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1.
For migratory birds, early arrival and physical condition on the breeding grounds are important determinants of reproductive success and fitness. Differences in arrival times often exceed a month, and later arriving individuals are often in poorer condition. Habitat-specific isotopic signatures indicate that the quality of winter habitats occupied by American redstarts (Setophaga ruticilla) determines their physical condition and spring departure dates, which in turn result in variable arrival schedules and condition on temperate breeding grounds. These findings link events in tropical winter grounds with those in temperate breeding areas for a migratory songbird and provide evidence that winter habitats may be limiting.  相似文献   

2.
三江自然保护区冬季鸟类生态调查   总被引:3,自引:0,他引:3  
1998年1月和2001年11月,两次对三江国家级自然保护区冬季鸟类进行了调查,共记录39种鸟类。其中,冬候鸟12种,仅占黑龙江省冬候鸟总数的52.2%,留鸟27种,仅占黑龙江省留鸟的46.5%。优势种5种,常见种6种,偶见种28种。两次调查比较可见,多数冬候鸟在11月份尚未迁入保护区境内。农田和岛状林生境食物资源丰富,分布的鸟类种类最多,沼泽生境鸟类最少。冬季鸟类食物组成多样,多种鸟类集群活动、觅食。  相似文献   

3.
海南东寨港红树林湿地鸟类监测与研究   总被引:1,自引:2,他引:1  
利用样线法年对海南东寨港红树林湿地的鸟类进行调查,并对鸟类的物种多样性和生境进行了分析。结果表明,东寨港红树林湿地共记录有鸟类11目26科65种,总数量为24531只,其中水鸟有41种,占调查总种数的63%。全年水鸟的种类和数量具有明显的季节性变化,均为越冬期较多,繁殖期较少。不同生境的鸟类群落组成及物种多样性在不同季节的差异性显著。  相似文献   

4.
潘红星  刘杰  涂朝勇  李容  朱东阳  刘宁 《安徽农业科学》2013,41(8):3386-3387,3402
2009年11月~2010年4月,采用样线调查法对雏鳳山及周边环境冬春两季白颊噪鹛(Garrulax sannio)数量及分布进行了调查。共记录实体4 073只次,其中冬季2 003只次,春季2 070只次。结果表明,白颊在调查区均有分布,乔灌林的种群数量明显高于河道,其遇见率为37.167只次/(h.km),河道遇见率为12.615只次/(h.km),其他区域遇见率约为12.667~17.308只次/(h.km);春季数量略高于冬季,与生存和繁殖相关资源条件(食物、水分、隐蔽条件)较优越的生境其分布数量明显较多,干扰较大的公路沿线绿化林地有相当大的数量。最后,对此次调查研究方法的可靠性及其数量分布的差异进行了分析,同时对城市及近郊开展鸟类保护工作提出了建议。  相似文献   

5.
【目的】对雅安市区冬季水鸟进行系统统计与记录,分析城市化进程对水鸟时空分布的影响,为雅安生态城市建设提供参考。【方法】2008年至2011年冬季,采用样线法对雅安市区冬季水鸟进行直接观察,记录物种、个体数量、生境、人为干扰等。【结果】记录水鸟7目11科44种,其中雁形目鸭科鸟类最为丰富,绿头鸭、斑嘴鸭、绿翅鸭、赤膀鸭及凤头潜鸭为优势物种。【结论】水鸟多样性在各个年度呈现相似的时间分布格局,但波动期与稳定期的共存表明雅安市区既是水鸟迁徙的中转地同时也是其越冬地。水鸟在不同生境中的分布差异则体现出滩涂、开阔水域、人为干扰对水鸟多样性的影响。  相似文献   

6.
洞庭湖鸟类资源分布及其栖息地质量评估   总被引:1,自引:0,他引:1  
洞庭湖越冬水鸟具有种类多、种群数量大、密集度高的特点。因洞庭湖在迁徙水鸟保护方面的重要意义,该区共有3块湿地被指定为国际重要湿地。由于三峡大坝的运行,洞庭湖越冬水鸟的生态安全受到严重威胁。准确掌握洞庭湖越冬水鸟分布和栖息地质量信息是越冬水鸟保护科学决策的基础。本研究依据洞庭湖保护区的边界,将洞庭湖湿地分为3块区域:东洞庭湖、南洞庭湖和西洞庭湖。以20082012年洞庭湖环湖鸟类同步调查数据为基础,分析了3块区域越冬水鸟的丰富度,包括:物种数、种群大小和珍稀濒危水鸟种群数量。此外,以2013年1月环境小卫星在洞庭湖区的影像为基础,运用遥感技术解译研究区内越冬水鸟栖息地分布数据。将3块区域的越冬水鸟丰富度和栖息地质量数据进行对比发现:东洞庭湖区域水鸟栖息地保存最为完好,越冬水鸟丰富度最高;而大规模的杨树林和芦苇种植则导致西洞庭和南洞庭栖息地破碎化严重,是西洞庭和南洞庭水鸟物种单一和种群丰富度低的主要原因。在此基础上提出现存良好的候鸟栖息地是洞庭湖越冬水鸟仅存的庇护所,应当严格保护。对于洞庭湖区一些已经被开发利用的洲滩湿地,应采取合理规划措施逐步恢复其原有的水文过程和湿地生态功能,以促进洞庭湖越冬水鸟及其栖息地的保护。研究结果可为洞庭湖越冬水鸟保护工作提供参考。   相似文献   

7.
Progress toward understanding factors that limit abundances of migratory birds, including climate change, has been difficult because these species move between diverse locations, often on different continents. For black-throated blue warblers (Dendroica caerulescens), demographic rates in both tropical winter quarters and north temperate breeding grounds varied with fluctuations in the El Ni?o Southern Oscillation. Adult survival and fecundity were lower in El Ni?o years and higher in La Ni?a years. Fecundity, in turn, was positively correlated with subsequent recruitment of new individuals into winter and breeding populations. These findings demonstrate that migratory birds can be affected by shifts in global climate patterns and emphasize the need to know how events throughout the annual cycle interact to determine population size.  相似文献   

8.
双台河口保护区是世界濒危鸟类丹顶鹤大陆种群西线群体不同生活史阶段的重要栖息地。2008-2010年3-4月,采用定点观察法、二维坐标法、方差分析、因子分析等方法对保护区内春迁期丹顶鹤觅食栖息地的多尺度选择进行了监测分析。研究结果表明:(1)春迁期,该保护区丹顶鹤觅食栖息地选择包括2个尺度3个选择,即大生境尺度内觅食生境类型选择和小生境尺度内觅食区选择、觅食微生境选择;(2)觅食生境类型偏好选择芦苇沼泽(90.00%),也偶选玉米地、泥滩、草甸等生境;(3)觅食区选择通过宏生境因子和干扰因子来判定,宏生境因子包括明水面、堤坝和火烧地,距离均在30m以内;干扰因子包括居民区和油田等强干扰因子和道路等弱干扰因子,均采取远离的方式进行回避,居民区保持在1km以上,油田保持在2km以上,道路保持在300-500m;(4)觅食微生境选择通过微生境因子来判定,包括植被高度、植被密度、植被直径等,选择盖度小(<5%)且植被高度小于喙长的区域觅食。  相似文献   

9.
[目的]研究中国林蛙人工池塘孵化与越冬技术。[方法]2005~2007年,在牡丹江自然保护区内挖人工池塘12个,分别设置不同水温进行林蛙孵化试验,计算孵化率和变态率;设置3个越冬池进行越冬试验,计算林蛙存活率。[结果]孵化池水温在10~12℃、12~14℃时的孵化率可达到97%以上,且明显高于其他温度下的孵化率;胚胎在8~20℃温度范围内均能正常发育,变态率达91%左右;越冬池放养密度为40只/m2左右,林蛙的越冬存活率可达95%。[结论]人工池塘孵化的最适温度是10~14℃,水深保持在2m左右;林蛙越冬的放养密度建议控制在40只/m2左右,并每月换水1次,水温控制在5℃左右。  相似文献   

10.
Saether BE 《Science (New York, N.Y.)》2000,288(5473):1975-1976
There has been increasing concern over the decline in many migratory bird species. As Saether discusses in his Perspective, evidence is accumulating (Sillett et al.) that climate change resulting from the El Ni?o Southern Oscillation affects both the survival rate of adult birds at tropical wintering sites and their reproductive rate at summer breeding grounds in the Northern Hemisphere.  相似文献   

11.
[目的]研究近年来乐山市中心城区越冬水鸟群落结构的变迁。[方法]于2008年1月和2014年1月分别对乐山市中心城区越冬水鸟群落结构进行了调查。[结果]伴随城市化的快速发展,乐山市中心城区“三江”水鸟的群落结构发生了明显变化,以红嘴鸥(Larus ridibundus)和崖沙燕(Riparia riparia)等为代表的中小型鸟类逐步取代大中型的鸭科(Anatidae)鸟类成为群落优势种。[结论]该研究可为评估经济活动和生态环境对乐山市中心城区水鸟群落的影响奠定基础。  相似文献   

12.
Bird migration is a seasonal movement between breeding and wintering grounds. Opinions are widely divided on the reasons for this movement. According to biological data including: geographic distribution, reproductive physiology,comparison of breeding and wintering habitats ,geological data including Qinghai-Tibetan Plateau uplift and Quatemary Period glaciation ,it is inferred that bird migration is a survival mechanism,and that migration originated on the breeding grounds.  相似文献   

13.
在分析陕北、渭北地区旱地冬小麦生育期水分盈亏量和不同月份降水自给率地区分异的基础上 ,研究了不同分区典型县旱地降水产量积分回归函数和降水对产量的影响规律 ,确定了陕西丘陵沟壑区和渭北台塬东部冬小麦最佳补充灌溉时期为 :冬前分蘖期和返青、拔节期 ;洛川塬区 :返青、拔节期 ;渭北台塬西部 :越冬期  相似文献   

14.
在大田条件下,研究了氮、磷、钾肥对西北寒旱区冬油菜越冬率、产量及经济性状的影响.结果表明:磷钾肥配合施用能有效促进冬油菜生长及提高抗寒性.磷钾处理的干物质积累量比不施肥处理增高了4.4%,其越冬率达到98.36%,比不施肥处理提高了5.76%.单施氮肥的越冬率比不施肥处理降低了2.8%,表明冬油菜冬前应少施氮肥,避免苗期过旺生长;适当的磷钾配施可提高冬油菜干物质的积累,增强冬油菜的抗寒性,提高冬油菜的越冬率,从而使冬油菜群体增大;同时磷钾配施可使冬油菜的角粒数、千粒质量增加,最终产量增加.  相似文献   

15.
宁夏贺兰山国家级自然保护区鸟类区系组成及其特征研究   总被引:1,自引:0,他引:1  
对宁夏贺兰山国家级自然保护区的鸟类进行了调查,共记录到鸟类196种,隶属17目41科。其中留鸟54种,夏候鸟84种,旅鸟53种,冬候鸟5种。繁殖鸟(夏候鸟和留鸟)138种。记录鸟类种数占宁夏地区鸟类总数的61.3%。鸟类区系组成以古北界种类为主,共160种,东洋界鸟类24种,广布型11种。古北界成分以北方型和中亚型占优势,有一定东北型成分,反映出蒙新区西部荒漠亚区特点。  相似文献   

16.
The arrival of humans on oceanic islands has precipitated a wave of extinctions among the islands' native birds. Nevertheless, the magnitude of this extinction event varies markedly between avifaunas. We show that the probability that a bird species has been extirpated from each of 220 oceanic islands is positively correlated with the number of exotic predatory mammal species established on those islands after European colonization and that the effect of these predators is greater on island endemic species. In contrast, the proportions of currently threatened species are independent of the numbers of exotic mammalian predator species, suggesting that the principal threat to island birds has changed through time as species susceptible to exotic predators have been driven extinct.  相似文献   

17.
Although albatrosses are paradigms of oceanic specialization, their foraging areas and migration routes when not breeding remain essentially unknown. Our continuous remote tracking of 22 adult gray-headed albatrosses for over 30 bird-years reveals three distinct strategies: (i) Stay in breeding home range; (ii) make return migrations to a specific area of the southwest Indian Ocean; and (iii) make one or more global circumnavigations (the fastest in just 46 days). The consistencies in patterns, routes, and timings offer the first hope of identifying areas of critical habitat for nonbreeding albatrosses, wherein appropriate management of longline fisheries might alleviate the plight of the world's most threatened family of birds.  相似文献   

18.
浙江湿地水鸟种群数量研究   总被引:14,自引:0,他引:14       下载免费PDF全文
1997年4月至1999年7月,采用系统抽样技术和样带法、样点法对浙江省湿地水鸟种群数量进行了研究。其间共记录到湿地水鸟97种,隶属于7目13科,其中赤颈鸊鷉、小滨鹬和阔嘴鹬3个种为浙江省分布新记录。浙江省湿地水鸟以冬候鸟为主,占53.6%。湿地水鸟的估计总量为92.6×104只,数量在万只以上的有25种,其中以黑腹滨鹬数量最多,海岸湿地水鸟的种群密度明显高于大陆和岛屿湿地水鸟,种群密度超过1.0只/km2的种类多达21种,岛屿湿地水鸟种群密度超过1.0只/km2的有5种,而所有大陆湿地水鸟的种群密度均未超过1.0只/km2。乐清湾和温州湾滩涂湿地是黑嘴鸥的最重要越冬地和黑脸琵鹭的主要迁徙停歇地。  相似文献   

19.
In birds and many other animals, there are large interspecific differences in the magnitude of annual variation in population size. Using time-series data on populations of solitary bird species, we found that fluctuations in population size of solitary birds were affected by the deterministic characteristics of the population dynamics as well as the stochastic factors. In species with highly variable populations, annual variation in recruitment was positively related to the return rate of adults between successive breeding seasons. In stable populations, more recruits were found in years with low return rates of breeding adults. This identifies a gradient, associated with the position of the species along a "slow-fast" continuum of life history variation, from highly variable populations with a recruitment-driven demography to stable, strongly density-regulated populations with a survival-restricted demography. These results suggest that patterns in avian population fluctuations can be predicted from a knowledge of life-history characteristics and/or temporal variation in certain demographic traits.  相似文献   

20.
After volcanic explosions or tidal waves had defaunated several islands near New Guinea, bird species number rapidly returned to equilibrium on coral islets and rapidly returned to quasi-steady-state values limited by regrowth of vegetation in lowland forest of larger islands. However, reequilibration in montane forest has been limited by slow dispersal of the birds. Colonists have been drawn disproportionately from r-selected "supertramrip" species, which maintain much higher population densities than do K-selected faunas, perhaps due to selection for resource overexploitation by the latter.  相似文献   

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