Diet selection is related to breeding status in two frugivorous hornbill species of Central Africa

2014 ◽  
Vol 30 (4) ◽  
pp. 273-290 ◽  
Author(s):  
Aaron M. Lamperti ◽  
Aaron R. French ◽  
Ellen S. Dierenfeld ◽  
Mark K. Fogiel ◽  
Kenneth D. Whitney ◽  
...  
Keyword(s):  
Nutrient Concentration ◽  
Diet Selection ◽  
Caloric Content ◽  
Fruit Pulp ◽  
Mineral Concentration ◽  
Monthly Basis ◽  
Frugivorous Birds ◽  
Sample Data ◽  
Pulp Sample ◽  
Breeding Status

Abstract:Avian diet selection is hypothesized to be sensitive to seasonal changes in breeding status, but few tests exist for frugivorous tropical birds. Frugivorous birds provide an interesting test case because fruits are relatively deficient in minerals critical for reproduction. Here, we quantify annual patterns of fruit availability and diet for two frugivorous hornbill (Bucerotidae) species over a 5.5-y period to test for patterns of diet selection. Data from the lowland tropical rain forest of the Dja Reserve, Cameroon, are used to generate two nutritional indices. One index estimates the nutrient concentration of the diet chosen by Ceratogymna atrata and Bycanistes albotibialis on a monthly basis using 3165 feeding observations combined with fruit pulp sample data. The second index is an estimate of nutrient concentration of a non-selective or neutral diet across the study area based on tree fruiting phenology, vegetation survey and fruit-pulp sample data. Fifty-nine fruit pulp samples representing 40 species were analysed for 16 nutrient categories to contribute to both indices. Pulp samples accounted for approximately 75% of the observed diets. The results support expected patterns of nutrient selection. The two hornbill species selected a diet rich in calcium during the early breeding season (significantly so for B. albotibialis in July and August). Through the brooding and fledging periods, they switched from a calcium-rich diet to one rich in iron and caloric content as well as supplemental protein in the form of invertebrates. Calcium, the calcium to phosphorus ratio and fat concentration were the strongest predictors of breeding success (significant for calcium and Ca:P for B. albotibialis in June). We conclude that hornbills actively select fruit based on nutritional concentration and mineral concentration and that the indices developed here are useful for assessing frugivore diet over time.

Diet selection in Arctic lemmings (Lemmus sibericus and Dicrostonyx groenlandicus): food preferences

1985 ◽  
Vol 63 (5) ◽  
pp. 1161-1173 ◽  
Author(s):  
Arthur R. Rodgers ◽  
Martin C. Lewis
Keyword(s):  
Selection Process ◽  
Food Preferences ◽  
Secondary Compounds ◽  
Diet Selection ◽  
Caloric Content ◽  
Dicrostonyx Groenlandicus ◽  
In Captivity ◽  
Preference Patterns ◽  
The Stability ◽  
Physical And Chemical

Testing of hypotheses relating lemming population dynamics to their food supply requires a detailed understanding of several major components of the diet selection process such as requirements, availability, preference, and selectivity. In this study, food preferences of Arctic lemmings were determined in cafeteria trials: Lemmus preferred graminoids and moss, while Dicrostonyx preferred shrubs and herbs. The stability of these preference patterns in each species was tested in further experimental cafeteria trials. Individuals of both species were pretreated on one of several diets, and two main types of trial were conducted involving limited and unlimited availability of test foods. Naive animals of both species, born and raised in captivity on artificial diets, were also used in the trials. In all cases, preference patterns in each species were maintained, suggesting that they are strongly heritable. Comparison of preference indices to the physical and chemical characteristics of tundra plants indicates that preference patterns in both species are related primarily to macronutrients and caloric content. Differences between Lemmus and Dicrostonyx are determined by secondary compounds and the physical characteristics of the plant species preferred by each. Comparison of ingestion rates and digestibility coefficients indicate that Dicrostonyx has a greater capacity than Lemmus in dealing with the negative characteristics of plants, such as secondary compounds or the presence of plant "hairs."

scholarly journals Effect of Arbuscular Mycorrhiza and Temperature Control on Plant Growth, Yield, and Mineral Content of Tomato Plants Grown Hydroponically

HortScience ◽  
2013 ◽  
Vol 48 (12) ◽  
pp. 1470-1477 ◽  
Author(s):  
Martin Makgose Maboko ◽  
Isa Bertling ◽  
Christian Phillipus Du Plooy
Keyword(s):  
Plant Growth ◽  
Nutrient Uptake ◽  
Temperature Control ◽  
Mycorrhizal Fungi ◽  
Nutrient Concentration ◽  
Growth Yield ◽  
Mineral Nutrient ◽  
Nutrient Concentrations ◽  
Mineral Concentration ◽  
Temperature Controlled

Mycorrhizal inoculation improves nutrient uptake in a range of host plants. Insufficient nutrient uptake by plants grown hydroponically is of major environmental and economic concern. Tomato seedlings, therefore, were treated with a mycorrhizal inoculant (Mycoroot™) at transplanting to potentially enhance nutrient uptake by the plant. Then seedlings were transferred to either a temperature-controlled (TC) or a non-temperature-controlled (NTC) tunnel and maintained using the recommended (100%) or a reduced (75% and 50%) nutrient concentration. Plants grown in the NTC tunnel had significantly poorer plant growth, lower fruit mineral concentration, and lower yield compared with fruit from plants in the TC tunnel. Leaves from plants in the NTC tunnel had higher microelement concentrations than those in the TC tunnel. Highest yields were obtained from plants fertigated with 75% of the recommended nutrient concentration, and not from the 100% nutrient concentration. Application of arbuscular mycorrhizal fungi (AMF) neither enhanced plant growth, nor yield, nor fruit mineral nutrient concentrations. However, temperature control positively affected the fruit Mn and Zn concentration in the TC tunnel following AMF application.

scholarly journals Seed Dispersal by Frugivores and Germination Success of the Invasive Alien Shrub Pyracantha Angustifolia in the Eastern Free State Province, South Africa

2021 ◽  
Author(s):  
Lehlohonolo Donald Adams ◽  
Grant D. Martin ◽  
Colleen T. Downs ◽  
Vincent Ralph Clark ◽  
Vuyisile Thabethe ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Bird Species ◽  
Camera Traps ◽  
Free State ◽  
Fruit Pulp ◽  
Frugivorous Birds ◽  
Alien Plant ◽  
Free State Province ◽  
Germination Success ◽  
Eastern Free State

Abstract Invasive alien plants can use animal-plant interactions to increase their invasiveness. This study investigated the role of frugivorous birds in seed dispersal and germination of the alien plant Pyracantha angustifolia (Rosaceae) in South African high elevation grasslands. We monitored which bird species fed on the fruit of the invasive P. angustifolia in some farms in the Eastern Free State Province using camera-traps and direct surveillance. Nine bird species visited P. angustifolia shrubs to perch or feed on fruits, but only one bird (Speckled Mousebird) fed on the fruits during timed observations. To assess the effect of ingestion by avian frugivores on P. angustifolia germination, P. angustifolia fruits were fed to captive Cape White-eyes (Zosterops virens), Dark-capped Bulbuls (Pycnonotus tricolor), Purple-crested Turacos (Gallirex porphyreolophus), Red-winged Starlings (Onychognathus morio) and Speckled Mousebirds (Colius striatus). Seeds collected from bird excreta, whole fruits, and depulped fruits were grown under greenhouse conditions and germination rates recorded. All captive bird species, except for Cape White-eyes, ingested the seeds; Cape White-eyes only fed on fruit pulp that they had manually removed. Bird species with relatively larger body mass had longer seed retention times compared with the smaller bird species. Germination success of both depulped and ingested P. angustifolia seeds was high (> 80%) and that of whole fruits low (7%). Ingestion by the four avian frugivore species did not affect germination rate and success; instead, the birds facilitate the spread and germination of seeds by removing the fruit pulp and spreading the seed away from the parent shrubs.

scholarly journals Comparación de la composición química proximal de la carne de Anadara Tuberculosa y A. Similis (Bivalvia: Arcidae) de Chomes, Puntarenas, Costa Rica

2012 ◽  
Vol 3 ◽  
pp. 95
Author(s):  
Rafael A. Cruz ◽  
Cristian Fonseca Rodríguez ◽  
Fabián Chavarría-Solera
Keyword(s):  
Seasonal Variation ◽  
Costa Rica ◽  
Proximate Composition ◽  
Biochemical Composition ◽  
Nutritional Value ◽  
Energy Content ◽  
Human Consumption ◽  
Caloric Content ◽  
Monthly Basis ◽  
Average Value

Se estudiaron la variación estacional de la composición química proximal y el contenido energético de la carne de las pianguas Anadara tuberculosa y A. similis. Mensualmente, entre marzo de 2010 y febrero de 2011, se recolectaron de 15 a 20 ejemplares de cada especie. La composición proximal se determinó siguiendo la metodología recomendada por la Asociación Oficial de Químicos Analíticos (AOAC). El valor promedio de las proteínas de la carne de A. similis fue de 57.9 ± 7.2%, carbohidratos 25.6 ± 4.4%, cenizas 6.87 ± 0.23% y lípidos 9.2 ± 0.2%. El contenido calórico promedio fue de 5.3 ± 0.2 kcal/g. Para A. tuberculosa se calculó 61.6% de proteínas, 21.6% de carbohidratos, 8.8% de cenizas, 7.9% de lípidos; el valor calórico fue de 5.2 kcal/g. Se puede concluir que tanto A. tuberculosa como A. similis presentan valores nutricionales óptimos para el consumo humano, por su bajo contenido de grasa y su aceptable contenido proteico. Abstract The seasonal variation in proximate biochemical composition and energy content of Anadara tuberculosa and A. similis were studied between March 2010 and February 2011 on a monthly basis. Fifteen to twenty individuals of each species were collected monthly. The proximate composition was determined following the methodology recommended by the Association of Official Analytical Chemists (AOAC). The average value of meat protein in A. similis was 57.9 ± 7.2%, carbohydrate 25.6 ± 4.4%, ash 6.87 ± 0.23%, and lipids 9.2 ± 0.2%. The average caloric content was 5.3 ± 0.2 kcal/g. For A. tuberculosa the values were protein 61.6%, carbohydrate 21.6%, ash 8.8%, and lipids 7.9%. The caloric value was 5.2 kcal/g. It can be concluded that both A. tuberculosa and A. similis have optimal nutritional value for human consumption, due to their low lipid and high protein contents.

Reversion Toward the Mean Independently of Regression Toward the Mean

Methodology ◽  
2009 ◽  
Vol 5 (1) ◽  
pp. 3-6 ◽  
Author(s):  
Merton S. Krause
Keyword(s):  
Random Error ◽  
Evaluation Studies ◽  
Internal Validity ◽  
Intervention Evaluation ◽  
Population Mean ◽  
Experimental Intervention ◽  
Sample Data ◽  
The Mean ◽  
Regression Toward The Mean

There is another important artifactual contributor to the apparent improvement of persons subjected to an experimental intervention which may be mistaken for regression toward the mean. This is the phenomenon of random error and extreme selection, which does not at all involve the population regression of posttest on pretest scores but involves a quite different and independent reversion of subjects’ scores toward the population mean. These two independent threats to the internal validity of intervention evaluation studies, however, can be detected and differentiated on the sample data of such studies.

Experience with Junk Food: Effects on Diet Selection

2010 ◽  
Author(s):  
Josephine F. Wilson ◽  
Rachel L. Radel
Keyword(s):  
Diet Selection ◽  
Junk Food ◽  
Food Effects

Improvement in the Fock test for determining the reactivity of dissolving pulp

TAPPI Journal ◽  
2013 ◽  
Vol 12 (11) ◽  
pp. 21-26 ◽  
Author(s):  
CHAO TIAN ◽  
LINQIANG ZHENG ◽  
QINGXIAN MIAO ◽  
CHRIS NASH ◽  
CHUNYU CAO ◽  
...  
Keyword(s):  
Moisture Content ◽  
Sodium Hydroxide ◽  
Constant Temperature ◽  
Carbon Disulfide ◽  
Testing Procedure ◽  
Dissolving Pulp ◽  
Water Bath ◽  
Testing Conditions ◽  
Pulp Sample ◽  
Fock Reactivity

The Fock test is widely used for assessing the reactivity of dissolving pulp. The objective of this study was to modify the method to improve the repeatability of the test. Various parameters that affect the repeatability of the Fock test were investigated. The results showed that Fock reactivity is dependent on testing conditions affecting the xanthation between cellulose and carbon disulfide, such as the moisture content of the pulp sample, sodium hydroxide (NaOH) concentration, xanthation temperature, carbon disulfide dosage, and xanthation time. The repeatability of the test was significantly improved using the following modified testing procedure: air dried sample in the constant temperature/humidity room, xanthation temperature of 66°F (19°C) in a water bath, xanthation time of 3 h, NaOH concentration of 9% (w/w), and 1.3 mL carbon disulfide.

Delivering Sustainable Water Systems Using Kalman Filter and Statistical Approach

2017 ◽  
Vol 4 (1) ◽  
pp. 41-52
Author(s):  
Dedy Loebis
Keyword(s):  
Kalman Filtering ◽  
Statistical Approach ◽  
Water Systems ◽  
Data Sets ◽  
Pressure Data ◽  
Burst Event ◽  
Sample Data ◽  
Other Information ◽  
Supply Systems ◽  
Frequency Features

This paper presents the results of work undertaken to develop and test contrasting data analysis approaches for the detection of bursts/leaks and other anomalies within wate r supply systems at district meter area (DMA)level. This was conducted for Yorkshire Water (YW) sample data sets from the Harrogate and Dales (H&D), Yorkshire, United Kingdom water supply network as part of Project NEPTUNE EP/E003192/1 ). A data analysissystem based on Kalman filtering and statistical approach has been developed. The system has been applied to the analysis of flow and pressure data. The system was proved for one dataset case and have shown the ability to detect anomalies in flow and pres sure patterns, by correlating with other information. It will be shown that the Kalman/statistical approach is a promising approach at detecting subtle changes and higher frequency features, it has the potential to identify precursor features and smaller l eaks and hence could be useful for monitoring the development of leaks, prior to a large volume burst event.

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