How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day leng...How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day length, temperature, food availabil- ity, are supposed to effect on activity budgets allocation of temperate primates. To examine the potential influence of these three variables, the activity budgets ofRhinopithecus bieti was studied at Xiaochangdu, Tibet from June 2003 to March 2005. Pearson correlations were utilized to assess potential relationships between activity budget and day length, food availability and temperature, and stepwise multiple regressions to identify the priority of resting and other activities （activities besides feeding, moving and resting）. Time spent resting and doing ＂other activities＂ is positively related to day length, temperature and food availability. No significant correlations were found between feeding/moving time and any of these variables. This suggests that foraging time （feeding ＋ moving） takes priority over rest and other activities. Day length and foraging time （as independent variables） were related to the time spent in the other two activities besides feeding/moving （as dependent variables）. Both time spent resting and in ＂other activities＂ were highly significant positive functions of day length, with the latter a highly significant negative function of feeding time and moving time. Resting time may therefore be interpreted as taking priority over ＂other activities＂ time. These results provide further evidence of the importance of day length, temperature and food availability to seasonal activity budgets [Current Zoology 56 （6）： 650q559, 2010].展开更多
Background:Timing of breeding season of temperate passerines has been considered to be adjusted to their food availability.There is little work to reveal the cell stress responses of the nestlings hatched asynchronize...Background:Timing of breeding season of temperate passerines has been considered to be adjusted to their food availability.There is little work to reveal the cell stress responses of the nestlings hatched asynchronized with the food abundance peak,which is important for understanding the physiological link between the timing of breeding and the fitness of offspring.Methods:Using gene expression level of blood HSP70 and HSP90 as indicators,we compared the cell stress response of Asian Short-toed Lark(Calandrella cheleensis)nestlings hatched under conditions of low,mid or high food(grasshopper nymph)availability in 2017.Results:Nymph biomass,sample time and interaction of these two factors significantly influenced the blood gene expression level of HSP70 and HSP90 of Asian Short-toed Lark nestlings.HSP70 and HSP90 gene expression levels of the nestlings at 14:00 were significantly higher than those at 5:00.At either 5:00 or 14:00,the gene expression levels of HSP70 and HSP90 increase with the decrease of nymph biomass.Conclusions:These results indicate that food availability is an important environment factor inducing cellular stress of Asian Short-toed Lark nestlings.The interactive effect of the nymph abundance and sample time on the HSPs response may be related with the daily temperature variation of the grassland.Over cell stress response may be one of physiological factor mediating the effect of food availability and the nestling’s fitness.展开更多
Understanding the determinants of ranging patterns in species susceptible to habitat fragmentation is fundamental for assessing their long-term adaptability to an increasingly human-dominated landscape.The aim of this...Understanding the determinants of ranging patterns in species susceptible to habitat fragmentation is fundamental for assessing their long-term adaptability to an increasingly human-dominated landscape.The aim of this study was to determine and compare the influence of ground-based food availability,remotely sensed plant productivity,and indigenous forest use on the ranging patterns of the endangered samango monkey(Cercopithecus albogularis schwarzi).We collected monthly ranging data on two habituated samango monkey groups,from February 2012 to December 2016,from our field site in the Soutpansberg Mountains,South Africa.We used linear mixed models to explore how food availability,plant productivity,and indigenous forest use influenced monthly ranging patterns,while controlling for group size,number of sample days and day length.We found that as more areas of high plant productivity(derived from remotely sensed EVI)were incorporated into the ranging area,both total and core monthly ranging areas decreased.In addition,both total ranging area and mean monthly daily path length decreased as more indigenous forest was incorporated into the ranging area.However,we found no effect of either ground-based food availability or remotely sensed plant productivity on ranging patterns.Our findings demonstrate the behavioral flexibility in samango monkey ranging,as samangos can utilize matrix habitat during periods of low productivity but are ultimately dependent on access to indigenous forest patches.In addition,we highlight the potential of using remotely sensed areas of high plant productivity to predict ranging patterns in a small ranging,forest-dwelling guenon,over ground-based estimates of food availability.展开更多
This paper presents a scenario-based assessment of global future food security. To do that,the socio-economic and climate change scenarios were defined for the future and were linked to an integrated modeling framewor...This paper presents a scenario-based assessment of global future food security. To do that,the socio-economic and climate change scenarios were defined for the future and were linked to an integrated modeling framework. The crop yields simulated by the GIS-based Environmental Policy Integrated Climate （EPIC） model and crop areas simulated by the crop choice decision model were combined to calculate the total food production and per capita food availability,which was used to represent the status of food availability and stability. The per capita Gross Domestic Product （GDP） simulated by IFPSIM model was used to reflect the situation of food accessibility and affordability. Based on these two indicators,the future food security status was assessed at a global scale over a period of approximately 20 years,starting from the year 2000. The results show that certain regions such as South Asia and most African countries will likely remain hotspots of food insecurity in the future as both the per capita food availability and the capacity of being able to import food will decrease between 2000 and 2020. Low food production associated with poverty is the determining factor to starvation in these regions,and more efforts are needed to combat hunger in terms of future actions. Other regions such as China,most Eastern European countries and most South American countries where there is an increase in per capita food availability or an increase in the capacity to import food between 2000 and 2020 might be able to improve their food security situation.展开更多
When small animals are faced with an unpredictable food supply,they can adapt by altering different components of their energy budget such as energy intake,metabolic rate,rate of non-shivering thermogenesis(NST)or beh...When small animals are faced with an unpredictable food supply,they can adapt by altering different components of their energy budget such as energy intake,metabolic rate,rate of non-shivering thermogenesis(NST)or behaviour.The present study examined the effect of stochastic food deprivation(FD)on body mass,food intake,resting metabolic rate(RMR),NST and behaviour in male Swiss mice.During a period of 4 weeks' FD,animals were fed ad libitum for a randomly assigned 4 days each week,but were deprived of food for the other 3 days.The results showed that body mass significantly dropped on FD days compared to controls.Food intake of FD mice increased significantly on ad libitum days,ensuring cumulative food intake,final body mass,fat mass,RMR and NST did not differ significantly from controls.Moreover,gastrointestinal tract mass increased in FD mice,but digestibility decreased.In general,activity was higher on deprived days,and feeding behaviour was higher on ad libitum days suggesting that Swiss mice are able to compensate for stochastic FD primarily by increasing food intake on ad libitum days,and not by reducing energy expenditure related to RMR or NST.展开更多
Food availability significantly affects an animal＇s energy metabolism, and thus its phenotype, survival, and reproduction. Maternal and offspring responses to food conditions are critical for understanding population...Food availability significantly affects an animal＇s energy metabolism, and thus its phenotype, survival, and reproduction. Maternal and offspring responses to food conditions are critical for understanding population dynamics and life-history evolution of a species. In this study, we conducted food manipulation experiments in field enclosures to identify the effect of food restriction on female reproductive traits and postpartum body condition, as well as on hatchling phenotypes, in a lacertid viviparous lizard from the Inner Mongolian desert steppe of China. Females under low-food availability treatment （LFT） had poorer immune function and body condition compared with those under high-food availability treatment （HFT）. The food availability treatments significantly affected the litter size and litter mass of the females, but not their gestation period in captivity or brood success, or the body size sprint speed, and sex ratio of the neonates. Females from the LFT group had smaller litter sizes and, therefore, lower litter mass than those from the HFT group. These results suggest that female racerunners facing food restriction lay fewer offspring with unchanged body size and locomotor performance, and incur a cost in the form of poor postpartum body condition and immune function. The flexibility of maternal responses to variable food availability represents an important life strategy that could enhance the resistance of lizards to unpredictable environmental change.展开更多
In spite of receiving a significant amount of food aid, achieving food security has been a major problem in Ethiopia. The claim is evidenced from the 2010 Global Hunger Index where the country fared dismally, coming o...In spite of receiving a significant amount of food aid, achieving food security has been a major problem in Ethiopia. The claim is evidenced from the 2010 Global Hunger Index where the country fared dismally, coming only fourth from the bottom. There are several factors attributing to this problem of food insecurity in a country like Ethiopia which depends highly on agriculture and allied activities. Some of the factors can be linked to low food production and productivity thereby leading to pervasive poverty. In order to assess these factors, the study was conducted on some selected members of agro-pastoral communities of Somali and Oromia regions in Ethiopia. Using availability of food in the household for the last one month as a proxy for food security, the estimated results of a logistic regression model indicated that the most significant factors affecting household food security are educational level of the spouse and that of the household head, size of farm land, availability of household assets including livestock, peace and security. The paper suggests some leads to how these amenities and resources can be provided to household members as they endeavor to reduce food insecurity.展开更多
The food availability, composition of the diets and selective grazing of the Mongolian gazelle (Procapra gutturosa) were studied in Hulunber Grassland in Nei Monggol. The food availability of Mongolian gazelle showed ...The food availability, composition of the diets and selective grazing of the Mongolian gazelle (Procapra gutturosa) were studied in Hulunber Grassland in Nei Monggol. The food availability of Mongolian gazelle showed seasonal changes. The plant biomass was higher in spring and summer than that in autumn and winter. The fecal compositions of the gazelle demonstrated that fibrous parts occupied 62.4%, 74.8%, and 66.0% in spring, autumn, and winter, respectively. The Mongolian gazelle preferred to grazeCompositeae, Leguminosae, Allium spp. and other forbs in spring and autumn, while the grasses, such asAneurolepidium chinense andStipa spp. were selectively feeding in winter.展开更多
Rural areas practice subsistence of the Mizoram state, India agriculture where shifting cultivation dominates the farming systems. As a result, output from crops is very low and thus, the rural areas suffer from food ...Rural areas practice subsistence of the Mizoram state, India agriculture where shifting cultivation dominates the farming systems. As a result, output from crops is very low and thus, the rural areas suffer from food insecurity. This paper analyses food security status in the rural areas of Mizoram and suggests the measures to attain food security. A case study of 16 villages, lying in all the eight districts of Mizoram, was conducted in 2014 and 1527 households （76%） out of total 2010 households were surveyed through purposive random sampling method. Structured questionnaire was constructed and questions on three food security components and 13 indicators were asked. We used Z score technique to calculate data and finally got a composite score of all the components of food security. Our result shows that food availability in the study villages is very less as composite score stands for o.oo3 whereas food accessibility is comparatively higher, mainly due to availability of fair price shops （mean value is one）, high agricultural working population （40.1%） and high literacy rate （70.6%）. Therefore, its composite score is 0.236. Food stability scores only -0.062 and finally overall food security stands for 0.178, which is inadequate. We have suggested that‘system rice intensification＇, which is already in practice, should be given priority. Adequate irrigation facilities, proper public distribution system, cultivation of fruits and vegetables, value addition in farm products and access to market may achieve food security.展开更多
In view of the fact that climate-related disasters are already taking a heavy toll, causing massive damage to crops and infrastructure and forcing some people to flee their homes, however, the potential impacts of cli...In view of the fact that climate-related disasters are already taking a heavy toll, causing massive damage to crops and infrastructure and forcing some people to flee their homes, however, the potential impacts of climate change are likely to trigger adaptive responses that influence environmental and socio-economic drivers of food system performance in positive as well as negative ways. This paper was conducted through the collection of some research materials with the projected balance of these various climate impacts on food system performance and food security outcomes at the local and global levels. More so that, food security is likely to be affected by climate change in several ways： food security depends not only on the direct impact of climate change on food production but also on its indirect impact on human nutrition and health, economic growth, trade flows and food aid policy. The paper further examined the effectiveness of managing new risks and uncertainty, improving the quality of information and its use, monitoring weather and improving scientific understanding of climate change, promoting insurance schemes, maintaining biodiversity and access to fund as some of the crucial measures for adaptation. The large amount of resources that would be necessary to avoid the worst case scenario suggests the necessity of continued support from the international community to improve food security at the local and global levels as a whole.展开更多
Abundant food supply is crucial for the survival of long-distance migratory birds.The continued population decline of the Spoon-billed Sandpiper(Calidris pygmeae),a critically endangered shorebird,is primarily attribu...Abundant food supply is crucial for the survival of long-distance migratory birds.The continued population decline of the Spoon-billed Sandpiper(Calidris pygmeae),a critically endangered shorebird,is primarily attributed to habitat loss and degradation.However,significant gaps remain in research on their diet and foraging habitat selection,limiting effective conservation and restoration efforts.In this study,we investigated the composition of macrobenthic communities,analyzing habitat and prey selection at the main foraging area of SBS in Tiaozini,Jiangsu Province of eastern China—their most critical staging site during southward migration.Our findings revealed 25 species of macrobenthos in foraging areas,with mobile epibenthos comprising the largest group by biomass,accounting for 73%,and having higher density and biomass nearshore.Observations of foraging Spoon-billed Sandpiper individuals indicated that shallow water habitats were their preferred foraging environments,where mobile epibenthos,which thrive in these habitats after the tide recedes,made up 81%of their biomass intake.We propose that shallow water habitats in intertidal mudflats serve as essential refuges for mobile epibenthos after tidal retreat,thereby providing Spoon-billed Sandpipers with access to high-quality food resources.Habitat protection efforts should prioritize habitats harboring extensive microhabitats with shallow water,especially the nearshore area,and further research is needed to explore the mechanisms underlying the formation of these microhabitats,with the ultimate goal of restoring more high-quality habitats for the Spoonbilled Sandpiper.展开更多
The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources. Cultivated land loss caused by disasters and the implementatio...The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources. Cultivated land loss caused by disasters and the implementation of the ＂Conversion of Cropland to Forest or Grassland＂ project make this situation even worse in China. Thus, there is a problem to be solved imminently that to what extent the cultivated land can guarantee food security of China. Based on time-series data on food production and cultivated land area from 1989 to 2003 and other research results, this paper constructs quality index of cultivated land according to different land quality. Regression models are adopted to predicate changes of main factors from 2004 to 2030, which have great effect on cultivated land area or grain productivity, and verify accuracy with coc^cient of determination （R2）. Nine results were got according to three scenarios of decreasing rate of population growth rate and three cases of urban and rural built-up area per capita. There results show that China＇s food supply can only be maintained at a low to middle level of 370-410kg per capita, that is, China has enough land productivity to meet primary demand of food independently. However, it cannot reach the safe target of 500kg per capita if there is no breakthrough in breeding or no remarkable improvement of irrigation works, when the grain self-sufficiency maintains no less than 80%. To breed productive crops and to improve land productivity by mefiorating low quality cultivated land are appropriate measures to shrink the gap between food demand and supply. The results may offer helpful information for the formulation of policies on population growth, land use, protection of cultivated land.展开更多
Year-round investigations were carried out to address the population dynamics of amphipod Ampithoe val- ida and its potential regulating factors in the Yundang Lagoon （a eutrophic subtropical coastal lagoon in Xiamen...Year-round investigations were carried out to address the population dynamics of amphipod Ampithoe val- ida and its potential regulating factors in the Yundang Lagoon （a eutrophic subtropical coastal lagoon in Xiamen City, China） from October 2007 to October 2008. The results show that A. valida population was largely composed of juveniles and reached a peak abundance （12.02× 10^3 ind./m2） in March, but sharply shrunk in July. The monthly variation pattern ofA. valida seemed to follow that of Ulva lactuca which is the main food resource for A. valida, indicating a strong influence of food availability on A. valida popu- lation dynamics. Life cycle studies in laboratory indicate that A. valida adopted an r-selected life strategy, e.g., rapid growth rate （0.216-0.302 mm/d）, consecutive breeding （4-10 times）, short reproductive rhythm （9-17 d） and huge fecundity （24-192 eggs or 6-94 juveniles per brood）, which contributed to the fast pop- ulation growth ofA. valida from January to March. Although temperature may also be a significant cause, A. valida could grow quickly and show normal reproductive traits （i.e., the timing of sexual differentiation or maturity, the reproductive rhythm, the number of broods all through its lifespan and offspring produc- tion） in temperature between 15-30~ C. Therefore, the temperature variation in the lagoon water should not account for the sharp variation of A. valida population by affecting the survival, growth and reproduction of the amphipod. However, negative correlation between water temperature and U. lactuca biomass in the lagoon suggested that temperature could have indirectly affected the population dynamics ofA. ualida by affecting its food availability. The authors conclude that, in the Yundang Lagoon, the population dynamics ofA. validawas mainly controlled by the food availability rather than water temperature.展开更多
We studied the mating tactics of Przewalski＇s gazelle on the Qinghal-Tibetan Plateau from 2002 to 2005. Przewalski＇s gazelle is a cluster mating animal whereby female groups, including juveniles, travel to and from ...We studied the mating tactics of Przewalski＇s gazelle on the Qinghal-Tibetan Plateau from 2002 to 2005. Przewalski＇s gazelle is a cluster mating animal whereby female groups, including juveniles, travel to and from their resting grounds along fixed routes and dominant males stand on or near these travel routes during rut. To explain rut patterns in male ga- zelles, we tested predictions arising from the ＂Resource-based Hypothesis＂ and ＂Female Traffic Version of the Hotspot Hypothe- sis＂. We marked the location of each rut stand and female travel route, measured food availability in each rut stand and recorded the mating opportunities of rut stand owners. We also conducted a field experiment to force female groups to change their daily travel route, and observed whether males abandon their original rut stands and shift their rut stands to new travel routes of females during the 3rdrut. We found that： （1） male gazelle defending rut stands closer to a female travel route had a higher chance of mat- ing; （2） food resources within rut stands had no effect on mating opportunities of the rut stand owner; （3） when the female travel route was obstructed, female groups changed grazing sites, and all males abandoned their original rut stands and defended new rut stands along the new female travel route. In conclusion, the location of rut stands in relation to female travel routes is the ultimate factor for consolidating mating opportunities in male gazelle, supporting the ＂Female Route Version of Hotspot Hypothesis展开更多
We examined time allocation by Sichuan snub-nosed monkeys Rhinopithecus roxellana in the montane, temperate and highly seasonal forests of the Shennongjia Nature Reserve in China, in order to improve our understanding...We examined time allocation by Sichuan snub-nosed monkeys Rhinopithecus roxellana in the montane, temperate and highly seasonal forests of the Shennongjia Nature Reserve in China, in order to improve our understanding of the ecological and social influences on monkey behavior. We collected data on activity budgets in relation to food availability in a group of monkeys from July 2003 to September 2004 （except February 2004）, using instantaneous scan samples. The monkeys spent 36.21% of daytime moving （ n = 21, 269 records）, 24.39% foraging, 9.33% inactive, 11,7% performing social behaviors, and 18.38% performing other behaviors. There were seasonal and annual variations in the proportions of time devoted to some activities. These variations were largely attributed to seasonal or annual fluctuations in the distribution and quality of food resources. Adult males spent more time moving, searching, and displaying other behaviors, but less time feeding and performing social behaviors than adult females. Adults performed other behaviors more often and moving less often than juveniles. These differences in activity budgets may reflect fundamental differences in reproductive biology, parental investment, and development among the different age/sex classes [ Current Zoology 55 （3） ： 173 - 179, 2009] .展开更多
Shelf-basin advection is essential to subsistence of the Arctic copepod Calanus hyperboreus population in high basin area. Its abundance, population structure and body size in pelagic layer were investigated with samp...Shelf-basin advection is essential to subsistence of the Arctic copepod Calanus hyperboreus population in high basin area. Its abundance, population structure and body size in pelagic layer were investigated with samples collected over a large range in the western Arctic Ocean during summer 2003, to evaluate the geographical variation in recruitment pattern. Calanus hyperboreus was absent from the shallow areas of the Chukchi Sea and most abundant in the slope area between the Chukchi Sea and Chukchi Abyssal Plain（CS-slope）. Total abundance varied between 1 110.0 and 5 815.0 ind./m^2 in the CS-slope area and ranged from 40.0 to 950.0 ind./m^2 in the other areas. Early stages（CI–IV） dominated in the CS-slope area, whereas CV and adult females were frequently recorded only in deep basin areas. Geographical difference of prosome length was most evident in CIII,with average ranging from 2.48 to 2.61 mm at the CS-slope stations and 2.16–2.37 mm at the others. Abundance of early developmental stages（CI–CIV） correlated positively with Chl a concentration, but negative correlation was observed in late stages（CV–adult）. Our results indicated that C. hyperboreus can benefit from primary production increase through accelerated development in the first growth season and the productive CS-slope area is a potential source for slope-basin replenishment.展开更多
Effects of Microcystis blooms on the crustacean plankton were studied using enclosure experiments during July-September, 2000. Eight enclosures were set in the hypereutrophic Donghu Lake. Different nutrient concentrat...Effects of Microcystis blooms on the crustacean plankton were studied using enclosure experiments during July-September, 2000. Eight enclosures were set in the hypereutrophic Donghu Lake. Different nutrient concentrations through additional nutrient and sediment in enclosures were expected to result in different abundance of Microcystis. From July to early August, the phytoplankton community was dominated by Chlorophyta, Cryptophyta, Bacillariophyta and Cyanophyta other than Microcystis aeruginosa. M. aeruginosa showed a rapid increase during early August in all enclosures and predominated. Crustacean plankton was dominated by the herbivorous Moina micrura, Diaphanosoma brachyurum and Ceriodaphnia cornuta, and the predaceous Mesocyclops sp. and Thermocyclops taihokuensis. During the pre-bloom period, the dynamics of M. micrura population appeared to be mainly affected by the predaceous cyclopoids. With the development of Microcystis blooms, such interaction between M. micrura and cyclopoids seemed weakened, especially when the Microcystis biomass was high. But there was no apparent influence on the interaction between Leptodora kindti and its zooplanktonic prey. The density of two cyclopoids decreased with the enhancement of Microcystis. The density decline of M. micrura was caused by both predation and inhibition by Microcystis. The low food availability of other edible phytoplankton during the blooms led to low densities of both C. cornuta and D. brachyurum by late August. It appears that dense Microcystis blooms exert strong negative effects on the herbivorous cladocerans and the predaceous cyclopoids.展开更多
It is often assumed that birds are able to choose a breeding territory that will later on have the most food for nestlings. Studies on this essential question are, however, few. We studied territory choice of a long-d...It is often assumed that birds are able to choose a breeding territory that will later on have the most food for nestlings. Studies on this essential question are, however, few. We studied territory choice of a long-distance migrant, the pied flycatcher Ficedula hypoleuca in southwestern Finland. In one study area, we monitored the territory choice of males via the order of territory settlement. Female territory choice was studied experimentally in another study area where the correlation between male and territory quality was removed by not allowing males a free choice of territory. We defined several habitat characteristics and es- timated the abundances of invertebrate prey from air, ground and trees with appropriate traps from the surroundings of the nest sites in both study areas. Against the expectation that parent birds would choose an arthropod-rich territory, neither males nor females seemed to choose those territories that later had the most food for nestlings. There was, however, some evidence that more eggs were laid in territories with more aphids and that more fledglings were produced in territories with high ant abundance. Our findings thus suggest that while it would be beneficial for birds to be able to choose food-rich territories, they may not be able to detect the right cues for doing so early in the breeding season. The possibility and importance of detecting the territories with the best prospects of rearing young may, however, vary among and within seasons and more studies on this topic are clearly needed [Current Zoology 61 （4）： 604-613, 2015].展开更多
Based on the photosynthesis-respiration reversible reaction and the available statistics, we attempted to quantify the planetary seasonal exchanges of CO<sub>2</sub> between air and water from 1970 and com...Based on the photosynthesis-respiration reversible reaction and the available statistics, we attempted to quantify the planetary seasonal exchanges of CO<sub>2</sub> between air and water from 1970 and compared them to the glacial ACC cycles as reported from ice cores archives. In 2020, the overall continental absorption (AW) was 8.0 giga tonnes of carbon per year (GtC/y). Emissions into the atmosphere (EW) resulting from mineral degradation by respiration and combustion of biomass and fossil hydrocarbons were 14.7 GtC/y, an increase of 2.4% per year since 1970. The continental surplus balance (-AW+EW) of 6.7 GtC/y was shared between the atmosphere, which received 5.1 GtC/y (GATM), and the ocean which absorbed 1.6 GtC/y. This ocean contribution (OC) corresponded to 17% of the 9.2 GtC/y emissions by combustion of fossil hydrocarbons (EFOS). Analysis of the ACC oscillations during 2020 in the northern hemisphere showed that the ocean absorbed 11.1 GtC during the warm season and outgassed 9.5 GtC during the cold season. Assuming proportionality to world population, the ACC, 414 parts per million (ppm) in 2021, would reach 584 ppm in 2080, still growing at a rate of 0.6% per year. The gain of atmospheric CO<sub>2</sub> (GATM) and its absorption by the ocean (OC) were expected to peak at 7.0 and 2.2 GtC/y, respectively, in 2080. This increase in the availability of atmospheric CO<sub>2</sub> resulted in improved yields of agriculture which more than compensated for the reduction by half of food-producing areas per capita from 1970.展开更多
基金supported by the Chinese Academy of Sciences (KSCX2-1-09)the National Natural Science Foundation of China (30870375,31071937)
文摘How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day length, temperature, food availabil- ity, are supposed to effect on activity budgets allocation of temperate primates. To examine the potential influence of these three variables, the activity budgets ofRhinopithecus bieti was studied at Xiaochangdu, Tibet from June 2003 to March 2005. Pearson correlations were utilized to assess potential relationships between activity budget and day length, food availability and temperature, and stepwise multiple regressions to identify the priority of resting and other activities （activities besides feeding, moving and resting）. Time spent resting and doing ＂other activities＂ is positively related to day length, temperature and food availability. No significant correlations were found between feeding/moving time and any of these variables. This suggests that foraging time （feeding ＋ moving） takes priority over rest and other activities. Day length and foraging time （as independent variables） were related to the time spent in the other two activities besides feeding/moving （as dependent variables）. Both time spent resting and in ＂other activities＂ were highly significant positive functions of day length, with the latter a highly significant negative function of feeding time and moving time. Resting time may therefore be interpreted as taking priority over ＂other activities＂ time. These results provide further evidence of the importance of day length, temperature and food availability to seasonal activity budgets [Current Zoology 56 （6）： 650q559, 2010].
基金supported by the National Natural Science Foundation of China(No.31872246)
文摘Background:Timing of breeding season of temperate passerines has been considered to be adjusted to their food availability.There is little work to reveal the cell stress responses of the nestlings hatched asynchronized with the food abundance peak,which is important for understanding the physiological link between the timing of breeding and the fitness of offspring.Methods:Using gene expression level of blood HSP70 and HSP90 as indicators,we compared the cell stress response of Asian Short-toed Lark(Calandrella cheleensis)nestlings hatched under conditions of low,mid or high food(grasshopper nymph)availability in 2017.Results:Nymph biomass,sample time and interaction of these two factors significantly influenced the blood gene expression level of HSP70 and HSP90 of Asian Short-toed Lark nestlings.HSP70 and HSP90 gene expression levels of the nestlings at 14:00 were significantly higher than those at 5:00.At either 5:00 or 14:00,the gene expression levels of HSP70 and HSP90 increase with the decrease of nymph biomass.Conclusions:These results indicate that food availability is an important environment factor inducing cellular stress of Asian Short-toed Lark nestlings.The interactive effect of the nymph abundance and sample time on the HSPs response may be related with the daily temperature variation of the grassland.Over cell stress response may be one of physiological factor mediating the effect of food availability and the nestling’s fitness.
文摘Understanding the determinants of ranging patterns in species susceptible to habitat fragmentation is fundamental for assessing their long-term adaptability to an increasingly human-dominated landscape.The aim of this study was to determine and compare the influence of ground-based food availability,remotely sensed plant productivity,and indigenous forest use on the ranging patterns of the endangered samango monkey(Cercopithecus albogularis schwarzi).We collected monthly ranging data on two habituated samango monkey groups,from February 2012 to December 2016,from our field site in the Soutpansberg Mountains,South Africa.We used linear mixed models to explore how food availability,plant productivity,and indigenous forest use influenced monthly ranging patterns,while controlling for group size,number of sample days and day length.We found that as more areas of high plant productivity(derived from remotely sensed EVI)were incorporated into the ranging area,both total and core monthly ranging areas decreased.In addition,both total ranging area and mean monthly daily path length decreased as more indigenous forest was incorporated into the ranging area.However,we found no effect of either ground-based food availability or remotely sensed plant productivity on ranging patterns.Our findings demonstrate the behavioral flexibility in samango monkey ranging,as samangos can utilize matrix habitat during periods of low productivity but are ultimately dependent on access to indigenous forest patches.In addition,we highlight the potential of using remotely sensed areas of high plant productivity to predict ranging patterns in a small ranging,forest-dwelling guenon,over ground-based estimates of food availability.
基金National Basic Research Program of China (973 Program),No.2010CB951504National Natural Science Foundation of China,No.40930101+1 种基金No.40971218Foundation for National Non-Profit Scientific Institution,Ministry of Finance of China,No.IARRP-2010-02
文摘This paper presents a scenario-based assessment of global future food security. To do that,the socio-economic and climate change scenarios were defined for the future and were linked to an integrated modeling framework. The crop yields simulated by the GIS-based Environmental Policy Integrated Climate （EPIC） model and crop areas simulated by the crop choice decision model were combined to calculate the total food production and per capita food availability,which was used to represent the status of food availability and stability. The per capita Gross Domestic Product （GDP） simulated by IFPSIM model was used to reflect the situation of food accessibility and affordability. Based on these two indicators,the future food security status was assessed at a global scale over a period of approximately 20 years,starting from the year 2000. The results show that certain regions such as South Asia and most African countries will likely remain hotspots of food insecurity in the future as both the per capita food availability and the capacity of being able to import food will decrease between 2000 and 2020. Low food production associated with poverty is the determining factor to starvation in these regions,and more efforts are needed to combat hunger in terms of future actions. Other regions such as China,most Eastern European countries and most South American countries where there is an increase in per capita food availability or an increase in the capacity to import food between 2000 and 2020 might be able to improve their food security situation.
基金supported by grant No.30800130 from the National Natural Science Foundation of China
文摘When small animals are faced with an unpredictable food supply,they can adapt by altering different components of their energy budget such as energy intake,metabolic rate,rate of non-shivering thermogenesis(NST)or behaviour.The present study examined the effect of stochastic food deprivation(FD)on body mass,food intake,resting metabolic rate(RMR),NST and behaviour in male Swiss mice.During a period of 4 weeks' FD,animals were fed ad libitum for a randomly assigned 4 days each week,but were deprived of food for the other 3 days.The results showed that body mass significantly dropped on FD days compared to controls.Food intake of FD mice increased significantly on ad libitum days,ensuring cumulative food intake,final body mass,fat mass,RMR and NST did not differ significantly from controls.Moreover,gastrointestinal tract mass increased in FD mice,but digestibility decreased.In general,activity was higher on deprived days,and feeding behaviour was higher on ad libitum days suggesting that Swiss mice are able to compensate for stochastic FD primarily by increasing food intake on ad libitum days,and not by reducing energy expenditure related to RMR or NST.
基金supported by the grant from the National Natural Science Fund for Distinguished Young Scholars(31525006)
文摘Food availability significantly affects an animal＇s energy metabolism, and thus its phenotype, survival, and reproduction. Maternal and offspring responses to food conditions are critical for understanding population dynamics and life-history evolution of a species. In this study, we conducted food manipulation experiments in field enclosures to identify the effect of food restriction on female reproductive traits and postpartum body condition, as well as on hatchling phenotypes, in a lacertid viviparous lizard from the Inner Mongolian desert steppe of China. Females under low-food availability treatment （LFT） had poorer immune function and body condition compared with those under high-food availability treatment （HFT）. The food availability treatments significantly affected the litter size and litter mass of the females, but not their gestation period in captivity or brood success, or the body size sprint speed, and sex ratio of the neonates. Females from the LFT group had smaller litter sizes and, therefore, lower litter mass than those from the HFT group. These results suggest that female racerunners facing food restriction lay fewer offspring with unchanged body size and locomotor performance, and incur a cost in the form of poor postpartum body condition and immune function. The flexibility of maternal responses to variable food availability represents an important life strategy that could enhance the resistance of lizards to unpredictable environmental change.
文摘In spite of receiving a significant amount of food aid, achieving food security has been a major problem in Ethiopia. The claim is evidenced from the 2010 Global Hunger Index where the country fared dismally, coming only fourth from the bottom. There are several factors attributing to this problem of food insecurity in a country like Ethiopia which depends highly on agriculture and allied activities. Some of the factors can be linked to low food production and productivity thereby leading to pervasive poverty. In order to assess these factors, the study was conducted on some selected members of agro-pastoral communities of Somali and Oromia regions in Ethiopia. Using availability of food in the household for the last one month as a proxy for food security, the estimated results of a logistic regression model indicated that the most significant factors affecting household food security are educational level of the spouse and that of the household head, size of farm land, availability of household assets including livestock, peace and security. The paper suggests some leads to how these amenities and resources can be provided to household members as they endeavor to reduce food insecurity.
文摘The food availability, composition of the diets and selective grazing of the Mongolian gazelle (Procapra gutturosa) were studied in Hulunber Grassland in Nei Monggol. The food availability of Mongolian gazelle showed seasonal changes. The plant biomass was higher in spring and summer than that in autumn and winter. The fecal compositions of the gazelle demonstrated that fibrous parts occupied 62.4%, 74.8%, and 66.0% in spring, autumn, and winter, respectively. The Mongolian gazelle preferred to grazeCompositeae, Leguminosae, Allium spp. and other forbs in spring and autumn, while the grasses, such asAneurolepidium chinense andStipa spp. were selectively feeding in winter.
基金Project funded by the Indian Council of Social Science Research,New Delhi,Grant No.F.02/15/2013-14 RPR
文摘Rural areas practice subsistence of the Mizoram state, India agriculture where shifting cultivation dominates the farming systems. As a result, output from crops is very low and thus, the rural areas suffer from food insecurity. This paper analyses food security status in the rural areas of Mizoram and suggests the measures to attain food security. A case study of 16 villages, lying in all the eight districts of Mizoram, was conducted in 2014 and 1527 households （76%） out of total 2010 households were surveyed through purposive random sampling method. Structured questionnaire was constructed and questions on three food security components and 13 indicators were asked. We used Z score technique to calculate data and finally got a composite score of all the components of food security. Our result shows that food availability in the study villages is very less as composite score stands for o.oo3 whereas food accessibility is comparatively higher, mainly due to availability of fair price shops （mean value is one）, high agricultural working population （40.1%） and high literacy rate （70.6%）. Therefore, its composite score is 0.236. Food stability scores only -0.062 and finally overall food security stands for 0.178, which is inadequate. We have suggested that‘system rice intensification＇, which is already in practice, should be given priority. Adequate irrigation facilities, proper public distribution system, cultivation of fruits and vegetables, value addition in farm products and access to market may achieve food security.
文摘In view of the fact that climate-related disasters are already taking a heavy toll, causing massive damage to crops and infrastructure and forcing some people to flee their homes, however, the potential impacts of climate change are likely to trigger adaptive responses that influence environmental and socio-economic drivers of food system performance in positive as well as negative ways. This paper was conducted through the collection of some research materials with the projected balance of these various climate impacts on food system performance and food security outcomes at the local and global levels. More so that, food security is likely to be affected by climate change in several ways： food security depends not only on the direct impact of climate change on food production but also on its indirect impact on human nutrition and health, economic growth, trade flows and food aid policy. The paper further examined the effectiveness of managing new risks and uncertainty, improving the quality of information and its use, monitoring weather and improving scientific understanding of climate change, promoting insurance schemes, maintaining biodiversity and access to fund as some of the crucial measures for adaptation. The large amount of resources that would be necessary to avoid the worst case scenario suggests the necessity of continued support from the international community to improve food security at the local and global levels as a whole.
基金funded by the National Natural Science Foundation of China(No.42361144873)Yellow Sea Wetland Project(No.HHSDKT202312)the“Saving Spoon-billed Sandpiper”project of Shenzhen Mangrove Wetlands Conservation Foundation(MCF)。
文摘Abundant food supply is crucial for the survival of long-distance migratory birds.The continued population decline of the Spoon-billed Sandpiper(Calidris pygmeae),a critically endangered shorebird,is primarily attributed to habitat loss and degradation.However,significant gaps remain in research on their diet and foraging habitat selection,limiting effective conservation and restoration efforts.In this study,we investigated the composition of macrobenthic communities,analyzing habitat and prey selection at the main foraging area of SBS in Tiaozini,Jiangsu Province of eastern China—their most critical staging site during southward migration.Our findings revealed 25 species of macrobenthos in foraging areas,with mobile epibenthos comprising the largest group by biomass,accounting for 73%,and having higher density and biomass nearshore.Observations of foraging Spoon-billed Sandpiper individuals indicated that shallow water habitats were their preferred foraging environments,where mobile epibenthos,which thrive in these habitats after the tide recedes,made up 81%of their biomass intake.We propose that shallow water habitats in intertidal mudflats serve as essential refuges for mobile epibenthos after tidal retreat,thereby providing Spoon-billed Sandpipers with access to high-quality food resources.Habitat protection efforts should prioritize habitats harboring extensive microhabitats with shallow water,especially the nearshore area,and further research is needed to explore the mechanisms underlying the formation of these microhabitats,with the ultimate goal of restoring more high-quality habitats for the Spoonbilled Sandpiper.
基金Under the auspices of the National Natural Science Foundation of China (No. 40671007), Innovation Project of Institute of Geographical Sciences and Natural Resources Research, CAS
文摘The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources. Cultivated land loss caused by disasters and the implementation of the ＂Conversion of Cropland to Forest or Grassland＂ project make this situation even worse in China. Thus, there is a problem to be solved imminently that to what extent the cultivated land can guarantee food security of China. Based on time-series data on food production and cultivated land area from 1989 to 2003 and other research results, this paper constructs quality index of cultivated land according to different land quality. Regression models are adopted to predicate changes of main factors from 2004 to 2030, which have great effect on cultivated land area or grain productivity, and verify accuracy with coc^cient of determination （R2）. Nine results were got according to three scenarios of decreasing rate of population growth rate and three cases of urban and rural built-up area per capita. There results show that China＇s food supply can only be maintained at a low to middle level of 370-410kg per capita, that is, China has enough land productivity to meet primary demand of food independently. However, it cannot reach the safe target of 500kg per capita if there is no breakthrough in breeding or no remarkable improvement of irrigation works, when the grain self-sufficiency maintains no less than 80%. To breed productive crops and to improve land productivity by mefiorating low quality cultivated land are appropriate measures to shrink the gap between food demand and supply. The results may offer helpful information for the formulation of policies on population growth, land use, protection of cultivated land.
基金Public Science and Technology Research Funds Projects of Ocean under contract No.201205009-3Key Sci-Tech Program of Xiamen City under contract No.3502Z20102004
文摘Year-round investigations were carried out to address the population dynamics of amphipod Ampithoe val- ida and its potential regulating factors in the Yundang Lagoon （a eutrophic subtropical coastal lagoon in Xiamen City, China） from October 2007 to October 2008. The results show that A. valida population was largely composed of juveniles and reached a peak abundance （12.02× 10^3 ind./m2） in March, but sharply shrunk in July. The monthly variation pattern ofA. valida seemed to follow that of Ulva lactuca which is the main food resource for A. valida, indicating a strong influence of food availability on A. valida popu- lation dynamics. Life cycle studies in laboratory indicate that A. valida adopted an r-selected life strategy, e.g., rapid growth rate （0.216-0.302 mm/d）, consecutive breeding （4-10 times）, short reproductive rhythm （9-17 d） and huge fecundity （24-192 eggs or 6-94 juveniles per brood）, which contributed to the fast pop- ulation growth ofA. valida from January to March. Although temperature may also be a significant cause, A. valida could grow quickly and show normal reproductive traits （i.e., the timing of sexual differentiation or maturity, the reproductive rhythm, the number of broods all through its lifespan and offspring produc- tion） in temperature between 15-30~ C. Therefore, the temperature variation in the lagoon water should not account for the sharp variation of A. valida population by affecting the survival, growth and reproduction of the amphipod. However, negative correlation between water temperature and U. lactuca biomass in the lagoon suggested that temperature could have indirectly affected the population dynamics ofA. ualida by affecting its food availability. The authors conclude that, in the Yundang Lagoon, the population dynamics ofA. validawas mainly controlled by the food availability rather than water temperature.
基金Acknowledgement This work was supported by the Na- tional Nature Science Foundation （31070469, 31070348）, the Knowledge Innovation Project of Chinese Academy of Sci- ences （KSCX2-EW-Z-4）, the Demo Project of Resource Monitoring and Conservation Technology and Application of Important Species in China （2008BAC39B04）, and the Sir Peter Scott Fund of the IUCN/SSC. We thank Li Zhongqiu, Cui Qinghu, Zheng Jie and Lu Ping for assistance during field work. Li Chunlin helped draw the figures.
文摘We studied the mating tactics of Przewalski＇s gazelle on the Qinghal-Tibetan Plateau from 2002 to 2005. Przewalski＇s gazelle is a cluster mating animal whereby female groups, including juveniles, travel to and from their resting grounds along fixed routes and dominant males stand on or near these travel routes during rut. To explain rut patterns in male ga- zelles, we tested predictions arising from the ＂Resource-based Hypothesis＂ and ＂Female Traffic Version of the Hotspot Hypothe- sis＂. We marked the location of each rut stand and female travel route, measured food availability in each rut stand and recorded the mating opportunities of rut stand owners. We also conducted a field experiment to force female groups to change their daily travel route, and observed whether males abandon their original rut stands and shift their rut stands to new travel routes of females during the 3rdrut. We found that： （1） male gazelle defending rut stands closer to a female travel route had a higher chance of mat- ing; （2） food resources within rut stands had no effect on mating opportunities of the rut stand owner; （3） when the female travel route was obstructed, female groups changed grazing sites, and all males abandoned their original rut stands and defended new rut stands along the new female travel route. In conclusion, the location of rut stands in relation to female travel routes is the ultimate factor for consolidating mating opportunities in male gazelle, supporting the ＂Female Route Version of Hotspot Hypothesis
基金supported by grants from the"973"program(code:2007CB411600)the National Science Foundation(code:30670354)
文摘We examined time allocation by Sichuan snub-nosed monkeys Rhinopithecus roxellana in the montane, temperate and highly seasonal forests of the Shennongjia Nature Reserve in China, in order to improve our understanding of the ecological and social influences on monkey behavior. We collected data on activity budgets in relation to food availability in a group of monkeys from July 2003 to September 2004 （except February 2004）, using instantaneous scan samples. The monkeys spent 36.21% of daytime moving （ n = 21, 269 records）, 24.39% foraging, 9.33% inactive, 11,7% performing social behaviors, and 18.38% performing other behaviors. There were seasonal and annual variations in the proportions of time devoted to some activities. These variations were largely attributed to seasonal or annual fluctuations in the distribution and quality of food resources. Adult males spent more time moving, searching, and displaying other behaviors, but less time feeding and performing social behaviors than adult females. Adults performed other behaviors more often and moving less often than juveniles. These differences in activity budgets may reflect fundamental differences in reproductive biology, parental investment, and development among the different age/sex classes [ Current Zoology 55 （3） ： 173 - 179, 2009] .
基金The National Natural Science Foundation of China under contract No.40406002the Public Science and Technology Research Funds Projects of Ocean under contract No.201105022
文摘Shelf-basin advection is essential to subsistence of the Arctic copepod Calanus hyperboreus population in high basin area. Its abundance, population structure and body size in pelagic layer were investigated with samples collected over a large range in the western Arctic Ocean during summer 2003, to evaluate the geographical variation in recruitment pattern. Calanus hyperboreus was absent from the shallow areas of the Chukchi Sea and most abundant in the slope area between the Chukchi Sea and Chukchi Abyssal Plain（CS-slope）. Total abundance varied between 1 110.0 and 5 815.0 ind./m^2 in the CS-slope area and ranged from 40.0 to 950.0 ind./m^2 in the other areas. Early stages（CI–IV） dominated in the CS-slope area, whereas CV and adult females were frequently recorded only in deep basin areas. Geographical difference of prosome length was most evident in CIII,with average ranging from 2.48 to 2.61 mm at the CS-slope stations and 2.16–2.37 mm at the others. Abundance of early developmental stages（CI–CIV） correlated positively with Chl a concentration, but negative correlation was observed in late stages（CV–adult）. Our results indicated that C. hyperboreus can benefit from primary production increase through accelerated development in the first growth season and the productive CS-slope area is a potential source for slope-basin replenishment.
基金The Key Project of Chinese Academy of Sciences(No. KZCX1_SW_12) and Chinese Postdoctoral Fundation(No.2003034392)
文摘Effects of Microcystis blooms on the crustacean plankton were studied using enclosure experiments during July-September, 2000. Eight enclosures were set in the hypereutrophic Donghu Lake. Different nutrient concentrations through additional nutrient and sediment in enclosures were expected to result in different abundance of Microcystis. From July to early August, the phytoplankton community was dominated by Chlorophyta, Cryptophyta, Bacillariophyta and Cyanophyta other than Microcystis aeruginosa. M. aeruginosa showed a rapid increase during early August in all enclosures and predominated. Crustacean plankton was dominated by the herbivorous Moina micrura, Diaphanosoma brachyurum and Ceriodaphnia cornuta, and the predaceous Mesocyclops sp. and Thermocyclops taihokuensis. During the pre-bloom period, the dynamics of M. micrura population appeared to be mainly affected by the predaceous cyclopoids. With the development of Microcystis blooms, such interaction between M. micrura and cyclopoids seemed weakened, especially when the Microcystis biomass was high. But there was no apparent influence on the interaction between Leptodora kindti and its zooplanktonic prey. The density of two cyclopoids decreased with the enhancement of Microcystis. The density decline of M. micrura was caused by both predation and inhibition by Microcystis. The low food availability of other edible phytoplankton during the blooms led to low densities of both C. cornuta and D. brachyurum by late August. It appears that dense Microcystis blooms exert strong negative effects on the herbivorous cladocerans and the predaceous cyclopoids.
文摘It is often assumed that birds are able to choose a breeding territory that will later on have the most food for nestlings. Studies on this essential question are, however, few. We studied territory choice of a long-distance migrant, the pied flycatcher Ficedula hypoleuca in southwestern Finland. In one study area, we monitored the territory choice of males via the order of territory settlement. Female territory choice was studied experimentally in another study area where the correlation between male and territory quality was removed by not allowing males a free choice of territory. We defined several habitat characteristics and es- timated the abundances of invertebrate prey from air, ground and trees with appropriate traps from the surroundings of the nest sites in both study areas. Against the expectation that parent birds would choose an arthropod-rich territory, neither males nor females seemed to choose those territories that later had the most food for nestlings. There was, however, some evidence that more eggs were laid in territories with more aphids and that more fledglings were produced in territories with high ant abundance. Our findings thus suggest that while it would be beneficial for birds to be able to choose food-rich territories, they may not be able to detect the right cues for doing so early in the breeding season. The possibility and importance of detecting the territories with the best prospects of rearing young may, however, vary among and within seasons and more studies on this topic are clearly needed [Current Zoology 61 （4）： 604-613, 2015].
文摘Based on the photosynthesis-respiration reversible reaction and the available statistics, we attempted to quantify the planetary seasonal exchanges of CO<sub>2</sub> between air and water from 1970 and compared them to the glacial ACC cycles as reported from ice cores archives. In 2020, the overall continental absorption (AW) was 8.0 giga tonnes of carbon per year (GtC/y). Emissions into the atmosphere (EW) resulting from mineral degradation by respiration and combustion of biomass and fossil hydrocarbons were 14.7 GtC/y, an increase of 2.4% per year since 1970. The continental surplus balance (-AW+EW) of 6.7 GtC/y was shared between the atmosphere, which received 5.1 GtC/y (GATM), and the ocean which absorbed 1.6 GtC/y. This ocean contribution (OC) corresponded to 17% of the 9.2 GtC/y emissions by combustion of fossil hydrocarbons (EFOS). Analysis of the ACC oscillations during 2020 in the northern hemisphere showed that the ocean absorbed 11.1 GtC during the warm season and outgassed 9.5 GtC during the cold season. Assuming proportionality to world population, the ACC, 414 parts per million (ppm) in 2021, would reach 584 ppm in 2080, still growing at a rate of 0.6% per year. The gain of atmospheric CO<sub>2</sub> (GATM) and its absorption by the ocean (OC) were expected to peak at 7.0 and 2.2 GtC/y, respectively, in 2080. This increase in the availability of atmospheric CO<sub>2</sub> resulted in improved yields of agriculture which more than compensated for the reduction by half of food-producing areas per capita from 1970.
