Polygyny and the breeding success of the great reed warblerAcrocephalus arundinaceus

Summary Settlement date, mating status, and breeding success of individually marked great reed warblers,Acrocephalus arundinaceus, were studied during the 1980–84 breeding seasons in Kahokugata, Ishikawa Prefecture, Japan. Twenty-five per cent of the territorial males were polygynous, of which the majority were bigamous. The settling periods of both sexes were long, extending for 65 days in males and 49 days in females. About 80% of males and females settled in the first half of the settling period, and the settlement date of 28–54% males overlapped with that of females. Many of the late settlers were bachelors and the males which mated earlier tended to be polygynous. The timing of a male's settlement is important in acquiring mates. Fifty-five per cent of eggs laid were lost before fledging, mainly due to predation. The mean number of fledglings was 3.19 per primary female, 2.41 per secondary female, and 2.80 per monogamous female. Comparison of the number of fledglings of females which mated during the same period showed that the presence of another female in the same territory did not adversely affect the breeding success of either of the polygynous females. Polygynous males have the advantage of decreasing the risk of breeding failure under high predation pressure.     

An introduction experiment of an herbivorous lady beetle: Characteristics of the adult population

In May 1971, 45 adults of an herbivorous lady beetleEpilachna niponica (Coleoptera: Coccinellidae) from Asiu Experimental Forest were introduced into a botanical garden of Kyoto University, where is 10 km south of the southern limits of its distribution with being 3–5°C warmer than the original site. The introduced population of the lady beetle was thus investigated from 1975 to 1981. Mark-release-recapture experiments were applied to individual adult beetles, to estimate population size and daily survival rate. Overwintering adults emerged from hibernation around early April, reaching peak numbers in late April to early May, then gradually declined to late June. No adults remained at the end of June. Adult survival was maintained at a high level to early May, and declined consistently until late in the reproductive season. New adults began to emerge in late June and quickly reached a peak in early July; thereafter they decreased in number and had entered hibernation by late October. In spite of seasonally deteriorating food resources and heat stress in summer, new adults showed moderately high survival during the inimical period. New adults which emerged later in the season tended to be smaller in body size than those that emerged early. The proportion of females in the new adult population gradually increased throughout the pre-hibernating period, suggesting that male-biased mortality occurred during this period. When compared to the source population, the introduced population had a higher rate of population growth. Coupled with the improved population growth, heavy leaf damage during the larval period suggested that intensive intraspecific competition was most likely to occur among larvae in the introduced population.     

A male fitness advantage to wing reduction in the oriental chinch bug,Cavelerius saccharivorus okajima (heteroptera: Lygaeidae)

Summary A male fitness advantage to wing reduction was investigated for the oriental chinch bug,Cavelerius saccharivorus, which is wing dimorphic. Field surveys for the frequency of matings between wing morphs showed that the mating probability was much higher in brachypterous males than in macropterous males in the early breeding season. Brachypterous males copulated with not only brachypterous females but also macropterous females in this season. This led to a considerable rate (30%) of insemination of macropterous females just before emigration even in the early breeding season. A rearing experiment for the pre-reproductive period of females revealed that females mated with brachypterous males copulated and oviposited earlier than females mated with macropterous males. These results indicate that there is a fitness advantage to wing reduction in the males ofC. saccharivorus in terms of the earlier sexual maturation.     

跨国移民与学缘网络——以日本D大学中国人研究者为个案

国际移民的研究中一直以关注移民的文化适应、移民与移入地居民的互动、移民网络的建构及移民社区的形成为主流,但是当今世界的国际移民群体已经发生了分化．不仅存在低人力资本的国际移民,同样存在着高人力资本的移民,他们的受教育程度、社会经济地位普遍高于移人地居民,本研究通过70个样本的个案研究发现,在他们的国际移民实践中,对血缘和地缘网络的依赖程度十分有限,他们更热衷于构建跨越区域空间的学缘网络、这不仅成为他们孤独的移民生活的情感寄托,也成为他们职业发展的需要。     

Demographic attributes of an introduced herbivorous lady beetle

Demographic attributes of the adults of an introduced herbivorous lady beetleEpilachna niponica (Coleoptera: Coccinellidae) were investigated from 1975 to 1981 in the Botanical Garden of Kyoto University. Population growth rate varied from 4.8 to 16.8 throughout the study period. Fecundity and mortality in the late larval period contributed most to annual changes in the population growth rate. Population growth rate was negatively correlated with the density of overwintering adults. Adult survival from emergence to the reproductive season, which varied from 0.03 to 0.36 throughout the study, was almost completely determined by survival during the pre-hibernation period. Adult survival to the preproductive season changed in a size- and sex-dependent manner. Larger adults survived better than smaller individuals; male-biased mortality occurred from adult emergence to the reproductive age. Severe intraspecific competition among late instar larvae due to host plant defoliation produced a higher proportion of small-sized adults, resulting in lower adult survival to hibernation. The introduced population had a higher population growth rate and a lower adult survival to the reproductive season than the source population.     

Kin-related social organization in a winter population of the voleClethrionomys rufocanus

Kinship amongClethrionomys rufocanus was investigated during the winter of 1992/93 in a 3-ha enclosure using both molecular and catch-mark-release techniques. Forty-six adult voles (22 males and 24 females) having high heterozygosities, which were collected from several natural populations, were released into the enclosure on 29 September 1992. Most fall-born individuals of both sexes stayed in their natal site during the non-breeding period (December–March), although reproductively active females dispersed during the fall breeding season (October–November). These philopatric individuals aggregated and formed an maternal family in the winter. Several females which failed to reproduce were solitary during this season. Some individuals which were derived from several families also aggregated into a mixed lineage group. Survival rate of fall-born voles from earlier litters was higher than that from later ones. Maternal families broke up soon after the onset of spring reproduction. Most females established a territory near the wintering site and made a kincluster, in which close relatives neighbored each other. Maternal families in winter bring about female kin-clusters in spring, which may influence reproductive output in the breeding season.     

Social organization of the voleClethrionomys rufocanus and its demographic and genetic consequences: A review

Recent findings on the relationship between social interaction and demographic process in the gray-sided voleClethrionomys rufocanus are reviewed with reference to the findings in other microtine rodents. Social behavior was particularly focused on spacing and dispersal, and their effects on population dynamics are discussed. Female territoriality can limit a population abundance as a density-dependent factor, although its regulatory effect is controversial. Female philopatry and male-biased dispersal should bring about the clumped distribution of female relatives and genetically random distribution of males during the breeding season. The sexual difference in dispersal patterns can contribute to the mating behavior of the vole; promiscuous mating and low frequency of incestuous mating. However, effects of social structure, including kinship, on reproduction and survival of individuals still remains to be clarified. Molecular markers may help to solve these issues and provide new field of population ecology in microtine rodents.     

Sex change and spatial distribution pattern in an intertidal holothurian Polycheira rufescens in the reproductive season

The patterns of sex change and spatial distribution in an intertidal holothurian, Polycheira rufescens (Chiridotidae; Echinodermata), were investigated on a stony beach in Amakusa, western Kyushu. Field caging experiments revealed that some individuals of P. rufescens underwent a sequential sex change from male to female via hermaphrodite stages and back to male again within a single reproductive season. The sex ratio of the population gradually changed from male dominance at first to equal proportions of males and females as the reproductive season progressed. Toward the end of the reproductive season, immature or spent individuals increased in proportion. Stone size appeared to be an important factor affecting the occurrence of P. rufescens individuals on a stony beach. Analysis of spatial distribution by means of Morisita's index of dispersion and nearest neighbor distances indicated that (i) males showed a slightly stronger tendency to aggregate than females, while females had a tendency toward uniform distribution; (ii) females tended to attract males, as shown by relatively short female-to-male distances; and (iii) there was a substantial variation in male-to-female distances, such that some males were positioned close to females while others were not. It may be suggested that spatial distribution of P. rufescens individuals during the reproductive period is partly dictated by the differential needs of individuals of different sexual states. Received: January 25, 1999 / Accepted: June 10, 1999     

中国超大城市常住外来和常住户籍人口居住－就业的空间错位--基于北京、上海和广州的实证

以北京、上海、广州作为中国超大城市的代表,探讨中国超大城市常住外来和常住户籍人口居住－就业空间错位的差异及其影响因素。总体而言,常住外来人口的居住－就业空间错位要高于常住户籍人口,且不同户籍属性人口的错位形态存在差异。分行业来看,公共管理和社会组织等公共服务业常住外来人口居住－就业空间错位程度相对较高,而制造业、居民服务和其他服务业常住户籍人口居住－就业空间错位程度相对较高。由计量分析发现,住房价格水平、就业集聚规模、高端产业比重和地区地方财政支出对不同户籍属性人口就业－居住空间分布差异均产生相似的影响;而租赁户数比重和低端产业比重对不同户籍属性人口的就业－居住空间分布则产生差异性的影响。     

A statistical analysis of the life expectancy of the residents of our country, 1973-75]

Statistical analysis of life expectancy is important in assessing population health and its characteristics and in studying human diseases and natural population changes. Life tables are constructed and statistical analysis is performed retrospectively on data accumulated over a 3-year (1973-1975) period. The data were supplied by the Office of Cancer Prevention and Treatment of the Ministry of Health, which originated from 24 provinces, representing an accumulated population of 2.04 billion, with a total mortality of 15.29 million. Results show that life expectancy in China has greatly improved since Liberation. Thus, in 1935, the average life expectancy for Nanjing residents was under 35 years. In 1951, the average life expectancy for male and female residents of Shanghai were 42.74 and 46.76 years respectively. But for the 1973-1975 period, the average Chinese life expectancy was 63.62 years for males and 66.31 years for females, with higher life expectancy for coastal provinces than for inland provinces. Cardiovascular diseases (excluding arteriosclerotic heart diseases), malignant tumors, and cerebrovascular diseases were the major causes of death in regions with higher life expectancy, while respiratory diseases, infectious diseases, and diseases of the newborn were the major causes of death in regions with lower life expectancy.     

Reproductive behavior of the Japanese treefrog,Rhacophorus arboreus (Anura: Rhacophoridae)

Reproductive behavior of the foam-nesting treefrog,Rhacophorus arboreus, is described. Oviposition was made either by an amplectant pair (a female, and an amplectant male) alone or by an amplectant pair and other males (joiners). The snout-vent length of males and females was negatively correlated with the date of the first appearance in the pond. The period of staying in the pond in males was longer than that in females. Physical body contacts of other males, and encounter calls by ampletant males were frequently observed before oviposition with joiners. Snout-vent length of the female and an amplectant male were positively correlated. Encounter calls by amplectant males were likely to precede movement of females. There was no difference of snout-vent length between amplectant males and joiners. Females moved the hindlimbs more frequently than males during oviposition. Amplectant males made encounter cells more frequently in oviposition with joiners, than oviposition without joiners. The patterns of transitions between acts of females and amplectant males were similar between oviposition with and without joiners. Females more frequently responded to amplectant males than joiners. Both the duration of a bout of the movements of hindlimbs of females and the interval between the bouts were longer in oviposition without joiners than that with joiners. The number of the movements per bout in oviposition without joiners was smaller than that with joiners. Encounter calls by amplectant males during oviposition tended to precede the hindlimb movements of females.     

Adult populations of the sugi bark borer,Semanotus japonicus Lacordaire (Coleoptera: Cerambycidae), in Japanese cedar stands: Population parameters, dispersal, and spatial distribution

Summary Adult populations of the sugi bark borer,Semanotus japonicus Lacordaire, which attacks the trunks of Japanese cedar and cypress, were studied in two cedar stands in 1981 and 1984, using a band-trapping method developed by the author. Adults began to emerge and fly earlier in 1981 than in 1984 because of the higher temperature after hibernation in 1981. Population size wasestimated by a markrelease-recapture method. The daily survival rate ranged from 0.86 to 0.92 and the mean longevity from 7.0 to 11.9 days. Females were fewer than males throughout the season, especially early in the flight period, because males consistently emerged earlier. The mean distances traversed among the cedar trees were 9.2 m for males and 16.3 m for females; maximum dispersal was 79.5 m for males, 149.5 m for females. There are two different patterns in their dispersal movement: the small-scale movement which consists of walking at cool temperatures and large-scale flight at warm temperatures. Adults of this species are somewhat sluggish and between-tree movement is infrequent. This lack of movement resulted in a contagious distribution pattern of adults.     

Legalization and human capital accumulation

This paper presents new evidence regarding the effects of legalization on the training of immigrants who were granted legal status through the US Immigration Reform and Control Act (IRCA) of 1986. Our findings point to a large increase in the immigrants’ incidence of training relative to comparable groups of natives following legalization. While training gains are higher for males, wage gains are higher for females. We also show that an important part of these changes in labor market outcomes occurs through occupation changes by newly legalized immigrants.     

Emigration from Canada in the 1960s

Summary Emigration from Canada can be assessed only by indirect means. Here, survival ratios have been applied to the total population enumerated in the 1961 Census and to particular segments of it, so that a comparison of the calculated numbers in 1971 with the population actually enumerated indicates the volume of emigration during the decade, both in the whole population and in certain groups. Amounting to two-thirds of the number of immigrants during the same period, the estimate for the ten years is exactly double the volume of emigration reported to the Joint Parliamentary Committee on immigration policy of 1975. Since 1971, the level of emigration has probably fallen. Of the 960,000 emigrants during the decade, 42 per cent were Canadian-born. Their favourite destination was the United States; immigrants, on the other hand, tended to return home. Many immigrants now stay in Canada for only a few years. Fewer Canadians emigrate to the United States. These two factors have contributed to a new pattern of emigration, up-to-date details of which will not be ascertained before the Census of 1981.     

Gender as a Moderator of the Relation Among Social Support Functions and Life Satisfaction in Older Malaysians

The aim of this study was to examine the moderating role of gender on relations among social support functions and life satisfaction in older Malaysians. The study sample was 1,800 older residents in a community; all were at least 60 years old. This study was a cross-sectional and corelational survey, and the data were collected by multistage stratified sampling. This study revealed that fewer social support functions, and therefore less life satisfaction, were available for females than for males. The results of moderated regression analyses demonstrated that gender interacted only on the relationship between positive social interaction support and tangible support with life satisfaction. Specifically, at a high tangible support level, females had lower life satisfaction when compared to a low tangible support level. There may be a need for new programs and services to provide other aspects of social support to older female adults to improve and maintain life satisfaction in later life.     

Evidence for and against the 'double penalty' thesis in the science and engineering fields

This study examines how race and gender affect the economic status of scientists and engineers. Using data from the 1989 Survey of Natural and Social Scientists and Engineers, the wage rates of minority females are compared with those of white males, white females, and minority males for the native-born population and immigrants. The results reveal Asian women's parity with white men in some contexts. Economic discrimination holds up for black and white women only. There is also evidence that institutional contexts affect men and women with similar characteristics in different ways. The findings challenge the claim for universalism but offer some support for the discipline-dependence hypothesis.     

A Concept Mapping Study on Social Inclusion in Hong Kong

A focus group study involving concept mapping was conducted in September 2012 to investigate how the concept of social inclusion was understood by Hong Kong residents. It was a replication of an earlier UK study. Seven groups involving 61 participants (38 females; 23 males) were interviewed, including non-professional workers at a Non-government Organisation service, senior centre users, a mixed group of community residents, people with severe mental illness, professional social service providers, communication studies students, and social work students. Data analysis using Nvivo 10 and systematic thematic analysis identified six major themes including: (1) material resources and wealth, (2) work, (3) social (dis)harmony and diversity, (4) discrimination, (5) communication, and (6) participation in activities. An overall final model of Social Inclusion for Hong Kong based on concept maps for all seven groups is presented. The results will inform the conceptualisation and development of a Chinese-language measure of social inclusion (SCOPE-C) based on translation and cultural adaption of the Social and Community Opportunities Profile (SCOPE) developed in UK.     

Social networks and the labour market mismatch

This paper assesses the extent to which social contacts and ethnic concentration affect the education-occupation mismatch of natives and immigrants. Using Australian panel data and employing a dynamic random effects probit model, we show that social capital exacerbates the incidence of over-education, particularly for females. Furthermore, for the foreign born, ethnic concentration significantly increases the incidence of over-education. Using an Alternative Index, we also show that social participation, friends and support and ethnic concentration are the main contributors in generating a mismatch, while reciprocity and trust does not seem to have any effect on over-education for both, immigrants and natives. Finally, we show that social networks are more beneficial for the relatively better educated.     

晚清东北地区人口婚姻状况探析

晚清时期,东北地区人口婚姻带有地域特色:已婚人口中女性婚配人口多于男性,婚龄普遍为早婚,且男小女大;未婚人口中,男性多于女性;男女终身不嫁的不婚人口很少,但男性较多;丧偶人口中,守寡女性占据绝大多数,鳏夫续娶较多,寡妇再嫁则很少;离婚人口中,有休妻、出妻等绝婚现象,但离婚人口很少。种种婚姻状况,主要是由于东北民族婚俗与陋习、东北移民人口的社会、经济状况决定的。     

The Subjective Well-Being of Immigrants: Pre- and Post-migration

In recent years, migration studies have increasingly shown that subjective well-being carries considerable weight in immigrant integration. Yet little is known about the subjective well-being of immigrants in their origin country (pre-migration) or its relation to their well-being in the host country. This paper examines the relationship between subjective well-being, both pre- and post-immigration, among North Americans who arrived in Israel during the past two decades. The study combines both quantitative and qualitative research methods. According to our quantitative findings, the labor market performance of North American immigrants in Israel is lower than in their origin countries. Further, we learned from the qualitative analysis that although the immigrants’ positions in the labor market were better in their origin countries, the immigrants perceived their standard of living in Israel to be the same as in their origin country—if not better—due to the low cost of services in Israel. The importance of the immigrant’s satisfaction from the current job in Israel was apparent in the findings of both methods. We also found that the subjective well-being of North American immigrants in Israel is relatively high, and most immigrants did not consider leaving Israel. The subjective well-being of the immigrants in Israel was found to be related to their social networks in their origin country, to their religious immigration motive and to their work satisfaction in Israel. The more supportive the immigrants’ families were of their decision to immigrate, the less the immigrants tended to consider leaving Israel. Immigrants with a religious motivation for immigrating to Israel were less inclined to leave, and the same was true for immigrants who were satisfied with their work in Israel. The qualitative data added important perspective on the immigrants’ social networks, this time in Israel. Interviewees reported having more supportive social networks in Israel, and a greater sense of community, although most of their contacts were within the Anglo community.