Are female-headed households energy efficient: A test of Klausner's hypothesis among Anglo,Spanish-speaking,and black texas households

Klausner has hypothesized that female-headed households are less efficient in the use of energy than male-headed households because they are less disciplined and ordered. The present study used multivariate analyses to determine whether female-headed households were less efficient in the use of electrical energy than male-headed households in a representative sample of 4638 Anglo, Spanish-speaking, and black homeowning Texas households. The results indicated that, after controlling for the effects of other variables known to affect the use of electricity, sex of household head had nostatistically significant independent effect on electricity consumption in any ethnic or marital status group. The authors compare their results to those obtained by Klausner and discuss implications for social organizational theory of household energy consumption.     

Child nutrition in the transition from nomadic pastoralism to settled lifestyles: individual, household, and community-level factors

The research reported here examines child nutrition in a population that is currently experiencing a transition in subsistence, shifting from nomadic pastoralism to a variety of settled lifestyles. We investigate the range of nutritional consequences of settlement both within and between communities by examining individual, household, and community-level predictors of child nutritional status. Data are drawn from the Rendille Demographic and Health Survey, which contains anthropometric data from 1,088 children ages 6 months to 10 years, as well as socioeconomic data from 640 households drawn from one nomadic and four economically and ecologically diverse settled communities. Comparisons allow us to test the widely held assumption that settlement results in nutritional improvements. The examination of individual and household-level factors highlights several important influences on child nutrition. We find a complex interaction between gender and birthorder, whereby firstborn sons have significantly higher weight-for-height scores than other children, potentially reflecting preference under a system of primogeniture. We also find a complex interaction between defacto female-headed households, where males are absent for over half of the year, and economic status. Young children from poor female-headed households have significantly lower weight-for-height than other children, possibly due to the fact that these households are amongst the poorest in the entire community. However, young children from economically sufficient female-headed households actually fare better than their counterparts in male headed households, suggesting that in households with any discretionary resources, female heads prioritize food acquisition relative to other concerns. Finally, our comparison of child nutritional status across communities, while controlling for individual and household-level variation, does not support the contention that settlement is associated with nutritional improvements. Rather, the effect of community, and its associated changes in subsistence and lifestyle, results in either no nutritional changes, or in the case of young children in the lowland desert community of Korr, diminished nutritional status. Our results underscore the importance of considering variation in sample composition and socioeconomic status when performing community comparisons, and highlight the central role of women in influencing the nutritional welfare of their families.     

Prevalence and Correlates of Food Insecurity among Palestinian Refugees in Lebanon: Data from a Household Survey

Lebanon hosts the highest per capita refugee concentration worldwide. The Palestinian presence in Lebanon dates from 1948 and they remain a marginalized population. No information on their food security status has been reported previously. A survey of a representative sample of Palestinian refugee households in Lebanon (n = 2501) was conducted using a stratified two stage cluster sampling approach. We measured food insecurity using a modified USDA household food security module, locally validated. We collected data on household demographic, socioeconomic, health, housing, coping strategies and household intake of food groups and analysed these by food security status. About 41% (CI: 39-43) of households reported being food insecure and 20% (CI: 18-22) severely food insecure. Poor households were more likely to be severely food insecure (OR 1.41 (1.06-1.86)) while higher education of the head of household was significantly associated with protection against severe food insecurity (OR 0.66 (0.52-0.84)). Additionally, higher food expenditure and possession of food-related assets were significantly associated with food security (OR 0.93 (0.89-0.97) and OR 0.74 (0.59-0.92), respectively). After adjusting for confounders, households where at least one member suffered from an acute illness remained significantly more likely to be severely food insecure (OR 1.31(1.02-1.66)), as were households whose proxy respondent reported poor mental health (OR 2.64 (2.07-3.38)) and poor self-reported health (OR 1.62 (1.22-2.13). Severely food insecure households were more likely to eat cheaper foods when compared to non-severely food insecure households (p<0.001) and were more likely to rely on gifts (p<0.001) or welfare (p<0.001). They were also more likely to have exhausted all coping strategies, indicating significantly more frequently that they could not do anything (p = 0.0102). Food insecurity is a significant problem among Palestinian refugees in Lebanon and is likely to be exacerbated at this time when the Syrian crisis amplifies the problem.     

Ethnobotanical Knowledge and Crop Diversity in Swidden Fields: A Study in a Native Amazonian Society

Crop diversity protects food consumption in poor households within developing nations. Here we estimate the association between crop diversity on swidden fields and ethnobotanical knowledge. We conducted research among 215 male household heads from a native Amazonian society. Using multivariate regressions, we found higher crop diversity among households that depend on agricultural production for household consumption. We also found a statistically significant and positive, but low, association between the ethnobotanical knowledge of the male household head and crop diversity. Doubling the stock of ethnobotanical knowledge of the male household head is associated with a 9% increase in the number of crops sown by a household. The association remained after we controlled for the household level of market exposure, but vanished after we controlled for the social capital of the male household head. Future research should compare the association between ethnobotanical knowledge and crop diversity across different agricultural systems (i.e., home gardens, fallow fields).     

Biodiversity and Nutrition in Rice-Based Ecosystems; the Case of Lao PDR

This paper presents results from a year-long household survey in which the aquatic resource collection and consumption activities of 240 households across Lao PDR were studied to assess the diversity of species used, their role in household food security and the overall importance of ricefield habitats in this respect. Results show that aquatic biodiversity, under threat in rice-based ecosystems, plays a larger role in household consumption than previous estimates. More than 90 % of these resources are collected by households themselves and the greatest quantities from ricefield habitats. This seasonal aquatic environment is therefore the principal habitat from which households acquire aquatic animals, both to eat fresh and to process and store for use during nutritionally vulnerable times of year. The importance of these habitats therefore goes far beyond their use for rice production and this multi-functionality needs to be understood and addressed in agricultural, conservation and food security policy.     

The Geography of Gender Inequality

Reducing gender inequality is a major policy concern worldwide, and one of the Sustainable Development Goals. However, our understanding of the magnitude and spatial distribution of gender inequality results either from limited-scale case studies or from national-level statistics. Here, we produce the first high resolution map of gender inequality by analyzing over 689,000 households in 47 countries. Across these countries, we find that male-headed households have, on average, 13% more asset wealth and 303% more land for agriculture than do female-headed households. However, this aggregate global result masks a high degree of spatial heterogeneity, with bands of both high inequality and high equality apparent in countries and regions of the world. Further, areas where inequality is highest when measured by land ownership generally are not the same areas that have high inequality as measured by asset wealth. Our metrics of gender inequality in land and wealth are not strongly correlated with existing metrics of poverty, development, and income inequality, and therefore provide new information to increase the understanding of one critical dimension of poverty across the globe.     

Out-of-Pocket Payments,Health Care Access and Utilisation in South-Eastern Nigeria: A Gender Perspective

Out-of-pocket (OOP) payments have severe consequences for health care access and utilisation and are especially catastrophic for the poor. Although women comprise the majority of the poor in Nigeria and globally, the implications of OOP payments for health care access from a gender perspective have received little attention. This study seeks to fill this gap by using a combination of quantitative and qualitative analysis to investigate the gendered impact of OOPs on healthcare utilisation in south-eastern Nigeria. 411 households were surveyed and six single-sex Focus Group Discussions conducted. This study confirmed the socioeconomic and demographic vulnerability of female-headed households (FHHs), which contributed to gender-based inter-household differences in healthcare access, cost burden, choices of healthcare providers, methods of funding healthcare and coping strategies. FHHs had higher cost burdens from seeking care and untreated morbidity than male-headed households (MHHs) with affordability as a reason for not seeking care. There is also a high utilisation of patent medicine vendors (PMVs) by both households (PMVs are drug vendors that are unregulated, likely to offer very low-quality treatment and do not have trained personnel). OOP payment was predominantly the means of healthcare payment for both households, and households spoke of the difficulties associated with repaying health-related debt with implications for the medical poverty trap. It is recommended that the removal of user fees, introduction of prepayment schemes, and regulating PMVs be considered to improve access and provide protection against debt for FHHs and MHHs. The vulnerability of widows is of special concern and efforts to improve their healthcare access and broader efforts to empower should be encouraged for them and other poor households.     

The Effect of Gender and Social Capital on the Dual Burden of Malnutrition: A Multilevel Study in Indonesia

Introduction

The paradoxical phenomenon of the coexistence of overweight and underweight individuals in the same household, referred to as the “dual burden of malnutrition”, is a growing nutrition dilemma in low- and middle-income countries (LMICs).

Aims

The objectives of this study were (i) to examine the extent of the dual burden of malnutrition across different provinces in Indonesia and (ii) to determine how gender, community social capital, place of residency and other socio-economic factors affect the prevalence of the dual burden of malnutrition.

Methods

The current study utilized data from the fourth wave of the Indonesian Family Life Survey (IFLS) conducted between November 2007 and April 2008. The dataset contains information from 12,048 households and 45,306 individuals of all ages. This study focused on households with individuals over two years old. To account for the multilevel nature of the data, a multilevel multiple logistic regression was conducted.

Results

Approximately one-fifth of all households in Indonesia exhibited the dual burden of malnutrition, which was more prevalent among male-headed households, households with a high Socio-economic status (SES), and households in urban areas. Minimal variation in the dual burden of malnutrition was explained by the community level differences (<4%). Living in households with a higher SES resulted in higher odds of the dual burden of malnutrition but not among female-headed households and communities with the highest social capital.

Conclusion

To improve household health and reduce the inequality across different SES groups, this study emphasizes the inclusion of women''s empowerment and community social capital into intervention programs addressing the dual burden of malnutrition.     

Household factors influencing participation in bird feeding activity: a national scale analysis

Ameliorating pressures on the ecological condition of the wider landscape outside of protected areas is a key focus of conservation initiatives in the developed world. In highly urbanized nations, domestic gardens can play a significant role in maintaining biodiversity and facilitating human-wildlife interactions, which benefit personal and societal health and well-being. The extent to which sociodemographic and socioeconomic factors are associated with engagement in wildlife gardening activities remain largely unresolved. Using two household-level survey datasets gathered from across Britain, we determine whether and how the socioeconomic background of a household influences participation in food provision for wild birds, the most popular and widespread form of human-wildlife interaction. A majority of households feed birds (64% across rural and urban areas in England, and 53% within five British study cities). House type, household size and the age of the head of the household were all important predictors of bird feeding, whereas gross annual household income, the occupation of the head of the household, and whether the house is owned or rented were not. In both surveys, the prevalence of bird feeding rose as house type became more detached and as the age of the head of the household increased. A clear, consistent pattern between households of varying size was less evident. When regularity of food provision was examined in the study cities, just 29% of households provided food at least once a week. The proportion of households regularly feeding birds was positively related to the age of the head of the household, but declined with gross annual income. As concerns grow about the lack of engagement between people and the natural environment, such findings are important if conservation organizations are successfully to promote public participation in wildlife gardening specifically and environmentally beneficial behaviour in society more generally.     

Garden Money Buys Grain: Food Procurement Patterns in a Malian Village

This study of a rural Malian community in West Africa investigates food procurement patterns that combine subsistence grain production with a variety of income generating activities. It finds dependence on food purchases widespread and revenue from the own-account activities of nonhousehold heads essential to food security. Gender and the wealth of households are found to influence some, but not all, income generating activities and expenditures. Three household food procurement profiles are identified: investment in cattle, market gardens and bush extraction, and remittances. The case study village has agroecological characteristics and market proximity, which set it and other urban hinterland villages apart from the more cotton- and cattle-based zones of southern Mali. Own-account income generating activities may be able to increase revenue for women and junior men through a reallocation of household resources without entirely undermining the basis for a larger subsistence-oriented household.     

Socioeconomic status and fertility in rural Bangladesh

Using a unique set of birth registration data from the Demographic Surveillance System of the International Center for Diarrheal Disease Research, Bangladesh, for the period 1974-77, and socioeconomic information collected in the 1974 census, fertility was studied in relation to occupation, size of dwelling, number of cows and number of boats owned. The total fertility rate was found to vary between 6 and 6.5 except in the famine year of 1975. There was no consistent relationship between fertility and education of women. The age-specific fertility rates by religion show that Muslims had higher fertility at all ages in 1974 and 1977 and at older ages in 1975 and 1976. Overall, however, fertility of Hindus is consistently lower than that of Muslims, but the relative differences are under 10%. Fertility differentials by occupation showed that the household heads who were farm laborers had relatively lower fertility compared to other occupational groups, except for the year 1977 where the families of service holders were found to have relatively lower fertility. Women in households whose heads were businessmen or farmers (owning their land) had above average fertility. In 1974, households in the business occupational groups had, on average, 1 birth more than other households. Women in households with fishermen as heads had below average fertility in 1974 and 1975, but very high fertility in 1976 and 1977. Fertility levels differed according to the type of household in which the family resided. Nuclear families had below average fertility up to the age of 35 and above average fertility at the end of the reproductive age. In the 15-19 age group, augmented families had higher fertility each year examined. The association between dwelling place and fertility is positive each year, the relative differences in fertility between the groups being largest in 1974. Positive relations were found between economic status and fertility.     

山地麻蜥个体发育过程中头部两性异形和食性的变化

研究了山地麻蜥(Eremias brenchleyi)个体发育过程中头部两性异形和食性的变化．成体个体大小(SVL)无显著的两性差异,但雄体具有较大的头部(头长和头宽)．头部两性异形在孵出幼体就已存在,成体头部两性异形比幼体(包括孵出幼体)更为显著,雄性较大的头部与其头部随SVL的增长速率大于雌性有关．两性头部总体上随SVL呈异速增长,表现为个体发育过程中头长和头宽与SVL的线性回归方程斜率有显著的变化．孵出幼体有相对较大的头部,这种形态特征是胚胎优先保证生态学意义更为显著的头部生长的结果,有利于孵出幼体的早期生存和生长．相对头部大小在个体发育过程中有显著的变化．不同性别和大小的山地麻蜥摄入食物的种类及各种食物在摄入食物中所占的比例有一定程度的差别,食物生态位宽度和重叠度因此有一定的差别．然而,没有直接的证据表明头部两性异形能导致两性食物生态位的明显分离,并有利于减缓两性个体对食物资源的竞争。     

Assessing the Impacts of Agrobiodiversity Maintenance on Food Security Among Farming Households in Sri Lanka’s Dry Zone

Farmers’ maintenance of agrobiodiversity is fundamental to global food security, particularly in a world increasingly affected by climate change. Biodiversity helps to buffer agroecosystems from stresses like climatic variability, and the crop genetic diversity conserved with biodiverse agroecosystems is critical for plant breeding both locally and globally. Yet, despite these benefits, few studies have directly assessed the implications of household–level agrobiodiversity maintenance on household food security. Drawing on survey data collected in Sri Lanka’s Hambantota District, we evaluated the plant diversity maintained by small–scale farming households in both homegardens and crop fields and determined the relationships between this diversity and their households’ food security. We also considered how a suite of additional demographic, household, community, and farm characteristics relate to both the plant diversity maintained by a household and their food security. Similar to previous studies, the age of the agricultural decision-maker and the age and size of households’ homegardens positively correlated with the overall species richness of farming systems. Older homegardens were also identified to be more evenly distributed in their species abundance, and market–oriented households had significantly higher species richness but lower Shannon Indices. Most notably, household socioeconomic status and material wealth were important to both agrobiodiversity maintenance and household food security, while no significant relationships between species richness and food security measures were detected. These findings suggest that effort aiming to increase the food security of small–scale farming households in Sri Lanka, and elsewhere, should target those farming households with a paucity of socioeconomic assets, as these households lack both agroecological and economic resources to overcome shocks, such as those associated with climate change.     

Impact of Illness and Medical Expenditure on Household Consumptions: A Survey in Western China

Background

The main goal of this study is to examine the associations between illness conditions and out-of-pocket medical expenditure with other types of household consumptions. In November and December of 2011, a survey was conducted in three cities in western China, namely Lan Zhou, Gui Lin and Xi An, and their surrounding rural areas.

Results

Information on demographics, income and consumption was collected on 2,899 households. Data analysis suggested that the presence of household members with chronic diseases was not associated with characteristics of households or household heads. The presence of inpatient treatments was significantly associated with the age of household head (p-value 0.03). The level of per capita medical expense was significantly associated with household size, presence of members younger than 18, older than 65, basic health insurance coverage, per capita income, and household head occupation. Adjusting for confounding effects, the presence of chronic diseases was negatively associated with the amount of basic consumption (p-value 0.02) and the percentage of basic consumption (p-value 0.01), but positively associated with the percentage of insurance expense (p-value 0.02). Medical expenditure was positively associated with all other types of consumptions, including basic, education, saving and investment, entertainment, insurance, durable goods, and alcohol/tobacco. It was negatively associated with the percentage of basic consumption, saving and investment, and insurance.

Conclusions

Early studies conducted in other Asian countries and rural China found negative associations between illness conditions and medical expenditure with other types of consumptions. This study was conducted in three major cities and surrounding areas in western China, which had not been well investigated in published literature. The observed consumption patterns were different from those in early studies, and the negative associations were not observed. This study may complement the existing rural studies and provide useful information on western Chinese cities.     

Cranial morphology and bite force in Chamaeleolis lizards--adaptations to molluscivory?

Anolis lizards have become a model system for the study of adaptive radiations as species with similar morphologies occupying similar habitats have arisen independently on all the larger islands in the Caribbean. However, on both, Cuba and Hispaniola unique forms have evolved that seemingly have no counterparts on any of the other Caribbean islands. Anoles of the genus Chamaeleolis comprise such a unique form and have been termed 'twig giants' because of their cryptic life style, slow locomotor mode, and short limbs. However, some of the most unusual features of these lizards are their large heads and molluscivorous diet. Here, we compare head shape, bite force, and muscle structure among sexes and age classes of Chamaeleolis lizards with Anolis crown giants. Our data show that Chamaeleolis lizards have a dramatically different head shape characterized by tall heads with a pronounced temporal ridge and long snouts. Analyses of bite force, surprisingly, show no differences between adult Chamaeleolis and Anolis crown giants. Juveniles of Chamaeleolis, however, have very tall heads for their size and bite harder than Anolis juveniles do. This can be related to the propensity of juveniles of this genus to eat snails, food items for which high bite forces are crucial. This observation is corroborated by the presence of well-developed jaw adductors in juveniles. Thus, our data suggest that the unusual phenotype of adults with large and tall heads may be due to selection on the juvenile life history stages.     

海南变色树蜥个体发育中形态和食性的变化

研究变色树蜥（Calotes versicolor)头,尾大小和食性在个体发育过程中的变化,以及头,尾大小两性异性的个体发生,成体体长（SVL）无显著的两性差异,两性异形主要表现为雄性个体有较大的头部（头长和头宽）和尾部。头,尾大小的两性异形在初生幼体就已存在,并随个体发育的进行变得更加显著。不同年龄组两性个体头长以及雌体头宽随SVL呈同速增长;雄性头宽随SVL呈异速增长,表现为雄性头宽的增长速率在个体发育过程中逐渐增大。头,尾部的相对大小在个体发育过程中有显著的变化,初生幼体头部相对较大,尾部相对较小,这种形态特征是胚胎优先保证生态学意义更为显著的部分（如头部）生长的结果,有利于初生幼体的早期生存和生长,不同性别和年龄组的变色树蜥摄入食物的种类及各种食物在摄入食物中所的比例有一定程度的差别,因而食物生态位宽度和重叠度有一定程度的差别,然而没有直接的证据表明头部大小的两性异形能导致两性食物生态位的明显分离。     

北京城市化进程中家庭食物碳消费动态

不可持续的家庭消费是造成全球环境问题的主要原因,食物碳消费研究是促进可持续家庭消费的重要内容。基于政府宏观统计数据,分析北京城市化进程中城市家庭食物碳消费的变化趋势和影响因素。结果表明,与1979年相比,1999年北京城市家庭人均及户均食物消费量分别减少了15.2%和38.6%,而食物碳消费总量增加了28.5%,食物碳消费结构由“以粮食为主”转变成“以粮食和肉类为主”。城市化进程中,以1993年为界,家庭食物人均及户均碳消费量均由明显减少趋势转变为明显增长趋势,变化的主要原因由“食物消费结构变化引起的人均谷物类碳消费量的减少”转变为“人均食物消费量增加引起的人均肉类碳消费量的增加”。北京城市家庭已基本完成食物消费结构的转变,人均食物消费量仍继续增加。GDP指数是影响人均食物碳消费量的主要经济因素,经济的继续增长可能带来人均食物碳消费量的增加,北京城市家庭食物碳消费尚未达到稳定状态。     

Barriers to insecticide-treated mosquito net possession 2 years after a mass free distribution campaign in Luangwa District, Zambia

Background and Methods

Roll Back Malaria set the goal of 100% of households in malaria endemic countries in Africa owning an insecticide-treated mosquito net (ITN) by 2010. Zambia has used mass free distribution campaigns and distribution through antenatal care (ANC) clinics to achieve high coverage.

Methodology and Principal Findings

We conducted a probability survey of 801 households in 2008 to assess factors associated with households that lacked an ITN after mass distribution. Community perceptions of barriers to ITN access were also obtained from in-depth interviews with household heads that reported not owning an ITN. Nearly 74% of households in Luangwa district reported owning ≥1 ITN. Logistic regression showed households without a child <5 years old during the ITN distribution campaigns were twice as likely to not have an ITN as those with a child <5 during distribution (Adjusted odds ratio (AOR)  = 2.43; 95% confidence interval (CI): 1.67–3.55). Households without a woman who attended an ANC in the past 2 years were more likely to be without ITNs compared to households with a woman who attended an ANC in the past 2 years (AOR  = 1.52; 95% CI: 1.04–2.21). In-depth interviews with heads of households without an ITN revealed that old age was a perceived barrier to receiving an ITN during distribution, and that ITNs wore out before they could be replaced.

Conclusions and Significance

Delivery of a large number of ITNs does not translate directly into 100% household coverage. Due to their design, current ITN distribution strategies may miss households occupied by the elderly and those without children or ANC access. ITN distribution strategies targeting the elderly, those with limited access to distribution points, and others most likely to be missed are necessary if 100% ITN coverage of households is to be achieved.     

The Importance of Bushmeat in the Livelihoods of West African Cash-Crop Farmers Living in a Faunally-Depleted Landscape

Bushmeat is an important resource in the livelihoods of many rural communities in sub-Saharan Africa and may be a crucial safety-net for the most vulnerable households, especially during times of economic hardship. However, little is known about the impacts of wildlife depletion on these functions. This study quantifies the role of bushmeat in diversified rural household economies in a wildlife depleted forest-farm landscape in Ghana, assessing its importance overall, as well as differentiated by the relative vulnerability of households. Using repeat socioeconomic questionnaires (N=787) among 63 households over a one-year period, the following hypotheses were tested: (a) vulnerable households harvest more bushmeat; (b) bushmeat contributes a greater proportion of household production in vulnerable households; (c) bushmeat is more important for cash income than consumption in vulnerable households; and (d) bushmeat sales are more important for vulnerable households. The bushmeat harvest value averaged less than US$1.0 per day for 89% of households and comprised less than 7% of household production value. Household wealth and gender of the household head had little effect on the importance of bushmeat. However, bushmeat harvest and sales were highest during the agricultural lean season. Overall, most harvested bushmeat (64%) was consumed, enabling households to spend 30% less on meat/fish purchases. These findings suggest that, despite heavily depleted wildlife and diversified livelihoods, bushmeat continues to have an important role in rural livelihoods by acting as a safety net for income smoothing and reducing household expenditure during times of economic hardship.     

蓝尾石龙子的头部两性异形和食性

通过测量头、体大小和胃检研究浙江泰顺产蓝尾石龙子 (Eumeceselegans)个体发育过程中两性异形和食性的变化。蓝尾石龙子成体个体大小和头部大小的两性差异显著 ,雄性大于雌性。不同发育阶段雌性头长与SVL的线性回归斜率无显著差异 ,头宽与SVL线性回归斜率的差异显著 ,成体和SVL <5 0mm幼体头宽随SVL的增长速率显著小于SVL为 5 0 - 6 9mm的幼体。雄性头部相对于SVL呈加速式异速生长。两性比较发现 :雌雄幼体头长和头宽随SVL的增长速率无显著差异 ,SVL <5 0mm幼体特定SVL的头长和头宽无显著的两性差异 ,但SVL为 5 0 - 6 9mm的雄性幼体头长和头宽大于SVL相同的雌性幼体 ;雄性成体头长和头宽随SVL的增长速率显著大于雌性。SVL <5 0mm的雌性幼体头部相对小于SVL为 5 0 - 6 9mm的同性幼体 ,性成熟雌体头部相对小于SVL为 5 0 - 6 9mm的同性幼体。雌性幼体、雄性幼体、雌性成体和雄性成体食物生态位宽度分别为 12 3、 12 5、 4 8和 14 4。雌雄幼体食物生态位重叠度最高 ,雌雄成体食物生态位重叠度次之 ,成体与幼体食物生态位重叠度较小。成体摄入食饵的大小 (用胃内完整食物长度的平均值表示 )和变化范围大于幼体。两性成、幼体摄入的食饵大小差异显著。两性个体摄入的食饵大小均与其SVL呈正相关 ,表明较大