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Boutin et al. (2006) claimed that American and Eurasian red squirrels use an unknown environmental cue to anticipate the availability of the abundant food of an autumn seed mast, and produce more young than usual in the previous s...
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Boutin et al. (2006) claimed that American and Eurasian red squirrels use an unknown environmental cue to anticipate the availability of the abundant food of an autumn seed mast, and produce more young than usual in the previous spring and summer. But these small mammals need increased supplies of protein to produce and support young, therefore they must have had access to some other protein-rich food that was available before the mast was ripe. There are other small mammalian seed-eaters that increase their reproductive output ahead of the maturation of a seed mast. It seems likely that, in each case, females are able to produce extra young in advance because they eat the amino acid-rich inflorescences and unripe seeds of the mast and/or larval insects that also increase their numbers in the spring of a mast year by eating the same enriched plant food.
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Studies from Latin America have shown that food insecurity reduces dietary diversity. However, dietary diversity measures do not account for the energy and nutrient supply in households. The objective of our study was to know whet...
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Studies from Latin America have shown that food insecurity reduces dietary diversity. However, dietary diversity measures do not account for the energy and nutrient supply in households. The objective of our study was to know whether there are differences in food, energy and nutrients supplies in Mexican households according to their food insecurity level. We analyzed the database of the National Household Income and Expenditure Survey performed in Mexico in 2014. The modified Latin-American and Caribbean Food Security Scale was used to determine the existence of household food security or insecurity. Participants registered foods and beverages available at their homes during the previous week. The supply of energy and nutrients was estimated using Mexican and American food composition references. Mexican food secure households had greater supply of healthy (e.g., fresh fruits and vegetables, fish and seafood, and fresh meats) and unhealthy (e.g., processed meats, fries, sugar-sweetened beverages, desserts, and alcoholic beverages) foods. By contrast, food insecure households rely on cheap staple food (e.g. maize, rice, pulses, eggs, and sugar). There was a linear relationship between the energy density and severity of food insecurity. Households with mild and moderate food insecurity had greater total energy supplies than households with food security and severe food insecurity. Food insecure households had greater supplies of carbohydrates, cholesterol, iron, and magnesium, but lower supplies of protein, fat, vitamin C, vitamin A, potassium, calcium, and sodium. Most of the results suggest that food insecure households are exposed mostly to negative aspects of the nutrition transition because they have greater?access to energy and lower availability of some micronutrients.
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The diet of the Orii's flying-fox, Pteropus dasymallus inopinatus, a subspecies of the Ryukyu flying-fox, was investigated on Okinawa-jima Island, Japan. The Orii's flying-fox is a generalist forager that feeds on 78 plant species...
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The diet of the Orii's flying-fox, Pteropus dasymallus inopinatus, a subspecies of the Ryukyu flying-fox, was investigated on Okinawa-jima Island, Japan. The Orii's flying-fox is a generalist forager that feeds on 78 plant species from 62 genera and 43 families. They consume fruits of 53 species, flowers of 20 species, and leaves of 18 species. Cultivated or naturalized plants composed almost half of the diet. Diversity in the diet may be an adaptation to unstable food conditions on this small subtropical island. The number of individual Orii's flying-foxes fluctuated greatly corresponding to monthly changes in food availability, especially that of Ficus microcarpa, which was the animal's main food resource throughout the year. Orii's flying-foxes may adapt to an urban environment by intensively using areas with abundant planted trees.
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1. Despite a long history of research on the influence of fruit availability on the population density of large-bodied vertebrate frugivores, operational understanding of the factors regulating density in these taxa remains elusiv...
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1. Despite a long history of research on the influence of fruit availability on the population density of large-bodied vertebrate frugivores, operational understanding of the factors regulating density in these taxa remains elusive. We propose that fruit resources can be distinguished from one another on the basis of their functional role for the animals in question, and that such a classification system can aid in identifying the most influential determinants of frugivore density. 2. We compared the availability of several resource classes between two sites in Kibale National Park, Uganda separated by only 12 km yet differing threefold in density of chimpanzees (Pan troglodytes). 3. We categorized plant species used for fruit by chimpanzees according to their availability relative to habitat-wide fruit productivity, and by their tendency towards inter-individual fruiting synchrony. We predicted that the site of high chimpanzee density would support a higher density of food plant species tending to produce crops during periods of high habitat-wide productivity [high fruit abundance (HFA foods)] and of those tending to fruit synchronously among individuals during times of low habitat-wide availability (sLFA foods). The first food class should provide chimpanzees with a high nutrient density (and thus promote population growth), whereas the second should provide stable subsistence during lean periods and thus a temporally consistent resource base. 4. Counter to our prediction, only sLFA resources were more abundant at the site of high chimpanzee density than at the site of low density. We suggest that sLFA resources are most important in influencing density of large-bodied frugivores.
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Optimal foraging theory assumes that a forager can adequately assess the quality of its prey and predicts that parents feed their young low-quality foods only when suffering unpredicted reductions in their ability to provision. Wi...
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Optimal foraging theory assumes that a forager can adequately assess the quality of its prey and predicts that parents feed their young low-quality foods only when suffering unpredicted reductions in their ability to provision. Wildland Florida scrub-jays feed their young exclusively arthropods, but suburban parents include human-provided foods in the nestling diet, with possible costs in terms of reduced growth and survival. We tested experimentally whether parents feed human-provided foods, given the apparent costs, because: 1) they do not discriminate between food types, 2) they switch to low-quality, abundant foods when natural food availability in the environment is low, or 3) they switch when the time needed to obtain natural food is high. Parents discriminated between natural and human-provided foods by showing a preference for natural foods when rearing young. When the handling time of natural foods was increased experimentally, parents in the suburban and wildland habitats switched to human-provided foods. Supplementation with natural foods increased preference for this food in both habitats. Suburban parents chose more natural foods than wildland parents, suggesting that they have a greater preference for natural foods. Regardless of preferences demonstrated at feeders, parents in both the suburbs and wildlands delivered mostly natural foods to nestlings, independent of natural food availability. Nonetheless, natural foods are likely to be scarcer in the environment than in our experimental tests. Because natural food availability is lower in the suburbs than in the wildland habitat, parents in the suburbs may be forced to switch to human-provided foods when feeding nestlings.
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Food and nutrition security are intimately interconnected, since only a food based approach can help in overcoming malnutrition in an economically and socially sustainable manner. Food production provides the base for food securit...
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Food and nutrition security are intimately interconnected, since only a food based approach can help in overcoming malnutrition in an economically and socially sustainable manner. Food production provides the base for food security as it is a key determinant of food availability. This paper deals with different aspects of ensuring high productivity and production without associated ecological harm for ensuring adequate food availability. By mainstreaming ecological considerations in technology development and dissemination, we can enter an era of evergreen revolution and sustainable food and nutrition security. Public policy support is crucial for enabling this.
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Poor soil fertility and erratic rains are major constraints to crop production in semi-arid environments. In the smallholder farming systems of sub-Saharan Africa, these constraints are manifested in frequent crop failures and end...
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Poor soil fertility and erratic rains are major constraints to crop production in semi-arid environments. In the smallholder farming systems of sub-Saharan Africa, these constraints are manifested in frequent crop failures and endemic food insecurity. We characterized a semi-arid smallholder farming system in south-western Zimbabwe to assess crop production, nutrient use and factors that constrain productivity. The farming system was studied using resource flow mapping, farmer interviews and calculations of crop production over three cropping seasons (2002/2003, 2003/2004 and 2004/2005) to capture variability between years. Farmers were categorized into three groups: better resourced, medium resourced and poorly resourced. Better resourced farmers produced adequate grain for basic household consumption, except in the drought year (2002/2003). Poorly resourced farmers had large grain deficits, whereas the medium resourced class had smaller deficits. Better resourced and medium resourced farmers produced adequate amounts of staple cereal in two of the seasons, while poorly resourced farmers produced inadequate amounts of food in all three seasons. All farmers produced less than 300 kg/ha of legumes per season. Lack of seed was cited as the main reason for poor legume production. Better resourced farmers used animal manure (2000-5000 kg per season) and some fertilizer on their cereal crops, while the medium resourced group used less manure (1000 kg or less) and no fertilizer. The use of manure varied strongly across the years. Poorly resourced farmers used no nutrient inputs on any of their crops. All groups had negative nitrogen balances during the three cropping seasons, although the values varied strongly between seasons. Investigation of the potential strategies for developing sustainable production systems are required to address the problems of food security in the semi-arid parts of the country and the region.
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Africanized honey bees (AHBs Apis mellifera) have been reported in NW Mexico since the mid 90s, but no study on the process of admixture with local European honey bees has been conducted. Morphometrics and haplotype analyses were ...
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Africanized honey bees (AHBs Apis mellifera) have been reported in NW Mexico since the mid 90s, but no study on the process of admixture with local European honey bees has been conducted. Morphometrics and haplotype analyses were used to investigate the frequency of African markers in honey bees from Sonora (SON), the north and south of Baja California (BCN and BCS). Morphometrics identified 42% of the samples from SON, 44% from BCN and 15% of BCS as Africanized. Honey bees from BCS had larger body size and formed a separate cluster from BCN and SON which were similar to each other. The molecular analysis revealed a higher frequency of African-derived haplotypes in SON (48%) and BCN (50%) compared to BCS (21%). The morphometric and molecular evidence suggests that the colonization of BCS by AHBs may be recent. Nest and food availability in desert areas and beekeeping practices are evoked to explain the reduced introgression of African genes into honey bee populations from this region of Mexico.
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The Asian shore crab, Hemigrapsus sanguineus (De Haan, 1853), is an opportunistic omnivore with well-developed predatory tendencies and a strong preference for animal food items over algae. In laboratory experiments, 71 percent (3...
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The Asian shore crab, Hemigrapsus sanguineus (De Haan, 1853), is an opportunistic omnivore with well-developed predatory tendencies and a strong preference for animal food items over algae. In laboratory experiments, 71 percent (319/448) of the crabs given a choice between macroalgae (Enteromorpha spp. and/or Chondrus crispus) and benthic invertebrates (Mytilus edulis and/or Semibalanus balanoides) consumed animals only. There were no significant differences in food preference between sexes or between juvenile and adult crabs. Relative abundance of food type, either algal or animal, in small food patches did not affect crab food preference. Crabs with prolonged starvation periods (5-d), however, consumed both food types more often than those that had been starved for 1-d only. Experiments to determine the effect of conspecifics on food selectivity showed that increased crab density leads to increased diet breadth, suggesting that competition for food can alter food selection patterns of H. sanguineus. Results reported here and in previous studies provide strong evidence that predation pressure exerted by H. sanguineus could play an important role in structuring the post-settlement population dynamics of its invertebrate prey, possibly leading to population declines of commercial shellfish, especially blue mussels.
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Matam is one of the poorest and most food-insecure regions of Senegal. In the past years, repeated environmental shocks such as drought have limited the access to food and it is unclear whether food insecurity is more a function o...
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Matam is one of the poorest and most food-insecure regions of Senegal. In the past years, repeated environmental shocks such as drought have limited the access to food and it is unclear whether food insecurity is more a function of food availability (FA) and accessibility at the community level (CL) or more related to FA at the household level (HL). To better understand the FA and food security (FS) situation in this region, in 2018, a cross-sectional study was conducted in 103 households living in four villages. Through focus group discussions and direct observations, data on food available at HL and CL were collected as well as on food affordability and household FS. Overall, between 49 and 64 different foods, mostly from plant source, were identified. Around 75% of households had 0 to 3 foods and 7%, 7 to 10; 64% of all households were severely food insecure. FA at HL and its socioeconomic status were positively associated with household FS whereas FA at the CL was negatively associated. Although food assistance may be required to respond to shocks in the area, investments could be made to improve households` socioeconomic level to enhance their access to food.
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