Periods Of Food Shortage Research Articles

Communal Cavity Roosting in Green Woodhoopoes: Consequences for Energy Expenditure and the Seasonal Pattern of Mortality

-Green Woodhoopoes (Phoeniculus purpureus) roost in cavities in groups throughout the year. It has been proposed that the energy savings achieved by roosting with conspecifics in a cavity could enable birds in poor body condition to remain normothermic during inclement weather. We tested the hypothesis that woodhoopoes conserve energy by roosting with conspecifics in cavities and found that a woodhoopoe roosting with four conspecifics can reduce its nighttime energy expenditure by 30% or more when the minimum ambient temperature is about 5?C. In areas where nocturnal temperatures sometimes drop below freezing, such energy savings are associated with mortality patterns among adults during winter. Our data support the idea that energy considerations may have been important in the evolution and/or maintenance of sociality in this species. Received 14 August 1992, accepted 25 November 1992. GREEN WOODHOOPOES (Phoeniculus purpureus; also known as Red-billed Woodhoopoes) are cooperative breeders that live in groups of 2 to 12 individuals (Ligon and Ligon 1978). Woodhoopoes obligately roost communally in cavities throughout their range even though they are unable to excavate these holes themselves. This dependence appears critical for their survival by either providing energetic benefits to individuals, protection against predators, or both (Ligon and Ligon 1978, 1988, Ligon et al. 1988, Du Plessis 1989a, b, Williams et al. 1991). The energy savings associated with communal cavity roosting have been implicated as an important driving force in the evolution of sociality in this species (Williams et al. 1991). In an earlier paper, Williams et al. (1991) reported that Green Woodhoopoes maintained normothermic body temperatures at ambient temperatures from -1O? to 40?C. However, birds that were in apparently poor body condition, as judged by their unusually low body mass, exhibited body temperatures slightly below 39?C, even at moderate ambient temperatures. We reasoned that birds in depressed body condition will be unable to thermoregulate at low ambient temperatures, but that they can do so when roosting in cavities with conspecifics. We suggested that I Present address: Department of Physiology, College of Medicine, University of Arizona, Tuscon, Arizona 85724, USA. cavity roosting may be particularly critical to first-year birds, and that it may also be important to adults that have experienced periods of food shortage. In this paper we examine the energetic benefits of Green Woodhoopoes' communal cavity-roosting behavior.

Enamel Hypoplasias in Permanent Teeth from Yellow Jacket Sites 5MT-1 and 5MT-3, Southwestern Colorado

Childhood stress is examined in a prehistoric population from the American Southwest, using dental enamel hypoplasias as indicators of nutrition and disease status. The hypoplasia sample consists of permanent anterior teeth from 43 individuals excavated from habitation sites 5MT-1 and 5MT-3 at Yellow Jacket, southwestern Colorado. Although most defects are mild, the prevalence of hypoplasias in the sample is high, involving 97.7 percent of the individuals and 71.7 percent of the teeth. Upper central incisors from the Pueblo II period at Yellow Jacket (A.D. 900 to 1100) have significantly higher hypoplasia frequencies (P < 0.05) than those from the Pueblo III period (A.D. 1100 to about 1250). The increased frequency of hypoplasias during the Pueblo II period appears to be associated with climatic changes that may have resulted in unreliable crop production, extended periods of food shortage, and widespread chronic nutritional stress.

Survival enhancement through food sharing: A means for parental control of natal dispersal

The value of food sharing among relatives is analyzed for a situation where fitness equals survival. In seasonal environments the minimum food abundance may set a limit to group living. Delayed dispersal is predicted to be linked to relaxed winter competition and high parental survival. Enhanced survival for the offspring when parents share food could be a sufficient reason to delay dispersal, while early dispersal in advance of food shortage periods may be induced by a competitive relationship. At low resource abundance dominant parents do best by being competitive and retaining all resources. For food abundance higher than the expected requirements food sharing with independent offspring is possible, although it has a non-zero cost. Food sharing parents still retain most of resources to themselves, but the resource share given to subordinate offspring gradually gets larger when food abundance increases. Except for at very low food abundance, where subordinates may adopt a “suicidal” behaviour and cede their resources to the dominant, there is a conflict over how to share the resources.

Food level reaction norms in size‐selected milkweed bugs (Oncopeltus fasciatus)

Abstract. 1. The hypothesis that the small size of nonmigratory milkweed bugs from Puerto Rico (relative to large migratory bugs from Iowa) might be an adaptation to low food levels was tested with bugs selected for large and small size as the consequence of positive genetic correlation between body size and wing length. The test involved examining reaction norms of life history traits to different food levels.2. When nymphs were reared on 3 milkweed seeds per nymph from hatch to adult eclosion, large bugs were adversely affected with only 50% and 60% in each of two replicates reaching adulthood. Control (unselected) and small bugs, however, were unaffected at this food level. None of the lines was affected at levels of 6 and 12 seeds per nymph.3. When adults were reared from eclosion on 12, 18 or 24 milkweed seeds per bug, large bugs were adversely affected relative to control and small bugs at all three food levels. At each food level fewer large bugs produced eggs than either small or control bugs which did not differ.4. The evidence from the food level reaction norms suggests that larger bugs will be selected against during periods of food shortage of the sort likely to occur in Puerto Rico.

Insufficient processing of cassava induced acute intoxications and the paralytic disease Konzo in a rural area of Mozambique

A small outbreak of paralysis was studied in a rural area of Mozambique. The seven subjects examined had an isolated spastic paraparesis with abrupt onset during a food shortage period following a drought. The diet at onset consisted almost exclusively of leaves and insufficiently processed roots from a recently introduced high‐yielding bitter cassava cultivar. Symptoms of acute intoxications some hours after meals were frequent. A high dietary cyanide exposure from cassava in the affected subjects was indicated by high urinary and serum levels of thiocyanate, the main metabolite. We conclude that the paraparesis observed was konzo, a disease recently reported from four widely separated rural areas of Africa. Our dietary findings are consistent with those in the other affected areas and indicate a causal role of cyanide exposure. Adherence to efficient processing is crucial to avoid toxic effects from cassava.

Settlement Period and Function of Long-Term Territory in Tropical Mangrove Passerines

We studied the territorial behavior of four insectivorous passerines residing in a tropical mangrove of northeastern Venezuela. Data were obtained through mist-netting and direct observation of color-banded individuals, regularly scheduled over two complete annual cycles. Seasonal variation in food resources (arthropods) and the birds’ diet also were evaluated. A chronological cluster analysis was used to determine the settlement periods of territories, the former being illustrated by the probabilistic Jennrich-Turner method. Three of the four species hold year-round territories. These long-term territories were settled only once a year, immediately after the breeding season when food was abundant. The territorial settlement was synchronous among all individuals ofa species, favoring strong modifications of the territorial mosaic. Considering the absence of territorial settlement prior to breeding and the high stability of territorial mosaics even during periods of low food abundance, territoriality during the non-breeding season primarily appears to ensure a breeding site for the next reproductive period. These results contrast with those from temperate regions where territoriality over the non-breeding season primarily enhances the survival of individuals during periods of food shortage.

Protein selection and avoidance strategies of contemporary and ancestral foragers: unresolved issues

During seasonal or inter-annual periods of food shortage and restricted total calorie intake, ethnographically and ethnohistorically documented human foragers, when possible, under-utilize foods that are high in protein, such as lean meat, in favour of foods with higher lipid or carbohydrate content. Nutritional studies suggest that one reason for this behaviour stems from the fact that pregnant women, particularly at times when their total calorie intake is marginal, may be constrained in the amount of energy they can safely derive from protein sources to levels below about 25% of total calories. Protein intakes above this threshold may affect pregnancy outcome through decreased mass at birth and increased perinatal morbidity and mortality. This paper briefly outlines the evidence for the existence of an upper safe limit to total protein intake in pregnancy, and then discusses several facets of the issue that remain poorly understood. The paper ends by raising two basic questions directed especially toward specialists in primate and human nutrition: is this protein threshold real and demographically significant in modern human foraging populations? If so, does an analogous threshold affect pregnant female chimpanzees? If the answer to both of these questions is yes, we can then begin to explore systematically the consequences such a threshold might have for the diet and behaviour of early hominids.

Biochemical composition of the parasitic amphipod Hyperia galba in relation to age and starvation

Hyperia galba was collected in the waters around Helgoland and in the Weser-Elbe-estuary during autumn. Its mode of life is a temporary but obligatory parasitism. The basal biochemical composition of the adults was analyzed in detail and related to the fresh, dry, and ash-free dry weight as well as sex and body length. Hyperia galba (males/females) consists of 85/86% water; the dry matter contains approximately 64/61% protein, 10/11% lipid, 1.2/1.5% carbohydrate, 10/8% chitin, and 23/23% ash. The analyses of basal elemental composition yielded approximately 38% C, 9% N and 6% H. Under natural conditions, individuals may encounter at least two periods of food shortage during their lives. Therefore, the analyses were carried out on individuals of different developmental stages also under food deprivation. The data are discussed with respect to the special mode of life of the species and compared with those found by other authors in several related crustacean species.

Food plants of the Luo of Siaya district, Kenya

Plants used for food by the Luo-speaking people of Siaya District, Kenya, were surveyed as part of a comprehensive ethnobotanical study. Fifty-two crops were observed under cultivation in the district; 69 species are gathered from the wild. Wild fruits, underground portions, leaves, and fungal fruiting bodies are probably important in Siaya as dietary supplements. These non-cultivated resources, particularly important in the driest areas of the district, warrant evaluation for their role as a buffer against periods of food shortage.

The use of wild foods during periods of food shortage in rural Zimbabwe

Studies in various parts of Africa have shown marked increases in the use of the wild as a source of food in times of severe food shortage. This paper examines the utilization of wild foods by rural people in seven villages located in the low rainfall regions of Zimbabwe. These regions experienced repeated droughts and food shortages during the 1980s. It is shown that, unlike in other parts of the continent, there was no marked increase in the use of wild foods as a strategy to mitigate the shortages. Instead, wild foods are used mainly as a supplement to the diet even during periods of severe stress. This is attributed to a number of factors, particularly the availability of alternative sources of cash which can then be used to purchase food as well as recourse to government food transfer programmes.

Household food consumption and seasonal variations in food availability in Sri Lanka

This paper discusses seasonal variations in food availability, and the relationship between access to land and household food consumption in a rural society in Sri Lanka. The paper is based on data collected through participant observation, formal and informal interviews, a questionnaire survey, and a dietary survey. It was found that periods of food shortage were different in households of the various socio‐economic strata. This was related to the way in which the members of these households participated in the cultivation of paddy. The dietary survey, which was conducted during a period of low food availability showed that the diet of low socio‐economic groups was marginal or low with respect to the provision of energy, calcium, vitamin A and riboflavin. This was mostly due to a low food intake in general rather than an unsuitable composition of the diet.

The Effect of Host Feeding on the Contribution of Endosymbiotic Algae to the Growth of Green Hydra

Previous work has shown that the advantage conferred by endosymbiotic algae on the growth of green hydra is most evident during periods of food shortage. This advantage disappears when hydra are amply fed. However, evidence is presented here which suggests that endosymbiotic algae are not sensitive to the nutritional needs of the host. In controlled feeding studies, green hydra produced more bud tissue than did aposymbionts at all feeding levels. Per capita algal contribution to host growth was independent of host feeding rate. Starvation had little effect on rates of algal photosynthesis. The algae of unfed hydra translocated a larger proportion of photosynthetically fixed 14C to the host than did the algae in recently fed hydra. The differences in algal translocation were small, however, and unlikely to significantly affect hydra growth rates. Evidence is presented suggesting that the decrease in the rate of algal translocation in fed hydra may result from an increased algal demand for photosynthate to support the rapid algal growth that follows host feeding.

Ecology of the intertidal pulmonate limpet Siphonaria diemenensis Quoy et Gaimard. II. Reproductive patterns and energetics

The reproductive patterns of the intertidal pulmonate limpet Siphonaria diemenensis Quoy et Gaimard were examined in populations on a rocky shore at two heights (Zones 1 and 2) with differing availabilities of food. The reproductive cycle and reproductive output of S. diemenensis were strongly correlated with seasonal differences in the availability of food, a relationship confirmed by experimental manipulation. Reproductive effort increased with size and age and size-specific reproductive effort was greater at the higher level (Zone 1), where food supply was very seasonal, than at the lower level (Zone 2). This may be because the probability of limpets from Zone 1 surviving the period of food shortage was low.

Digestibility of Vegetative Rye for White-Tailed Deer

Common rye (Secale cereale) vegetation, seeded in May and grazed as the sole food source (except for small amounts of contaminating lambsquarters goosefoot [Chenopodium album]) from mid-June to 7 July, was cut with grass whips and fed to 3 female white-tailed deer (Odocoileus virginianus) in metabolism cages from 7 to 21 July. Apparent digestibility estimates by total collection were as follows: dry matter (DM) 71%, gross energy (GE) 67%, crude protein (CP) 77%, ether extract (EE) 36%, neutral detergent fiber (NDF) 73%, and acid detergent fiber (ADF) 66%. Ninety-five percent of dietary acid detergent lignin (ADL) was recovered in the feces. Use of ADL as an internal indicator (uncorrected for recovery) produced digestibility estimates about 2% lower than those determined by total collection. When estimates of rye digestibility were made with grazing deer (using ADL as an internal indicator), values for GE, CP, and EE were 68, 75, and 25%, respectively, and were not different from those determined in metabolism cages. However, digestibility estimates for DM, NDF, and ADF were lower than by total collection because of contamination of feces by ingested soil. Based on analytical composition (24% CP and 5.17 kcal GE/g DM), estimated digestibility, and previously established agronomic characteristics, rye has significant potential as a part of deer habitat improvement in Michigan. J. WILDL. MANAGE. 51(1):51-53 Habitat management for white-tailed deer in several states includes use of plantings to supplement native vegetation (Crawford 1984). Because agricultural areas often support large deer populations (Nixon 1970) and there is obvious deer use of certain forage crops, interest has developed in use of plantings specifically for deer that might be of benefit during critical periods of food shortage. In Michigan plants that are cold tolerant and begin growth in early spring and in which growth persists into late fall would be particularly useful. Early spring growth would provide nutritious food for deer that nearly have exhausted their energy reserves during the winter, and late fall growth would provide nutrients to support the development of the large stores of body fat that are so essential for winter survival (Verme and Ozoga 1980). Common rye meets these criteria, is readily established (even on poor soils), and is relatively inexpensive. However, there are few data on the ability of white-tailed deer to make effective use of such forage. Therefore, this study was designed to measure the digestibility of freshly cut rye vegetation when fed to these animals in metabolism cages and to establish whether ADL might be used as an indigestible internal indicator to estimate digestibility of rye vegetation when grazed. This study was supported in part by funds from Pittman-Robertson Aid to Wildl. Restor., Mich. Proj. W-117-R. This paper is Mich. Agric. Exp. Stn. J. Art. 11723. EXPERIMENTAL PROCEDURE Common rye was seeded in 9x 18-m pens at the Houghton Lake Wildlife Research Station in May 1976. The pens were rototilled, rye was seeded at 125 kg/ha, and the seed was covered by raking. The plants were allowed to grow until there was sufficient vegetation to permit grazing by deer or to permit cutting so that fresh vegetation could be fed in metabolism

Interdependence among egalitarian societies

Egalitarian societies are rarely entirely self-sufficient for subsistence. The conditions fostering interdependence, however, have yet to be studied systematically. Utilizing ecological models, this research analyses the process by which interdependence involving food resource sharing and exchange develops among egalitarian societies. Two distinct types of interdependence are defined: buffering, which alleviates periodic food shortages, and mutualism, in which complementary foods (carbohydrates, fats, and proteins) are exchanged on a regular basis. The utility of these models is then evaluated using ethnographic data. The article concludes with a discussion of the evolutionary trajectories of interdependent egalitarian systems.

A 'Crisis' Reconsidered: Social and Demographic Dislocation in London in the 1590s

THE 1590swas a difficult decade for the English people. High prices, failed harvests from 1594to 1597, increasing poverty and vagrancy, and war commitments in Ireland and against Spain all imposed strain, bringing a gloomy end to the Tudor century. How the City of London coped during this period, and, in particular, how those in authority kept control of the situation, has been the subject of a previous paper. 1 Food shortage was made good by importing corn from English counties and the Baltic. The privy council encouraged prosperous residents of the City to give charity to their less fortunate brethren. Vagrants were kept under control by increased watches, by efforts to provide extra employment at Bridewell, the City workhouse, and by appointing provost marshals. And the demands of national government for war taxes and ships and troops were met, though by Christmas Eve 1596 they elicited a comprehensive complaint from the City government about the hardships of the City since 1594 and its inability to contribute more. Despite this London seems to have coped with the crisis successfully. As far as can be judged Londoners were fed even in the worst period of food shortage in 1596 and 1597 and the spectre of the hungry mob was kept firmly at bay. Only one outbreak of serious disorder, in June 1595, interrupted the peaceful control exercised during a difficult time. This picture of a city more or less peacefully managing in conditions which might easily have provoked a crisis (1597 saw the lowest real wages in English history) is puzzling.2 Did Londoners remain quiet because their living conditions were not as bad as the real wage index suggests? Or did they suffer in silence, cowed by the seeming inevitability of hardship? This paper seeks to explore the extent to which Londoners did suffer during the 1590s. Evidence for those suffering, often the old and young members of the community, and those with least hope, the unemployed and vagrant, is, however, sparse. They did not speak for themselves. We have, therefore, to use indirect evidence of social distress: intensified efforts to collect money for poor relief, the abandonment of children, harsher measures against strangers and vagrants, and changes in criminal activity and demographic behaviour. It is these problems that this paper will address.3

Body Weight and Carcass Composition of Nonbreeding Green-Winged Teal on the Southern High Plains of Texas

Body weight and carcass composition of nonbreeding green-winged teal (Anas crecca) were analyzed from September to March 1980-82 on the Southern High Plains (SHP) of Texas. Body weight and lipid content of each sex and age class were low when teal arrived on the SHP in September. Body weights and probably lipid reserves then increased to highest levels by December but declined during JanuaryFebruary. There were no significant differences (P > 0.05) among sex and age classes in the lipid reserves present during mid-winter. Food resources and weather conditions did not restrict energy intake of teal throughout winter. Therefore, declines in body weights and lipid reserves appeared to be an adaptation to, rather than a consequence of, winter conditions. However, annual differences in levels of lipid reserves may be caused by factors such as snowfall, low temperatures, and high wind speeds. J. WILDL. MANAGE. 50(3):420-426 Fluctuations in body weights and associated nutrient reserves are important to waterfowl during nonbreeding periods because such changes can affect survival and reproduction (Johnson et al. 1985). For example, stored lipids can provide energy of selective advantage during periods of food shortage or severe weather (Blem 1976). Reproductive performance of some waterfowl also is influenced by lipid and protein reserves accumulated away from breeding sites (Ankney and MacInnes 1978, Raveling 1979, Krapu 1981). Several studies have recorded declines in body weights and/or lipid reserves of Anatinae during winter and proposed such causative factors as limited food supplies and low temperatures (Milne 1972, Ryan 1972, Owen and Cook 1977, Kaminsky and Ryan 1981, Paulus 1984). These studies, however, could not substantiate that food supplies were inadequate because available food was measured cursorily, if at all. Also, contradictory evidence exists for geese (Raveling 1968), passerines (Berthold 1974, Klein 1974), shorebirds (Dugan et al. 1981), and ducks (Reinecke et al. 1982) that winter decreases in lipid reserves and body weights may be a regulated loss. Conversely, Joyner et al. (1984) concluded that winter weight loss among a small number (13) of captive Canada geese (Branta canadensis) reflected food availability and weather conditions. These conflicting hypotheses were investigated relative to green-winged teal on the SHP where waterfowl field-feeding ecology (Baldassarre and Bolen 1984) and teal activity budgets (Quinlan and Baldassarre 1984) were investigated concurrently with this study. Greenwi ged teal are a desirable focal species because prealternate molt largely is completed by late fall (Palmer 1976:347-351) and courtship activity on the SHP was not intense until February-March (Quinlan and Baldassarre 1984). Therefore, these events would not greatly influence body weight and lipid dynamics during mid-winter, allowing effects of weather and food supply to be viewed more clearly. Our objectiv s were to: (1) determine dynamics of body weight and carcass composition of nonbreeding green-winged teal on the SHP and (2) assess withinand betweenseason changes in body weight and carcass composition relative to food supplies and weather conditions. We sincerely thank the following farmers for access to their land: T. J. and W. J. Hill, C. L. Lee, J. R. Davis and family, J. D. Myrick and family, Mr. and Mrs. E. E. Davis, H. A. McLain, and D. W. Brown. R. J. Baker, Dep. Biol., Texas Tech Univ., contributed many teal for the study. This research was supported by the Caesar Kleberg Found. Wildl. Conserv.; the U.S. For. Serv., Rocky Mt. For. and Range Exp. Stn. through the Great Plains Wildl. Res. Lab. at Texas Tech Univ.; and Organ. Res., Texas Tech Univ. S. L. Paulus, K. J. Reinecke, and R. M. 'Present address: Department of Zoology and Wildlife, Auburn University, Auburn, AL 36849. 2 Present address: Camden Acres, Narellan, New South Wales 2567, Australia.

Niche Expansion and Contraction in a Variable Environment

When food is abundant, sparrows are found in great variety of habitats and appear to specialize on particularly profitable types of seeds. However, during periods of food scarcity, each sparrow species occupies a very narrow range of habitats but consumes a great variety of seeds within each occupied habitat. As a result, average dietary overlap may underestimate the potential for competition for food within habitats during periods of food shortage whereas average habitat overlap overestimates the potential for competition since each species occupies a different habitat during periods of food shortage.

Different metabolic strategies of northern birds for nocturnal survival

1. The regulation of O2-consumption and body temperature, especially the occurrence and utilization of nocturnal hypothermia, was studied in three small-sized northern species of birds occupying different ecological niches. Being sympatric, the Willow titParus montanus, the Great titP. major and the Common redpollAcanthis flammea encounter the same environmental conditions during the winter-time, i.e. long nights, low ambient temperatures, a snow-cover, and the possibility of periods of food shortage. 2. When fed ad libitum, neither the Great tit nor the Common redpoll utilized nocturnal hypothermia. The Willow tit lowered the body temperature to a value which was significantly correlated with that of the ambient temperature. 3. During fasting experiments the evening body weights of the birds were depleted 10–20% below the normal value. In all three bird species the O2-consumption during the night was positively correlated to the body weight of the birds. Consequently, the depth of hypothermia achieved at thermal homeostasis was inversely correlated to body weight. 4. When energy reserves in terms of body weight, are less than normal, both Willow tit, Great tit and Common redpoll utilize nocturnal hypothermia in order to make the energy reserves last throughout the night. The reason why the latter two species, in contrast to the Willow tit, do not use nocturnal hypothermia under normal conditions, may be due to differences in body size and also feeding strategies.

Women's health in a marginal area of Kenya

As eco-demographic pressure on the cultivable areas of tropical Africa increases, women, the main food producers in such areas, are experiencing serious threats to their physical health. Eco- demographic pressure may be defined as the effect of a rapidly-growing population, dependent largely on subsistence production, on the human carrying capacity of an ecological region. Continued subdivision of plots from father to sons, overgrazing, and soil erosion lower agricultural productivity and create periodic food shortages, the main burdens falling most heavily upon the poorest people. Migration to cities in search of wage employment, or to lower-potential areas in search of land are common responses. Eco-demographic pressure in the high potential areas of Kenya has been responsible over many years for the migration of agriculturalists into marginal lands. The partial break-up of traditional modes of production and the difficulties of cultivating in a semi-arid environment greatly increase the demands on available labour, whilst levels of health are poor and health care delivery inadequate. It is suggested that women, in particular, are subject to a high degree of stress and evidence of such stress and accompanying ill-health is presented using data from a survey conducted in Kibwezi Division of Machakos District, Kenya. Higher-than-average economic dependence on women is shown in the demographic structure. Water collection patterns show that 70% of all trips are made by women over 15 years over a median distance of 3.5 km and that 87% of women collecting water carry loads without any mechanical assistance compared with 42% of men. Fertility levels remain high and anthropometry revealed that women in the survey were thinner and shorter than a comparable group from a more fertile part of the district. Using functional criteria, the data suggest a higher prevalence of chronic disablement amongst women, compared with men, and the disabilities mentioned tend to reflect the hard lifestyle and high fertility levels of women in Kibwezi.