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1.
白鹡鸰(Motacilla alba alboides)在拉萨地区的繁殖生态   总被引:4,自引:0,他引:4  
在拉萨地区,白雌雄共同筑巢,巢的平均内径为7.87±1.65cm(n=4)、外径16.5±2.38cm(n=4)、巢高12.75±5.62cm(n=4)、巢深7.3±0.96cm(n=4)、平均离地高为0.35±0.64m(n=4)、巢重61.75±8.34g(n=4)。每窝产4~6枚卵,平均长径为21.3 ,短径为15.8 ,卵平均重2.3g。孵卵期为11~12天,双亲共同育雏,平均育雏期为15天,幼鸟离巢后仍靠亲鸟为生,雏鸟主要以鳞翅目的幼虫、蚯蚓、蜘蛛以及鞘翅目昆虫为食。  相似文献   

2.
宁夏苍鹭和夜鹭的数量及生态研究   总被引:6,自引:0,他引:6  
作者于1985~1990年在宁夏银川、卫宁平原等地用5年时间对苍鹭、夜鹭的数量和生态进行了调查研究。结果表明:苍鹭和夜鹭在宁夏为夏侯鸟,由于繁殖地减少、过度猎捕、环境污染而数量锐减,成为稀有鸟.苍鹭三月下旬开始营巢,产卵3~5枚,孵化期约26天,育雏期65天。夜鹭四月上旬开始营巢,产卵4~6枚,孵化期约27天,育雏期60天,苍鹭和夜鹭混合营巢,营巢、孵化、育雏均由双鸟共同承担.  相似文献   

3.
文章报道了小云雀inopinata亚种(Alauda gulgula inopinata)(以下称为小云雀亚种)在西藏拉萨地区的繁殖生态。小云雀亚种在拉萨地区一般4月下旬进入繁殖期,选择本地的冬小麦地等作为它们的繁殖生境。雌雄鸟均参加筑巢,筑巢期为3.8±1d(n=4),10个巢的大小为5.6±0.7cm×8.7±0.9cm(n=10),巢深4.1±0.3cm(n=10),巢的平均重量24.6±4.3g(n=5)。平均窝卵数为2.6±0.5枚(2~3枚,n=7),其中3枚者居多;产一窝卵需要2~3d,卵平均重量2.2±0.3g(1.8~2.8g,n=7),卵的大小为20.4±0.5mm(19~21)×14.2±3mm(14~15),(n=7)。平均孵卵期为15±0.6d(14~16,n=6),孵化率为67%,育雏期12±0.6d(11~13,n=6),雏鸟成活率仅50%。农业活动及天敌是影响孵化率及雏鸟成活率的主要因子。  相似文献   

4.
郑州鹭类的生态习性   总被引:9,自引:0,他引:9  
1999~2003年对河南郑州市区鹭鸟的生态习性进行了研究。结果表明:郑州市区共有夜鹭(Nycticoraxnycticorax)、池鹭(Ardeolabacchus)、白鹭(Egrettagarzetta)及苍鹭(Ardeacinerea)4种鹭鸟营巢繁殖,栖息地道路总长4600m,道路面积约132400m2。2003年栖息地共有鹭巢6762个,巢密度为0.051个/m2。平均每株行道树有鹭巢12.47个,多的超过30个。鹭类对营巢树的利用具有选择性。从种群数量上看,夜鹭占绝对优势,占98.05%,其次是池鹭,白鹭和苍鹭数量较少。据2003年统计,在市区停留的时间为:夜鹭212天,池鹭158天,白鹭147天。雏鸟留巢期为夜鹭49.17±0.835天,池鹭32.7±1.059天,白鹭41.43±1.134天,均较荒野地长。平均出雏数为:夜鹭2.85±1.268只,池鹭4.50±1.35只,白鹭4.43±1.27只。鹭鸟在市区繁殖是人类活动影响的结果,并对市区环境造成一定的影响。  相似文献   

5.
1996年乌鸫开始栖息于新乡地区,成为当地留鸟,但其繁殖状况并不清楚.为了弄清该地区乌鸫的繁殖生态,2017年3~7月,采用定位观察法,对新乡黄河湿地鸟类国家级自然保护区乌鸫的繁殖生态及巢址选择进行了详细研究,结果表明:新乡乌鸫3月初进入发情期,3月中旬可见到乌鸫配对,具有明显的占区行为.3月下旬开始营巢,营巢任务由雌鸟承担,营巢需时4~10d.最早产卵是3月28日,最晚产卵是5月16日,窝卵数为(5.09±0.70)(n=11)枚,产卵期为一周.卵长径(31.16±2.06)mm,卵短径(23.11±0.68)mm,卵质量(6.73±0.85)g.孵化期为13~14d,由雌鸟承担,孵化率为85.71%.育雏期为13~15d,成活率为54.17%.  相似文献   

6.
青海沙蜥雌性生殖对策及进化   总被引:2,自引:0,他引:2  
青海沙蜥是分布于青藏高原的卵胎生蜥蜴 ,雌性性成熟的最小 SVL是 5 0 .0 mm.窝卵数 1~ 5枚 ,平均 2 .74± 0 .86枚 (n=2 3) ,常见窝卵数 2~ 3枚 ,窝卵数随 SVL的增加而明显增加 (r=0 .70 30 ,P<0 .0 0 2 ) .单卵干重 0 .10~ 0 .2 0 g,平均 0 .14± 0 .0 0 5 g,随窝卵数的增加而显著变轻 (r=- 0 .70 77,P<0 .0 0 2 ) .窝卵干重 0 .2 0~ 0 .5 5 g,平均 0 .38± 0 .0 0 7g,随窝卵数和 SVL的增加而增加 (r=0 .8730 ,P<0 .0 0 1;r=0 .8776,P<0 .0 0 1) .与其卵生的近缘种相比 ,青海沙蜥雌性发育缓慢 ,性成熟较晚 ,年产单窝和较多窝卵数 .其生殖对策及进化是高寒环境选择的结果 .  相似文献   

7.
北京雨燕每年4月中句迁来,于5月末产卵,(1986年5月25日,1987年5月19日)多数雨燕每巢产卵三枚,通常每隔一日产一枚卵。卵呈橄榄状,纯白色。鲜卵重3.6820.16克,大小为25.7×16.1毫米(N=26)。孵卵期间卵失水率为11.7%-34.2%,孵卵期20-22天。育雏期为38-42天。雨燕年仅孵化一窝,孵化率为70.8%(N=23),存活率为93.89%(N=16)每对亲鸟可育雏1.82只。双雏幼鸟生长曲线与单雏幼鸟生长曲线不同。根据Ricklefs’的幼鸟生长方程(Gompertz与Logistic),Logistic方程为Wt=42[1 e^-0.22(t-1088)]^-1;Gompertz方程为Wt=42e^-0.159^-0.149(t-8.9)。根据Ricklefs’的检验方法。双雏幼鸟生长更符合Gompertz方程。幼雏于19日龄后体温相对稳定为35℃±2℃。北京雨燕每年8月离开呼和浩特。  相似文献   

8.
风头鸊鷉每年3月初迁来乌梁素海,10月末11月初离去.它们在蒲苇地营水面浮巢,巢材主要为苇茎,蒲叶和水草,巢的外径65cm,内径17cm,深3.5cm。窝卵数3~5枚,平均4枚,日产一枚卵圆形污白色卵。卵径平均36.39×54.87mm,卵重37.89。  相似文献   

9.
2014年5月21日,在内蒙古鄂尔多斯市库布齐沙漠发现苍鹭(Ardea cinerea)繁殖群,共658巢,分布在南北长约573m、东西长约2 400m的杨树林带中.苍鹭营巢于胸径为(0.34±0.02)m(n=56)杨树上,树高为(21.38±1.24)m(n=56).该发现是对库布齐沙漠苍鹭集中繁殖的首次记录  相似文献   

10.
树栖型苍鹭生态习性研究   总被引:1,自引:0,他引:1  
1998、1999年2月-10月,在辽宁省朝阳县对苍鹭的生态习性进行观察研究.该鸟在辽宁省为夏候鸟,每年最早2月26日迁来,最晚9月28日迁离,居留期210天左右.产卵始期为3月21日,隔日一枚,窝卵数5枚-7枚.产出第1枚卵后开始孵化,孵化期24天-26天,孵化率92.3%.幼鸟为晚成鸟,育雏期40天左右.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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