Relative Importance of Algae and Emergent Plant Litter to Freshwater Marsh Invertebrates

1994 ◽  
Vol 51 (3) ◽  
pp. 681-692 ◽  
Author(s):  
Suzanne Campeau ◽  
Henry R. Murkin ◽  
Rodger D. Titman
Keyword(s):  
Food Source ◽  
Algal Growth ◽  
Plant Litter ◽  
Freshwater Marsh ◽  
Artificial Substrate ◽  
Food Sources ◽  
Relative Importance ◽  
Algal Food ◽  
Major Food ◽  
Scirpus Lacustris

We test the hypotheses that (1) algae are a major food source for marsh invertebrates and (2) plant litter serves mainly as cover for invertebrates and a substrate for algal growth rather than as a direct source of nutrition. Twelve enclosures (5-m diameter) were deployed in May in a nutrient-poor marsh of the Interlake region of Manitoba, six of which were fertilized to increase algal levels. The hardstem bulrush (Scirpus lacustris glaucus) litter present was replaced with a nonnutritive artificial substrate in half of the fertilized and unfertilized enclosures. Dominant taxa of nektonic herbivores–detritivores increased in abundance and biomass following algae manipulations but were not affected by the replacement of plant litter with a nonnutritive substrate. Epiphytic herbivores–detritivores responded to changes in both detritus and algal food sources, the importance of each factor varying among taxa. Fertilization resulted in early peaks of emergence for chironomids. In the first weeks of the study, chironomid emergence was not affected by the replacement of plant litter with a non-nutritive substrate. In August, however, more chironomids emerged in the treatments where plant litter was provided when compared with the artificial litter treatments.

RED JUNGLE FOWL HAVE MORE CONTRAFREELOADING THAN WHITE LEGHORN LAYERS: EFFECT OF FOOD DEPRIVATION AND CONSEQUENCES FOR INFORMATION GAIN

Behaviour ◽  
2002 ◽  
Vol 139 (9) ◽  
pp. 1195-1209 ◽  
Author(s):  
Per Jensen ◽  
Karin Schütz ◽  
Christina Lindqvist
Keyword(s):  
Food Deprivation ◽  
Food Source ◽  
Information Gain ◽  
High Gain ◽  
Alternative Food ◽  
Food Sources ◽  
Production Environment ◽  
White Leghorn ◽  
Wood Shavings ◽  
Red Jungle Fowl

AbstractContrafreeloading (CFL), i.e. choosing food which requires work over free food, occurs at a higher rate in red jungle fowl (Gallus gallus) compared to White Leghorn layers. We examined whether this difference between breeds was altered by food deprivation and whether it affected the information gained about alternative food sources. In a first experiment, twenty birds of each breed were deprived for zero, three and six hours and then allowed a choice of feeding from freely available food or food mixed with wood shavings. In both breeds, CFL tended to decrease after deprivation, but jungle fowl consistently showed more CFL than Leghorns also after food deprivation. This shows that differences in CFL between breeds were not altered by food deprivation, and the larger CFL in jungle fowl may represent a genetically based difference in feeding strategy. In a second experiment, we examined whether the differences in CFL affected how the birds acquired information about alternative food sites of different quality. Twenty birds of each breed were allowed to forage during three 10 min sessions in a four armed maze, where symbols in each end of the arms indicated the location of four different quality food sources; 'high gain' (freely available food), 'medium gain' (70% food, 30% wood shavings), 'low gain' (30% food), and 'no gain' (100% wood shavings). Each bird was then tested in the same maze when the 'high gain' food source and its symbol had been removed, and the other three sources contained only the symbols and wood shavings. Jungle fowl chose the symbol indicating the best available food source significantly more often than the Leghorns. The results indicate that Leghorn gain less information during foraging, which may have consequences for their adaptation capacity in a production environment. This could either be a consequence of Leghorns showing less CFL, or a generally impaired learning capacity of Leghorns compared to jungle fowl.

scholarly journals The contribution of the Canary Island date palm (Phoenix canariensis) to the winter diet of frugivores in novel ecosystems

2019 ◽  
Vol 5 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Dirk HR Spennemann
Keyword(s):  
Urban Areas ◽  
Canary Island ◽  
Food Source ◽  
Date Palm ◽  
Food Sources ◽  
Novel Ecosystems ◽  
Date Palms ◽  
Phoenix Canariensis ◽  
Winter Diet ◽  
Native Foods

Abstract With the increasing expansion in urban areas, many species have adapted to utilising horticulturally used plants as alternate or augmentary food sources, in particular, during winter – when native foods are largely absent. Ornamental palms, particularly Canary Island Date Palms, fruit continuously during most of the year and thus provide a stable food supply. Based on observational, metric and bio-chemical data, this paper examines the role Canary Island Date Palms can and do play in the nutrition of frugivorous animals, in particular, for birds. It demonstrates that with its nearly year-round provisioning of drupes, the palm plays a major role as a ‘staple’ and backup food source for several species.

scholarly journals MODIFIKASI BARU ALGORITMA KOLONI LEBAH BUATAN UNTUK MASALAH OPTIMASI GLOBAL

2018 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Nursyiva Irsalinda ◽  
Sugiyarto Surono
Keyword(s):  
Food Source ◽  
Artificial Bee Colony ◽  
Selection Process ◽  
Optimization Technique ◽  
Food Sources ◽  
Abc Algorithm ◽  
Average Value ◽  
Bee Colony ◽  
Objective Function Values ◽  
Better Than

Artificial Bee Colony (ABC) algorithm is one of metaheuristic optimization technique based on population. This algorithm mimicking honey bee swarm to find the best food source. ABC algorithm consist of four phases: initialization phase, employed bee phase, onlooker bee phase and scout bee phase. This study modify the onlooker bee phase in selection process to find the neighborhood food source. Not all food sources obtained are randomly sought the neighborhood as in ABC algorithm. Food sources are selected by comparing their objective function values. The food sources that have value lower than average value in that iteration will be chosen by onlooker bee to get the better food source. In this study the modification of this algorithm is called New Modification of Artificial Bee Colony Algorithm (MB-ABC). MB-ABC was applied to 4 Benchmark functions. The results show that MB-ABC algorithm better than ABC algorithm

Digestive physiological characteristics of black soldier fly larvae reared on five organic wastes

2021 ◽  
pp. 1-18
Author(s):  
Q.X. Sun ◽  
X.C. Li ◽  
X.H. Tan ◽  
Y.W. Dong ◽  
C.H. You ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Growth Performance ◽  
Food Source ◽  
Digestive Enzyme ◽  
Organic Wastes ◽  
Food Sources ◽  
Black Soldier Fly ◽  
Ph Values ◽  
Black Soldier Fly Larvae ◽  
Luminal Ph

Black soldier fly larvae (BSFL) are able to utilise a broad range of organic wastes to fulfil their growth needs. To acquire this basic knowledge of its digestive adaptation to various food, five organic wastes (soybean meal [SBM], wheat bran [WB], beer yeast [BY], kitchen waste [KW] and chicken manure [CM]) were fed to 3-day-old BSFL for 16 days. The growth performance, luminal pH of the gut, midgut histology, digestive enzyme activity and intestinal bacterial microbiota of the larvae were assessed. Growth performance was greatest in the KW group followed by the SBM group and was worst in the CM group. Nutrient compositions of larvae were not significantly affected by those of the food sources, with the exception of crude ash. The ultrastructural observations of midgut showed the number of mitochondria in CM and BY groups was less than other three groups. Twenty-four hours after feeding, weakly acidic, acidic, strongly acidic, and alkaline luminal pH values were detected in the anterior, middle and posterior segments of the gut in all groups, but the luminal pH values of the hindgut varied with food source. Significant lipase and esterase activity, cellulase activity, and amylase activity were detected in the intestines of larvae reared on KW, WB and BY, respectively, revealing that digestive enzyme activity was closely associated with the nutrient composition of the food source. Bacterial composition and diversity differed significantly between groups and were characterised by specific indicator bacteria, which may play important roles in food digestibility. The results suggested that different food sources induced adaptive physical, chemical and biological changes in the digestive tracts of BSFL and may indicate that BSFL developed specific strategies for nutrient utilisation and accumulation. The knowledge acquired here will be beneficial for developing rearing protocols to optimise bioconversion in this insect for their various applications.

Pinpointing food sources: olfactory and anemotactic orientation in desert ants, Cataglyphis fortis

2000 ◽  
Vol 203 (5) ◽  
pp. 857-868 ◽  
Author(s):  
H. Wolf ◽  
R. Wehner
Keyword(s):  
Food Source ◽  
Video Tracking ◽  
Food Sources ◽  
Integration Scheme ◽  
Experimental Conditions ◽  
Feeding Site ◽  
Desert Ants ◽  
Feeding Station ◽  
Visually Based ◽  
Cataglyphis Fortis

Desert ants, Cataglyphis fortis, search for a repeatedly visited food source by employing a combined olfactory and anemotactic orientation strategy (in addition to their visually based path-integration scheme). This behaviour was investigated by video-tracking consecutive foraging trips of individually marked ants under a variety of experimental conditions, including manipulations of the olfactory and wind-detecting systems of the ants. If the wind blows from a constant direction, ants familiar with the feeding site follow outbound paths that lead them into an area 0.5-2.5 m downwind of the feeding station. Here, the ants apparently pick up odour plumes emanating from the food source and follow these by steering an upwind course until they reach the feeder. If the food is removed, foragers usually concentrate their search movements within the area downwind of the feeding site. Only when the wind happens to subside or when tail-wind conditions prevail do the ants steer direct courses towards the food. Elimination of olfactory input by clipping the antennal flagella, or of wind perception by immobilising the bases of the antennae, altered the foraging behaviour of the ants in ways that supported these interpretations. Ants with clipped flagella were never observed to collect food items.

scholarly journals Changes in added sugar intake and its major food sources in older Australians during a 15—year follow-up

2014 ◽  
Vol 1 ◽  
pp. 16
Author(s):  
H. Moshtaghian ◽  
J. Louie ◽  
V. Flood ◽  
K. Charlton ◽  
Y. Probst ◽  
...  
Keyword(s):  
Food Sources ◽  
Added Sugar ◽  
Sugar Intake ◽  
Major Food
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