Common Food Supply Research Articles

A Comparison of the Fecal Compositions of Sympatric Populations of Sika Deer and Japanese Serows on Mt. Sanrei in Shikoku, Southwestern Japan

Two ruminants, sika deer (Cervus nippon) and Japanese serows (Capricornis crispus), inhabit the Japanese archipelago. The range of sika deer includes nearly the entire archipelago from Hokkaido to Kyushu, including habitats from the coastal zone to the montane zone. In contrast, the distribution and the habitat of Japanese serows are limited: they inhabit deciduous broad-leaved forests from Honshu to Kyushu (Ohdachi et al. 2009). These two ruminants occur in sympatry in some localities. Information on such cases would help to document how two animal species within the same guild can share a common food supply. However, only one study at Mt. Yatsugatake, central Japan, has compared the diets of sika deer and serows (Kobayashi and Takatsuki 2012). Their study demonstrated that sika deer subsisted on dwarf bamboo, whereas serows mainly fed on forbs and browses (Kobayashi and Takatsuki 2012). The diet compositions of the two species were more similar in winter, likely because food was limited and both ungulates were forced to feed on similar food plants (Kobayashi and Takatsuki 2012). Although it is known that there are many more sympatric populations of these two ruminants, no other studies have been done. Further, quantitative food analyses of Japanese serows are limited, and no study has been done for southern serow populations. The present study, therefore, compares the diets of sympatric populations of these two ruminant species in the eastern part of Shikoku, an island in western Japan, representing

Agriculture, Food and Competition Law: Moving the Borders

The food supply chain accounts for 5 per cent of EU value added and 7 per cent of employment, bringing together the agricultural sector, the food processing and manufacturing industry, wholesale trade, and the distribution sector. Food spending represents about 15 per cent of the average EU household budget. There is no single, homogeneous, and common food supply chain at European level. The length and the degree of complexity of the food supply chains depends on the product and market characteristics. Figure 1 provides a simplified description of food supply chains. On the supply side, for certain raw products, production and processing are closely integrated (for milk or sugar) at local level and the product can be processed and sold through a rather short supply chain to retailers in national markets. For other raw products, for instance for fruit and vegetables, a large number of atomised producers sell locally to many wholesalers who in turn supply many local retailers, especially in south-eastern Europe. For manufactured food (such as biscuits and cereal-based products) large food manufacturers operate in many national markets but often organise their distribution networks, their marketing and promotion activities along national borders and operate a more or less centralised production system depending inter alia on how expensive it is to transport the product and how necessary it is to adapt it to local markets. On the demand side, wide differences exist between consumers of different Member States in terms of spending, price sensitivity and attachment to brands as is shown by the varied degree of development of the private labels of retailers. Further consumers tend to shop essentially at local stores (distance selling remains limited). Due to these supply and demand characteristics, food markets are first defined by the level in the chain and remain predominantly national or regional in scope. In other words in terms of competition analysis, product markets are usually defined at each level in the chain and geographic markets are often national (eg wholesale supply of many raw and manufactured products) or local (eg retail sales to the end-consumer). In order to understand the competition issues arising in the food supply chains, it is worth presenting the market structure at each of the following levels: agricultural, wholesale, processing, manufacturing, and retail levels. Primary/agricultural producers form the least concentrated level in the food supply chain. The most common situation across sectors and Member States is that agricultural producers remain atomised or grouped in small cooperatives. This is particularly true for eastern Member States, where history has created a negative image for farmer organisations which led to a very low degree of penetration of cooperatives (below 25 per cent compared to 40 per cent or above in other Member States). In

Probe of Norovirus Outbreaks Yields LTC Clues

Probe of Norovirus Outbreaks Yields LTC Clues

A STUDY ON THE FEEDING ECOLOGY OF CHITONS USING ANALYSIS OF GUT CONTENTS AND FATTY ACID MARKERS

Diet composition and food sources of five species of chiton coexisting in the same biotope on a rockyboulder reef were studied using a combination of two methods: gut contents analysis and analysis of marker fatty acids composition in the digestive tract tissue. Despite the common food supply, there was considerable interspecific selection in consumption. In the gut contents of Ischnochiton hakodadensis, Tonicella granulata and Mopalia retifera, diatoms as well as fragments of red calcareous algae (Corallinaceae) and other macrophytes dominated. Harpacticoid and amphipod crustaceans were most frequent in the digestive tract of the chiton Placiphorella borealijaponica. The meiobenthic prey of Lepidozona albrechti was mostly harpacticoids, nematodes, ostracods, acarins and foraminiferans. In large L. albrechti, juvenile cirripedes constituted up to 95% of the gut contents. For all the investigated chitons, the fatty acid composition of total lipids in the digestive tract was determined for the first time. The species I. hakodadensis, T. granulata and M. retifera were characterized by a 16:0/16:1n-7 ratio � 1 and an 18:1n-9/18:1n-7 ratio � 1 along with a low content of the acid 22:6n-3. In contrast, the content of the acid 22:6n-3 in the lipids of the other two chiton species (L. albrechti and P. borealijaponica) was higher and the 16:0/16:1n-7 ratio � 1 and the 18:1n-9/18:1n-7 ratio � 1. The marker fatty acid distributions suggested that diatoms prevailed in the diet of I. hakodadensis, T. granulata and M. retifera, i.e. the three chiton species were mainly herbivorous. This was in agreement with the gut content data, and differentiated them from the other two chitons L. albrechti and P. borealijaponica which were carnivorous, as indicated by analysis of both marker fatty acid composition and gut contents. The share of macrophytes and insignificant bacterial contribution to the chiton diets as well as the possibility of shifts in the feeding strategy of chitons were discussed.

Continuous rise of urinary iodine excretion and drop in thyroid gland size among adolescents in Mecklenburg-West-Pomerania from 1993 to 1997.

Improved legislation (1989, 1993), as well as education of the public, are likely to improve the iodine supply for the German population. Children and adolescents will be the first to profit. We investigated thyroid size and urinary iodine excretion in a total of 2906 students aged 10 to 18 in Mecklenburg-West-Pomerania in 1993, 1995, and 1997. The median urinary iodine excretion rose from 73 microg/g creatinine in 1993 to 133 microg/g in 1997. The prevalence of goiter, according to the reference range of Gutekunst, dropped from 33% to 10% over the same interval, and the median thyroid size declined from 11 ml to 6 ml. While only 6% of the test subjects excreted more than 150 microg iodine per g creatinine in 1993, this figure rose to 33% in 1997. The improved alimentary iodine supply is due to the increased use of iodine enriched salt by the food industry, food factories and in common food supply services.

Food patch structure and plant resource partitioning in interspecific associations of amazonian tamarins

Avila-Pires’ saddle-back tamarins (Saguinus fuscicollis avilapiresi) and red-cap moustached tamarins (S. mystax pileatus), coexisting in highly stable mixed-species groups, overlapped considerably in their use of plant food resources at an Amazonian terra firme forest site. Overlap between food types consumed by the two species was particularly high during periods of lowest fruit availability, when they resorted to a common food supply, primarily the pod exudates of two emergent species of legume trees (Parkia nitida andParkia pendula) and nectar ofSymphonia globulifera. Within-group interspecific competition did not covary with independent measures of resource availability, contrary to predictions based on resource partitioning models. A greater number of both saddle-back and moustached tamarins were able to feed for longer patch residence periods within larger and more productive food patches, whereas small and clumped patches could be monopolized by the socially and numerically dominant moustached tamarins to the physical exclusion of the smaller-bodied saddle-back tamarins. Overall rates of interspecific aggression were extremely low, however, partly because patches that could be monopolized contributed with a minor proportion of either species’ diet. Saddle-backs foraged at lower levels in the understory and encountered smaller food patches more often, whereas moustached tamarins foraged higher and encountered more larger patches in the middle canopy. Although the two species led one another to differently-sized patches, moustached tamarins initiated most feeding bouts and encountered significantly larger and more productive patches that tended to accommodate the entire mixed-species group. Disadvantages of exploitative and interference feeding competition over plant resources, and advantages of shared knowledge of food patches, are but one component of the overall cost-benefit relationship of interspecific associations in tamarins.

Clutch Sizes of Two Marine Snails with a Changing Food Supply

When food becomes more abundant, most species can produce more offspring, and individuals that do so should be more fit than ones that do not. Fecundities of two marine snails, thais lamellosa and Thais emarginata, were monitored to determine how these snails responded in increases in their common food supply. For both species, clutch size is directly proportional to body size. Each T. lamellosa spawns once each year, and therefore annual fecundity is proportional to body size. Adults responded to a steady increase in food supplies, 1968—1973, by growing, and consequently, the average clutch increased from 930 to 1,428 eggs/♀. In contrast, T. emarginata adults remained about the same size. However,individuals spawned many times during the year, and spawning frequency was closely correlated with food supply. At Shady Cove, each T. emarginata ♀ produced about as many eggs as each T. lamellosa ♀ during 1969 and 1970. The species that responds to increasing food supplies by growing also has a longer juvenile period, a larger adult size, and a longer life—span than the species that responds by spawning more frequently. The high—stress upper shore environment of T. emarginata precludes a long juvenile period, and, therefore dictates clutch size and spawning frequency. Each clutch requires 23—37% of the prespawning body weight, and requires a higher proportion of the body weight of larger snails.

Computer simulation models : applications to the study of ecological systems

Abstract Tho role of state-space and feedback concepts in the dovolopmont of simulation models for ecological systems is discussed The modelling process as applied to ecology is illustrated by the development of models for three ecological systems ; the growth of a single species limited by food supply, the competition between two species for a common food supply and a predator–prey relationship. Information available in the literature concerning these systems is used to determine the model structures. Digital simulation results for each model are presented and the effect of parameter variations on model behaviour is investigated While no attempt is made at formal validation, model behaviour is compared to that observed in nature. The three models appear to possess much of the general dynamic behaviour of actual animal populations, most notably that of cyclic oscillations.

Relationships between Natural Populations of the Ciliated Protozoa Loxodes magnus Stokes and L. striatus Penard

Gause (1934, 1935) in classical experiments with Paramecium caudatum Ehrb. and P. aurelia Ehrb. demonstrated that interspecific competition for a limiting food supply, which can lead to the competitive exclusion of one species, may take place in cultures of ciliated protozoa. More recently, considerable work on interspecific relationships in ciliates, both in culture and in the field, has been carried out by Hairston and co-workers. In culture experiments, examples which may be quoted of interspecific competition leading to exclusion are as follows. (1) Between P. aurelia-2 and P. aurelia-3 (Hairston & Kellermann 1965). Sonneborn's numbered syngens of P. aurelia may be regarded as distinct species (Hairston 1958); the nomenclature is that of Gill & Hairston (1972). (2) Between all possible pairs of P. caudatum, P. bursaria (Ehrb.) Focke, P. aurelia-3 and a species of Blepharisma (Vandermeer 1969). Although interspecific competition between ciliates may be demonstrated in culture it is not clear how important it is under natural conditions. Hairston (1958), on the basis of a series of samples from the Huron River near Ann Arbor, Michigan and from a tributary stream and associated woodland seeps, suggested that competition took place between natural populations of Paramecium aurelia-2 and P. aurelia-3 and that environmental conditions were such that P. aurelia-3 won in the river and P. aurelia-2 in the stream. Hairston (1967), however, considered that competition between P. aurelia species was sometimes important but thought that a population of P. aurelia-2 in a woodland seepage area was not influenced by competition with other P. aurelia species, and Gill & Hairston (1972) concluded, from the results of field experiments which involved both separate and simultaneous introductions of P. aurelia-2 and P. aurelia-5 to a woodland seep, that there was no evidence for the competitive exclusion of one species by the other. In other habitats, Brown (1964) considered that alternation of peaks of growth rate shown by species of Vorticella and Aspidisca costata (Dujardin), in an activated sludge plant, indicated competition between these ciliates and Grabacka (1971) suggested that there were inverse relationships between numbers of Loxodes magnus Stokes and L. striatus Penard and between Spirostomumfilum (Ehrb.) Penard and S. minus Roux, in the benthos of some fishponds in Katowice Province, south-west Poland, which indicated competition for a common food supply (algae in the case of Loxodes and bacteria for Spirostomum species). This last suggestion is based on data which are published as histograms in Figs. 9 and 10 of Grabacka's (1971) paper and which may be to some extent re-appraised. Grabacka collected samples, from marginal and mid-pond sites, which were 150-ml mixtures of sediment and overlying water. In samples from coarse-textured sediments, therefore, populations from several adjacent microha-bitats were probably combined in

Food Selection Experiments with Young Geese

Young Canada geese (Branta canadensis) and blue geese (Chen caerulescens) were tested experimentally for food preferences among six speces of grasses and sedges. Fifty-cm2 sods of two plant species were presented to two goslings in a test enclosure. The time intervals that individual birds spent feeding on each sod during a 90-minute test were recorded. Two pairs of goslings of each species were tested against all pair combination of the six plants. Each species show significant preference for some plants over others, and the preferences of the two species were demonstrably different. Faults in experimental design are discussed, and it is shown that results cannot be extended directly to free-ranging wild geese. Five species of geese nest on the coastal plains and larger islands of western and northern Hudson Bay. During the brood rearing period, two or more species may frequently be observed grazing together, apparently from a common food supply. This experiment, part of a broad study of food resources and their use by nesting geese, was designed to discover if young Canada and blue geese developed preferences for a restricted range of the available plant species, and, if so, whether the preferences differed between species. In food preference studies involving seeds, it is standard procedure to present test animals weighed amounts of seeds and either to record the order of disappearance (Michael and Beckwith 1955), or the weight differences after a given period of time (McFarland and George 1966). Because both species of geese were eating aerial parts of green vegetation, neither of these approaches was deemed suitable for the present test. In order to maintain the most natural conditions, geese were presented with fresh intact plants still rooted in sod. Although the six plant species tested were all identified in the feces of free-ranging geese, the principal criterion for choosing these species was their availability in sufficient pure stands to provide sods for the experiment. Description of the test plants appears in Table 1. This study was supported by contracts from the Canadian Wildlife Service, and by grants from the National Research Council of Canada, The Wildlife Management Institute, and the Arctic Institute of North America. The generous support of all these agencies is gratefully acknowledged. We wish also to thank R. Jones, T. T. McNulty, M. Harvey, P. Prevett, and W. Baumann or their assistance during the experiments. Special thanks are due to H. Boyd who reviewed manuscript.

Differential Feeding and Niche Relationships among Orthoptera

The acridian species Melanoplus bivittatus (Say), Melanoplus differentials (Thomas) and Melanoplus lakinus (Scudder) occur in the same habitat, utilizing the same foods. Such coexistence suggests that these species are in the same niche and in competition for a common food supply. Their food usages were investigated by offering samples of dominant and semi—dominant vegetation from the common habitat to caged populations of each species, then estimating the amount consumed. The overall usual of foods of each species formed a preferential pattern sufficiently different from the patterns of the other two species to indicate that the three grasshopper populations occupy separate niches in the community and are not in complete competition for food.

Riboflavin Metabolism of Young Women on Self-Selected Diets

The purpose of this study was to determine the riboflavin intake in food and the excretion in the urine and feces of young college women living in the home management house and eating a self selected diet from a common food supply.