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1.
The population density and relative abundance of some bird species reach the highest values in the communities of habitats with a high degree of anthropogenic transformation. The species diversity of birds shows an inverse correlation with the index of anthropogenic impact (in grades) calculated with regard to a number of parameters. Relevant correlations change periodically, with the correlation coefficient reaching the highest values in the nesting period and decreasing to a minimum during the flight period.  相似文献   

2.
Quantitative data of winter bird censuses in forest habitats of the Ilmen Nature Reserve (1986–2010) have been analyzed with regard to changes in the monthly average, maximum, and minimum temperatures and precipitation in the period from December to February. No warming trend has been revealed in the reserve over the study period, The dynamics of bird population structure in winter has proved to be independent of weather conditions, despite significant interannual fluctuations. The most significant factors of long-term dynamics of abundance of wintering birds include population density in the previous nesting period, the seed yield of the main food plants, and local migration of wintering species.  相似文献   

3.
The results of long-term studies (1973–1982) have been used to analyze specific features in the distribution of larid bird colonies in the Selenga River delta over an 11-year climate cycle. It has been shown that the spatial distribution of these birds has distinct patterns in years with different water levels (high, medium, or low) in the delta and is based on preference for certain nesting biotopes, which is well manifested in all species studied and depends on their ecological niches. The main factors determining the distribution of birds over the study area include water level, terrain topography, and locations of major aggregations of food organisms.  相似文献   

4.
The results of long-term observations (1983–2013) on the dates of arrival of migratory birds to the Ilmen State Reserve are presented. Based on their analysis, it is conclude that (1) there is no significant positive trend of spring temperatures in the territory of the reserve, and (2) an earlier arrival of the majority of bird species is not observed, unlike in Europe. The arrival has shifted to earlier dates in the Common Chaffinch (Fringilla coelebs), White Wagtail (Motacilla alba), and Black Kite (Milvus migrans). On the other hand, the arrival of the Tree Pipit (Anthus trivialis) is observed later than usual. Multiple regression analysis has shown that the arrival dates of most species that nest in the reserve are determined by the temperature regime of spring months in their nesting area.  相似文献   

5.
Changes in zooplankton developing under the effect of waste products from water-loving bird colonies were studied in water bodies of different types. The trophic status index in the nesting area showed no difference from its background values in an oligomesotrophic water body but was decreased in mesoeutrophic and eutrophic-hypertrophic water bodies. The abundance and biomass of zooplankton in the oligomesotrophic and mesoeutrophic water bodies were consistently higher than background values, while in the eutrophichypertrophic water body they were higher only at the beginning and in the middle of the nesting period. Irrespective of the trophic state of water body, the species diversity of zooplankton in the zone of impact from bird colonies was increased, but the number of dominant species remained unchanged, and no mass development of species indicating high organic load was observed; the proportion of Rotifera in the total abundance and biomass of zooplankton was decreased, that of Copepoda was increased, and the abundance of Cladocera was found to increase with the degree of overgrowing. Among possible explanations, this specific response of zooplankton is most likely due to changes in the ratio of nitrogen and phosphorus in the water.  相似文献   

6.
The size of Larus schistisagus nesting colony on Shelikan Island (8 ha in area) has increased from 2000 to 6000 pairs over 18 years. Today, this is the largest colony in the Sea of Okhotsk. The growth of the bird population has entailed catastrophic deterioration of the plant cover accompanied by a decrease in the species diversity of vascular plants: more than one-third of plant species recorded on the island in 1986 have already disappeared, and the establishment of several new plant species cannot compensate for this loss. If the size of the colony increases further, woody vegetation will fully deteriorate and only a thinned herbaceous layer consisting of 15–20 most resistant species will remain on the island.  相似文献   

7.
Based on the concept of an ecological niche, the processes of segregation in the Lower Volga populations of great and little bustards (Otis tarda L. and Tetrax tetrax L). have been studied in the evolutionary and adaptive aspects. The results have shown that segregation of the ecological niches of the two species occurs mainly on a trophic basis, when bird specialization in the use of food resources provides the possibility of changing the nesting biotopes. Some trophic adaptations are temporary and do not modify a species-specific stereotype, whereas other adaptations lead to the development of new forms of behavior and their evolutionary stabilization. Spatial characteristics (biotopic preference, nest location, etc.) complement the identified hierarchical series of parameters characterizing the ecological niches of the species studied. In the Transvolga region of Saratov oblast, the total sizes of great and little bustard populations in the breeding season reach approximately 4100 and 5900 birds, respectively.  相似文献   

8.
The results of census mapping over nine nesting seasons have been used to calculate frequency distributions of minimum distances between male singing chaffinches. Comparison of these distributions shows consistent, high, and significant similarity of spatial structures within each population, despite considerable fluctuations in bird density (from 204 to 118 territories per hectare) and basic differences between spatial structures of different populations (two significantly different classes are distinguished). An approach to estimation of habitat quality by assessing the spatial structure of populations is proposed.  相似文献   

9.
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   

10.
Landscape structure affects farmland bird species richness and diversity at different scales. We develop a predictive, metric-based model for farmland bird species richness in different bird guilds and study how the research area size influences the relationship between bird diversity and landscape metrics. Thirty research locations (randomly selected, each containing four counting points) were located in three counties of Estonia. In early summer 2002 and 2004, two bird counts per point were carried out in each research location. Three landscape metrics (patch density, edge density and Shannon’s diversity index) were calculated at three spatial scales: 100- and 200-m buffer zones around the count points and in a 1 km2 at 1 m × 1 m grain size. Using generalized additive mixed models with repeated measures, we found in most cases that the proportion of variance explained between the bird variables and landscape metrics increased with an increased study area thus demonstrating the effect of scale. Thus, a larger research area is recommended for landscape metrics. At large scales, however, all used landscape metrics were equally good predictors for bird species richness.  相似文献   

11.
Diets of the Long-eared and Short-eared Owls, closely related species with overlapping ranges, have been studied in the south of Western Siberia (the Baraba Lowland) by analyzing bone remains in pellets. The results show that both species in the south of the Baraba Lowland employ similar strategies of food resource use, which, however, differ in some aspects. In the Short-eared Owl, the hunting range is apparently more restricted. During the nesting period, these birds occupy relatively moist habitats along riverbanks and protect their hunting grounds. The Long-eared Owl nests in mainly mesic habitats, in forest outliers, and can supplement its diet with shrews (Sorex) and steppe rodent species. The diets of both species largely consist of murine rodent species that are dominant or subdominant in the small mammal community of the Baraba forest-steppe. Seasonal and interannual variations in the food spectra of both species have been revealed.  相似文献   

12.
湖北省湿地冬季水鸟多样性研究   总被引:11,自引:1,他引:11  
报道了2004年1~4月湖北冬季水鸟调查结果,记录水鸟 66 种,种群数量 59 613 只,分属8目15科,其中列入国家重点保护的一级鸟类 4 种,115 只,国家二级 7 种,2 968 只。分析了冬季水鸟群落结构、分布和种群变动,并用生物多样性指数、物种丰富度与生物量3个不同的测度指标对其中12个湖泊的水鸟群落进行了评价,认为沉湖、梁子湖、龙感湖和网湖是较为成熟稳定的群落;并从沉湖东方白鹳(Ciconia boyciana)、龙感湖白头鹤(Grus monacha)、洪湖鸭科水鸟近40年的种群动态探讨了湿地水鸟现状,认为种群衰退趋势明显、湿地干扰和威胁严重。对此提出了加强湿地保护区的建设,理顺管理体制,合理规划与发展湿地产业和保护湿地资源对策。  相似文献   

13.
The level of fidelity to potential nest site in representatives of different bird of prey species (Falconiformes) has been studied as dependent on population density and land-use status of the nesting area (a specially protected natural area or unprotected forest area). Species with high and low parameters of nest site fidelity and occupancy have been distinguished. The former group includes the Common Buzzard (Buteo buteo), Booted Eagle (Hieraaetus pennatus), and White-tailed Sea Eagle (Haliaeetus albicilla): no less than 60% of observed pairs have not changed their nest sites and nests during 5 years. The latter group includes the Common Kestrel (Falco tinnunculus), European Honey Buzzard (Pernis apivorus), and, at the nest level, Northern Goshawk (Accipiter gentiles).  相似文献   

14.
The results of long-term bird censuses in the Ilmen State Reserve are presented. Analysis of dynamic processes in the forest ornithocomplexes has shown that factors influencing changes in the abundance of birds in multispecies communities have unequal effects on different species. It has been found that the abundance dynamics of some species is correlated with spring meteorological parameters and the timing of phenological phases.  相似文献   

15.
The response variable (often the presence of a species) in predictive habitat models relies on a set of environmental predictors. Among all known environmental predictors, vegetation has the most effect on species abundance and on their habitat preferences, due to the wide range of necessary resources that it provides for the survival of bird species. However, other predictors, in turn, affect bird distribution, and some-times they play a more important role in habitat selection, depending on the natural history and ecological needs of the bird species. In this regard, different analyses have been conducted to predict the distribution, and define habitat suitability (such as discriminant function analysis, General Linear Models, and ANOVA). In this study, all three analytical designs were used to investigate the relationship of seven bird species to the major environmental gradients in the study area, to find out the significance of each of these factors on habitat selection. GIS has been used to prepare spatial distributional data, and to overlay and calculate different aspects of the environmental factors. The results suggest that potential individual habitat patches play a small role compared to the landscape (entire corresponding habitat patches), when considering vegetation. The influence of built-up areas is significant for all the species, and the proximity to the sea shore is very significant for at least one of the species, however, it is not neutral for all other species.  相似文献   

16.
Surveys at southwestern China were conducted from November 2004 to July 2005 in three habitat types. A total 3319 individual of 69 bird species were recorded. Although urbanization was presumed to be responsible for decreasing species richness and diversity, our results showed bird species richness, diversity and density in urban habitats were not different in rural habitats. Whereas, the wasteland with low human disturbances, was the lowest bird species richness, diversity and density than others habitats. We inferred habitats structural complexity, large forest patches, native trees and human litter sustain many bird species in campus and park. However, human disturbances, habitats substrate and predation from domestic animals may reduce species richness and diversity. Therefore, we suggested that high vegetative cover should be in urban areas, because it may increase the number of bird species, support larger populations of insectivores, and perhaps create suitable habitat for some ground nesters. Moreover, by recreating or preserving natural islands decreased human disturbance and predation from domestic animals.  相似文献   

17.
The structure of the long-eared owl (Asio otus L.) settlements in anthropogenic landscapes has been studied in the Zhuravlinaya Rodina protected territory in the northern Moscow region in 2001–2005. The possible factors that cause the formation of such settlements have been analyzed. The differences in the breeding success between owls nesting near and away from human settlements have been estimated. Aggregated nesting of owls is assumed to be mainly related to a lower predator pressure in the vicinity of human dwellings in the incubation period. Aggregated nesting is regarded as an expression of synanthropization of the species.  相似文献   

18.
Over 2500 species of invertebrate macrofauna and over 177 species of avifauna live in the forest–tundra of the Lower Ob region and adjacent areas of the northern taiga and shrub tundra. About half of the invertebrate species of the study area are northern—mostly hypo- and hemiarctic—tundra species; the rest are boreal and arctomontane-boreal Holarctic and trans-Palearctic species. The anthophilic and aerobiont insect assemblages include many boreal forest forms. A total of 153 species have been observed nesting at the taiga–foresttundra boundary; 81 species have been observed nesting at the tundra–forest-tundra boundary. The avifauna of the forest–tundra becomes enriched with taiga species in floodplain forests and with tundra species on the flat interfluve, in areas of tundra and tundra-like wetlands. The forest–tundra of the Lower Ob region has no avifauna and entomofauna of its own and contains a mixture of taiga and tundra faunas. It has been found that the ecotone effect is not pronounced in the taxonomic composition of birds and insects in the forest–tundra, where only some particular groups (such as amphibiont insects) have increased abundance.  相似文献   

19.
The effect of rise in spring air temperature on the breeding phenology and reproductive success of the Song Thrush in the Voronezh Nature Reserve have been studied over the periods of 1987 to 1990 and 2008 to 2012. The results show that relatively high air temperatures provide for earlier arrival of the birds from wintering grounds, earlier and more synchronous breeding of the majority of nesting pairs, and an increase in clutch size and proportion of pairs producing two broods per season. Predation pressure on bird nests decreases under such conditions, which markedly improves reproductive success. Climate warming is conducive to increasing breeding productivity of the Song Thrush population as a whole.  相似文献   

20.
The results of censuses of 335 bird species and estimation of environmental factors in 1163 habitats located in undeveloped areas of the Western Siberian Plain were analyzed. The data for analysis were obtained from the databank of the Laboratory of Zoological Monitoring of the Institute of Animal Ecology and Systematics (Siberian Division, Russian Academy of Sciences). The material was collected in the first half of summer (between May 16 and July 15) in 1936–1938 and 1959–1999 (mostly beginning from 1967). A learning sample (863 variants) was used to approximate the abundance of each species with respect to each factor (including calculation by the principal-component method), and the approximation was integrated with respect to all these factors. The approximation coefficients were used to make a prognosis of species abundance based on the values of environmental factors in the control sample (300 variants). For the 50 most prevalent species, accounting for more than 80% of total bird abundance, the values of explained variances of approximation and prognosis averaged 53.5 (r = 0.73) and 47% (r = 0.68), respectively.  相似文献   

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