河北塞罕坝秋季黑琴鸡种群密度调查

2009年10月对河北塞罕坝地区的黑琴鸡(Lyrurus tetrix)秋季种群密度进行了专项集中调查。结果表明,秋季种群密度为2.20只/km2;与历史资料对比,该地区黑琴鸡种群密度呈明显下降趋势;种群分布发生了变化;繁殖基数、繁殖成功率下降和秋季猎捕是造成黑琴鸡秋季数量下降的主要因素。目前,加强管理、阻止盗猎活动是保护当地黑琴鸡种群的最有效措施。     

黑琴鸡北方亚种mtDNA D-loop遗传多样性初步研究

黑琴鸡(Tetrao tetrix)为国家Ⅱ级保护动物,但近年来种群数量不断减少。因此,了解不同种群的遗传变异情况,可为制定保护管理策略提供依据,以便恢复野外种群的数量。本文测定加格达奇(42个个体)和呼伦贝尔市扎兰屯(76个个体)两个黑琴鸡种群的共118个个体的mtDNA D-loop 序列,共发现25个变异位点,定义了33个单倍型,整体的平均核苷酸差异数(K)为2.608,核苷酸多样性(π)为0.228%,种群的遗传多样性偏低,两个种群有一定的基因交流,N_m为14.63,群体间无显著的遗传分化。Tajima's D和Fu&Li's D的估算结果表明,这两个黑琴鸡种群相对于中性的歧异度并没有明显的偏离(P>0.1),两个种群可能未经过大规模的种群扩张过程。     

CO Ⅰ SEQUENCE VARIATIONS AND PHYLOGENETIC RELATIONSHIPS AMONG 13 SPECIES OF TETRAONIDAE BIRDS

线粒体DNA中的细胞色素C氧化酶亚基Ⅰ基因,即CO Ⅰ是DNA条形编码的主要基因,是一个很好的物种鉴定工具,目前广泛应用于鸟类系统发育研究.通过测定花尾榛鸡和黑琴鸡CO Ⅰ基因的序列,并结合GenBank中松鸡科13种鸟类的同源序列,对松鸡科鸟类进行了序列变异和系统发育分析.结果显示,松鸡科物种的种间变异大于种内变异.序列分歧和系统分析结果支持花尾榛鸡Tetrastes bonasia归于松鸡科Tctraonidae榛鸡属Tetrastes.黑琴鸡Lyrurus tetrix与Tetrao属中其它物种的分歧小于松鸡科其它属间分歧,且黑琴鸡聚在Tetrao内,研究结果倾向支持黑琴鸡归于松鸡属Tetrao.     

广西融水县发现雷山琴蛙

广西境内的琴蛙有多个地理种群,主要分布于桂东北地区的龙胜、灌阳,北部地区的融水,中部地区的金秀和南部地区的上林及武鸣,现己证实在灌阳都庞岭的种群为湘琴蛙(Nidirana xiangica),在大瑶山的种群为瑶琴蛙(N.yaoica),在大明山的种群为广西琴蛙(N.guangxiensis).雷山琴蛙(N.leisha...     

五指山黑桫椤(Alsophila podophylla)种群特征与森林立木密度和土壤的关系

研究了五指山黑桫椤(Alsophila podophylla)种群密度、高度和胸径等基本特征及种群与立木密度和土壤因子的关系.结果表明:山地雨林和低地雨林黑桫椤平均密度及立木平均密度各自差异极显著,黑桫椤平均高度和平均胸径各自差异不显著.低地雨林黑桫椤平均密度(0.12 ind·m-2)是山地雨林(0.06 ind·m-2)的2倍,后者的立木平均密度(0.467 ind·m-2)是前者(0.343 ind·m-2)的1.4倍,在一定海拔范围内,随海拔升高,黑桫椤种群密度逐渐减少,立木平均密度增大.山地雨林黑桫椤平均密度与平均高度正相关,黑桫椤种群趋于稳定;低地雨林中两者负相关,黑桫椤种群呈增长型,其相关关系都可用二项式方程拟合.山地雨林黑桫椤平均密度与立木平均密度负相关,低地雨林中两者正相关,相关关系可用一元线性方程拟合.山地雨林与低地雨林比较,土壤有机质、全氮、水含量和pH总体上表现为增大趋势,而全磷和全钾含量总体上表现为下降趋势;黑桫椤种群平均密度、高度和胸径与土壤pH、全磷含量和全钾含量关系密切,各自可用二元线性回归方程拟合;3个土壤因子对黑桫椤的作用大小是全钾含量＞pH＞全磷含量.可以根据以上模型指导黑桫椤保护、繁殖和栽培研究.     

黑琴鸡的生活习性

黑琴鸡Lyrurus tetrix,在东北俗称黑野鸡、黑鸡或乌鸡。在我国,主要分布在大、小兴安岭、张广才岭、黑龙江和乌苏里江流域以及新疆天山山脉。一只雄性黑琴鸡一般都在3斤以上,有的重达4斤以上。秋、冬季结群觅食,有时达100—200只以上。黑琴鸡的肉味     

松鸡科13种鸟类COⅠ序列变异及系统发育分析

线粒体DNA中的细胞色素C氧化酶亚基Ⅰ基因,即COⅠ是DNA条形编码的主要基因,是一个很好的物种鉴定工具,目前广泛应用于鸟类系统发育研究。通过测定花尾榛鸡和黑琴鸡COⅠ基因的序列,并结合GenBank中松鸡科13种鸟类的同源序列,对松鸡科鸟类进行了序列变异和系统发育分析。结果显示,松鸡科物种的种间变异大于种内变异。序列分歧和系统分析结果支持花尾榛鸡Tetrastes bonasia归于松鸡科Tetraonidae榛鸡属Tetrastes。黑琴鸡Lyrurus tetrix与Tetrao属中其它物种的分歧小于松鸡科其它属间分歧,且黑琴鸡聚在Tetrao内,研究结果倾向支持黑琴鸡归于松鸡属Tetrao。     

五指山热带雨林黑桫椤种群及其所在群落特征

黑桫椤(Alsophila podophylla)属国家二级保护植物.作者在海南岛五指山山地雨林和低地雨林分别设立样地对黑桫椤种群及其所在群落进行了调查,分析了热带雨林黑桫椤种群的年龄结构、空间分布格局、数量分布以及群落结构和物种多样性.结果表明,山地雨林和低地雨林中黑桫椤种群分别为稳定型种群和增长型种群,都是完全集群分布.低地雨林的黑桫椤平均密度是山地雨林的1.7倍.土壤pH值对黑桫椤种群密度有负的影响,全磷含量对其有正的影响.山地雨林林地土壤pH值大而全磷含量低,低地雨林刚好相反.土壤酸碱度和全磷含量的差异是导致两地黑桫椤数量差异的原因之一.pH值对黑桫椤平均密度的影响效应是全磷含量的2.5倍,说明pH值是影响黑桫椤种群密度的主要因素.黑桫椤所在群落垂直结构分为3个乔木亚层、2个灌木亚层及草本层.山地雨林黑桫椤所在群落的Simpson指数和Shannon-Wiener指数分别为0.957和5.305,均匀度为0.811;低地雨林黑桫椤所在群落的Simpson指数和Shannon-Wiener指数分别为0.937和5.484,均匀度为0.804.总之,五指山山地雨林和低地雨林的黑桫椤种群年龄结构、分布格局和数量分布都有一定差异,这些差异是由生境差异造成的.热带雨林黑桫椤所在群落结构复杂,物种多样性丰富.     

2种调查方法对四川黑竹沟国家级自然保护区3种雉类种群密度调查的比较

种群数量是物种的重要生态学基础资料,合适的密度调查方法是数量估算的基础。2016年4-5月,采用广泛应用于鸡形目Galliformes鸟类种群密度调查的样线法和样点法,调查了四川黑竹沟国家级自然保护区3种鸡形目鸟类(白腹锦鸡Chrysolophus amherstiae、红腹角雉Tragopan temminckii和血雉Ithaginis cruentus)的种群密度。样线法和样点法估算的雄体密度分别是:白腹锦鸡1.20只/km^2和(6.31±0.98)只/km^2,红腹角雉5.41只/km^2和(0.39±0.17)只/km^2,血雉3.01只/km^2和(5.97±2.70)只/km^2。除红腹角雉外,样点法估算的白腹锦鸡、血雉种群密度均大于样线法。建议针对不同鸡形目鸟类采用不同的调查方法,并尽量扩大样本数量,从而提高调查结果的准确性。     

山西五鹿山保护区褐马鸡种群密度调查

1997年12月－1998年3月对山西五鹿山保护区的褐马鸡种群密度进行了调查。越冬期和繁殖期的种群密度分别为12．67只／km^2和7．39只／km^2。通过对三个地区繁殖密度的比较,发现五鹿山地区繁殖种群密度偏低。这可能与该地区栖息地的质量日益恶化有关。     

Home range and movements of the Namib Desert golden mole, Eremitalpa granti namibensis (Chrysochloridae)

Eremitalpa granti namibensis is a small, blind, subterranean insectivore endemic to the Namib desert sand dunes. Unlike most other subterranean mammals, E. g. namibensis lacks a permanent burrow system and is a surface forager. Population density and home range utilization were studied by following surface trails and capture, mark and recapture. Population density was low but stable and home range size large, a reflection of the low food availability in the Namib dune environment. No permanent nests or burrows were found while the pattern of home range utilization was nomadic but circumscribed. Home ranges overlapped with those of neighbouring animals.     

Spatial Analysis of Heterodera glycines Populations in Field Plots

Spatial heterogeneity in nematode population densities presents an obstacle to the precise determination of infestation levels. Three field plots were intensively sampled for soybean cyst nematode (Heterodera glycines Ich.) cysts before and after spring cultivation to quantify the spatial attributes of the population. Population density strata were detected running parallel to plant rows. Highest population densities before cultivation were found in the plant row and the middle furrow, Population density in the plant row averaged 26% higher and 4% lower than the whole-plot mean before and after cultivation, respectively. Cysts containing fewer than 25 eggs were not stratified, indicating that most were produced before the previous season. Sample population counts were fit to the negative binomial distribution model before cultivation, but distributions differed among plots. The Neyman type A and negative binomial distributions both fit the data after cultivation disturbed the soil. Population clusters 1-3 m long were detected in plant beds before cultivation. Heterogeneity in population density increased with plant row length after cultivation. Optimum plot length for minimal spatial heterogeneity in four-row mechanically tended field plots was estimated at 6 m after trimming plot ends.     

Effects of extra food on population fluctuation patterns of the muroid rodent Calomys venustus

Population dynamics in the South American muroid rodent Calomys venustus are described from a 14‐year continuous data series, using the auto‐regressive integrated moving average (arima ) model. Population responses to experimental food addition were analysed in two experimental areas, over two periods, using intervention analysis. There was no consistent evidence that food quantity leads to peaks in population density. Significant increases were related to densities of transients and juvenile individuals.     

Seasonal differences in habitat selection by Black Grouse Tetrao tetrix in the northern Pennines, England

Between-season differences in habitat use by Black Grouse Tetrao tetrix were studied on four moors in the northern Pennines between 1989 and 1992. Heather moor and bogs were preferred at all times of the year, apart from during the breeding season. In spring, large quantities of Cotton-grass Eriophorum vaginatum flowers were consumed, whereas in autumn and winter Heather Calluna vulgaris was more important. Enclosed fields on the edge of the moors were regularly used in autumn and winter by large flocks of cock birds, and hens were found in smaller groups. Where present, overgrazed grass moorland was generally avoided, apart from during the summer. Similarly, enclosed rough grazing allotments rich in rushes were favoured during the summer months by breeding hens and moulting cocks.     

Goshawk predation during winter, spring and summer in a boreal forest area of central Sweden

Predation by goshawks was studied in a central Swedish boreal forest area. Data were collected in winter (January–February) 1977-81 by tracking radio-tagged goshawks, and in the breeding season (April–July) by collecting prey remains at the nest. In the breeding season birds dominated the prey, amounting to 86% of prey number and 91% of prey biomass. Wood pigeon Columba palumbus , black grouse Tetrao tetrix , hooded crow Corvus corone cornix and jay Garrulus glandarius accounted for more than 50% of the prey animals, whereas capercaillie Tetrao urogallus and black grouse accounted for more than 50% of prey biomass. There was no functional response to black grouse density fluctuations. Every year goshawks killed significantly more females than males of both capercaillie and black grouse, due to high vulnerability of the grouse hens while laying and incubating. It was estimated that during spring and early summer goshawk predation removed 25% of the female, and 14% of the male black grouse population. In winter squirrel was the dominating prey, both in terms of number (79%) and weight (56%). The proportion of squirrel in the diet was equally high both in winters of low and high squirrel density. The high proportion of squirrel in the winterdiet, as compared to the breeding season, is believed to be due to squirrels having to accept an increased predation risk in winter, in order to feed efficiently enough.     

Functional and physical characteristics of rat Leydig cell populations isolated by metrizamide and Percoll gradient centrifugation

The physical and functional properties of Leydig cell populations obtained by centrifugation of testicular cells in two different density gradient media, Percoll and Metrizamide, were compared. Percoll-gradient centrifugation yielded two Leydig cell bands (Peak I and Peak II) that were comparable, as to their density and testosterone-producing capacity, to the respective Leydig cell bands, Population I and Population II, isolated in a Metrizamide gradient. The denser Leydig cell band (II) had a greater capacity for testosterone production than the less dense band (I), regardless of the type of gradient used for its isolation. Metrizamide gradient centrifugation separated the majority of germ cells from the "light" (Population I) Leydig cells, whereas in the Percoll gradient, germ cells comigrated with Peak I Leydig cells. Leydig cell separation by Percoll gradients was highly dependent on the presence of Ca2+ and Mg2+ in the medium, while these cations had no effect on the separation of Leydig cells by Metrizamide. In conclusion, Metrizamide gradient centrifugation yielded two Leydig cell populations of similar functional and physical properties to the respective populations isolated in Percoll gradients.     

Reproduction of Mountain hares (Lepus timidus) in relation to density and physical condition

Population estimates of Mountain hares were done on three islands off the west coast of Sweden. Three different relative measures of hare reproduction were negatively related to density. Most of this relationship was accounted for through a positive correlation with body condition. However, there was no significant density trend in litter size or number of litters. The start of the reproductive season each year was related to mean air temperature during spring, so when spring was early so was conception.