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1.
Summary Total lipids were extracted from 161 redpolls (Acanthis spp.) collected each month of the year from October 1962 to September 1963, in interior Alaska. A lipid index (Weight of ether extract x100/live body weight) was calculated for each sample. Lipids were also extracted from sections of pectoral muscle, livers and hearts representing each month.Body weight and lipid index were significantly positively correlated being highest in January and lowest in September. Total lipid content was significantly inversely correlated with air temperature; the high autumn and spring pre-migratory lipid peaks of migratory species were only weakly expressed in the redpolls. Liver lipid showed a significant annual variation being highest in December and lowest in August, while lipid from heart and pectoral muscle did not vary seasonally.Five birds were held in captivity during spring and summer at a constant temperature of 22°C. Food consumption was 5.1 g/day or 22.4 kcal. The caloric value of the most extensively utilized natural food, birch seed (Betula papyrifera), was determined (5.4–5.5 kcal/g dry wt). When esophageal diverticulae are full (2.0 g wet wt) of birch seeds, the resulting energy yield may sustain an individual for only a fraction of a 24 h winter day in contrast to other arctic herbivores (e.g. ptarmigan, Lagopus sp.) in which a full crop may suffice for the full 24 h period.  相似文献   

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Terrestrial and aerial populations of L. cerealium were studied simultaneously; ovarian dissections were made to detect different generations. The annual life cycle can be arbitrarily divided into six stages based primarily on the amount of flight activity: the females feed mainly on winter cereals and grasses in spring, many moving to later sown cereals in June and July, where most eggs are laid in the sheaths of the young leaves. First generation females leave cereals in August to feed on grasses before entering hibernation.Wheat ears with a water content of less that approx. 45% were not favoured by thrips. When winds blew consistently from the same quarter the initial infestation was greatest on the windward edge of the wheat crop.
Sommaire Les populations terrestres et aériennes de l'espèce L. cerealium (Thysanoptères) étaient étudiées simultanément: des dissections ovariques étaient faites pour discerner les générations différentes. On peut arbitrairement diviser la vie de ces insectes en six périodes, basées principalement sur l'activité aérienne: au printemps les femelles se nourrissent pour la plupart d'herbes et de céréales d'hiver; en juin et juillet beaucoup d'elles passent sur les céréales de printemps, où elles pondent la plupart des oeufs dans les gaines des jeunes feuilles. Les femelles de la première génération laissent les céréales en aôut pour se nourrir d'herbes avant d'hiverner.Les Thysanoptères abandonnaient les épis dont la teneur en eau était approximativement moins de quarante-cinq pour cent. Quand le vent soufflait constamment du même côté l'infestation initiale était plus forte au bord du champ qui se trouvait exposé au vent.
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In this article, I argue that human social behavior is a product of the coevolution of human biology and culture. While critical of attempts by anthropologists to explain cultural practices as if they were independent of the ability of individual human beings to survive and reproduce, I am also leery of attempts by biologists to explain the consistencies between neo-Darwinian theory and cultural behavior as the result of natural selection for that behavior. Instead, I propose that both biological and cultural attributes of human beings result to a large degree from the selective retention of traits that enhance the inclusive fitnesses of individuals in their environments. Aspects of human biology and culture may be adaptive in the same sense despite differences between the mechanisms of selection and regardless of their relative importance in the evolution of a trait. The old idea that organic and cultural evolution are complementary can thus be used to provide new explanations for why people do what they do.This article was prepared from remarks I presented at the Smithsonian Conference on Human Biogeography in April 1974. Help with phenotypic costs came from an NSF Pre-doctoral Fellowship and the University of Michigan Society of Fellows.  相似文献   

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R. J. Safford 《Ostrich》2013,84(2-4):58-67
Safford, R.J. 1997. The annual cycle and breeding behaviour of the Mauritius Fody Foudia rubra. Ostrich 68 (24): 58–67.

The Mauritius Fody Foudia rubra, a highly endangered species of weaver (Ploceidae) endemic to Mauritius, was studied from 1989–1993. The plumage, various display postures (typical of the family), and seven adult and two juvenile vocalisations are described. The diet consisted of insects, nectar and fruit. Males were in breeding plumage, and breeding took place, between late August and early April, although severe weather in February 1992 terminated breeding activity early. The species appeared to be monogamous and was suspected to maintain a long-term pair bond. Pairs occupied exclusive territories of not less than 0.9 ha. Both sexes built the nest from the outset, but only the female lined it. Between breeding attempts, some pairs habitually started but then abandoned one or more nests. Clutch sizes of two to four were recorded, three being the norm. Incubation and brooding were carried out by the female; the male joined in feeding the young after daytime brooding ceased. Juvenile dependency appeared to last around two weeks after which the young were ousted from the territory. The potential productivity of up to three broods per pair per year was not achieved by any pair studied because of poor nesting success. A complete moult followed breeding. Territorial defence continued throughout the year, and no evidence for seasonal movements was seen. Two behavioural features seem unexpected: 1) male nest invitation and nest advertisement behaviour appeared to be absent; 2) females participated from the outset of nest-building (including prospecting). These could be explained by the existence of a long-term pair bond, which needs to be confirmed but would not be surprising in a species that remains on territory all year. Hypotheses that could be tested to find a mechanism responsible for the unusual features of the fody are suggested. In comparison with other fodies studied, the breeding behaviour most resembled that of the Seychelles Fody F. sechellarum (also a monogamous, non-graminivorous omnivore that breeds in solitary pairs in evergreen forest). The annual cycle was similar to that of other native passerines and most other fody taxa.  相似文献   

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This study replicated Kleinman's research on family-based popular health care in Taiwan among the Puyallup Indians of Washington. Standardized interviews were conducted among 80 Puyallup families to determine family health practices and beliefs, and the patterns of referral to professional practitioners. Comparisons are made between the Puyallup and Taiwanese family health care practices and health care seeking processes. The author concludes that the relative absence of folk medicine and the availability of free medical care among the Puyallup are the most important factors causing the variance between the rates of family treatment and the patterns of health care seeking behaviors between the Puyallup and the Taiwanese.  相似文献   

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Does moral culture contribute to the evolution of cooperation? Here, we examine individuals' and communities' models of what it means to be good and bad and how they correspond to corollary behavior across a variety of socioecological contexts. Our sample includes over 600 people from eight different field sites that include foragers, horticulturalists, herders, and the fully market-reliant. We first examine the universals and particulars of explicit moral models. We then use these moral models to assess their role in the outcome of an economic experiment designed to detect systematic, dishonest rule-breaking favoritism. We show that individuals are slightly more inclined to play by the rules when their moral models include the task-relevant virtues of “honesty” and “dishonesty.” We also find that religious beliefs are better predictors of honest play than these virtues. The predictive power of these values' and beliefs' local prevalence, however, remains inconclusive. In summary, we find that religious beliefs and moral models may help promote honest behavior that may widen the breadth of human cooperation.  相似文献   

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The annual cycle of glycogen in estuarine benthic animals   总被引:1,自引:0,他引:1  
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A population-based hospital survey of 3628 women in the postpartum period was conducted in the Ottawa-Carleton region in 1983 to determine the prevalence of smoking before and during pregnancy, the demographic and socioeconomic characteristics of women who smoke during pregnancy and the use of health care services by these women. Of the 3628 women 91% completed a full-length questionnaire and 4% completed a shorter questionnaire. Before pregnancy 37.4% of the women smoked cigarettes. Overall, 61.1% of the smokers changed their smoking habit: 31.1% stopped, 28.1% decreased the amount smoked and 2.0% increased the amount smoked. Two thirds of the women who stopped smoking did so as soon as they realized they were pregnant. Over 50% of teenagers, single women, women living common-law and women with less than a grade 11 education smoked after the 3rd month of pregnancy. The physician is in an ideal position to identify as soon as possible pregnant women who smoke and to initiate a health education program. Only a few women who smoked during pregnancy attended early prenatal classes. Physicians and class organizers must work to improve this situation if such classes are to have an impact on smoking during pregnancy.  相似文献   

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A. J. F. K. CRAIG 《Ibis》1996,138(3):448-454
Moult, breeding and seasonal occurrence of the Wattled Starling Creatophora cinerea throughout its range in Africa are reviewed based on data from museum specimens and the published literature. Neither moult nor breeding follows a rigid seasonal pattern, although there are some regional differences, and overlap between moult and breeding is unlikely. The regular occurrence of interrupted wing-moult may be associated with nomadic movements rather than opportunistic breeding.  相似文献   

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Jill Rafuse 《CMAJ》1995,153(3):321
The CMA Board of Directors has taken the unprecedented step of organizing a series of strategic-issue sessions focusing on the future of health and health care. They will be held during the annual meeting Aug. 13-16. The objective is to establish a set of principles that will guide the board in developing short- and midterm policies and give direction for a CMA action plan dealing with the future Canadian health care system.  相似文献   

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Studies in birds show that testosterone (T) concentrations vary over the annual cycle depending on mating system and life history traits. Socially monogamous species show pairing behavior throughout the year and low levels of male-male aggression and are underrepresented in these studies, yet the function of testosterone could be particularly important for sexual and social interactions occurring outside the breeding season. We measured fecal T concentrations over the annual cycle and the frequency of interactions between male and female downy woodpeckers (Picoides pubescens) from late fall through early spring. We validated the fecal assay by collecting blood in conjunction with a subsample of our fecal samples: fecal T correlated with circulating levels in the blood. The annual peak level of T in males was relatively low and short-lived, similar to that of other bird species with low levels of male-male aggression and high paternal care. The annual cycle of female T resembled the male pattern, and the ratio of male T to female T was close to 1.0. Likewise, the frequency of aggression among females was similar to the frequency among males. Overall, testosterone levels in both sexes were variable, even in winter. In other bird species, sexual behavior during nonbreeding periods correlates with circulating levels of T in males. Based on this observation, we tested the hypothesis that T in winter was positively related to the frequency of interaction between mated downy woodpeckers. The results showed no such relationship. We discuss this finding and further relate the annual cycle of T in both males and females to behaviors that appear to facilitate mate choice and retention of the pair bond during conspecific challenge.  相似文献   

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Ntiamoa-Baidu, Y. & Nuoh, A. A. 2000. The role of the Ghana coast in the annual cycle of migratory terns. Ostrich 71 (1 & 2): 183.

Data are presented on counts of migratory terns on the Ghana coast over a ten-year period, 1986–1996. Fourteen species of terns were recorded during the period. Influx of terns begins in late August, peaking in September/October, with the highest likelihood of tern occurrence on the Ghana coast recorded in August-November and April-May. Terns fed mostly offshore and used the coastal lagoons as roosting sites, although a few species e.g. Black Tern Chlidonias niger and Little Tern Sterna albifrons, foraged also on the lagoons. Two sites, Songor Lagoon and Densu Delta, regularly held over 50 % of the total count recorded for all sites. A comparison of the day-time counts with dusk roost counts indicate that the day time counts under-represent the total numbers of terns using the Ghana coast. Trends in the populations of the four most abundant tern species: Black Tern, Common Tern Sterna hirundo, Sandwich Tern S. sandvicensis and Royal Tern S. maxima, are analysed; and the implications for conservation of the species are discussed.  相似文献   

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The purpose of this study was to examine the relationships among exercise behavior, the ability to live independently as assessed by functional activities of daily living (ADL), and psychological health as measured by the Philadelphia Geriatric Center morale scale, using data from 202 elderly residents aged 70 and living in their own home. The main results obtained from the analysis were as follows. 1. Exercise behavior had a significant effect on functional ADL. In particular, subjects who had been exercising regularly for 6 months or longer had higher functional ADL than subjects who did not exercise. 2. For psychological health, the functional ADL level was statistically significant, whereas exercise behavior was not. 3. Multiple regression analysis showed a positive and significant association between psychological health and functional ADL, but not between psychological health and exercise behavior, gender or family type. The results of this study demonstrated that elderly people's efforts to maintain and enhance their psychological health play important roles in their ability to live independently, and that regular exercise is necessary to an elderly person's ability to live independently.  相似文献   

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