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１９８８￣１９９６年，在兴凯湖泊自然保护区对春季迁徒的雁鸭类多样性进行了观察，共记录到雁鸭类３１种，包括５种雁，２种天鹅２４种鸭。每年春季经兴凯湖北迁的雁鸭类数量为３０万￣５０万只，集中迁徒期为３月２０日￣４月１０日，同时，对１０ａ来雁鸭类数量变化及原因进行了分析。为水禽迁徒行为及种群结构的研究提供了基础资料，对制定水禽保护政策及开发利用具有重要参考价值。 相似文献
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New Anatidae population estimates for eastern China: Implications for current flyway estimates 总被引：2，自引：0，他引：2
Soundly-based conservation plans for Anatidae require abundance and distributional data to provide accurate estimation of population sizes and trends and to identify key sites for protection. Here, we report the first ever extensive surveys throughout eastern China’s wetlands for Anatidae, 80% of which occurred in the Yangtze floodplain. Population estimates for 24 species with sufficient data are provided, allowing assessment of the accuracy of current flyway population estimates; fourteen species are far less numerous than previously believed and three far more numerous. Further improvement of the population estimates for eastern China will need coordinated counts across the region requiring a large, skilled counter network. 相似文献
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为了解天津北大港湿地的鸭科鸟类种类,2004年11月~2008年3月采用定位观察和线路调查相结合的方法,用计数法和网格计数法取得鸟类种类和数量,并对所得数值采用频率指数估计法,结果为鸭科鸟类8属24种。旅鸟24种,占总种数的100%;冬候鸟4种,占总种数的16.7%;留鸟1种,占总种数的4.2%。古北种13种,占总种数的54.2%;全北型9种,占总种数的37.5%;古北-东洋种2种,占总种数的8.3%。明确豆雁(Anser fabalis)、赤膀鸭(Anas strepera)、绿翅鸭(Anas crecca)、绿头鸭(Anas platyrhynchos)、斑嘴鸭(Anas poe-cilorhyncha)和斑头秋沙鸭(Mergellus albellus)6种为优势种。Shannon-Weiner多样性指数(H′):春季>秋季>冬季>夏季。有国家二级保护鸟类4种。 相似文献
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Janusz Kloskowski Andy J. Green Marcin Polak Javier Bustamante Jarosław Krogulec 《水产资源保护:海洋与淡水生态系统》2009,19(7):815-826
- 1. The Doñana wetland complex (SW Spain) holds more wintering waterfowl than any other wetland in Europe.
- 2. This study focused on the use made by 12 common waterbirds (eight ducks and four waders) of the natural seasonal marshes in Doñana National Park (DNP) and the adjacent Veta la Palma (VLP) fish ponds created in the early 1990s. Data used were from aerial and terrestrial surveys collected between October and February during six consecutive winters from 1998/99 to 2003/04. Changes in distribution of each bird taxon were related to changes in the extent of flooded marshes within DNP. Up to 295 000 ducks were counted in VLP during dry periods, and up to 770 000 in DNP when it was flooded.
- 3. The timing and extent of flooding in DNP was highly variable, but there was a consistent pattern in which ducks concentrated in VLP during dry months and winters but redistributed to DNP as more of it was flooded. This refuge effect was also strong for black‐tailed godwits Limosa limosa, but much less so for other waders. Waders feed mainly on invertebrates, and invertebrate biomass in VLP was found to be higher than in DNP. Ducks feed mainly on seeds and plant material, which are more abundant in DNP when flooded.
- 4. When water levels in DNP were stable over the course of a winter, or controlled for in multivariate models, the numbers of ducks at VLP declined over time, probably due to reduced availability of plant foods. In contrast, numbers of waders at VLP were more stable, and their invertebrate prey became more abundant over time, at least in the winter 2003/4.
- 5. In this extremely important wetland complex, the value of natural and artificial wetlands for wintering waterbirds are complementary, providing suitable habitat for different species and for different conditions in a highly variable Mediterranean environment.
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《African Zoology》2013,48(4):299-305
The status of waterbirds breeding in protected areas in North Africa needs constant monitoring because of a naturally fluctuating environment and permissive attitudes towards illegal activities likely to negatively affect population dynamics of threatened species. We present the results of a study conducted at a protected site, Lake Tonga, north-eastern Algeria, on a breeding population of Ferruginous Duck Aythya nyroca, a Near-Threatened duck subjected to considerable pressure from egg-pilfering and illegal hunting. Two distinct habitats within the lake were used by Ferruginous Duck: an Alder carr (Alnus glutinosa) and floating islets across the lake. The mean clutch size was 9.51±1.84 eggs (N = 51 clutches) with hatching rate of 80.7% for successful clutches. Breeding success was low (37%) with predation (33%) and clutch desertion (17%) accounting for the majority of failed nests. The probabilities of nest failure and nest desertion increased with a delayed onset of egg laying. Predation was not significantly associated with egg laying date and vegetation cover, but late breeders nesting in dense vegetation seemed to suffer less predation. Conspecific brood parasitism was positively associated with nest size, whereas interspecific brood parasitism was marginally associated with water depth. We discuss different hypotheses concerning nest desertion, and argue that illegal hunting and disturbance may best explain why birds desert their nests. 相似文献
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试验使用GenBank中已知的鸟类细胞色素b(Cyt b)基因部分序列(1044 bp)(共13条序列,其中鸡形目4条、鸭科鸟类9条)作为本研究的数据集,并以鸡形目与雁形目(鸡/绿头鸭)的分歧时间(89.8 MYA)为锚定点,用核苷酸不同替代模型对鸭科的分子钟进行标定。雉科与鸭科间的分歧时间的估计值为116.3785 MYA("1+2TiTv"),雁属与5个鸭属间的分歧时间为63.8823 MYA("1+2TiTv"), 鸡与鹌鹑的分歧时间为37.6708 MYA("1+2TiTv"),灰雁、白额雁与鸿雁间的分歧时间的估计值为1.879331 MYA("1+2TiTv")。以上结果说明:用"1+2TiTv"模型分析得到的鸭科鸟类的分歧时间比较可靠;雉科与鸭科、雁属与鸭属两个接近基部类群的分歧时间发生在白垩纪(137-65 MYA),支持鸟类早期历史发生在白垩纪的观点。 相似文献
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【目的】估计鸭科鸟类间的分歧时间,了解鸭科不同鸟类的遗传背景。【方法】测定鸿雁家鹅15个品种、灰雁家鹅2个品种共44个个体的细胞色素b基因的全序列。将获得的鸿雁家鹅和灰雁家鹅的一致序列（2条）与GenBank中已知的鸟类细胞色素b基因部分序列（共13条;其中,鸡形目4条、鸭科鸟类9条）一起组成共15条序列作为本研究的数据集,并以鸡形目与雁形目（鸡/绿头鸭）的分歧时间（89.8 MYA）为锚定点,对鸭科的分子钟进行顺序标定。【结果】雉科（Gallus gallus和Coturnix japonica1、Coturnix japonica4、Coturnix chinensis）与鸭科（Anas platyrhynchos、Anas poecilorhyncha;Bucephala clangula;Chloephaga picta;Cairina moschata;Somateria mollissima和 Anser anser、Anser cygnoides、Anser albifrons,共6个属）间的分歧时间的估计值为101.798 MYA（泊松模型）和129.461 MYA（Г模型）;雁属（Anser anser、Anser cygnoides和Anser albifrons）与5个鸭属（Anas platyrhynchos、Anas poecilorhyncha;Bucephala clangula;Chloephaga picta;Cairina moschata和Somateria mollissima）间的分歧时间为55.1225 MYA（泊松模型）和62.5223 MYA（Г模型）。【结论】雉科与鸭科、雁属与鸭属两个接近基部类群的分歧时间发生在白垩纪（146—65 MYA）,支持鸟类早期历史发生在白垩纪的观点。 相似文献
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Highly pathogenic avian influenza (HPAI) virus subtype H5N1 threatens poultry production and human health. Understanding the role that migratory waterfowl play in introducing and maintaining this infection is critical to control the outbreaks. A study was conducted to determine if the occurrence of HPAI subtype H5N1 outbreaks in village poultry in Romania, 2005-2006, was associated with proximity to populations of migratory waterfowl. Reported outbreaks--which could be grouped into three epidemic phases--and migratory waterfowl sites were mapped. The migratory waterfowl site closest to each outbreak was identified. The distances between outbreaks occurring in phase 1 and 2 of the epidemic and the closest migratory waterfowl site were significantly (P<0.001) less than in phase 3, but these distances were only useful in predicting when outbreaks occurred during phase 1 (October-December, 2005) of the epidemic. A spatial lag (rho=0.408, P=0.041) model best fit the data, using distance and [distance]*[distance] as predictors (R2=0.425). The correlation between when outbreaks were predicted to occur and when they were observed to occur was 0.55 (P=0.006). Results support the hypothesis that HPAI virus subtype H5N1 infections of village poultry in Romania during the autumn of 2005 might have occurred via exposure to migratory populations of waterfowl. 相似文献
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为鉴定一株从雁鸭脏器内分离到的革兰氏阴性细菌,本研究对该菌进行分离培养、细菌16S rRNA序列比对、动物试验和药物敏感性试验。结果表明该分离菌与多杀性巴氏杆菌(P.mutocida)(AF224297)同源性达99.88%,毒力强,能够致死家兔、小鼠和鸡,对氧氟沙星等药物敏感。分离菌的荚膜抗原血清型特异性基因PCR产物与荚膜血清A型P.mutocida hyaD-hyaC基因同源性达99.9%,确定该菌株为荚膜血清A型P.mutocida。本研究首次从雁鸭体内分离到A型P.mutocida。 相似文献