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 187 毫秒
1.
河北塞罕坝冬季黑琴鸡种群密度调查   总被引:3,自引:1,他引:2       下载免费PDF全文
2007年12月对河北塞罕坝地区的黑琴鸡(Lyrurus tetrix)冬季种群密度进行了专项集中调查.越冬期种群密度为3.26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.这与该地区栖息地的质量恶化、人类活动日益加剧和偷捕偷猎活动有关.  相似文献   

2.
黑琴鸡北方亚种mtDNA D-loop遗传多样性初步研究   总被引:1,自引:1,他引:1       下载免费PDF全文
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,Nm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。  相似文献   

3.
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.  相似文献   

4.
杨再学  郑元利  金星 《生态学报》2007,27(6):2425-2434
黑线姬鼠(Apodemus agrarius)是我国广大地区的主要害鼠之一,是余庆县农田害鼠优势种,占总鼠数的94.81%。探讨其种群繁殖参数的变动规律及其地理分异特征,对其种群数量预测预报具有重要意义。通过对1987-2005年贵州省余庆县黑线姬鼠种群繁殖参数分析结果表明:研究期间共解剖标本5497只,其中,雌鼠2698只,雄鼠2799只,黑线姬鼠在当地1-11月份均可繁殖,主要繁殖期在3-10月份,每年4-5月份和8-9月份出现2次妊娠高峰。种群总性比(♀/♂)为0.96,多年平均怀孕率为36.91%±6.79%,平均胎仔数为5.33±1.07只,平均繁殖指数为0.81±0.17,平均睾丸下降率为59.13%±7.89%。不同年龄组种群繁殖力存在显著差异,随着种群年龄的增长繁殖力不断增加,成年Ⅰ组、成年Ⅱ组、老年组是种群繁殖的主体。种群繁殖参数不同年度之间比较稳定,不同月份、不同季节之间变化差异较大,具有明显的季节变化特征。年均种群密度与年均繁殖指数呈极显著正相关,与胎仔数显著正相关,与年均怀孕率、睾丸下降率、性比相关性不显著,繁殖指数是影响黑线姬鼠种群密度的重要因子。比较全国各地黑线姬鼠种群繁殖参数的地理分异特征认为,黑线姬鼠种群繁殖参数具有明显的地理分异现象,胎仔数、生殖强度由南向北逐渐增加,具有随纬度的升高趋向增加的特征;在高纬度地区繁殖时间较短;性比与纬度、经度的变化关系密切;各繁殖参数与海拔的变化相关性不明显,可排除海拔因素的影响。  相似文献   

5.
子午沙鼠(Merionesmeridianus)广泛分布于我国西北部地区,是荒漠啮齿动物群落的优势鼠种。种群繁殖特征是动物生活史参数中的一个重要组成部分,是种群数量补充的重要来源,而干扰是影响繁殖特征的重要因素。本研究于2012~2014年,在位于蒙古阿拉善左旗南部典型荒漠的野外实验区,设置禁牧、开垦、过牧、轮牧4种不同干扰样地,使用铗日法对实验样地子午沙鼠相对数量及繁殖特征进行调查。4种不同干扰生境中的子午沙鼠种群数量具有显著差异,禁牧过牧轮牧开垦;雌雄性比在轮牧生境中最高,开垦生境次之,禁牧生境最低;4种干扰生境中,轮牧样地子午沙鼠雌鼠怀孕率显著高于禁牧、过牧和开垦样地;雄鼠的睾丸下降率在过牧干扰样地显著高于其他3种干扰方式样地,轮牧样地雄鼠睾丸下降率最低;雌鼠平均胎仔数在4种干扰生境间无显著性差异;轮牧干扰样地繁殖指数显著高于其他3种干扰方式样地;繁殖指数、怀孕率及睾丸下降率对密度的反馈作用最为明显,但在不同的干扰生境中其反馈特征有差异。综上,子午沙鼠在轮牧生境中各繁殖特征指数最高,繁殖能力最强,种群密度相对较高,更适合其生存,其密度制约效应表现最为明显。  相似文献   

6.
福建省莆田地区小家鼠种群繁殖的研究   总被引:3,自引:1,他引:2  
洪朝长  陈小彬 《兽类学报》1992,12(2):153-158
1987—1989年,作者在福建省蒲田地区采集小家鼠标本1616号(雌865,雄751),解剖、观察雌雄生殖器官的特征和变化,对种群中的性比、睾丸下降率、繁殖雌鼠率、怀孕率、胎仔数、繁殖指数的季节变化和年度差异作了分析。结果表明,该地区小家鼠全年均可繁殖。雄性小家鼠体重≥10克,雌性体重≥11克时,已有75%以上达性成熟,故体重可作为划分成体的标准。种群密度对种群繁殖有明显的反馈调节作用。  相似文献   

7.
自1984年4月至1999年8月,我们沿铁路轨道检测了农田中暮鼠(Calomys venustus)的多度,研究了种群密度、越冬种群结构和繁殖期长度之间的关系,发现种群具有增长、高数量和下降年份。将动物按照同生群(种群内在相同时间内出生的一些个体)分开,利用2×2列联表卡方检验对不同性别的越冬种群结构与数量(高数量和种群下降)间的关联性进行了分析。就高密度与种群密度下降年份中的同生群组成而言,不同密度的年份显示种群结构有显著差异。在数量增长和高密度的年份里,在繁殖季节的起始期,前一年秋季出生的个体比同年夏季出生的个体在数量上要占优势,而在同生群数量下降年份则相反,特别是雌性。高密度年份具有繁殖期缩短的特征,而种群增长年份繁殖期延长。结果表明,这些变化不能只归结于繁殖期长或繁殖率引起密度变化。我们的结论是:解释C·venustus种群消长不能仅考虑动物同生群本身,需要考虑其社会和环境因子的作用。  相似文献   

8.
山西五鹿山保护区褐马鸡种群密度调查   总被引:12,自引:0,他引:12       下载免费PDF全文
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。  相似文献   

9.
黑线姬鼠(Apodemus agrarius)是贵州地区分布广泛的主要农田害鼠之一,掌握其种群繁殖特征可为种群动态的预测预报提供基础资料。1984~2014年间,采用夹夜法逐月调查了贵州省余庆县8个县(市)监测点黑线姬鼠种群动态数据,分析了其种群性比、雌鼠怀孕率和平均胎仔数、雄鼠睾丸下降率等主要繁殖生物学指标及其地理差异和季节性变动规律,明确了贵州地区黑线姬鼠种群的繁殖特征。共捕获黑线姬鼠20 113只,不同地区种群间,除平均胎仔数有显著差异外(χ~2=36.503,df=7,P0.01),其他繁殖特征值均没有差异。从时间序列看,种群中雌鼠怀孕率和雄鼠睾丸下降率的季节性变化均表现为春季(4~5月)及夏末秋初(8~9月)达到高峰的双峰型。雌鼠产仔数一般2~10只,4~7只最为常见(占93.87%)。不同季节平均胎仔数差异不大。贵州地区黑线姬鼠繁殖的总体特点为全年繁殖,春秋两季为繁殖的高峰期,冬季(12月份和翌年1、2月份)繁殖强度明显低于其他季节(F_(11,84)=61.92,P0.01),但种群密度表现为6月达到最高点的单峰型特点。  相似文献   

10.
黑琴鸡的生活习性   总被引:4,自引:0,他引:4  
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  相似文献   

11.
Annual variation in harvested animals (hereafter bag size) is often used as an index of population abundance when investigating population dynamics. Few studies have evaluated how well bag size tracks population change despite its widespread use. Two recent studies on grouse harvest statistics have reached contrasting conclusions. Th ere is limited information about the functional response of hunters in relation to varying game densities, and effort is seldom recorded. We investigated how much of the variation in bag size (total number of harvested grouse km?2) is explained by variation in willow grouse Lagopus lagopus density (adult and young grouse km?2) and hunting eff ort (total number of hunting days km?2). We also evaluated catch per unit effort (CPUE) as an index of grouse abundance, and estimated the response in harvest rate (total bag size in relation to total grouse density) to varying hunting effort. We used data from the 88 management areas on state land in Jämtland county, Sweden (1996–2007), where hunting days and bag size are recorded in detail. Willow grouse density was estimated in four of these management areas in August using line transects and distance sampling. The hunting effort and total grouse density explained most of the variation in bag size (R2= 0.89). Bag size was twice as sensitive to changes in hunting effort compared to changes in grouse density. More than a ten times change in the grouse population density was required to one unit change in bag size. The use of CPUE did not provide a better alternative index of grouse density, and variation in density only explained 23% of the variation in CPUE. Harvest rate showed a strong relationship with hunting effort, and we suggest that an upper limit in hunting effort can be used to reduce the risk of high harvest rates. Hunters became more efficient at low densities and controlling hunting effort is most important when there are indications of population lows and/or poor breeding. CPUE may be less sensitive to changes in game abundance than previously assumed, and bag size as a proxy for population density would then depend on the ability of hunters to adjust their effort according to population change. We speculate that this ability will depend on whether or not hunters have long‐term experience of a hunting area where they can return to hunt throughout the hunting season. We propose that recording hunting eff ort should be encouraged and possible correlations with game abundance and other factors such as weather should be investigated for game species.  相似文献   

12.
Arndt Brüning 《Oecologia》1991,86(4):478-483
Summary The predation on spiders in a forest ecosystem by a colony of red wood ants, Formica polyctena, was estimated using a barrier to isolate the colony. Of the ants' total prey, 4.6% were spiders. In order to estimate the effect of F. polyctena within their hunting area on the spider population, the spiders' population density was studied inside and outside the hunting area. Samples of the forest floor were taken, spider webs were counted and pitfall traps were used. No significant difference was found in density or composition of the spider fauna inside and outside the hunting area.  相似文献   

13.
The wild boar is a native animal species of the Czech Republic that has significantly increased its population density in recent years. Objective methods of population density estimation are required to inform the intensity of regulation needed for the sustainable management of the wild boar. Population estimation and regulation of the abundance of the wild boar are problematic in comparison to those of other ungulates, and the only widely used method of control is intensive hunting. The purpose of this study was to test if faecal pellet group (FPG) counting was a reliable method of wild boar population censusing in a forest environment. The density of wild boars was evaluated in an area of 22.56 km2, circumscribed by both natural and man-made barriers that restrict wild boar migration. As it is essential for proper application of FPG count methods, a separate trial was carried out to determine the daily defecation rate of wild boars. The distribution of faeces in different types of habitat in a forest environment was tested. As the period of faeces accumulation fell within the intensive hunting season, the result is biased by the fact that the calculation includes FPGs produced by animals removed from the population through hunting during winter. The average daily defecation rate of adults and piglets was 4.29 and 5.82, respectively. The corrected (without shot animals) average density of wild boars in the study area estimated by the FPG count at the time of the census was 6.08 individuals (ind.)/km2. We have confirmed that an FPG count conducted in winter is applicable for estimation of wild boar abundance on a forested area.  相似文献   

14.
Griffon vulture (Gyps fulvus) population surveys were conducted during 1996–2002 in the island of Crete (Greece) to document population status and structure. Fieldwork was carried out during the breeding period when birds could be monitored in their colonies. Total population size was estimated at 379 individuals (range = 341–417) with adult birds comprising 63%. The breeding population was estimated at 141 pairs, which were distributed on an average in 23 colonies per year (range = 16–30) while the mean number of breeding pairs that laid eggs was 98 (range= 64–126). Crete thus supports the largest insular population of the species in the world and hosts 70–80% of the breeding population of the species in Greece. Population density was estimated at 6.9 individuals/100 km2, 2.6 breeding pairs/100 km2 and 1.8 nesting pairs/100 km2. The average home range of an occupied colony (i.e., breeding group) was estimated at ca. 204 km2 producing a theoretical foraging range of 8 km radius around the breeding cliff. No trends in the total number of individuals and breeding pairs appeared to exist, although significant differences in population size of individual colonies occurred between the years. The majority of the population was concentrated in small-sized colonies, which showed a low occupancy rate. The number of abandoned sites and the colonization of new ones could represent a shift of breeding pairs to alternative colonies provoked by local food abundance and conspesific attraction.  相似文献   

15.
The white-browed guan (Cracidae: Penelope jacucaca) is an endemic bird species to the Caatinga, the largest centre of dry forest in South America. This taxon was considered Vulnerable by the International Union for Conservation of Nature (IUCN) due to continued habitat loss within its distribution and intense hunting pressure that contributed to population declines. However, information on population aspects and habitat use by P. jacucaca, which is fundamental for monitoring its conservation status, is not available. We studied habitat use (analysed in a Generalized Linear Model) and population density (estimated by distance sampling) in a specific area in Northeast Brazil. Using species distribution modelling (SDM), forest cover loss data (performed in the MaxEnt program) and quantitative information about hunting, more rigorous estimates of the distribution limits, available habitat, and population declines of P. jacucaca were generated. Based on the IUCN criteria, we applied analysed data to reassess the conservation status of the white-browed guan. Local density was estimated at 13.1 individuals/km2 and the estimated number of individuals removed per year due to hunting was 121.7 in the forest cover area (110.46 km2) of the Serra de Santa Catarina. Consequently, the annual removal rate of hunted individuals in the study area corresponds to approximately 11% of the population. The habitat use analysis pointed to a strong positive association with seasonally dry deciduous forest (SDDF) vegetation and with arboreal vegetation. The SDM indicated a potential distribution (climatically favourable) area of 675,823 km2, and forest cover and loss calculations indicated a total of 81,307 km2 of available suitable habitat in 2013. Therefore, comparing these results to the IUCN criteria, we recommend that P. jacucaca remain in the Vulnerable category.  相似文献   

16.
We studied factors affecting breeding habitat selection in a population of cliff-nesting peregrines Falco peregrinus across multiple spatial levels (cliff site, cliff context and land-use of the surrounding landscape), over a 2,100 km2 study area in the Alps (Italy and Switzerland). We detected 30 breeding pairs (density: 1.43 territorial pairs/100 km2), whose territories were uniformly distributed over the study area. We compared 15 habitat features characterising occupied cliffs and 30 randomly selected unoccupied cliffs by means of stepwise forward logistic regression and hierarchical partitioning. The logistic regression analysis showed that occupied cliffs were longer (horizontal length), steeper, and had a greater extension of urban areas in the surrounding landscape compared to non-occupied cliffs. The model had a discrimination ability of 0.95. Hierarchical partitioning indicated that the logistic regression model was appropriate. Neither the distance of cliffs to the nearest site occupied by a potential competitor and predator, the eagle owl Bubo bubo, which occurred at a low density (0.67 pairs/100 km2), nor the distance to the nearest site occupied by peregrines had any effect on the cliff suitability model. Therefore, habitat selection in cliff-nesting peregrines was mainly influenced by cliff site features and surrounding landscape characteristics, whereas the proximity to conspecifics and to an intraguild predator had no apparent effects on peregrine settlement in our study population.  相似文献   

17.
The effects of intensive Tsetse Control hunting operations on a duiker population (Sylvicapra grimmia) were investigated in a 200 sq. mile area in Eastern Zambia. Two years of hunting were insufficient to reduce this population so significantly that a marked shift of its age composition towards the juvenile age classes resulted. There were, however, indications of beginning accelerated population growth through increased breeding and inclusion of more juveniles in the reproduction process, as a first response to the hunting pressure. Although general availability of duiker did not diminish, they became increasingly difficult to shoot because of behavioural adaptation and changing periods of feeding activity. Neither hunting nor various other human disturbances provoked emigration from the area or a change of the seasonal pattern of localised movement. The studied hunting operation failed to remove more than the annual increment to the duiker population and in respect of this species was thus ineffective as a means of Tsetse Control. Implications of the results of this study for the management of duiker for sustained meat production are discussed.  相似文献   

18.
Many different ecological factors affecting the size, use, and spatial configuration of home ranges have been investigated, yet the chronology of the breeding cycle has been relatively under studied. Here, we studied peregrine falcons (Falco peregrinus) to describe variation in home range within and between breeding seasons in the Yamal peninsula, a region of the Russian Arctic with a high breeding density of peregrines. We used satellite telemetry to investigate variation in home range at different stages of the breeding cycle during three breeding seasons (2009–2011). We fitted Argos satellite transmitters to 10 breeding peregrines (nine females and one male) and two male fledglings. All breeding females showed fidelity to the region of the southwestern Yamal peninsula, but they were not necessarily faithful to their specific breeding ranges with 33 % dispersing to new ranges up to 40 km away. The population of peregrines in our study area was relatively synchronous in their breeding chronology, with clutches initiated in close synchrony in early June despite the birds arriving on their breeding ranges ca. 3 weeks earlier. The average home range size for breeding females was 98 km2 (95 % Maximum Convex Polygon). Over the breeding season, the home range area utilized by females increased in the late nestling period and again after the chicks fledged. Expansion of the home range coincided with changes in behavior associated with parental care, resulting in greater activity and more time spent away from the nest area when the female began hunting to provision nestlings and fledglings.  相似文献   

19.
The Steinfeld in Lower Austria supports a population of European Nightjar (Caprimulgus europaeus) which was extensively studied during 1997 and 1998. The study area encompassed a pine forest of 20 km2. The population densities of 1.05 and 1.25 territories/km2, respectively, lies within the range found in central European populations. Annual monitoring until 2001 has shown the population to be stable. To gain an insight into habitat use of the species, various habitat-related parameters were measured inside and outside the territories, namely structure of trees, density of trees, structure of undergrowth vegetation and structure of clearings. Discriminant analysis was applied to assess the factors responsible for habitat choice of the Nightjar population. The findings showed that the Nightjars territories were frequently centered on a large clearing with an area of at least 0.7 ha. Clearings less than 50 m wide were not colonized. The requirement for a minimum width of a clearing in addition to a minimum area probably relates to better hunting conditions. Nightjars prefer trees where the lower edge of the crown is on average 4.38 m higher than at control points so that males can churr from dead branches immediately below the canopy. Such trees were found on the edge of clearings in the forest, and the edge of a clearing thus had a pronounced effect on the quality of a territory. In contrast to reports in the literature, neither the proportion of bare patches of ground nor the average height of undergrowth vegetation was found to be decisive for territory selection.  相似文献   

20.
A study on the distribution and population density of the western lowland gorilla (Gorilla g. gorilla) and the central chimpanzee (Pan t. troglodytes) was undertaken between December 1997 and August 2000 in the Campo and Maan Forests in southwestern Cameroon. The aim of this survey was to estimate the densities of the apes in different parts of the area, to assess the importance of the region for the conservation of these endangered species and to determine the influence of human activities such as logging and hunting. The survey was based on night nest counts on a total of 665.5 km of line transects. The overall density in the Campo Forest was estimated at 0.2 gorillas/km2 and at 0.63–0.78 chimpanzees/km2. The overall density of chimpanzees in the Maan Forest was estimated at 0.8–1 individuals/km2. Gorilla density in this area was too low to allow an estimation. The highest gorilla nest density was found in secondary forest. The gorilla density in unlogged forest was significantly lower. Chimpanzees showed a clear preference for less disturbed areas. In unlogged forest, old secondary forests (logging more than 23 years ago) and areas of recent logging with large remaining patches of primary forest, significantly higher densities were calculated than inside the more heavily exploited logging concession. In areas with both logging and high hunting pressure both species were rare or even absent. The Campo Maan area is considered a very important area for the conservation of gorillas and chimpanzees. Conservation measures are urgently required to reduce the impact of logging and hunting. The creation of the Campo Maan National Park in January 2000 is an important measure to preserve the unique biodiversity in this so far hardly protected area.  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