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11.
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   
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青海湖区普氏原羚及鸟类栖息草地的调查与研究   总被引:1,自引:0,他引:1  
青海湖流域普氏原羚与鸟类栖息的草地类型,以温性草原类、高寒草原类、温性荒漠草原类及高寒草甸类草地为主.本文分别简述了各草地型的植被结构、植物种类以及草地生物量,同时对普氏原羚、鸟类栖息地各草地型的生物量进行了比较分析.  相似文献   
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Several studies have documented negative effects of persecution by humans on the population dynamics of large birds of prey. Several areas have seen a reduction in persecution in modern times, but the demography of large raptors still makes these birds vulnerable to such effects. In a GIS analysis, utilising data collected during two national censuses of the golden eagle Aquila chrysaetos in Scotland and contemporary data on the distribution of poisoning incidents (a common method of raptor persecution in Scotland), we show that persecution was associated with a reduction in the age of first breeding, territory vacancies, and the use of territories by non-breeding immatures. Persecution was therefore reducing adult survival and distribution and was probably creating ecological traps that attract mobile immatures, increasing subadult mortality in birds that may originate from persecution-free areas. Mapping a form of land management unique to moors managed for red grouse Lagopus lagopus scoticus shooting, where most poisoning occurs, we also show similar associations between golden eagle demography and grouse moor management. As such, persecution may be having a major impact on the golden eagle population of Scotland, since it occurs over a wide area and at least in some areas has continued unchecked over many decades.  相似文献   
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The need to prioritize species based on their perceived endangerment has led to the development of systems for categorizing and assessing their degree of vulnerability. Systems with divergent biological and geographical scopes can result in conflicting lists of high-priority species, potentially confusing conservationists and hampering the efficient allocation of resources. To assess conservation priorities for North American birds, we compare three priority-setting systems; those of the International Union for the Conservation of Nature (IUCN), NatureServe, and Partners in Flight (PIF). We found highest correspondence among the three systems in the highest and lowest categories of the respective systems with lower levels of correspondence in intermediate categories. We suggest that this is because the systems, while using different formulations of criteria, are based on the major factors known to be correlated with extinction risk. The few examples of species listed as a high conservation priority by one group but not one or both of the others appear to be the result of differences in availability or interpretation of data. Better communication and collaboration among those responsible for compiling the priority lists for each system is needed.A primary difference among the systems was the total number of species identified as conservation priorities. IUCN identified the fewest species (47) and PIF the most (157). This difference is the result of differences in geographic and taxonomic scope of each system. However, when considered as the percent of the total number of taxa evaluated by each system, all systems identified approximately 20% of species as of conservation concern. To reconcile disparate lists, we urge that conservationists use a hierarchical approach that first considers species that meet thresholds for endangerment under global systems, followed by species considered most vulnerable relative to all continental biota.  相似文献   
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We compared breeding bird communities and vegetation characteristics at paired point locations in primary (undisturbed) and mature secondary forest (70-100 years old) sites in Great Smoky Mountains National Park, USA to understand how sites logged prior to creation of the park compare to undisturbed sites following 70 years of protection from human disturbance. We found that bird and vegetation communities are currently similar, but retain some differences in species composition. Rank abundance curves for primary and secondary forest bird communities showed very similar patterns of species dominance. Species composition was also similar on the two sites which shared 24 of the 25 most frequently recorded species. Nonetheless, comparisons of density estimates derived from distance sampling showed three bird species were more abundant on primary forest sites and that one bird species was significantly more abundant on secondary forest sites. Notably, comparisons based on raw counts (unadjusted for potential differences in detectability) produced somewhat different results. Analyses of vegetation samples for the paired sites also showed relative similarity, but with some differences between primary and secondary forests. Primary forest sites had more large trees (trees greater than 50 cm diameter at breast height) and late successional species. Primary forest sites had a denser tall shrub layer while secondary forest sites had a denser canopy layer. Nonetheless, tree species richness, basal area of live trees and number of standing snags did not differ between primary and secondary forest sites. Results indicate that breeding bird communities on sites within the park that were logged commercially 70 years ago are currently quite similar to bird communities on sites with no history of human disturbance. Similarities between the bird communities on previously disturbed and undisturbed sites in Great Smoky Mountains National Park may exceed those on more fragmented landscapes because large patches of primary forest, adjacent to commercially logged sites, remained in the park when it was established in 1935. These patches of primary forest may have served as source areas for commercially logged sites.  相似文献   
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2013年6月在广西涠洲岛自然保护区进行动物资源调查时,观察并拍摄到一群褐翅燕鸥,属广西鸟类新记录种。对该物种的分类、分布及种群状况进行了记述和讨论。  相似文献   
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Wild birds have been identified as a relevant reservoir of Campylobacter spp., therefore, a potential source of infection in humans and domestic animals. The objective of this study was to determine the occurrence of Campylobacter spp. on birds of prey in Spain. In addition, antibiotic resistance profiles of the isolates were evaluated. A total of 689 specimens of 28 raptor species were analyzed, with a resulting individual prevalence of 7.5%. C. jejuni was the most frequently isolated species (88.5%), followed by C. coli and C. lari (3.8% each). The occurrence of Campylobacter was significantly higher (p < 0.05) in nocturnal birds of prey (15.3%), in spring season (12.2%) and in carnivorous species (9.4%). Isolates displayed a remarkable resistance to nalidixic acid (69.9%), ciprofloxacin (69.9%), and tetracycline (55.6%), and a low resistance to streptomycin (6.7%).Our findings highlight the importance of birds of prey as reservoirs of Campylobacter strains and their significant role as carriers of antimicrobial resistance.  相似文献   
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甜樱桃对环境条件要求严格,冻害、裂果、鸟害等自然灾害或异常气候成为限制甜樱桃栽培区域及生产的严重障碍.甜樱桃大棚栽培有效防御了低温的危害、果实遇雨裂果及鸟害等,有效地扩大了甜樱桃的栽培区域,使生产安全.  相似文献   
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