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1.
The patterns of molt in the chiffchaffs of the nominotypical subspecies from central Europe and eastern European subspecies from the Ladoga region are compared with that of the Siberian subspecies from the lower Ob region. The onset dates of postjuvenile molt in the Siberian subspecies are controlled endogenously, while in the nominative and, probably, eastern European subspecies they are under photoperiodic control. The molt of chiffchaffs from central Europe is no less complete than in birds from the Ladoga region and more complete than in Siberian birds. The individual duration of molt is the shortest in Siberian birds and the longest in central European birds, being intermediate in birds from the Ladoga region. Differences in the pattern of postnuptial molt between chiffchaffs from the Ladoga and Ob regions concern its duration and completeness. The completeness of molt proved to be reduced in half of examined birds from the Ladoga region and in some birds from the Ob region. The duration of complete molt in birds from the Ob region is smaller (40 days vs. 60 days in birds from the Ladoga region) at a longer daylight period, which is evidence for a higher rate of feather growth. The completeness and timing of prenuptial molt do not differ between the subspecies.  相似文献   

2.
Body size variation across environmental gradients has received considerable attention in evolutionary ecology in recent years. In this study, we investigated body sizes and age structure using skeletochronology in male Polypedates megacephalus from five sites with the attitude ranging from 449 to 1300 m. The results showed age at sexual maturity in males was 2 years old, and the longevity was 5 years old except for Changning population of 3 years. Body size was significantly correlated with age within each population except for Changning population. Average age did not differ significantly among populations. Body size of individuals also did not differ across populations when removing the effect of age, which did not follow Bergmann’s rule.  相似文献   

3.
Body size-dependent mating pattern is thought to a consequence of the sexual selection on phenotypic characters. In the view, we investigated the mating patterns in Bufo andrewsi from three populations at different latitude in three Nature Reserves (i.e. Wanglang, Yele and Fengtongzhai) in China from early- March to late-May 2013 and 2014. The results showed that average body size did not differ significantly between amplectant and non-amplectant males within each population. We found a significantly positive relationship in body size between the amplectant males and amplectant females in Wanglang population, but not in Qiqiao and Yele populations. The strength of size-dependent mating was not correlated with the malebiased operational sex ratios (OSRs), suggesting that intensity of male-male competition at nights do not result in variation in size-dependent mating patterns in B. andrewsi among populations.  相似文献   

4.
Variability of the length of the white area on the outermost quill feathers of the great tit from two cities in the Middle Ural has been investigated. Dynamics of the average length of the white area in the birds from the city of Asbest reproduced the dynamics observed in the city of Yekaterinburg with a one-year lag in the females and a two-year lag in the males. Phenotypic changes in the great tit population did not occur simultaneously in the whole population, but rather moved along the living range with a certain velocity (50–60 km/year for the females and 25–30 km/year for the males). The results obtained are discussed in view of the concepts of population biology.  相似文献   

5.
On the basis of long-term studies on the ecology of pied flycatcher in Karelia, it has been shown that male nonparticipation in nestling feeding is due to the course of postnuptial molt rather than to the mode of mating relationships, as it was considered previously. This is confirmed by the results of selective capture of birds that have stopped to feed their brood. It is suggested that reduction of parental care is associated with changes in the hormonal balance of molting birds.  相似文献   

6.
Populations from different environmental habitats indicate variation in life history traits and these differences are mostly related to longevity, age and size at maturity. In this study, age structure, longevity, survivorship and sexual size dimorphism of Near Eastern fire salamander (Salamandra infraimmaculata) were assessed by means of skeletochronological analysis. Maximum lifespan was recorded to be twelve years in females and eleven years in males and age at maturity was estimated as three and four years for both sexes. Females had significantly larger SVL than that of males, while age structure and mean age did not differ between sexes. Age and body size were positively correlated with each other for both females and males. Since the populations of the Near Eastern fire salamander in Turkey are in decline, the present study which provides preliminary data on life history traits of this species could be helpful for future biological studies.  相似文献   

7.
Complete seasonal replacement of European robin populations takes place in the Crimea: local birds of the subspecies E. r. valens depart from the peninsula to be replaced by birds of the nominative subspecies E. r. rubecula, which arrive for wintering. The overall population dynamics of the European robin in the Highland Crimea are determined by seasonal changes in the abundance of local birds, fluctuations in the abundance of birds from northern populations, or variation in the ratio between these groups of birds during their staying together in the Crimea during the periods of seasonal migrations.  相似文献   

8.
The return of willow ptarmigans to the sites in which they nested the previous year has been studied using color banding. No factors influencing the return index have been revealed, except for its dependence in males on the time when spring begins in a given year. In northernYamal, in contrast to the temperate zone, some surviving birds fail to return to their former nesting sites. Polymorphism of individuals with respect to territorial behavioral strategy is proposed for L. lagopus populations at the northern boundary of the species range.__________Translated from Ekologiya, No. 3, 2005, pp. 215–221.Original Russian Text Copyright © 2005 by Tarasov.  相似文献   

9.
We investigated the variability of anthropogenic radionuclide content of the edible fractions of individual edible crabs (Cancer pagurus L.) and European lobsters (Homarus gammarus L.) caught commercially in the Sellafield offshore area. Sixteen female and 18 male crabs and 20 female and 17 male lobsters were selected from commercial catches made between 25 May and 5 June 1997. Each gender group was selected to be within the known weight range for commercially caught crustacea from the area. Four artificial radionuclides (60Co, 110mAg, 137Cs or 241Am) were detected by gamma-spectrometry. The edible fraction content of these radionuclides between males and females for either species were not statistically significantly different. 99Tc was analysed by chemical separation and beta-counting. 99Tc concentrations in female crabs tended to be higher (172 +/- 205 (16) Bq kg-1(wet); mean +/- standard deviation (n samples)) than those in males (85 +/- 58 (18) Bq kg-1 (wet)), although this was not a statistically significant difference. For both male and female crabs, 99Tc concentrations tended to decrease with increasing whole live weights. For 99Tc in lobsters the picture is less clear. Female lobsters contained more activity (14800 +/- 7400 (20) Bq kg-1 (wet)) than males (7100 +/- 3900 (17) Bq kg-1 (wet)). The results were used to discuss the implications for sampling and monitoring.  相似文献   

10.
水动力学法预测三峡工程对洞庭湖洲滩的影响   总被引:3,自引:1,他引:3  
用水动力学方法,根据三峡建库前后不同的时空边界条件,模拟长江水情要素,并建立长江水位与洞庭湖水位的回归方程,从而预测三峡工程对洞庭湖区洲滩面积的影响。  相似文献   

11.
Despite low levels of organochlorine contaminants (OCs) in Antarctic biota, some compounds may exceed the levels in equivalent Arctic species, and previous studies have found biochemical evidence of pollutant exposure in south polar skuas (Catharacta maccormicki), a common marine top predator in the region. In this study we examined relationships between fitness components (fecundity and adult return rate between breeding seasons) and concentrations of OCs in this species. In 65 nests, both males and females were caught, and using principal component analyses (PCA) we produced composite measurements (PC1 and PC2) of six highly correlated OCs measured in blood samples. Although the concentrations of OC were below those documented to have reproductive effects in other aquatic birds, we found that the eggs of females with high levels of OCs in the blood hatched later, and their chicks were in poorer condition at hatching, than females with low OC levels. Thus OCs may delay reproduction and reduce foetal growth in the skuas. However, there was no relationship between the parents' OC residues and the occurrence of non-viable eggs, although the proportion of nests containing non-viable eggs was high (47%). Moreover, there were no significant relationships between OCs and reproductive variables in males, even if males had higher OC levels than females, and no associations between OCs and adult return rate between breeding seasons.  相似文献   

12.
To evaluate the status of polybrominated diphenyl ethers (PBDEs) contamination in poultry and sequentially human exposure through consumption of poultry in an e-waste recycling site in South China, two kinds of free-range domestic birds, chicken and duck, were collected and their muscle and liver tissues were analyzed for 16 PBDE congeners. Chicken shows higher PBDE concentrations (summation of 16 PBDE congeners) in both muscle and liver tissues, ranged from 5.7 to 4381 and from 1.5 to 7897 ng/g (lipid weight, the same hereinafter), respectively, compared to duck, ranged from 2.4 to 51 and from 1.9 to 134 ng/g. Different living habitat and feeding habits between the two species might be responsible for this observation. No sex-related differences in PBDE concentrations were found for the two species, while the PBDE concentrations in muscle were higher than those in liver for chicken. The PBDE concentrations in muscle of chicken in the present study were higher than the levels of PBDEs in chicken from other studies reported by far. BDE209 and nona-BDEs were the major congeners in poultry. Comparison of PBDE profiles between birds and environmental matrix implied that the biodebromination of BDE209 might occur in poultry. The intake of PBDEs through consumption of poultry ranges from 7.8 ng/day to 3582 ng/day with a medial 68 ng/day, which is comparable to the calculated values through consumption of all foodstuffs in other studies. The present study suggested that the total dietary PBDEs intake for local residents might be considerably enhanced due to the e-waste recycling activity.  相似文献   

13.
Effects of toxic emissions (heavy metals and sulfur dioxide) on reproductive parameters of adult pied flycatchers (Ficedula hypoleuca Pall.) and morphophysiological characteristics of their progeny have been studied in the vicinity of the Middle Ural Copper-Smelting Plant. In polluted areas, the fecundity of adult birds is lower, mortality among the progeny is higher, and changes in the physiological parameters of birds are observed. The effects of toxic load are better manifested in nestlings than in adult birds. They include an increase in the liver index, the reduction of hemoglobin concentration, and an increase in the proportion of immature erythrocytes in the peripheral blood. The proportion of anemic birds also increases. The weakening of nestlings facilitates their infestation by the larvae of parasitic flies. Changes in the differential blood count of nestlings reflect the combined impact of toxic pollutants and parasites.  相似文献   

14.
BackgroundIn animals, exposure to certain phthalates negatively affects the male reproductive function. Human results are conflicting and mostly based on subfertile males, in whom the association between exposure and reproductive function may differ from the general population.ObjectivesTo study if levels of phthalate metabolites were associated with semen quality and reproductive hormones in general Swedish men.MethodsWe recruited 314 young men delivering semen, urine and blood samples at the same visit. We analyzed reproductive hormones and several semen parameters including progressive motility and high DNA stainability (HDS)—a marker for sperm immaturity. In urine, we analyzed metabolites of phthalates, including diethylhexyl phthalate (DEHP). We studied associations between urinary levels of the metabolites and seminal as well as serum reproductive parameters, accounting for potential confounders.ResultsDEHP metabolite levels, particularly urinary mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), were negatively associated with progressive sperm motility, which was 11 (95% CI: 5.0–17) percentage points lower in the highest quartile of MECPP than in the lowest. Further, men in the highest quartile of the DEHP metabolite monoethylhexyl phthalate had 27% (95% CI: 5.5%–53%) higher HDS than men in the lowest quartile.ConclusionsDEHP metabolite levels seemed negatively associated with sperm motility and maturation.  相似文献   

15.
武汉沉湖湿地水鸟群落特征及其与富营养化关系研究   总被引:1,自引:0,他引:1  
富营养化是水中氮、磷等营养物质大量积累引起的水质污染现象,直接导致水体群落结构的改变,这一定程度上引起了以水生生物为食的水鸟的群落特征的变化。为找寻水鸟群落特征与富营养化两者的关系,2010年1月~2013年1月3年内按春夏秋冬4季对武汉沉湖湿地自然地保护区水鸟进行了调查,沉湖和张家大湖的水鸟多样性有明显的周年变化规律,多样性指数冬季最高,最高值分别为12.19和9.89;春夏季最低,最低值分别为7.53和2.45;对比分析了两个子湖,沉湖湖区与张家大湖湖区富营养化指数TLI分别为64和78,沉湖水鸟种类、数量和多样性指数皆高于张家大湖,湖泊富营养化会影响水鸟多样性。  相似文献   

16.
Chromosome aberration frequency in relation to population dynamics and demographic parameters was studied for six years in a bank vole population in the Middle Urals. The frequencies of structural chromosome aberrations, chromatid gaps, aneuploidy, and polyploidy in males and females and in animals of different ages did not differ significantly. In the breeding period, the frequencies of structural aberrations and changes in chromosome number increased in the somatic cells of voles. Highly significant differences between the levels of chromosome instability in different years manifested a tendency toward a negative correlation with population size.  相似文献   

17.
Male and female bank voles (Clethrionomys glareolus) were compared with respect to seasonal variation in hippocampus size and dynamics of spatial behavior during the annual population cycle. The winter decrease in the size of the hippocampus (the brain region involved in the processing of spatial information about the environment) in young autumn-born voles coincided in time with reduction of their home ranges and did not differ significantly between males and females. The growth of the hippocampus in spring, after winter regression, was higher in males (19–28% in different populations) than in females (8–20%) and coincided with an increase in spatial activity, which was also more distinct in males. A significantly greater hippocampus size in males during the breeding period correlated with their higher mobility (reflected in capture rate) and greater size of home ranges. Thus, parallel seasonal modulation of sex-related differences in hippocampus size and spatial behavior was revealed: sexual dimorphism in these characters was insignificant among young voles in autumn; disappeared in winter; manifested itself again, synchronously in both characters, in early spring (with the onset of puberty); and reached a peak in summer.  相似文献   

18.
19.
In this study, we investigated whether bird feathers can be used as a non-destructive biomonitor for organic pollutants. We analysed the outermost tail feathers of 8 terrestrial and aquatic bird species from Belgium (8 species, n=108) for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs). Every compound class could be quantified in one single tail feather of the birds under study (sum PCBs ranging from 5.5 to 510 ng/g feather, sum PBDEs from 0.33 to 53 ng/g feather, sum DDTs from 1.5 to 730 ng/g feather), except for PBDEs in feathers of the common moorhen (Gallinula chloropus). Further, we calculated Pearson correlations between concentrations of organic pollutants in feathers and concentrations in corresponding muscle or liver tissue from the birds. Correlations were found significant in half of the cases of the terrestrial species, but were found not significant for the aquatic species, with the exception of a significant correlation of sum PCBs in the common moorhen. Only for the common buzzard (Buteo buteo) (n=43) all correlations were found significant (0.32相似文献   

20.
Demographic characteristics of marsh frog (Rana ridibunda Pall.) populations have been studied in cooling reservoirs of Middle Ural thermal power plants, where this species was introduced accidentally. The reservoirs are similar in hydrochemical characteristics but differ in the thermal regime. The populations studied have been found to differ from the reference (natural) populations and from each other in a number of parameters, including the size and age composition of spawners, the type of spawning, and fecundity. Analysis of the results indicates that the observed differences have adaptive significance.  相似文献   

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