Differential autumn migration of the aquatic warbler Acrocephalus paludicola

Relatively little attention has been paid to sex differences in the migration of birds in autumn. We studied the autumn migration strategy of molecularly sexed males and females in the globally threatened aquatic warbler Acrocephalus paludicola. We captured 176 birds at a stopover site in the Loire estuary at Donges, France. The median date for the passage of adults was 8 days earlier in males than females, although the timing of migration in first-year males and females was similar. This indicates that males, who are without parental duties, can start their migration earlier than females and first-year birds. Adults were significantly heavier than immature birds but did not have higher fat scores. In both age categories, more males (two to three times more) were captured. However, various factors (including tape-luring) can affect observed sex ratio.     

Sex- and age-related differences in the timing and body condition of migrating Reed Warblers Acrocephalus scirpaceus and Sedge Warblers Acrocephalus schoenobaenus

The migration strategies of birds may vary strongly between species and also between age and/or sex groups. We studied the autumn migration and body condition of molecularly sexed Reed Warblers Acrocephalus scirpaceus and Sedge Warblers Acrocephalus schoenobaenus (211 and 208 ind., respectively) at a stopover site on Lake Druzno, Northern Poland, in 2008. Immature male Reed Warblers were caught significantly later than females (median dates 9 days later), but in the Sedge Warbler, both sexes of immatures migrated at about the same time. Adult males and females of both species did not differ in their time of migration. Adult and immature males of both species were larger (wing length and body mass) than females. In both species, fat reserves were similar in both sexes of both age classes. Adults of both sexes of Reed and Sedge Warbler were generally caught earlier than immatures. In both species, the body mass and fat reserves of immatures were generally less than in adults. The autumn protogyny of immature Reed Warblers may allow smaller females to limit competition with bigger males during migration and at the wintering grounds. In the Sedge Warbler, which tends to match its migration to peak of occurrence of superabundant food at stopover sites, both sexes gain an advantage from migrating at the same time. Since part of the measured wing length variation in both species was explained by sex differences, temporal trends in wing length recorded at stopover sites should be interpreted with caution.     

Cognitive ability correlates positively with son birth and predicts cross-cultural variation of the offspring sex ratio

Human populations show remarkable variation in the sex ratio at birth which is believed to be related to the parental condition. In the present study, the global variation of sex ratio at birth (SRB, proportion of male offspring born) was analyzed with respect to indirect measure of condition, the intelligence quotient (IQ). IQ correlates strongly with lifespan across nations, which makes it a good indicator of health of the large populations. Relation between three standard measures of average national IQ and SRB was studied using multiple linear regression models. Average national IQ was positively correlated with SRB (r?=?0.54 to 0.57, p?<?0.001). Further, IQ emerged as a powerful predictor of SRB after controlling for the effects of all the known covariates like fertility, maternal age, polygyny prevalence, wealth, son preference, latitude, low birth weight, and neonatal mortality in the regression models. These results suggest that the striking variation of offspring sex ratio across nations could be caused in part by the difference in general condition of populations.     

An equal sex ratio followed by differential sex mortality causes overestimation of females in gall midges: no evidence for sex ratio regulation

Monogeny, the production of unisexual broods by individual females, has been recognized for nearly 80?years. The genetic nature of gall midges' sex determination predicts an equal numbers of male-producing and female-producing females in the populations such that the overall sex ratio is expected to be nearly 1:1. However, observations of some strictly monogenous populations with biased sex ratio, mainly toward females, have raised the question of whether gall midges are able to adjust their offspring sex ratio in response to changes in environmental conditions, and some authors have even considered sex ratio regulation as a strong force in the course of the evolution of monogeny. In this paper, first, by studying the sex ratio variations of the predatory gall midge, Aphidoletes aphidimyza within a generation, we showed that adult males emerge up to 1?day earlier and have shorter life span than females (less than 4?days and up to 6?days, respectively). Although, the sex ratio of A. aphidimyza at the time of emergence was nearly 1:1 (52.41?% males), a simple population simulation indicated that the differential mortality of sexes can lead to a female-biased sex ratio estimation (57.88?% females) under random sampling in the natural environments. Our results imply that the primary sex ratio of monogenous gall midges is nearly 1:1 and that the arrhenogenic/thelygenic gall midges are not able to alter the number of their male/female progenies in response to changes in environmental conditions.     

夏秋季长江口及毗邻海域N、P营养盐分布及其潮汐变化

根据2005年7月和11月在长江口及毗邻海域进行的现场观测数据,分析表明:夏秋季表层N、P营养盐的高值区(N＞65 μmol/L,P＞1.3 μmol/L)多位于长江口及杭州湾海域,而低值区(N＜40 μmol/L,P＜0.5μmol/L)多存在于长江口东北海域以及舟山东南海域,底层N、P营养盐在夏季存在-向东北方向的舌状扩散,而秋季等值线比较均匀且呈南北向分布;调查海域表层N/P值都超过30,羽状锋区可达到200以上,表明浮游植物的生长存在着磷限制;连续观测站位的PO-P含量在夏秋季大都表现为小潮高于大潮,而NO3-N含量变化复杂.     

Aggressive behavior of the male parent predicts brood sex ratio in a songbird

Brood sex ratio is often affected by parental or environmental quality, presumably in an adaptive manner that is the sex that confers higher fitness benefits to the mother is overproduced. So far, studies on the role of parental quality have focused on parental morphology and attractiveness. However, another aspect, the partner’s behavioral characteristics, may also be expected to play a role in brood sex ratio adjustment. To test this hypothesis, we investigated whether the proportion of sons in the brood is predicted by the level of territorial aggression displayed by the father, in the collared flycatcher (Ficedula albicollis). The proportion of sons in the brood was higher in early broods and increased with paternal tarsus length. When controlling for breeding date and body size, we found a higher proportion of sons in the brood of less aggressive fathers. Male nestlings are more sensitive to the rearing environment, and the behavior of courting males may often be used by females to assess their future parental activity. Therefore, adjusting brood sex ratio to the level of male aggression could be adaptive. Our results indicate that the behavior of the partner could indeed be a significant determinant in brood sex ratio adjustment, which should not be overlooked in future studies.     

Bird species migration ratio in East Asia, Australia, and surrounding islands

Bird migration and its relationship with the contemporary environment have attracted long-term discussion. We calculated the avian migration ratio (the proportion of breeding species that migrate) in the areas from 70°E to 180°E and examined its relationship with the annual ranges of ambient temperature, primary productivity (estimated by the Enhanced Vegetation Index), and precipitation, along with island isolation and elevational range. The avian migration ratio increased with increasing latitude in general but varied greatly between the two hemispheres. Additionally, it showed minimal differences between continents and islands. Our analyses revealed that the seasonality of ambient temperature, which represents the energy expenditure of birds, is the dominant factor in determining bird species migration. Seasonality in primary productivity and other environmental factors play an indirect or limited role in bird species migration. The lower avian migration ratio in the Southern Hemisphere can be attributed to its paleogeographical isolation, stable paleoclimate, and warm contemporary environment. Under current trends of global warming, our findings should lead to further studies of the impact of warming on bird migration.     

Interannual differences in the relative timing of southward migration of male and female western sandpipers (Calidris mauri)

In the shorebird subfamily Calidridinae, one of the parents shortens parental care and initiates southward migration before the other. We estimated the difference in passage date between male and female western sandpipers (Calidris mauri) at their first major stopover on the southward migration from breeding areas in Alaska, in 18 years between 1978 and 2000. Overall, adult females preceded adult males by 1.22 days. A novel finding was that among juveniles, which migrate approximately a month later than adults, females preceded males by similar magnitude (1.14 days). There was wide variation among years, however, and males actually preceded females in years with late hatch. We relate these findings to hypotheses for female-first southward migration in sandpipers.     

论沈阳市“十一五”水环境保护

全面分析了沈阳市“十一五”期间水环境面临的主要问题,确定了“十一五”水环境保护的目标,提出了实现水环境保护目标的方案措施。强化城市（镇）污水处理厂建设、大力推进中水回用、实施河流综合整治、加强污染源管理是实现沈阳市水环境保护目标的保证。     

春季角毛藻对N/P值响应的FRD判别

首次运用FRD判别法,探讨了角毛藻(Chaetocerossp.)生长对N/P值的响应过程。通过大亚湾春季现场观测的角毛藻细胞数量与DIN/PO4比值关系分析,构建关系曲线的完全样本进行泛函回归分割(FRD)判别。FRD判别表明,角毛藻是以3种不同的生长状况响应N/P值变化,即在N/P<15.79(±1.41)时,角毛藻数量随N/P值增大处于缓慢生长状况;在N/P=15.79(±1.41)～59.90(±4.28)之间时,角毛藻数量则随N/P值增大而迅速增长;而当N/P>59.90(±4 28)时,角毛藻数量达到最大生长值,并处于上下涨落状态。     

Geographical variation in sexual behavior and body traits in a sex role reversed wolf spider

Mating partners need to recognize, assess each other, and exchange information through behavioral events that occur before, during, and after mating. Sexual signals, as well as life history traits, are influenced by selective pressures and environmental factors that can vary across distant geographical areas. Allocosa senex is a sand-dwelling wolf spider which constructs burrows along the sandy coasts of Argentina, Brazil, and Uruguay. Females are the mobile sex that searches for males and initiates courtship. They prefer males which construct longer burrows, and males prefer virgin females in good body condition. The objective of this study was to compare sexual behavior patterns, as well as body characteristics and burrow dimensions, between two geographically distant locations of A. senex, one in Uruguay (Uruguayan location) and the other from central Argentina (Argentinean location). We found differences in the number of male abdominal vibrations, male and female touches during mating, and number of erections of male leg spines, which all were higher in matings of Argentinean pairs. On the other hand, male body mass and female body condition were higher in Uruguayan individuals. The wide distribution of A. senex could be determining variations in the biotic and abiotic features that affect the species, generating differences in the strength of selective forces acting on individuals from the two studied locations.     

全氟辛烷磺酸盐和全氟辛酸在水环境及水生生物体内积累的研究进展

全氟辛烷磺酸盐(PFOS)和全氟辛酸(PFOA)是全氟化合物中2种最典型的化合物,在不同环境介质(水、土壤、沉积物等)及水生生物体内被广泛检出。PFOS和PFOA具有良好的化学、物理性能,被广泛地运用于工业领域,PFOS和PFOA的污染范围已涉及全球。综述了PFOS和PFOA在水环境体系的污染现状及其在水生生物体内积累特征,探讨影响水生生物积累的主要因素,为全氟化合物污染控制提供基础。     

Differential sex- and age-related migration of Bluethroats Luscinia svecica at Eilat, Israel

This paper examines the phenology and biometrics of Bluethroats staging in the Eilat region. This is of special interest because of the extreme conditions with which this temperate zone breeding species has to contend because Eilat is a desert habitat and is the last green area before the crossing of the deserts in autumn or after it in spring. Data were collected during 20 spring and 18 autumn migration seasons in the years 1984–2003, and a total of 7,464 Bluethroat were recorded. The number of trapped birds was much higher in autumn than in spring. The majority of Bluethroats caught in both the autumn and spring migrations were juveniles. We found differences in sex ratio in the individual age classes only in the autumn wherein among both adults and juveniles, males were in greater numbers. We also found significant differences in the dates of ringed birds from different sex–age classes in the spring and in autumn migrations. In spring, males from both age classes were caught earlier than females. In autumn, adult birds arrived earlier than juveniles. We think that it is important to identify and conserve the high quality stopover habitats such as Eilat wherein not only Bluethroats have been shown to stopover but also several hundred other species.     

The migration and transformation of dissolved organic matter during the freezing processes of water

This study investigated the partitioning behavior of dissolved organic matter(DOM) in liquid and ice phases, as well as the changes in the optical properties and chlorine reactivity of DOM during the freezing processes of water. DOM was rejected from the ice phase and accumulated in the remaining liquid phase during water freezing. Moreover, the decrease in freezing temperature, as well as the increase in dissolved organic carbon(DOC)concentration of feed water, caused an increase in DOM captured in the ice phase. The ultraviolet-absorbing compounds, trihalomethane precursors, as well as fulvic acid- and humic acid-like fluorescent materials, were more liable to be to be rejected from the ice phase and were more easily retained in the unfrozen liquid phase during water freezing, as compared with organics(on average) that comprise DOC. In addition, it was also found a higher accumulation of these organics in the unfrozen liquid phase during water freezing at higher temperature. The freeze/thaw processes altered the quantity, optical properties, and chlorine reactivity of DOM. The decrease in ultraviolet light at 254 nm as well as the production of aromatic protein- and soluble microbial byproduct-like fluorescent materials in DOM due to freeze/thaw were consistently observed. On the other hand, the changes in DOC, trihalomethane formation potential, and fulvic acid- and humic acid-like fluorescence caused by freeze/thaw varied significantly between samples.     

四十里湾赤潮高发期营养盐与叶绿素a的年际变化

通过分析四十里湾海域连续6 a(2003～2008年)赤潮高发期(5～9月)的监测数据,发现2003～2008年该海域总无机氮、硅酸盐、COD和叶绿素 a 含量均呈上升趋势;磷酸盐没有明显的上升或下降趋势;叶绿素 a 含量与总无机氮浓度、磷酸盐浓度均呈显著的正相关;N/P值明显高于Redfield比值,且逐年上升,显示该海区处于相对的磷限制状态.     

Maternally derived carotenoid pigments affect offspring survival, sex ratio, and sexual attractiveness in a colorful songbird

In egg-laying animals, mothers can influence the development of their offspring via the suite of biochemicals they incorporate into the nourishing yolk (e.g. lipids, hormones). However, the long-lasting fitness consequences of this early nutritional environment have often proved elusive. Here, we show that the colorful carotenoid pigments that female zebra finches (Taeniopygia guttata) deposit into egg yolks influence embryonic and nestling survival, the sex ratio of fledged offspring, and the eventual ornamental coloration displayed by their offspring as adults. Mothers experimentally supplemented with dietary carotenoids prior to egg-laying incorporated more carotenoids into eggs, which, due to the antioxidant activity of carotenoids, rendered their embryos less susceptible to free-radical attack during development. These eggs were subsequently more likely to hatch, fledge offspring, produce more sons than daughters, and produce sons who exhibited more brightly colored carotenoid-based beak pigmentation. Provisioned mothers also acquired more colorful beaks, which directly predicted levels of carotenoids found in eggs, thus indicating that these pigments may function not only as physiological ‘damage-protectants’ in adults and offspring but also as morphological signals of maternal reproductive capabilities.     

Biased sex ratio and low population density increase male mating success in the bug Nysius huttoni (Heteroptera: Lygaeidae)

Demographic factors such as operational sex ratio (OSR) and local population density (LPD) are temporally and spatially dynamic in the natural environment but the influence of these variables on male mating success and the mechanisms behind it are still poorly understood and highly controversial. Here, we manipulated the OSR and LPD of a seed bug, Nysius huttoni, and carried out a series of mating trials to test how these variables affected male mating success. The two demographic factors had no significant interactions, suggesting that they affect male mating success independently in N. huttoni. In this species male mating success was significantly higher in both male- and female-biased OSR than in even OSR. It is suggested that, in male-biased OSR, the increased intensity of competition and interference does not result in lower male mating success; rather, males may make more effort in courting and females may have more chance to encounter better males, resulting in higher male mating success. In female-biased OSR, females may become less choosy and less likely to reject male mating attempt, leading to the higher male mating success. Lower male mating success in N. huttoni in high LPD may be due to increased interference between males and/or delayed female receptiveness for mating. OSR had a stronger effect on male mating success than LPD in N. huttoni, suggesting that OSR and LPD affect mating success in different ways and intensities.     

我国煤中汞含量水平及洗选过程汞流向分析

介绍了我国煤中汞含量与分布特征、煤中汞的赋存形态,分析了汞释放对环境的影响以及汞的脱除与控制技术。结果表明:我国(华南)晚三叠世(T3)煤中汞含量最高,平均含量为0.26μg/g;贫煤和无烟煤中汞含量最高,平均含量都超过0.20μg/g。含汞较高的晚三叠世、晚二叠世煤田主要分布于华南各地;多数煤中汞含量在0.300μg/g以下,但华南的江西、广西、贵州等地煤中汞含量总体水平较高;汞的赋存形态可分为有机结合态和无机结合态,煤中汞的控制方法可分为利用前脱汞、利用(燃烧)后脱汞和过程中汞形态转化。提出了煤炭洗选过程汞分布、脱除率和汞平衡等计算公式,指出了煤炭洗选过程中汞迁移行为的主要影响因素。     

关于水生生态系统中汞的国内外研究进展评述

本文介绍了国内外对于水生生态系统中汞的生物地球化学循环研究的各项进展,从汞对水生动植物的毒性、汞的迁移转化、甲基汞的形成以及甲基汞对食物链及人体健康的影响等几方面进行评述。     

水生植物在乡镇生活污水处理中的应用实例

乡镇地区的生活污水富含氮磷等营养性物质,水生生物通过附着、吸收、积累、降解作用,可高效、快速去除水体中的营养物质。江苏省宝应县曹甸镇污水处理厂采用生物接触氧化曝气处理＋水生植物综合处理工艺,每日处理3 000 m^3生活污水,排水达到国家一级排放标准。利用水生植物法净化乡镇生活污水具有投资少,维护和运行费用低,管理简便,污水处理效果好,可改善和恢复生态环境等优点,是一种低成本高效益的生态工程技术。