首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
黑翅鸢(Elanuscaeruleus)近年来在福建省的分布范围逐渐扩大,在福建省南部和东部为留鸟.对黑翅鸢的繁殖生态学研究结果说明,黑翅鸢繁殖期从4月~12月,筑巢对树种具有一定的选择性,每次繁殖都要重新筑巢,主要巢材为枯树枝,巢离地高度都在11m以上(n=4),巢外径为40cm,巢高30cm,巢深10cm(n=1).黑翅鸢每窝繁殖雏鸟3~4只,离巢时的雏鸟成活率都达到100%(n=4).繁殖期的黑翅鸢食物主要为鼠类.黑翅鸢的繁殖期长,繁殖力强,雏鸟成活率高,对人类活动环境的适应能力强,这可能是近年来黑翅鸢分布范围能够扩大的主要原因.  相似文献   

2.
河南郑州白鹭的繁殖习性   总被引:1,自引:0,他引:1  
于 2 0 0 0~ 2 0 0 3年繁殖季节对河南郑州市区白鹭的生态习性进行了研究 ,结果表明白鹭于每年 4月上旬至 8月底在市区营巢繁殖 ,在营巢地居留期约 1 45 d.白鹭窝卵数为 5 .1 4± 0 .69( 4~ 6)枚 ,出雏数为4.43± 1 .2 7( 2~ 6)只 ,孵化期为 2 5 .1 4± 0 .69( 2 4~ 2 6) d.孵化率为 86.1 1 % ,育雏期约 42 d,雏鸟滞留巢区比荒野地长 1 0 d左右 .雏鸟 2 0日龄统计成活率为 87.1 0 % ,雏鸟死亡原因多为恶劣气候条件所致 ,如大风、暴雨等  相似文献   

3.
于2008和2009年4—8月,在吉林省左家自然保护区和土门岭地区对黑枕黄鹂(Oriolus chinensis)的巢树和巢址特征进行了研究.运用逐步判别分析的方法对25处巢址和30个对照样方的生态因子进行分析,通过对Wilksλ值的检测确定各因子对判别模型的贡献率,根据生态因子的重要性和贡献率大小确定影响黑枕黄鹂选择的主要生态因素.在黑枕黄鹂选择的巢树中,蒙古栎(Quercus mongolica)所占比率最高,黑枕黄鹂偏爱选择树身高大、树冠体积较大的阔叶树筑巢.巢均位于水平侧枝上,距树主干平均距离为(3.5±0.9)m.逐步判别分析结果表明,树冠盖度、胸径、乔木密度和乔木高度是影响黑枕黄鹂巢址选择的重要生态因素.  相似文献   

4.
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   

5.
文章对黑喉石即鸟Saxicola torquata stejnegeri(Parrot)雏鸟的详细生长情况进行了描述.包括从0.5 d到12.5 d雏鸟离巢前的12~13 d,同时对雏鸟的体温也进行了测量.结合它们之间的关系提出了雏鸟的三个生长阶段.即变温阶段(0.5~4.5 d)、积累阶段(5.5~8.5 d)和恒温阶段(9.5~12.5 d).  相似文献   

6.
红腹角雉(Tragopan temminckii)的孵卵和育雏行为研究   总被引:2,自引:0,他引:2  
于2005年4-7月、2006年3-7月,采用焦点动物取样法和所有事件取样法对四川老君山自然保护区红腹角雉(Tragopan temminckii)的孵卵和育雏行为进行了研究.对3个孵化期内的树上巢分别观察16、5和9 d,记录到典型行为8种.观察的时段包括孵卵中期、孵卵后期和巢内育雏期.孵卵中、后期以出雏前7 d为界,中、后期之间的行为频次和累计时间均存在明显差异.Spearman秩相关检验显示翻卵日频次和日翻卵时间与观察时间呈极显著正相关(P<0.01).离巢时间和平均气温存在极显著正相关(P<0.01).孵卵期间日离巢0~2次,通常在上午和傍晚离巢,离巢平均时间(27.6 ± 4.4) min (n=29).离巢率孵化中期为4.86%,孵化后期为5.37%.雏鸟在巢期间为(3754.5±42.5) min (n=2),此期雌鸟不离巢,行为复杂.  相似文献   

7.
野生朱鹮2003年开始在城固县营巢繁殖,至2008年的6年中,在6个镇(乡),8个村的繁殖地,成功繁殖23窝,成活雏鸟51只。繁殖地分属秦岭南坡中山区;秦岭南坡丘陵低山区和巴山低山丘陵区三种生境,巢位树主要是马尼松和油松,分别占73.91%和21.74%。城固县已成为重要的野生朱鹮繁殖地。  相似文献   

8.
曲阜孔林春季鸟类群落生态的初步研究   总被引:3,自引:0,他引:3  
对孔林春季鸟类的调查表明,该区鸟类群落的主要鸟类共计28种,其中优势种有4种,根据栖息地内植被类型和分布其中的鸟类优势种,划分为四种鸟类群落;落叶阔叶林-大山雀金翅雀+小蝗莺+黑枕黄鹂群落;针阔混交林-大山雀+灰喜鹊+金翅雀+小蝗莺群落、针叶林-夜鹭+大山雀+金翅雀+山斑鸠群落和杂灌林-灰喜鹊+大山雀金翅雀+黑枕黄群落,各鸟类群落的种类组成、种群密度多样性和均匀度存在着不同程度的差异,鸟类群落间相  相似文献   

9.
厦门白鹭自然保护区的白鹭繁殖行为和繁殖力研究   总被引:8,自引:4,他引:8  
2 0 0 1年 3月至 7月对厦门白鹭自然保护区鸡屿岛的白鹭 (Egrettagarzetta)繁殖行为和繁殖力进行了研究 .白鹭集群、择巢、筑巢于 2月中旬至 3月中旬 ,3月底部分亲鸟开始产卵和孵化 ,4月中旬雏鸟开始出壳 .白鹭窝卵数为 4.43± 0 .6 8(SD)枚 ,孵化期为 2 3.2± 1.4d ,孵化率为 88.5 0 % ,窝雏数为 3.8± 0 .8只 ,育雏期 2 8~ 35d ,雏鸟成活率为 87.7% .每年每只白鹭的繁殖力为 1.96只雏鸟 ,每巢成功繁殖 3.37只雏鸟 .鸡屿岛白鹭繁殖前期的种群数量为 5 0 32只 ,繁殖结束时亲鸟和成活雏鸟数量共 135 0 6只 .本文分析影响白鹭繁殖的主要因素 ,并提出白鹭繁殖期的管理和保护措施  相似文献   

10.
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   

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.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号