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1.
勺嘴鹬(Calidris pygmaea)是全球极危鸟类,估计其种群数量为360~600只。根据近年来的野外调查和历史资料查阅,勺嘴鹬在中国沿海各省级行政区域均有分布。本文介绍了勺嘴鹬在中国的种群数量和分布。其中江苏省的东台市和如东县的滩涂湿地是目前已知的勺嘴鹬全球数量最大的迁徙停歇地。东台市滩涂单次调查记录的勺嘴鹬最大数量为144只,如东县滩涂单次调查记录的勺嘴鹬最大数量为103只。广东省雷州半岛的滩涂和福建省闽江口的滩涂为勺嘴鹬在中国最大的两个越冬地。滩涂栖息地的丧失和退化、非法捕猎、环境污染以及人类活动干扰是勺嘴鹬面临的主要威胁。为了更好地保护勺嘴鹬,我们建议加强对勺嘴鹬关键栖息地的保护与管理,加强对滩涂湿地保护的宣传教育,加强对中国沿海勺嘴鹬的调查研究以及同其他国家地区的交流合作。  相似文献   

2.
段后浪  于秀波 《生态学报》2023,43(15):6354-6363
中国滨海湿地是东亚-澳大利西亚迁徙路线上候鸟重要的停歇地、繁殖地和越冬地,土地利用变化所引发的滨海湿地退化导致水鸟栖息地类别和面积发生了很大转变,影响迁徙水鸟种群数量的稳定性。然而,土地利用变化在哪些区域和多大程度上影响了迁徙水鸟的栖息地分布尚不清晰。以土地围垦典型区域黄渤海滨海湿地为研究区,以受胁濒危水鸟物种勺嘴鹬、大滨鹬、大杓鹬、小青脚鹬、黑脸琵鹭、黄嘴白鹭、遗鸥、黑嘴鸥为研究对象,结合物种分布模型MaxEnt和GIS空间分析,模拟2000、2015、2020年水鸟栖息地时空分布,探索过去20年栖息地分布的时空变化,分析水鸟种群变化趋势,识别水鸟栖息地保护优先区域,提出水鸟栖息地保护管理建议。结果显示:2000—2020年,8个水鸟物种栖息地主要分布在渤海湾、莱州湾、江苏盐城沿岸、如东-东台沿岸区域。所有物种的栖息地面积均呈不同程度的下降趋势,其中7个物种栖息地下降比例超过50%,下降的区域主要分布在渤海湾、江苏盐城沿岸、东台条子泥、小洋口沿岸,滨海湿地丧失是导致水鸟栖息地面积下降的直接因素。7个物种种群数量呈下降趋势。研究所确定的水鸟保护优先区面积达240.32 km2...  相似文献   

3.
树叶变黄,气温降低,南迁的水鸟陆续起程,开始漫长的迁徙之旅,准备到达越冬栖息地度过寒冷的冬季。鸟类在繁殖地与越冬地之间定期、有规律的移动称为鸟类迁徙,是自然界最壮观的景象之一。水鸟是指那些生态上依赖湿地生存的鸟类。如水中游泳的天鹅、雁、鸭、鹈鹕、鸬鹚;水域边缘活动的鸥、燕鸥、鹬和鸺;沼泽、苇地、农田等地常见的各种鹤、鹃、鹳、和鹭以及海洋性鸟类鹱、信天翁、海燕等。这些鸟的种类繁多,数  相似文献   

4.
树叶变黄,气温降低.南迁的水鸟陆续起程.开始漫长的迁徙之旅,准备到达越冬栖息地度过寒冷的冬季。鸟类在繁殖地与越冬地之间定期、有规律的移动称为鸟类迁徙,是自然界最壮观的景象之一。  相似文献   

5.
该文报道了西滨鹬 (Calidris mauri) 在美国阿拉斯加州育空-卡斯科奎姆河三角洲相对较小的空间尺度上所表现的集群繁殖行为。在开始产卵之前, 西滨鹬雄鸟聚集在一处 36 hm2的区域鸣唱飞行, 进行求偶炫耀。随后在该区域营巢时, 西滨鹬也保持着集群状态。检验了三个常用于解释具领域行为的物种的集群繁殖的假说:社会成员选择假说、捕食假说和物质资源限制假说。结果表明, 与斑块可利用性相比, 分散的个体常栖息于地势平坦的苔原栖息地斑块, 而集群个体常筑巢于地势起伏的苔原栖息地斑块, 因此, 该研究支持物质资源限制假说。在地势起伏的苔原栖息地斑块集群营巢的西滨鹬繁殖成功率较低, 这表明西滨鹬的这种栖息地占有模式符合理想的等级分布。在研究样地中, 年长且更具攻击性的雄鸟向雌鸟求偶的次数更多, 并且保卫位于地势平坦的苔原栖息地斑块上更大的领域; 相比之下, 年幼且攻击性较弱的雄鸟则聚集在地势起伏的苔原栖息地斑块。通常情况下, 繁殖期的集群多集中于某种关键资源的分布区内或分布区附近, 但西滨鹬繁殖集群的出现是由于年长和处于优势地位的个体将年幼和处于从属地位的个体排斥出高质量的栖息地。虽然, 繁殖领域的集群现象在很多非群居的鸟类中都曾有报道, 但该文是首次对非群居的单配制鸻鹬类物种在孵卵之前的集群繁殖行为进行了定量研究。  相似文献   

6.
鸟类的行为还吸引了人们的想象力。它们仅仅凭借着飞翔就能激发几代诗人的灵感,它们的迁徙让科学家们感到震惊。斑尾塍鹬每年在夏季繁殖地和冬季觅食地之间的迁徙距离达到11500公里,从阿拉斯加到新西兰,不间断的8日飞行,如同史诗般令人瞠目。  相似文献   

7.
浙江舟山五峙山列岛夏季繁殖水鸟资源及其分布动态   总被引:1,自引:0,他引:1  
1989~2007年,对浙江舟山五峙山列岛自然保护区繁殖水鸟进行调查和监测,记录繁殖水鸟的种类、数量、分布及其繁殖生态。在五峙山列岛繁殖的水鸟主要有黑尾鸥Larus crassirostris、黄嘴白鹭Egretta eulophotes、小白鹭E.garzetta、中白鹭Mesophoyx intermedia、大凤头燕鸥Sterna bergii、黑枕燕鸥S.sumatrana和蛎鹬Haematopus ostralegus等7种。自1988年保护区建立以来,尤其是近年来,五峙山列岛繁殖水鸟的种类和珍稀鸟类黄嘴白鹭的繁殖数量呈上升趋势,其中黄嘴白鹭和大凤头燕鸥大繁殖群的出现大大提高了保护区的保护价值,不同年份间鸟类总体数量保持相对稳定。五峙山列岛繁殖水鸟的资源和分布动态呈现两个值得关注的现象:一方面,由于繁殖资源限制,繁殖种类间存在竞争替换;另一方面,不同繁殖年间繁殖水鸟在不同岛屿的分布数量存在较大的波动。其内在的影响因素值得进一步探讨,这对有针对性地制订保护和管理对策,降低黄嘴白鹭的竞争压力,最大限度地提高保护区繁殖水鸟的多样性具有重要价值。  相似文献   

8.
追踪候鸟的迁徙活动是全面认识其生活史年周期的重要途径。中杓鹬(Numeniusphaeopus)在全球广泛分布,但在东亚-澳大利西亚候鸟迁飞区的迁徙活动一直缺乏追踪研究。2018年2月,在澳大利亚西北部的布鲁姆为捕捉到的中杓鹬成鸟佩戴平台发射终端或全球定位系统-全球移动通讯系统追踪器,以确定其迁徙日程、迁徙路线以及迁徙停歇地和繁殖地的地理位置。我们从成功追踪的7只个体获取了6 378条精度高于1 km的位点数据。分析结果表明,在春季,中杓鹬的迁徙时长为(36±4)d,其间在1~3个迁徙停歇地的停留日期为(23±2)d,从越冬地到繁殖地的迁徙距离为(9 795±346)km(n=7)。追踪的中杓鹬在俄罗斯东部和中部区域繁殖,不同个体的繁殖地纬度相近而经度范围较广。在秋季,中杓鹬的迁徙时长为(90±27)d,相比春季迁徙时长更长;其间,在2~4个迁徙停歇地停留(79±29)d,从繁殖地到越冬地的迁徙距离为(10 101±520)km(n=5)。无论在春季还是秋季迁徙,迁徙停歇地广泛分布于东亚、东南亚沿海及内陆区域。大部分个体春季和秋季的迁徙路线相近,成功追踪的个体均在秋季返回了上一年的越冬地,这表明中杓鹬对越冬地具有很高的忠诚度。  相似文献   

9.
盐地碱蓬(Suaeda salsa)盐沼湿地是黄渤海地区河口区域的重要湿地类型, 是水鸟迁徙停歇期的重要栖息地。本研究以辽河口国家级自然保护区为研究地点, 通过对盐地碱蓬盐沼湿地和相邻泥质滩涂两个固定样区连续三年的水鸟组成调查和行为观察, 分析盐地碱蓬盐沼湿地在鸻鹬类多样性维持和栖息地利用中的作用。共记录到鸻鹬类水鸟28种6,348只次, 其中盐地碱蓬湿地记录到4科13种, 泥质滩涂记录到4科27种, 泥质滩涂的物种多样性显著高于盐地碱蓬盐沼湿地。此外, 盐地碱蓬盐沼湿地与相邻的泥质滩涂的鸻鹬类鸟类群落组成存在较大差异, 盐地碱蓬盐沼湿地的鸟类群落组成以体型较大的大杓鹬(Numenius madagascariensis)、白腰杓鹬(N. arquata)、灰鸻(Pluvialis squatarola)等为主, 而泥质滩涂以环颈鸻(Charadrius alexandrinus)、黑腹滨鹬(Calidris alpina)等小型鸻鹬类为主, 这说明两种生境在鸟类多样性维持中具有不同的功能。行为分析发现, 泥质滩涂中栖息鸟类的主要行为为取食(58.71%-93.26%), 而盐地碱蓬盐沼湿地鸟类的行为既包括较大比例的取食, 也包括休息, 特别是在春季迁徙期。这进一步说明, 两种生境在水鸟的栖息地利用中具有一定的生态功能差异。尽管盐地碱蓬盐沼湿地记录到的鸟类物种数和数量均低于泥质滩涂, 但是, 两种生境中存在较大比例的共同分布物种, 这说明其生态功能具有较强的生态互补性, 二者作为一种独特的湿地景观组合, 在鸻鹬类迁徙停歇期的栖息地利用和物种多样性维持中发挥着不可替代的作用。  相似文献   

10.
海南清澜港红树林湿地鸟类初步研究   总被引:14,自引:0,他引:14  
记录到清澜港红树林湿地鸟类52种,隶属于19科9目。其中水鸟31种,陆生鸟类21种;留鸟29种,迁徙鸟类23种。在这些鸟类中有国家二级保护鸟类3种,中日候鸟协定名录中的鸟类17种,中澳候鸟协定名录中的鸟类18种。清澜港鸟类物种数量存在季节变化,无论是从总的鸟类种类看,还是从水鸟种类看,都是以冬季鸟类种数最多,而夏季鸟类种数最少,年变化趋势是:冬季>秋季>春季>夏季。鸟类物种数量季节变化的最重要原因是迁徙鸟类的周年变化。不同栖息地的食物条件和滩涂面积不同,鸟类的组成和数量也不同。本文还对清澜港鸟类的多样性进行了分析。  相似文献   

11.
Purulent wounds in 88 victims of the Armenian earthquake with the syndrome of long-term squeezing were examined microbiologically and the experience with using antimicrobial drugs for their treatment was analyzed. In all the cases microbial associations were detected, coliform and nonfermenting gram-negative bacilli, enterococci, anaerobes and yeast-like fungi being isolated from 80, 20, 15 and 25 per cent of the patients respectively. 130 bacterial strains were studied in detail. 80 to 100 per cent of the bacterial isolates were resistant to the antibiotics routinely used in surgical practice, i.e. benzylpenicillin, tetracycline, levomycetin, kanamycin, cephalothin and cefazolin and highly sensitive to new antimicrobial drugs belonging to ureidopenicillins (mezlocillin), quinolones (ciprofloxacin) and cephalosporins of the 3rd generation (cefoperazone and ceftazidime). Retrospective estimation of the antibiotic therapy revealed its inadequacy in 55.7 per cent of the patients for the most part because of the isolates resistance. The 19 variants of the antibiotic use prescribed by the physicians mainly included penicillins, aminoglycosides and their combinations (in 67.2 per cent of the cases). The use of the highly efficient drugs of the groups of ureidopenicillins and quinolones was extremely rare which was likely due to lacking of information on the drugs.  相似文献   

12.
N A Dmitrieva 《Tsitologiia》1986,28(7):745-748
The developing taste buds of vallate papillae were studied with electron microscope in rats during the first 7 days after birth. Two types of cells--light and dark--are identified in the taste buds of a one day old animal. The apical parts of dark cells are characterized by numerous dark granules. A distinguishing feature of light cells is the presence of synaptic contacts with afferent intragemmal nerves. On the 4th day of development on the top of the apical parts of the cell, a microvillar apparatus is seen to form, which does not yet communicate with the oral cavity. On the 7th day, basal cells appear in the taste buds. Some of these cells are seen mitotically dividing. The differentiated microvillar apparatus now communicates with oral cavity. The structure of the taste buds is getting similar to that in the adults. The structural and functional peculiarities of the developing taste buds are discussed in association with the period of ontogenesis under consideration.  相似文献   

13.
The changes in the size of Purkinje cell (PC) nucleolus in the lateral and medial cerebellum zones were studied in dogs with different degree of neurologic status recovery after clinical death of various etiology and duration. PC always possess one nucleolus in the control and experimental groups. In the case of complete neurologic status recovery of animals the area of PC nucleolus increases in both zones studied, irrespective of the cause of clinical death. In the case of neurologic disorders the increase in PC nucleolus area is clearly expressed only in the medial zone of the cerebellum, being insignificant in the lateral zone. It is suggested that adaptive characteristics of PC are distinct in the two compared zones, which leads to greater PC vulnerability in the lateral zone during deep hypoxia.  相似文献   

14.
This study determined the optimum number of tubules to be counted per testis cross section, and the number of animals per treatment group, when changes in stage frequencies in the cycle of the seminiferous epithelium are criteria for assessing effects of treatment on spermatogenesis. A data base of 9,672 observed and staged tubules was collected from testicular cross sections of 15 Sprague-Dawley rats. A significant variation between animals was found for the frequencies of Stages I, II, IV, VI, VIII, and XIII. Computer simulation was used to randomly select different combinations of animal and tubule numbers from the observed data. Stage frequency means from each simulation experiment were compared statistically to observed mean frequencies. A model that used data from all 14 stages was analyzed. The following conclusions were made: a) a minimum of 200 tubule cross sections/testis is recommended for estimating stage frequencies; b) for a fixed number of tubules scored, the number of animals sampled is more important than the number of tubules per animal in reducing variance; c) to detect a difference of 2 standard deviations from the mean with a 2% error rate and examining 200 tubules/testis, at least 12 animals must be used per group when assessing all 14 stages; d) when individual stages are examined using 10 animals per group, only Stage VII has 80% or greater power of test (alpha = 0.05) to detect a frequency difference; e) pooling stages into 3-4 groups is recommended to improve the power of detecting a treatment difference.  相似文献   

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The authors of the article focus on the transition of the former Soviet state of Ukraine to a market economy. One aspect of the analysis is the cultural values and attitudes of the citizens in a new situation. Market economy and entrepreneurship demand new types of motivation and individual values from people. A challenge for social psychology in the country is the further elaboration of methodological basis of research.  相似文献   

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The presence, location and degree of immunoexpression of various microfilament (MF) and intermediate filament (IF) systems (actin, cytokeratins, desmin, vimentin) were studied in the excurrent ducts of the testis in sexually mature and active galliform (Japanese quail, domestic fowl, turkey) and anseriform (duck) birds. These proteins were variably expressed between the epithelia and periductal tissue (periductal smooth muscle cell layer and interductal connective tissue) types and between species. Variable heterogeneous co-expression of filament systems was also found in the various duct epithelia and periductal tissue types: co-expression of filament systems was the rule rather than the exception. In the duck, neither vimentin nor cytokeratin was present in any of the tissues, whereas actin and desmin (absent in the rete testis) were co-expressed in the efferent ducts and epididymal duct unit (comprising the ductus conjugens, ductus epididymidis and ductus deferens). Actin, desmin and vimentin were generally co-expressed in the rete testis, efferent ducts and epididymal duct unit of the quail, domestic fowl and turkey, with vimentin being more strongly immunoreactive than actin and desmin in the epididymal duct unit, but more weakly immunoexpressed in the efferent ducts. Cytokeratin was present and co-expressed with actin, desmin and vimentin in the rete testis, efferent ducts and epididymal duct unit of the domestic fowl and turkey, but not in the quail and duck. The periductal smooth muscle cell layer and interductal tissue co-expressed actin, desmin and vimentin variably in all birds. Luminal spermatozoa of both the turkey and duck were immunonegative for all protein systems, whereas those of the quail and domestic fowl co-expressed actin, desmin and vimentin moderately or strongly. The tissues of the reproductive tract of male birds thus contain cytoskeletal protein systems that are variably but mostly co-expressed and whose contractile ability appears necessary and sufficient for transportation through the various excurrent ducts of the voluminous testicular fluid and its high sperm content, characteristic features of male avian reproduction.  相似文献   

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