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荣成天鹅湖湿地越冬大天鹅食性分析   总被引:7,自引:2,他引:7       下载免费PDF全文
2005年12月~2006年3月以大天鹅(Cygnus cygnus)为对象,研究其越冬期间的食性,利用粪便显微组织分析法定量调查其食物组成。结果表明,大天鹅的越冬食物主要为小麦(Triticum aestivum)、海带(Laminaria japonica)和大叶藻(Zostera marina),其中,小麦的比例最大,分别占冬季食物组成的99.67%和早春的90.17%。对冬季与早春的食物组成的差异进行分析,发现大天鹅在天鹅湖保护区发生了食物替代现象。结合以往资料,认为生态污染和湿地结构性破坏导致大天鹅传统食物减少,致使食物替代现象的发生。  相似文献   

3.
The maintenance of species and genetic diversity within zooplankton egg banks may be crucial to the re-establishment of zooplankton communities following historical disturbance, such as anthropogenic acidification which globally caused widespread damage to ecological communities. Despite this, no other study has described basic characteristics of zooplankton egg banks among lakes with different acidification histories, such as variation in resting egg concentration. Theoretically, habitats with frequent periods of harsh environmental conditions are expected to select for resting egg production or prolonged dormancy in zooplankton, which would increase the size of the resting egg bank in lake sediments. In this study, we compared abundances of viable and inviable calanoid copepod resting eggs among three freshwater lakes with different acidification histories. While Swan Lake underwent major chemical and biological changes from acid and metal deposition, Teardrop and Bat lakes were relatively unaffected by historical acidification and had comparatively constant, but different pH over time. We also tested the effect of age on the viability of resting eggs. As predicted, higher numbers of viable resting eggs were found in recent sediments from acid-recovering Swan Lake compared to study lakes with relatively temporally constant environments (Teardrop and Bat lakes) when the total number of eggs was held as a covariate. We detected this result in spite of similar pelagic abundances of Leptodiaptomus minutus, the dominant species in zooplankton communities of these lakes. This pattern did not necessarily hold for inviable egg concentrations since these eggs were more abundant in both Swan and Bat lakes compared to Teardrop Lake in older sediments (1939–1951, 1800s). Within study lakes, the abundance of viable resting eggs declined with increased egg age. Further study is required to test mechanisms underlying these patterns. Handling editor: S. I. Dodson  相似文献   

4.
The freshwater isopod Paramphisopus palustris is ubiquitous and abundant in the groundwater-fed wetlands of the Swan Coastal Plain around Perth, Western Australia. Taxonomically, an additional variety (P. palustris fairbridgei) and species (P. montanus) are recognized from geographically outlying localities. Here a 486 bp fragment of cytochrome c oxidase subunit I (COI) mtDNA was sequenced in 68 individuals from 23 localities in order to evaluate the accepted taxonomy, to examine the evolutionary history of the species, and to identify lineages to prioritize conservation of wetlands already substantially modified. MtDNA showed individual populations to be largely distinct and differentiated. The 41 unique haplotypes formed seven independent, geographically defined networks. Phylogenetic analysis retrieved corresponding subclades, with three well-supported larger clades occurring (1) north of the Swan River, (2) south of the Swan River, and (3) in an area further south. A clear pattern of isolation by distance was detected suggesting an ancient serial founder event, with the pattern possibly persisting in the face of limited gene flow through priority effects. The possibility of incipient speciation, the monophyly of the recognized subspecies and the paraphyly of P. palustris with respect to P. montanus, suggest that the current taxonomy is invalid and requires re-examination. Divergences suggest a mid- to early Pliocene divergence of the major clades, with early Pliocene divergences among subclades probably driven by documented intense arid periods. Lineages are present in wetlands in geologically younger environments suggesting in situ survival and persistence. Seven Evolutionarily Significant Units were identified for the conservation of Paramphisopus, two of which are not currently represented in conservation reserves. With increased water demand and the negative impact of surrounding land-use, the current study provides a first phylogeographic assessment of conservation priorities for wetlands of the Swan Coastal Plain. Electronic supplementary material The online version of this article (doi: ) contains supplementary material which is available to authorized users. Handling editor: C. Sturmbauer  相似文献   

5.
Non-native species of fish threaten native fishes throughout North America, and in the Rocky Mountains, introduced populations of lake trout threaten native populations of bull trout. Effective management of lake trout and other exotic species require understanding the dynamics of invasion in order to either suppress non-native populations or to prevent their spread. In this study, we used microsatellite genetic data to estimate the number of lake trout that invaded a population of bull trout in Swan Lake, MT. Examination of genetic diversity and allele frequencies within the Swan Lake populations showed that most of the genes in the lake trout population are descended from two founders. This emphasizes the importance of preventing even a few lake trout from colonizing new territory.  相似文献   

6.
From Australia to Asia (China),the main species of the migratory bird are the waders and terns. In Oct. 1999,an invitation was extended by Dr. Clive Minton of the chairman of the Victorian Wader Study Group (VWSG) to catch and band waders and terns at Sandy Point,Swan Bay,Swan Island,Anderson Inlet/Inverloch,Phillip Island,Mud Islands,Geelong and Werribee and so on. The paper summarizes the methods (catch,bio-metric data,banding,recoveries,flagging,satellite tracking,data analysis on computer,fox control et al.)and results (species of wader and tern,number of banding from 1975 to 1999,calculate the minimum age,breeding success,age of first breeding,levels of fat deposits,molt,the distance of moved) and discuss. The total 141 787 waders,about 35 species (from 1975 to 1999) and 6 057 chicks and adults of terns,about 7-9 species (1998-1999) were captured and banded by the Victorian Wader Study Group.  相似文献   

7.
X Zhu  L A Burgoyne  J D Skinner 《Génome》1991,34(3):493-494
A putative old and ubiquitous interspersed DNA repeat family was identified from TaqI restriction, M13 cloning, and sequencing of the genomic DNA of a Mallard (Anas platyrhynchos), a Muscovy Duck (Cairina moschata), a Toulouse Goose (Anser anser), and a Black Swan (Cygnus atratus). A 425-bp consensus core sequence was obtained for the interspersed family. The 425-bp unit was about 2% of the avian genome and was found to be conserved in at least four genera of the order Anseriforme: Anas, Anser, Cairina, and Cygnus.  相似文献   

8.
The impact of Quaternary glaciation on the development of phylogeographic structure in plant species is well documented. In unglaciated landscapes, phylogeographic patterns tend to reflect processes relating to persistence and stochasticity, yet other factors, associated with the palaeogeographical history of the landscape, including geomorphological events, can also have a significant influence. The unglaciated landscape of south‐western Western Australia is an ideal location to observe these ancient drivers of lineage diversification, with tectonic activity associated with the Darling Fault in the late Pliocene attributed to patterns of deep phylogeographic divergence in a widespread tree from this region. Interestingly, other species within this region have not shown this pattern and this palaeogeographical boundary therefore presents an opportunity to examine age and historical distribution of plant species endemic to this region. In this study, we assess patterns of genetic diversity and structure across 28 populations of the widespread shrub Banksia sessilis using three cpDNA markers and nine nuclear microsatellite markers. Sixteen cpDNA haplotypes were identified, comprising two major chloroplast DNA lineages that are estimated to have diverged in the Pliocene, approximately 3.3 million years ago. This timing coincides with major geomorphological processes in the landscape, including the separation of the Darling Plateau from the adjacent Swan Coastal Plain, as well as eustatic changes on the Swan Coastal Plain that are likely to have resulted in the physical isolation of historical plant lineages. Chloroplast lineages were broadly aligned with populations associated with older lateritic soils of the Darling Plateau and Geraldton sandplains or the younger sandy soils associated with the Swan Coastal Plain and Southern Coastline. This structural pattern of lateritic versus non‐lateritic division was not observed in the nuclear microsatellite data that identified three genetic clades that roughly corresponded to populations in the North, South, and Central portions of the distributions.  相似文献   

9.
为查清内蒙古乌梁素海湖泊湿地疣鼻天鹅(Cygnus olor)繁殖期和秋季迁徙前期种群数量,2014至2017年采用路线统计法和样点统计法对其进行精确计数统计,结合近十余年来的文献数据和监测记录,探讨了种群数量的变化及原因。结果显示,2015至2017年春季繁殖成鸟数量依次为84只、92只、80只,基本稳定;2014至2017年,秋季种群数量依次为411只、302只、281只、153只,逐年减少;近几年适宜繁殖地和觅食地面积不断缩小、天敌偷袭、捡蛋和投毒等因素影响亚成鸟和幼鸟的生存。根据文献和保护区监测数据,1996至2004年种群数量逐年增多,与自然保护区的建立、严禁捡蛋和没收猎枪有关,而2005至2013年因干旱缺水、水域被开发利用、芦苇(Phragmites australis)和宽叶香蒲(Typhalatifolia)面积扩增、水质恶化、富营养化加重等原因种群数量下降。研究表明,近几年乌梁素海被过度开发利用,人为干扰频繁,影响疣鼻天鹅正常繁殖栖息;栖息地的科学管理和严禁捡蛋及投毒行为,对该种群的生存及增长至关重要。  相似文献   

10.
包头南海子湿地春季北迁大天鹅食性初步分析   总被引:2,自引:0,他引:2  
2013年2~4月,采用粪便显微组织学分析方法对在包头南海子湿地越冬的大天鹅(Cygnus cygnus)的食性进行了分析。大天鹅的春季食物主要为酸模叶蓼(Polygonum lapathifolium)、玉米(Zea mays)、光果甘草(Glycyrrhiza glabra)和香蒲(Typha amgustifolia)。通过频率转换分析发现,黄河开河之前,首批迁徙到湿地的18只大天鹅,采食酸模叶蓼为主,占食物组成的99.4%;黄河开河之后,迁徙到湿地的120只大天鹅,采食玉米为主,占食物组成的69.7%,光果甘草、香蒲所占比例相对较小,分别为18.3%和11.2%。两个时间段迁徙至南海子湿地的大天鹅,采食植物的种类存在明显差异。大天鹅采食植物的种类与本地的优势植物以及农业生产有着紧密的关系。  相似文献   

11.
《Plains anthropologist》2013,58(94):31-42
Abstract

Craniometric comparisons were used to determine tribal affiliation of three Le Beau Phase sites and one Bad River Phase site from South Dakota: Four Bear (39DW2), Oahe Village (39HU2), Swan Creek (39WW7), and Stony Point Village (39ST235). Oahe Village and Swan Creek classified as Arikara in all analyses. Four Bear and Stony Point Village probably also represent Arikara populations although the evidence is less conclusive. Some individuals were assigned to the Mandan in each site. While alternative explanations are possible, those cases may indicate that some Mandan were living in these villages. If Mandan burials are present at Four Bear and Swan Creek, they are not associated with the presence of secondary burials as suggested by Hurt (1957). Arikara populations of the Post-Contact period show considerable variation through time and space.  相似文献   

12.
Using to analysis of hypervariable fragment polymorphism in the control region of mitochondrial DNA(268 bp), the genetic variability of Swan goose Anser cygnoides L., included in the first category of endangered species in the Russian Red Book, has been investigated. Samples from the two main groups nesting in Russia—the Far Eastern group (Khabarovsk krai, n = 38) and the Dauric group (Chita region, n = 10) were examined. Eleven haplotypes were described. The genetic diversity of Swan geese was low comparable with that observed in some other globally endangered Eurasian goose species. Nucleotide and haplotype diversity of goose from Khabarovsk krai was 0.0031 and 0.65, respectively; in those from Chita region, 0.0041 and 0.80; and for in total group, 0.0074 and 0.77, respectively. No identical haplotypes in Swan goose from Far Eastern and Daurical groups have been demonstrated. However, the small sample size does not allow us to make final conclusions on the degree of genetic differentiation between these groups.  相似文献   

13.
Kirby  Jeff  Delany  Simon  Quinn  John 《Hydrobiologia》1994,279(1):467-482
We review the recent history of the Mute Swan in Great Britain and discuss the factors known to be affecting the population. Following a rise in the national population during the 1950s, numbers decreased sharply during the 1960s, and changed relatively little between 1970/71 and 1984/85. However, there has been considerable regional variation in the fortunes of Mute Swan populations during this period, with dramatic declines in some areas. Although several factors were thought to be contributing to such declines, poisoning from the ingestion of lead fishing weights was shown to be the largest single cause of death amongst swans in a number of areas. Voluntary measures to address this problem were initiated in 1982 and culminated in the banning by law of use of lead weights in 1987.Winter counts were used to investigate the current status and distribution of the Mute Swan in Great Britain and to examine long-term regional trends. The maximum total count reached 12600 birds in January 1990, which compares with an average of 9550 for the previous five winters. However, accounting for birds missed, the population may now number at least 25 000. Peak total numbers have mostly occurred in September, after which numbers remain approximately stable until December and then decline. Patterns of seasonal abundance vary between regions and habitats and these are discussed.The British population has increased dramatically since 1986/87 and reached its highest level for 27 years in 1987/88. There have been recent increases in most regions with record levels being reached mostly in 1987 or 1988, and there has been growth in the numbers on all habitat types, especially on reservoirs, gravel extraction pits and freshwater marshes. The timing of these increases corresponds very closely with the introduction of legislation against the use of lead fishing weights, and the incidence of lead poisoning is known to have been considerably reduced by such measures.  相似文献   

14.
ABSTRACT

The venerid bivalve Eumarcia fumigata was a common species in Western Australia (WA) during the Pleistocene, where it was distributed as far north as Shark Bay. It became extinct in WA as the climate changed several thousand years ago but remains common in eastern Australia from southern Queensland to South Australia and Tasmania. The species has recently reappeared in the Swan River, probably due to shipping movements. Of the > 60 marine and estuarine species introduced into WA it is only the third confirmed introduction from eastern Australia, and the first that is a reappearance in the Swan River of a species present in the geological past. The present reappearance of E. fumigata, and the introduction of other species, has been made possible by the removal of a rocky bar at the mouth of the estuary and the creation of more marine conditions in the lower Swan estuary.  相似文献   

15.
P. Howey    R. G. Board    D. H. Davis  Janet  Kear 《Ibis》1984,126(1):16-32
A sophisticated radiotelemetry system was used to monitor continuously the temperature, relative humidity and the incidence of parental movement sufficient to admit light to, or turn the eggs in, the nest cup of (number of days recordings m parenthesis): Black Swan Cygnus atratus (68); Barnacle Goose Hrantal leucopsis (70); Whooper Swan Cygnus cygnus (28) and Greylag Goose Ansev anser (26). The following features were common to all the nests: (1) a slow rise in the temperature of the nest cup with the onset of incuhation; (2) a temperature gradient in the vertical plane of the nest cup throughout incubation; (3) a diurnal rhythm in the temperature and humidity of the nest cup, this being caused by bird behaviour rather than the ambient environment; (4) nesting materials dried out during incubation thereby accentuating the steepness of the diffusion gradient between a real egg and the atmosphere of the nest cup; (5) the eggs, which were turned between 0.594.95 times an hour, were rotated mainly around their long axes.  相似文献   

16.
The prevalence of Austrobilharzia terrigalensis infection in the Silver Gull (Larus novaehollandiae) population of the Swan Estuary, Western Australia was shown from autopsies to be 80.7% with a median worm load of five pairs. Maximum egg-output was recorded about 3 weeks after the first eggs were voided in the faeces of experimentally-infected birds. Few worms were thought to live longer than 2–3 months. Egg-output from naturally infected L. novaehollandiae was generally low, with a median rate of 24 eggs/g for birds living within 125 km radius of Perth. The liver, duodenum and small intestine were the organs most heavily involved in A. terrigalensis infection.  相似文献   

17.
Summary Zwitterion buffers are often used to modulate the pH of cell culture medium but their effect on cultured cells is controversial. We found that addition of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) caused superoxide dismutase (SOD) inhibitable increases in nitroblue tetrazolium dye reduction and SOD and catalase inhibitable decreases in the growth of cultured bovine pulmonary artery endothelial cells. The findings suggest that HEPES stimulates endothelial cells to make toxic oxygen metabolites that contribute to decreased cell growth. This work was supported in part by the National Institutes of Health, Colorado and American Lung Associations, Colorado and American Heart Associations, the Council for Tobacco Research, and the Kroc, Hill, Swan and Kleberg Foundations. Dr. Bowman is a Clinician Scientist Awardee of the American Heart Association.  相似文献   

18.
Samples collected monthly from the Swan Estuary between March 1978 and May 1979, together with environmental data for 1977 to 1980, have been used to elucidate various aspects of the reproductive biology of Amniataba caudavittata in this estuary. The gonads of A. caudavittala started to develop rapidly in the spring, when day length, water temperatures and salinities were increasing markedly. Spawning, which occurred mainly towards the top end of the upper estuary, was initiated in November, when water temperatures and salinities in that region were c. 24° C and 9‰, and it peaked in December/January when they were c. IT C and 17%○, Maturity is attained by at least the majority offish at the end of the second and each subsequent year of life. Although some of the larger 1-year-old fish attained maturity, this occurred in only one of the two tributary rivers, possibly reflecting differences in the salinity regimes in these rivers. Fecundities ranged from 50 000 in a 150-mm fish to 705 000 in a 254-mm fish, with a mean of 310 000. The mature, unfertilized eggs are small and spherical and have a diameter of 560 μm. The larvae are pelagic and characterized by an elongate body, which becomes moderately deep and laterally compressed during development, a short to moderate, tightly-coiled gut, a distinct gap between the anus and the origin of the anal fin and 25 or 26 myomeres. The development of fins and settlement of A. caudavittata larvae occurs at a smaller size than in the larvae of other terapontid species previously described. The success of A. caudavittata in the Swan Estuary can be attributed in part to its production of very large numbers of eggs at a time when, due to low fresh water discharge and a smait tidal range, conditions in the estuary are relatively stable. Comparisons between the biology of A. caudavittata and that of other abundant teleosts that spawn in south-western Australian estuaries show that these species exhibit a wide range of reproductive strategies.  相似文献   

19.
The changes in the serum level of free fatty acids (FFA) in the migratory Canada goose (Branta canadensis interior) breeding in Ft. Churchill (Manitoba, Canada) and wintering in Swan Lake (Missouri, U.S.A.), were studied during the different periods of its yearly life cycle. The lowest serum FFA level was noted during the spring premigratory phase (early March) at Swan Lake, and the highest during moult (early August) at Ft. Churchill. Serum FFA level during the spring postmigratory period (early May at Ft. Churchill) was significantly higher than that during the spring premigratory period and the breeding period (early at Ft. Churchill). No signigicant difference in FFA levels was noted between the fall premigratory (early September at Ft. Churchill) and the fall postmigratory (mid-October at Swan Lake) periods. The significance of the seasonal variations in serum FFA level is discussed in relation to the cyclic physiological events taking place in the bird.  相似文献   

20.
迁徙水鸟保护对生物多样性保护具有重要意义。开展水鸟种群数量和幼鸟比例监测,对科学评估其种群变化趋势、制定长期保护策略具有重要价值。长江中下游湿地是东亚-澳大利西亚迁徙路线上重要的水鸟越冬区之一。本研究采用野外同步调查等方法对该区域87个湿地的亟需保护和具有代表性的10种大型越冬水鸟,其中雁形目6种,分别是鸿雁Anser cygnoides、豆雁A.fabalis、灰雁A.grus、白额雁A.albifrons、小白额雁A.erythropus和小天鹅Cygnus columbianus;鹤形目4种,分别是白鹤Leucogeranus leucogeranus、白枕鹤Antigone vipio、灰鹤Grus grus和白头鹤G.monacha,进行了长期监测(2003—2019年冬季),并结合相关文献,评估其种群变化趋势、幼鸟比例和死亡率。研究结果如下:(1)2005—2019年3种水鸟(豆雁、灰雁和灰鹤)的种群数量呈上升趋势,7种水鸟(鸿雁、白额雁、小白额雁、小天鹅、白鹤、白枕鹤和白头鹤)种群数量呈下降趋势;(2)种群趋势下降组(N=7)和上升组(N=3)的幼鸟比例均值在2016—2...  相似文献   

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