scholarly journals Importance of Seed Ingestion to an Avian Frugivore: An Experimental Approach to Fruit Choice Based on Seed Load

The Auk ◽  
2002 ◽  
Vol 119 (1) ◽  
pp. 175-184
Author(s):  
Margaret C. Stanley ◽  
Alan Lill
Keyword(s):  
Seed Size ◽  
Frugivorous Birds ◽  
Visual Cue ◽  
Fruit Choice ◽  
Faecal Samples ◽  
Artificial Fruit ◽  
Mean Size ◽  
Seed Ingestion ◽  
Avian Frugivore ◽  
The Cost

Abstract Frugivorous birds may be able to reduce the cost of processing seeds by discarding seeds, selecting fruits that have a high pulp-to-seed ratio, or by choosing fruit in which seeds are packaged in a way that the frugivore's gut can void them more rapidly. A preference for fruit based on pulp-to-seed ratio or seed composition within a fruit is likely to have important implications for plants and evolution of seed size. We tested whether captive Silvereyes (Zosterops lateralis) discriminate among artificial fruit on the basis of seed presence by presenting birds with artificial fruit with or without a seed. In the first experiment, fruit were translucent so that birds could see which fruit contained a seed. In the second experiment, the visual cue was removed. When Silvereyes were presented with a choice between translucent, artificial fruit with or without a seed, they showed a strong preference for fruit that did not contain a seed. However, when the visual cue to seed presence was removed, preference for seedless fruit was still significant, but markedly reduced. We also tested seed-size preference of Silvereyes in the field in Victoria, Australia. Seeds from a fruit commonly consumed by Silvereyes, fragrant saltbush (Rhagodia parabolica), were recovered from Silvereye faecal samples and their volumes measured. Comparisons were made between seed volumes of fruit consumed by Silvereyes and those within fruit available on the plant. Silvereyes consumed significantly smaller seeds than the mean size available on saltbush plants. When Silvereyes were presented with a cereal-based diet containing artificial seeds (designed to mimic large fruit containing many small seeds), they avoided seed ingestion and were able to consume proportionally more cereal than seeds, even when on a high seed-load diet (30%). Seed dispersal by Silvereyes may be inefficient for plant species with large fruit containing many small seeds, because Silvereyes in this experiment were able to avoid ingesting seeds.

Improving the Quality of a Groundnut Population in Zambia by Bulk Selection of Seed

1974 ◽  
Vol 10 (3) ◽  
pp. 185-192 ◽  
Author(s):  
R. L. Thomas ◽  
A. J. Prior ◽  
J. E. Grafius
Keyword(s):  
Seed Size ◽  
Total Yield ◽  
Substantial Improvement ◽  
Mass Selection ◽  
Large Seed ◽  
Mean Size ◽  
Pedigree Selection ◽  
Positive Correlations ◽  
Selection Of

SUMMARYSubstantial improvement is reported in a quality measure, large seed size, after only one generation of mass selection from a bulk ‘Chalimbana’ population of Zambian land races of the inbred species Arachis hypogaea L. There were large positive correlations between seed size as planted and the subsequent mean size harvested. Large seed also tended to produce an increased proportion of 2- rather than 3-seeded pods, further improving both crop uniformity and quality. Total yield was unaffected, or possibly even slightly enhanced, by planting larger kernels. The circumstantial advantages of mass as opposed to pedigree selection methods are discussed.

The role of the olive baboon (Papio anubis, Cercopithecidae) as seed disperser in a savanna-forest mosaic of West Africa

2008 ◽  
Vol 24 (3) ◽  
pp. 235-246 ◽  
Author(s):  
Britta Kerstin Kunz ◽  
Karl Eduard Linsenmair
Keyword(s):  
West Africa ◽  
Seed Size ◽  
Papio Anubis ◽  
Olive Baboon ◽  
Seed Disperser ◽  
Faecal Samples ◽  
North Eastern ◽  
Forest Mosaic ◽  
Seed Handling ◽  
The Tropics

Abstract:Primates are among the major groups of frugivores in the tropics, but little is known about their role in natural regeneration of African savanna ecosystems. In the savanna-forest mosaic of north-eastern Ivory Coast the olive baboon (Papio anubis Lesson) harvests fruit from at least 79 plant species. Over a 24-mo study period, 396 faecal samples from 10 groups of baboons were analysed in terms of quantitative and qualitative aspects of seed handling and dispersal (excluding grasses and sedges). Seventy-three per cent of seeds in faecal samples were undamaged. Intact seeds were from 65 species. On average, defecations contained intact seeds from 2.0 species (range = 0–10). Seed size varied between 1 and 27 mm, and 77% of the species had medium-sized to large seeds. No linear correlation between mean seed size and seed damage was found. Eighteen out of 19 species tested were viable after ingestion, but effects of gut passage upon germination varied widely. The baboon population in the study area (145 km2) dispersed an estimated 1483 intact seeds d−1km−2(129 seeds > 2 mm in size). The results suggest that the olive baboon is an important seed disperser in the savanna-forest ecosystem of West Africa.

scholarly journals Habitat selection drives dietary specialisation in Sorex minutus

2020 ◽  
Author(s):  
Roselyn L. Ware ◽  
Annie L. Booker ◽  
Francesca R. Allaby ◽  
Robin G. Allaby
Keyword(s):  
Habitat Selection ◽  
High Mortality ◽  
Residential Buildings ◽  
Parasite Burden ◽  
The Other ◽  
Faecal Samples ◽  
Food Requirement ◽  
The Cost ◽  
Sorex Minutus ◽  
Two Populations

AbstractTo meet their demand for food, Eurasian pygmy shrews (Sorex minutus) require large territories, normally in fields, woodlands, and meadows. Their high metabolism and food requirement often leads to high mortality during winter. However, evidence of shrews in the roof voids of residential buildings has recently been observed, contrary to ecological expectations. Here, five faecal samples collected from different locations were studied by metagenomic analysis to gain information about the shrew’s diets and environments. Two of the samples were collected from novel indoor locations, while the other three were from outdoors in ‘traditional’ habitats. Distinct differences were observed between the diets of the two populations, suggesting a commensal niche expansion has occurred in S. minutus. We found that S. minutus exploit man-made spaces for foraging, potentially at the cost of a greater parasite burden.

scholarly journals Does Seed Packaging Influence Fruit Consumption and Seed Passage in an Avian Frugivore?

The Condor ◽  
2002 ◽  
Vol 104 (1) ◽  
pp. 136-145
Author(s):  
Margaret C. Stanley ◽  
Alan Lill
Keyword(s):  
Morphological Characters ◽  
Passage Rate ◽  
Fruit Consumption ◽  
Zosterops Lateralis ◽  
Transit Times ◽  
Morphological Adaptations ◽  
Artificial Fruit ◽  
Fruit Processing ◽  
Consumption Rates ◽  
Avian Frugivore

AbstractSeed packaging is one fruit characteristic that may influence post-ingestional fruit processing in avian frugivores. We tested the response of a facultative frugivore, the Silvereye (Zosterops lateralis), to fruit containing different forms of seed packaging. Wild-caught, captive Silvereyes were presented with artificial fruit containing either one large seed or three small seeds of equivalent total volume, and their consumption rates were recorded over 90 min. In a second experiment, the seed transit times (ingestion to excretion) for similar large-seeded and small-seeded fruit consumed by Silvereyes were recorded. Silvereyes consumed significantly more large-seeded fruit than small-seeded fruit. The transit time of seeds was also significantly shorter for large-seeded (mean = 22 min) than for small-seeded fruit (mean = 29 min). Thus seed packaging had a significant influence on the rate at which fruit were processed. Silvereyes were able to consume more large-seeded than small-seeded fruit because the seeds in large-seeded fruit were defecated faster than those in small-seeded fruit. It is likely that Silvereyes can compensate for the costs of seed ingestion through having a rapid gut passage rate and hence an increased fruit consumption rate. The gut of Silvereyes showed morphological characters intermediate between insectivores and specialist frugivores. The dimensions of the intestine and gizzard were like those of insectivores and the gizzard was substantially larger than those of specialist frugivores. Facultative frugivores appear to have few morphological adaptations to frugivory and we argue that this facilitates plasticity in the diet and the processing of insects when fruit is not available.¿Influencia el Empaquetamiento de Semillas el Consumo de Frutos y el Tiempo de Tránsito en Aves Frugívoras?Resumen. El empaquetamiento de semillas es una característica que puede influenciar el procesamiento de frutos post ingestión en aves frugivoras. Pusimos a prueba la respuesta de un frugívoro facultativo (Zosterops lateralis) a frutos con distintas formas de empaquetamiento de semillas. Individuos de Z. lateralis silvestres fueron capturados y expuestos a frutos artificiales de volumen equivalente con una semilla grande o con tres semillas pequeñas y su tasa de consumo fue registrada durante 90 minutos. En un segundo experimento, se registró el tiempo de tránsito (de ingesta a defecación) de frutos similares con semillas grandes y pequeñas. Z. lateralis consumió una significativamente mayor cantidad de frutos con semillas grandes que de frutos con semillas pequeñas. El tiempo de tránsito de semillas grandes fué significativamente menor (promedio = 22 min) que el de semillas pequeñas (promedio = 29 min). Por lo tanto, el empaquetamiento de semillas tuvo una influencia significativa sobre la tasa a la que los frutos fueron procesados. Z. lateralis fue capaz de consumir más frutos con semillas grandes ya que sus semillas fueron defecadas más rápidamente que las de frutos con semillas pequeñas. Es probable que Z. lateralis pueda compensar el costo de la ingesta de semillas con un paso rápido a través del tracto digestivo lo que se traduce en un aumento en la tasa de consumo de frutos. El tracto digestivo de Z. lateralis muestra caracteres morfológicos intermedios entre los de insectívoros y frugívoros especialistas. Las dimensiones de los intestinos y la molleja son similares a las de insectívoros y la molleja es sustancialmente más grande que la de los frugívoros especialistas. Los frugívoros facultativos parecieran tener pocas adaptaciones morfológicas a la frugivoría. Sugerimos que esto facilita una mayor plasticidad en la dieta y en el procesamiento de insectos cuando existe poca disponibilidad de frutos.

The response of captive silvereyes (Zosterops lateralis) to the colour and size of fruit

2002 ◽  
Vol 50 (2) ◽  
pp. 205 ◽  
Author(s):  
M. C. Stanley ◽  
E. Smallwood ◽  
A. Lill
Keyword(s):  
Fruit Size ◽  
Bird Species ◽  
The Other ◽  
Sugar Concentration ◽  
Fleshy Fruit ◽  
Green Fruit ◽  
Fruit Choice ◽  
Zosterops Lateralis ◽  
Small Fruit ◽  
Artificial Fruit

Birds are important consumers and dispersers of the seeds of fleshy fruit and some have been shown to be selective in their choice of fruit. However, our knowledge of how birds respond to a variety of fruit characteristics is poor. Some birds are known to avoid green fruit or consume them less than fruit of other colours. The fruit of many plant species are green when they are unripe and contain low concentrations of sugars and high concentrations of secondary compounds. In this study, captive silvereyes (Zosterops lateralis) were presented with a choice of red, white and green artificial fruit. Half of them were given these fruit with equal sugar concentrations (15%) and the other half were given the choice but with the green fruit having a sugar concentration twice that of the other two colours (30%). Green fruit were not strongly avoided by silvereyes and were actually preferred when they had a higher sugar concentration than the other two fruit types (red and white). Sugar concentration was therefore a more important determinant of fruit choice than colour. Fruit size is also known to affect fruit choice in some bird species. Small fruit are easier to consume than larger fruit, but contain less pulp. To maximise energy gain, birds should consume fruit that are large, but not large enough to incur high handling costs. Silvereyes in this study were presented with a choice between 20 artificial fruit 4 mm in diameter (large fruit) and 20 artificial fruit 2 mm in diameter (small fruit), both of which they are able to consume. In this experiment, silvereyes exhibited a strong preference for large fruit over small fruit. In general, larger fruit contain more pulp and therefore more energy than smaller fruit. However, other fruit traits, such as seed load, are likely to influence fruit choice by silvereyes in the wild and result in a trait hierarchy.

The effect of seed rate on the yield of potatoes

1954 ◽  
Vol 44 (4) ◽  
pp. 465-476 ◽  
Author(s):  
D. A. Boyd ◽  
W. J. Lessells
Keyword(s):  
Seed Size ◽  
Certified Seed ◽  
Potato Crop ◽  
Average Weight ◽  
Minor Importance ◽  
Seed Rate ◽  
Spacing Distance ◽  
Average Loss ◽  
The Cost ◽  
Different Parts

This paper, which forms part of a series of investigations on the potato crop, presents evidence obtained from experiments reported in the literature on the relation between seed rate and yield of maincrop potatoes. The available experiments are sufficient to indicate what is the average relationship between seed rate and yield, but are insufficient to demonstrate any clear differences between different parts of the country, soil types or even different varieties.Using this average relationship, optimum seed rates are presented for a range of prices of seed and produce. These optimal rates are compared with estimates from surveys of the actual amounts planted by growers in different parts of the country.Provided the optimum seed rate is attained the precise combination of seed size and spacing distance appears to be of minor importance; that is, a grower should aim to plant at the optimum seed rate regardless of seed size. There is, however, an upper limit of spacing between sets which should not be exceeded however large the seed may be.The optimum rate of planting at 1952 prices of ‘A’ or ‘H’ certificate seed is estimated to be 16–17 cwt. in most of the main potato-growing areas of the country, though it may be a little higher where a grower has a market for once-grown seed. Surveys indicate, however, that the normal planting rate of certified seed is over a ton to the acre in these districts.For a grower's own once-grown seed, on the other hand, for which the cost is not more than the price received for ware, the optimum seed rate is at least one ton per acre, whilst the average weight of seed actually planted is only about 17 cwt. per acre. It is estimated that the average loss per acre due to this failure to plant at the optimum seed rate amounts to 20–25s. per acre planted with certified seed and 10–15s. per acre for once-grown seed.

scholarly journals A Consumer-Friendly Machine Learning Based Mechanism to Recognize the Quality of Commercially Available Fruits

2020 ◽  
Vol 9 (3) ◽  
pp. 3833-3839
Keyword(s):  
Machine Learning ◽  
Nondestructive Method ◽  
Machine Learning Techniques ◽  
Android Application ◽  
Test Image ◽  
Ripening Process ◽  
Learning Techniques ◽  
Artificial Fruit ◽  
The Cost

Cultivators and sellers of many high-in-demand fruits traditionally preferred natural ripening after picking. Greed of hefty profits has motivated some of them to artificially hasten the ripening process at the cost of people’s health. Artificial ripening processes tend to degrade the entire quality of the fruit. The focus of this work is to describe a nondestructive method to detect artificial fruit ripening. To aid the detection, the proposed solution utilizes image processing and machine learning techniques to find the artificially ripened fruits. An input fruit image is selected as the test image. The next stage involves comparison of the features (histogram values) of the test image with the image of a naturally ripened one. A smartphone runs an android application to identify artificially ripened fruits. This work specifically concentrates on the commonly preferred Indian Mango and Indian Apple. The developed mechanism has an efficiency of 89-94% in correct detection.

Accessibility as a factor influencing frugivory by silvereyes (Zosterops lateralis): field comparisons with aviary experiments

2001 ◽  
Vol 49 (2) ◽  
pp. 171 ◽  
Author(s):  
Margaret C. Stanley ◽  
Alan Lill
Keyword(s):  
Plant Morphology ◽  
Plant Structure ◽  
Fruit Removal ◽  
Frugivorous Birds ◽  
Captive Group ◽  
Zosterops Lateralis ◽  
Field Situation ◽  
Artificial Fruit ◽  
Foraging Method ◽  
Fruiting Plant

The influence of accessibility on the fruit preferences of frugivorous silvereyes (Zosterops lateralis) was examined in three different contexts: for captive individuals, in a captive group and in a field situation. Individual silvereyes in small cages were presented with identical artificial fruit that differed only in their accessibility from a perch. The birds removed fruit that could be obtained by ‘picking’ rather than by ‘reaching up’ and avoided ‘hanging’ to remove fruit. A second experiment tested the response of silvereyes to fruit accessibility in a large aviary where birds fed in a group. The artificial fruit were presented at a larger and more natural scale on artificial trees. In this experiment, silvereyes again avoided ‘hanging’ to obtain fruit; however, these birds showed no preference for ‘picking’ over ‘reaching up’. Foraging observations of silvereyes were recorded for three different plant species in the field. Silvereyes generally avoided ‘hanging’ to remove fruit, although the foraging method used varied with the species of plant on which the bird was foraging. The foraging method used by avian frugivores to remove fruit is likely to be influenced by plant morphology, as well as the morphology of the bird. The strong preference shown by silvereyes for fruit that are more accessible suggests that when other fruit characteristics are equal, accessibility is important in influencing fruit-removal patterns. However, this may be affected by the context in which the fruit is presented. Properties of the fruiting plant, such as the branching pattern, perch stability and position of the fruit display, are likely to influence fruit preference. These aspects of plant structure should be considered when assessing foraging behaviour and resource use by frugivorous birds.

scholarly journals Persistence of Seed Dispersal in Agroecosystems: Effects of Landscape Modification and Intensive Soil Management Practices in Avian Frugivores, Frugivory and Seed Deposition in Olive Croplands

2021 ◽  
Vol 9 ◽  
Author(s):  
Pedro J. Rey ◽  
Francisco M. Camacho ◽  
Rubén Tarifa ◽  
Carlos Martínez-Núñez ◽  
Teresa Salido ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Habitat Loss ◽  
Soil Management ◽  
Agricultural Landscapes ◽  
Livestock Grazing ◽  
Olive Grove ◽  
Frugivorous Birds ◽  
Seed Deposition ◽  
Avian Frugivore ◽  
Dispersal Function

Farming impacts animal-mediated seed dispersal through mechanisms operating on at least two spatial scales. First, at the landscape scale, through habitat loss and land conversion to agriculture/livestock grazing, and second, at the farm scale, via a local intensification of agricultural practices. These two scales of farming impact seed dispersal function but have rarely been integrated. In particular, studies evaluating the effect of agriculture on the seed dispersal function of frugivorous birds in Mediterranean ecosystems are lacking. This study evaluates the role of landscape transformation, from fruit-rich woodland habitats to olive grove landscapes, together with local intensive practices of soil management on the persistence of the seed dispersal function for Mediterranean fleshy-fruited plants in olive landscapes of south Spain. We used bird censuses, mist-nets, and seed traps to characterize avian frugivore assemblages, frugivory, and seed deposition in the seminatural woodland habitat (SNWH) patches and olive fields of 40 olives farms spanning 20 localities distributed across the whole range of olive cultivation in Andalusia (southern Spain). We found that despite the remarkable dispersal function of olive grove landscapes, avian frugivore abundance and diversity, frugivory, and seed arrival decreased in olive fields compared to SNWH patches. Likewise, SNWH cover loss and/or olive growing expansion decreased avian frugivory and seed arrival. Interestingly, the habitat effects in the olive farms often depended on the landscape context. In particular, less diverse fruit-eating bird assemblages pooled in SNWH patches as olive grove cover increased or SNWH decreased in the landscape, while remaining relatively invariant in the olive fields. Finally, compared to conventional intensive agriculture, low-intensity management increased frugivory and seed deposition. We conclude that olive fields are less permeable to frugivores than expected due to the agroforest-like nature of these landscapes and that the presence of SNWH patches is crucial for the maintenance of frugivory and seed dispersal in agricultural landscapes. These results evidence that woodland habitat loss by olive expansion and intensive practices seriously threaten the dispersal service in olive-dominated landscapes. Maintenance, restoration, and promotion of woodland patches should be prioritized for the conservation of seed dispersal service and for enhancing the functional connectivity in human-shaped olive landscapes.

scholarly journals Ectopic expression of TaBG1 increases seed size and alters nutritional characteristics of the grain in wheat but does not lead to increased yields

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Matthew J. Milner ◽  
Sarah Bowden ◽  
Melanie Craze ◽  
Emma J. Wallington
Keyword(s):  
Protein Content ◽  
Seed Size ◽  
Ectopic Expression ◽  
N Fertilization ◽  
Essential Elements ◽  
Nutritional Profile ◽  
Control Seed ◽  
Wheat Gene ◽  
Lower Protein ◽  
The Cost

Abstract Background Grain size is thought to be a major component of yield in many plant species. Here we set out to understand if knowledge from other cereals such as rice could translate to increased yield gains in wheat and lead to increased nitrogen use efficiency. Previous findings that the overexpression of OsBG1 in rice increased yields while increasing seed size suggest translating gains from rice to other cereals may help to increase yields. Results The orthologous genes of OsBG1 were identified in wheat. One homoeologous wheat gene was cloned and overexpressed in wheat to understand its role in controlling seed size. Potential alteration in the nutritional profile of the grains were also analyzed in wheat overexpressing TaBG1. It was found that increased TaBG1-A expression could indeed lead to larger seed size but was linked to a reduction in seed number per plant leading to no significant overall increase in yield. Other important components of yield such as biomass or tillering did not change significantly with increased TaBG1-A expression. The nutritional profile of the grain was altered, with a significant decrease in the Zn levels in the grain associated with increased seed size, but Fe and Mn concentrations were unchanged. Protein content of the wheat grain also fell under moderate N fertilization levels but not under deficient or adequate levels of N. Conclusions TaBG1 does control seed size in wheat but increasing the seed size per se does not increase yield and may come at the cost of lower concentrations of essential elements as well as potentially lower protein content. Nevertheless, TaBG1 could be a useful target for further breeding efforts in combination with other genes for increased biomass.

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