Plastic and unpredictable responses of stream invertebrates to leaf pack patches across sandy-bottomed streams

2011 ◽  
Vol 62 (4) ◽  
pp. 394 ◽  
Author(s):  
Barbara J. Downes ◽  
Jill Lancaster ◽  
Robin Hale ◽  
Alena Glaister ◽  
William D. Bovill
Keyword(s):  
Food Sources ◽  
Stream Invertebrates ◽  
Patch Use ◽  
Leaf Pack ◽  
Bare Sand ◽  
Eastern Australia ◽  
Type Ii Errors ◽  
Potential Food ◽  
Power Analyses

Detrital inputs to ecosystems provide potential food sources and can produce trophic cascades, but this effect is influenced by whether species specialise in consuming or inhabiting accumulations of detritus. To test whether species are differentially associated with leaves or sand, we compared densities of stream invertebrate species in patches of leaves and bare sand in two sandy-bed creeks in south-eastern Australia, in summer and spring. We also assessed the quality of information on diet and substrate association in the literature. Most species showed no density differences between leaf and sand patches (‘microhabitat generalists’), but categorisation as generalists, leaf or sand species differed between datasets. We developed a method for identifying important effect sizes; power analyses showed that many species were true generalists, but many non-significant results were potentially Type II errors. The literature provided information that was broadly consistent with our data, but few studies publish reliable information about either diet or patch use. Our results support a contention that few Australian stream invertebrates are obligate shredders, and this may also be true for streams elsewhere. Predicting and detecting the responses of such generalist taxa to detrital inputs will be very challenging.

scholarly journals Information use in foraging flocks of songbirds - no evidence for social transmission of patch quality

2019 ◽  
Author(s):  
F. Hillemann ◽  
E. F. Cole ◽  
B. C. Sheldon ◽  
D. R. Farine
Keyword(s):  
Null Model ◽  
Population Level ◽  
Food Sources ◽  
Diffusion Of Information ◽  
Bird Feeders ◽  
Social Associations ◽  
The Cost ◽  
Post Hoc ◽  
Potential Food

ABSTRACTAnimals use behavioural cues from others to make decisions in a variety of contexts. There is growing evidence, from a range of taxa, that information about the locations of food patches can spread through a population via social connections. However, it is not known whether information about the quality of potential food sources transmits similarly. We studied foraging behaviour in a population of wild songbirds with known social associations, and tested whether flock members use social information about the profitability of patches to inform their foraging decisions. We provided artificial patches (ephemeral bird feeders) that appeared identical but were either profitable (contained food) or unprofitable (contained no food). If information about patch profitability spreads via social associations, we predicted that empty feeders would only be sampled by individuals that are less connected to each other than expected by chance. In contrast, we found that individuals recorded at empty feeders were more closely associated with each other than predicted by a null model simulating random arrival of individuals, mirroring pattern of increased connectedness among individuals recorded at full feeders. We then simulated arrival under network-based diffusion of information, and demonstrate that the observed pattern at both full and empty feeders matches predictions derived from this post-hoc model. Our results suggest that foraging songbirds only use social cues about the location of potential food sources, but not their profitability. These findings agree with the hypothesis that individuals balance the relative economic costs of using different information, where the costs of personally sampling a patch upon arrival is low relative to the cost of searching for patches. This study extends previous work on information spread through avian social networks, by suggesting important links between how animals use information at different stages of the acquisition process and the emerging population-level patterns of patch use.

Methyl mercury in zooplankton—the role of size, habitat, and food quality

2002 ◽  
Vol 59 (10) ◽  
pp. 1606-1615 ◽  
Author(s):  
Martin Kainz ◽  
Marc Lucotte ◽  
Christopher C Parrish
Keyword(s):  
Organic Matter ◽  
Fatty Acid ◽  
Body Size ◽  
Methyl Mercury ◽  
Size Fraction ◽  
Food Sources ◽  
Calanoid Copepods ◽  
Bacterial Food

Pathways of methyl mercury (MeHg) accumulation in zooplankton include ingestion of organic matter (OM). We analyzed fatty acid (FA) biomarkers in zooplankton to (i) investigate the effect of allochthonous and autochthonous OM ingestion on MeHg concentrations ([MeHg]) in zooplankton and (ii) examine how algal and bacterial food sources affect MeHg bioaccumulation. We partitioned bulk zooplankton samples (i.e., >500, 202, 100, and 53 μm) from Lake Lusignan (Québec) and measured [MeHg] and [FA] in each fraction. [MeHg] increased with increasing body size and was significantly higher in pelagic than in littoral macrozooplankton (>500 μm). The amount of the ingested terrestrial FA biomarker 24:0 indicated that less than 1% of the total FA in zooplankton was derived from allochthonous sources. More than 60% of the ingested FA originated from algal biomarkers and <10% from bacterial biomarkers. Relative amounts of algal-derived essential FA and bacterial FA were not associated with [MeHg] in any size fraction. In pelagic zones, the amount of MeHg in zooplankton related positively to the number of large organisms such as Calanoid copepods and Daphnia. We propose that the accumulation of MeHg in lacustrine zooplankton depends on the zooplankton habitat rather than on the quality of ingested food.

scholarly journals Nesting Preferences for Two Woodpecker Species (Dendrocopos Major and Dendrocopos Medius) in Comana Forest, Southern Romania/ Preferințele de cuibărit la două specii de ciocănitori (Dendrocopos Major şi Dendrocopos Medius), în Pădurea Comana, Sudul României

2015 ◽  
Vol 57 (1) ◽  
pp. 35-45 ◽  
Author(s):  
Ioana Damoc ◽  
Tiberiu Sahlean ◽  
Roxana Ion ◽  
Mihaela Ion ◽  
Lotus Elena Meşter
Keyword(s):  
Food Sources ◽  
Pedunculate Oak ◽  
Large Trees ◽  
Nesting Sites ◽  
Turkey Oak ◽  
Nest Height ◽  
Middle Spotted Woodpecker ◽  
Dendrocopos Major ◽  
Nesting Preferences

Abstract The main goal of this study is to get a better insight of the habitat requirements for the Great- and Middle Spotted Woodpeckers. Woodpeckers are forest specialists, threatened all over Europe mainly by the loss of forest habitats and also by the loss in quality of the habitat by reducing the food sources and nesting sites. Both species showed a strong preference for oaks, lime, large trees and dead wood for nesting, but Middle Spotted Woodpecker proved to be more selective in terms of tree species. Nest-height was influenced by tree diameter. Both species have the same nesting preferences for Turkey oak, lime and Pedunculate oak, in a Quercetum farnetto-cerris type of forest. The orientation of the nest hole on the tree was mainly NE-E-SE for Middle Spotted Woodpecker and N-NE-E for Great Spotted Woodpecker.

Life Conditions and Health in Early Farmers

Early Farmers ◽  
2014 ◽  
Author(s):  
Clark Spencer Larsen
Keyword(s):  
Quality Of Life ◽  
Food Sources ◽  
General Picture ◽  
Settlement Systems ◽  
Life Conditions ◽  
Research Programmes ◽  
Comparative Results ◽  
Early Farmers ◽  
Skeletal Samples

Human remains provide a fund of data for documenting and interpreting the quality of life, living conditions, and the costs and benefits of the foraging-to-farming transition and the dependence on domesticated food sources, especially those related to the adoption and spread of plant staples that today feed much of the world’s population, including the superfoods—wheat, rice and maize. This chapter presents comparative results of human bioarchaeological research programmes where human skeletal samples are large and well documented and where archaeological context (settlement systems, dietary reconstruction) is comprehensive: west and east Asia, Europe, and North America. These investigations reveal largely similar but variable health outcomes relating to the foraging-to-farming transition. The record shows a general picture of compromised health either with the shift from foraging to farming or with intensified farming.

scholarly journals Protein Quality of Rice Drinks Fortified with Bovine and Porcine Blood Plasma

2015 ◽  
Vol 68 (1) ◽  
pp. 7487-7496 ◽  
Author(s):  
Piedad Margarita Montero Castillo ◽  
Yesid Alejandro Marrugo Ligardo ◽  
Lesbia Cristina Julio González
Keyword(s):  
Amino Acid ◽  
Blood Plasma ◽  
Protein Content ◽  
Protein Quality ◽  
Amino Acid Profile ◽  
Food Sources ◽  
In Vitro Digestibility ◽  
Porcine Blood ◽  
Bovine Plasma

The future of nutrition in Colombia, and perhaps in other developing countries, will depend in large part on the ability of food technology to take full advantage of the food sources available in the country and to adapt and develop new products that will vary and complement the diets of the majority of the population at a low cost. The objective of this study was to evaluate the protein quality of rice-based drinks fortified with bovine and porcine blood plasma. Six treatments were prepared with different levels of fortification (14.5%, 18.5% and 29%). The effects of the plasma type and the addition levels on the protein content, the amino acid profile, and the in vitro digestibility of the drinks were observed. The AOAC method was employed for the determination of the protein content; the amino acid profile was created using HPLC. The protein digestibility was determined by subjecting a dispersion of the drink to the action of a multi-enzymatic solution. The protein content increased with the level of fortification. The drinks fortified with bovine plasma (104%) and porcine plasma (89%) presented a better protein quality index than the unfortified drink. The digestibility of the fortified drinks did not demonstrate significant improvements in comparison with the unfortified drink. The chemical score of the drinks fortified with porcine plasma (71.6) and bovine plasma (78.5) showed that the latter had the best nutritional quality.

Color and side preferences in Palestine sunbirds (Nectarinia osea)

2014 ◽  
Vol 60 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Rainee L. Kaczorowski ◽  
Gali Blumenfeld ◽  
Avi Koplovich ◽  
Shai Markman
Keyword(s):  
Food Sources ◽  
Separate Experiment ◽  
Significant Preference ◽  
Floral Color ◽  
Foraging Decisions ◽  
Quality Of Food ◽  
Color Bias ◽  
Preference Experiment ◽  
Side Bias

Floral color is an important cue that converged in many ornithophilous flowers and can be used by nectarivorous birds to make foraging decisions. Wild ornithophilous flowers are frequently red, although they are more often yellow in Israel. The Palestine sunbird (Nectarinia osea) is the only nectarivorous bird in Israel and surrounding Mediterranean areas. Given the prevalence of yellow flowers in their habitats (along with sunbirds' expected sensitivity increase in this region of color vision), we predicted that Palestine sunbirds prefer yellow food sources over red. We examined sunbird foraging behavior when they were presented simultaneously with a yellow and red feeder, each containing the same quantity and quality of food. We investigated whether sunbirds had a side bias in the color preference experiment, but also in a separate experiment where both feeders were white. Sunbirds did not exhibit a significant color bias, while they did have a significant preference for a particular side of the cage. Location appears to be a more important cue than color to Palestine sunbirds, likely because location can offer information on the most rewarding plants and recently depleted flowers. However, color may still provide useful information that could influence foraging decisions in different contexts.

Detection, identification and mapping of cyanobacteria — Using remote sensing to measure the optical quality of turbid inland waters

1994 ◽  
Vol 45 (5) ◽  
pp. 801 ◽  
Author(s):  
DLB Jupp ◽  
JTO Kirk ◽  
GP Harris
Keyword(s):  
Remote Sensing ◽  
Algal Species ◽  
Optical Quality ◽  
High Spectral Resolution ◽  
Turbid Waters ◽  
Eastern Australia ◽  
Processing Techniques ◽  
Compact Airborne Spectrographic Imager

The advantages of airborne scanning for the detection, identification and mapping of algal species, cyanobacteria and associated water parameters (such as turbidity) can be realized if current research outcomes are developed into operational methods based on images with high spectral resolution. Evidence for this has become available through data obtained recently in Australia from the Compact Airborne Spectrographic Imager. This paper shows how pigments associated with cyanobacteria are detectable, even in the very turbid waters typical of eastern Australia. It demonstrates how, if the waterbodies and their constituents can be characterized by a programme of field and laboratory measurement, current processing techniques and models allow the concentrations of different constituents (algae and particles) in the photic zone to be estimated and mapped. The challenge for operational remote sensing of optical water quality in Australia (and throughout the world) is seen to have two components. One is to provide an effective characterization of the target inland and adjacent coastal waters and the other is to streamline the data analysis to provide maps of water properties in the time and cost frameworks required for operational use.

scholarly journals Impact of the quality of food sources on the wing beating of honey bee dancers

Apidologie ◽  
2020 ◽  
Vol 51 (4) ◽  
pp. 631-641 ◽  
Author(s):  
Sylwia Łopuch ◽  
Adam Tofilski
Keyword(s):  
Honey Bee ◽  
Food Sources ◽  
Quality Of Food

scholarly journals Pea Protein for Hempseed Oil Nanoemulsion Stabilization

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4288 ◽  
Author(s):  
Maciej Jarzębski ◽  
Farahnaz Fathordoobady ◽  
Yigong Guo ◽  
Minghuan Xu ◽  
Anika Singh ◽  
...  
Keyword(s):  
Droplet Size ◽  
Entrapment Efficiency ◽  
Box Behnken Design ◽  
Pea Protein ◽  
Challenge Tests ◽  
Oil Emulsions ◽  
The Stability ◽  
Potential Food ◽  
Potential Use

In this paper, we present the possibility of using pea protein isolates as a stabilizer for hempseed oil (HSO)-based water/oil emulsions in conjunction with lecithin as a co-surfactant. A Box-Behnken design was employed to build polynomial models for optimization of the ultrasonication process to prepare the emulsions. The stability of the system was verified by droplet size measurements using dynamic light scattering (DLS) as well as centrifugation and thermal challenge tests. The z-ave droplet diameters of optimized emulsion were 209 and 207 nm after preparation and 1 week storage, respectively. The concentration of free Linoleic acid (C18:2; n-6) was used for calculation of entrapment efficiency in prepared nanoemulsions. At optimum conditions of the process, up to 98.63% ± 1.95 of entrapment was achieved. FTIR analysis and rheological tests were also performed to evaluate the quality of oil and emulsion, and to verify the close-to-water like behavior of the prepared samples compared to the viscous nature of the original oil. Obtained results confirmed the high impact of lecithin and pea protein concentrations on the emulsion droplet size and homogeneity confirmed by microscopic imaging. The presented results are the first steps towards using hempseed oil-based emulsions as a potential food additive carrier, such as flavor. Furthermore, the good stability of the prepared nanoemulsion gives opportunities for potential use in biomedical and cosmetic applications.

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