up predictive factor is a broad categorization, as canopy cover controls both the amount of light allowed into a pond and the nutrient load through leaf litter. To test how light and nutrients influence pond ecosystems, we manipulated inorganic nutrients and light in a 2 × 3 full-factorial, large-scale mesocosm experiment. Larval American Bullfrogs (Lithobates catesbeianus (Shaw, 1802)) were reared for 6 weeks at low densities and then assessed for development, growth, and survival at the end of the experiment. We also collected weekly samples of potential food resources (phytoplankton and periphyton) for the estimation of algal production and stoichiometric quality (carbon:nitrogen:phosphorus). Light had strong effects on food resource quality; however, resource quality did not significantly predict tadpole growth or development. Instead, nutrients seemed to be the most important factor as a stimulator of total algal primary production and some unknown pathway, which in turn affected tadpole development. Ours is the first study to investigate canopy cover using a comprehensive causal model, and our results suggest in regards to tadpole growth and development, canopy cover is important mainly as a source of nutrients to ponds.

Factors affecting undergraduates’ selection of online library resources in academic tasks

2015 ◽  
Vol 33 (2) ◽  
pp. 272-291 ◽  
Author(s):  
Soohyung Joo ◽  
Namjoo Choi
Keyword(s):  
Undergraduate Students ◽  
Resource Selection ◽  
Ease Of Use ◽  
Resource Quality ◽  
Content Type ◽  
Factors Affecting ◽  
Multiple Factors ◽  
Library Resource ◽  
Library Resources ◽  
Online Library

Purpose – The purpose of this paper is to explore multiple factors affecting online library resource selection by undergraduate students. Three dimensions of factors are investigated including usefulness and ease-of-use, resource quality, and individual differences. Design/methodology/approach – An instrument was developed to measure various aspect factors and online library resource use intention. A survey was administered to 332 undergraduate students. Quantitative analysis, including structural equation modeling, ANOVA, and t-tests, was used to statistically examine the effects of the identified 11 factors on the use intention of online library resources. Findings – The findings indicated that both usefulness and ease-of-use positively influenced the undergraduates’ use intention of online library resources. Also, five resource quality constructs – accessibility, credibility, coverage, currency, and format – were the determinants of online library resources use intention. Interestingly, the effect of accessibility was the strongest, while that of credibility was the weakest. In addition, this study found that familiarity with sources and use of good search skills had a significant effect on users’ use intention at the individual user level. Originality/value – This study is one of the few studies investigating multiple factors comprehensively that influence online library resource selection.

scholarly journals Probiotic Potential, Iron and Zinc Bioaccessibility, and Sensory Quality of Uapaca kirkiana Fruit Jam Fermented with Lactobacillus rhamnosus Yoba

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Armistice Chawafambira ◽  
Moosa Mahmood Sedibe ◽  
Augustine Mpofu ◽  
Matthew Achilonu
Keyword(s):  
Rural Areas ◽  
Food Resource ◽  
Nutrient Content ◽  
Biochemical Properties ◽  
Fruit Tree ◽  
Sub Saharan Africa ◽  
Probiotic Potential ◽  
Uapaca Kirkiana ◽  
Iron And Zinc ◽  
Sub Saharan

Uapaca kirkiana is an underutilised indigenous fruit tree (IFT) found in the miombo ecological zone in sub-Saharan Africa. Furthermore, sub-Saharan Africa is home to many nutritionally insecure people who suffer from micronutrient deficiency. The incorporation of probiotic strains in jams as a possible way of enhancing mineral accessibility, food quality, and health is limited in Africa. This study monitored the probiotic potential, bioaccessible iron and zinc, and organoleptic properties of U. kirkiana fruit jam fermented with L. rhamnosus yoba. U. kirkiana fruits were collected from semiarid rural areas of Zimbabwe. The L. rhamnosus yoba strain was obtained from the Yoba for Life Foundation, Netherlands. Mineral and biochemical properties of the probiotic jam were analysed using AOAC standard methods. The U. kirkiana fruit tree was ranked first as a food resource by most rural populations in Zimbabwe. The probiotic jam formulation had 55% (wt/vol) U. kirkiana fruit pulp, 43% (wt/vol) sugar, 1.25% (wt/vol) pectin, 0.5% (wt/vol) citric acid, and 0.25% (wt/vol) L. rhamnosus yoba strain. The probiotic jam had 6.2 ± 0.2 log CFU/mL viable L. rhamnosus yoba cells. Iron and zinc content (mg/100 g w.b.) was 4.13 ± 0.22 and 0.68 ± 0.02 with pH 3.45 ± 0.11 , respectively. Nutrient content was g/100 g w.b., carbohydrate 66 ± 4.1 , fat 0.1 ± 0.01 , crude protein 0.2 ± 0.01 , ash 0.7 ± 0.02 , and crude fiber 0.3 ± 0.01 . Bioaccessible iron and zinc were 6.55 ± 0.36 % and 16.1 ± 0.50 % and increased by 4% and 2% in the probiotic jam, respectively. Mineral bioaccessibility and nutrient content were significantly different ( p < 0.05 ) in jam with 0.25% L. rhamnosus yoba. Jam acceptance rating was 83%. The probiotic jam can be used as a sustainable food containing probiotic with potential nutritional and health benefits.

scholarly journals Remoción de Semillas en Hábitats Transformados: Pogonomyrmex barbatus (Hymenoptera: Formicidae) y Cinco Especies de Cactáceas del Centro de México

Sociobiology ◽  
2014 ◽  
Vol 59 (1) ◽  
pp. 49
Author(s):  
Leticia Ríos-Casanova ◽  
Héctor Godínez-Álvarez ◽  
Gabriala Martínez Morales
Keyword(s):  
Human Activities ◽  
Removal Rate ◽  
Seed Removal ◽  
Foraging Activity ◽  
Harvester Ants ◽  
Pogonomyrmex Barbatus ◽  
Intermediate Transformation ◽  
Crop Field ◽  
A Site ◽  
Harsh Conditions

One of the main consequences of human activities in semiarid zones is the transformation of habitats. In this work we studied the effect of this transformation on seed removal of five cacti species by the harvester ant Pogonomyrmex barbatus in the Tehuacán-Cuicatlán valley, a semiarid zone in central Mexico. Seed removal was quantified at three sites which have been under the effect of human activities: an abandoned crop field (CCA), a site with evidence of current human activities (TAH), and a site inside a botanic garden ( JB). We hypothesized that sites which have been under intense human activities would have low rates of seed removal because they offer harsh conditions for harvester ants, reducing their foraging activity. Results showed that vegetation and surface soil characteristics of the sites studied are affecting the rates of seed removal of the five cacti species studied. The lowest seed removal rate was found at CCA, the most transformed site. In contrast with our hypothesis the highest seed removal was found at TAH, the site which represents the intermediate transformation condition, because this site still conserves some characteristics which permit intense foraging activity by harvester ants. We also found that the seed removal rate varied among the different cacti species studied. Seed of E. chiotilla had the highest removal rate, whereas O. decumbens had the lowest. Differences in seed removal rate could be associated with the high heterogeneity found in sites with intermediate levels of transformation. Another factor that must be considered is the external morphology of seeds since smaller seeds presented highest removal rates.

scholarly journals Patterns of foraging activity and fidelity in a southeast Asian flying fox

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Elodie Schloesing ◽  
Rémi Chambon ◽  
Annelise Tran ◽  
Kinley Choden ◽  
Sébastien Ravon ◽  
...  
Keyword(s):  
Foraging Behavior ◽  
Animal Movement ◽  
Foraging Ecology ◽  
Nipah Virus ◽  
Food Resource ◽  
Habitat Type ◽  
Pathogen Transmission ◽  
Foraging Activity ◽  
Residential Areas ◽  
Fruit Bat

Abstract Background Improved understanding of the foraging ecology of bats in the face of ongoing habitat loss and modification worldwide is essential to their conservation and maintaining the substantial ecosystem services they provide. It is also fundamental to assessing potential transmission risks of zoonotic pathogens in human-wildlife interfaces. We evaluated the influence of environmental and behavioral variables on the foraging patterns of Pteropus lylei (a reservoir of Nipah virus) in a heterogeneous landscape in Cambodia. Methods We employed an approach based on animal-movement modeling, which comprised a path-segmentation method (hidden Markov model) to identify individual foraging-behavior sequences in GPS data generated by eight P. lylei. We characterized foraging localities, foraging activity, and probability of returning to a given foraging locality over consecutive nights. Generalized linear mixed models were also applied to assess the influence of several variables including proxies for energetic costs and quality of foraging areas. Results Bats performed few foraging bouts (area-restricted searches) during a given night, mainly in residential areas, and the duration of these decreased during the night. The probability of a bat revisiting a given foraging area within 48 h varied according to the duration previously spent there, its distance to the roost site, and the corresponding habitat type. We interpret these fine-scale patterns in relation to global habitat quality (including food-resource quality and predictability), habitat-familiarity and experience of each individual. Conclusions Our study provides evidence that heterogeneous human-made environments may promote complex patterns of foraging-behavior and short-term re-visitation in fruit bat species that occur in such landscapes. This highlights the need for similarly detailed studies to understand the processes that maintain biodiversity in these environments and assess the potential for pathogen transmission in human-wildlife interfaces.

scholarly journals Normative theory of patch foraging decisions

2020 ◽  
Author(s):  
Zachary P Kilpatrick ◽  
Jacob D Davidson ◽  
Ahmed El Hady
Keyword(s):  
Foraging Behavior ◽  
Optimal Foraging ◽  
Food Resource ◽  
Optimal Foraging Theory ◽  
Foraging Theory ◽  
Normative Theory ◽  
Optimal Decision ◽  
Inference Problem ◽  
Foraging Decisions ◽  
Neural Underpinnings

Foraging is a fundamental behavior as animals’ search for food is crucial for their survival. Patch leaving is a canonical foraging behavior, but classic theoretical conceptions of patch leaving decisions lack some key naturalistic details. Optimal foraging theory provides general rules for when an animal should leave a patch, but does not provide mechanistic insights about how those rules change with the structure of the environment. Such a mechanistic framework would aid in designing quantitative experiments to unravel behavioral and neural underpinnings of foraging. To address these shortcomings, we develop a normative theory of patch foraging decisions. Using a Bayesian approach, we treat patch leaving behavior as a statistical inference problem. We derive the animals’ optimal decision strategies in both non-depleting and depleting environments. A majority of these cases can be analyzed explicitly using methods from stochastic processes. Our behavioral predictions are expressed in terms of the optimal patch residence time and the decision rule by which an animal departs a patch. We also extend our theory to a hierarchical model in which the forager learns the environmental food resource distribution. The quantitative framework we develop will therefore help experimenters move from analyzing trial based behavior to continuous behavior without the loss of quantitative rigor. Our theoretical framework both extends optimal foraging theory and motivates a variety of behavioral and neuroscientific experiments investigating patch foraging behavior.

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