上思县海南嗀活动区的水鸟研究

海南（开 鸟）(Gorsachius magnnficus)是世界上最为濒危的鸟类之一。在上思县海南的活动区，分布有水鸟32种；其中在海南（开 鸟）主要觅食地浅水区活动的有14种，包括11种白昼活动的水鸟和3种夜行性水鸟，海南（开 鸟）属夜行性水鸟。由于生境使用时间不同，海南（开 鸟）与大部分白昼活动的水鸟形成生态分隔；夜鹭在觅食生境的使用和活动时间上，与海南（开 鸟）重叠最多，有可能对海南（开 鸟）产生重要的生态影响，值得进一步深入研究。研究还表明，冬季和初春是调查海南（开 鸟）的分布和数量的重要季节。     

湿地鸟类旅游开发研究--以泉州湾为例

湿地是濒危鸟类、迁徙候鸟的主要栖息、繁殖地，鸟类及其生存、栖息的环境具有极强的观赏性，为湿地开展旅游提供了得天独厚的自然优势。但是，目前国内的湿地鸟类旅游只是简单地涉及到观鸟等单个项目，系统、理论的研究还比较少。本文以泉州湾湿地鸟类为研究对象，在全面分析鸟类的赋存状况、可观赏性的基础上，结合鸟类旅游开发的若干原则，提出鸟类旅游专项产品，指出湿地鸟类旅游开发的保障措施，以期对湿地鸟类旅游开发提供借鉴。     

陕西黄河湿地的保护开发与利用

陕西黄河湿地是我国面积最大的内陆河流湿地之一,是多种鸟类栖息与多种候鸟迁徙中转、繁殖的重要区域。如何妥善处理湿地保护与农业开发之间的矛盾,如何开发利用湿地资源,引导当地农民实现农业可持续发展是应解决的主要问题。笔者就陕西黄河湿地开发利用提出自己的见解,坚持保护第一的原则,重视科学研究,拯救珍稀濒危物种,发展生物资源,在实验区内有控制地合理开发利用自然资源,在保证生态效益第一的前提下,实现生态效益、社会效益和经济效益的统一。     

基于韧性景观视角下的黄(渤)海候鸟栖息地保护探究

我国长江三角洲、珠江三角洲地区汇聚了大量的城市人口,但伴随着城市的快速发展,生态问题越来越严重,生物脆弱性日益显著。基于此,以盐城黄(渤)候鸟栖息地保护为目的,提出现今候鸟栖息地存在的问题,通过恢复河流滩涂水文条件、改善河流形态等多种手段,为鸟类、鱼虾、昆虫等提供一个良好的生境,提高生态环境韧性,为候鸟迁徙提供一个舒适的中转场地,以达到保护栖息地的目的。     

红树林人工恢复造林技术分析

红树林是一种生长在亚热带以及热带地区海岸边的木本植物,构成沿海地区防护林十分重要的部分。从当前红树林的生长现状来看,红树林带栖息着诸多鱼类、鸟类以及虾蟹类动物,具备了物种多样性生长环境,并且在经济利用以及生态保护等多个方面都有着突出的价值。人工恢复成了红树林造林生态中重要的一项内容。如今,随着人们物质生活水平的逐渐提升以及生物保护学的逐步发展,人们渐渐认识到加强生态环境保护的重要性,红树林自然也是人们关注的重点。所以,研究如何实现红树林人工恢复以及人工造林有着十分重要的现实意义。     

在俄亥俄州CRP对野生动物的影响

联邦的农业计划对野生动物的多样性有很大影响。例如,像“保护专用地计划”（CRP）等的实施,能够建立起永久性植被覆盖层,草地鸟类将因此而受益。对现行的保护计划的评价,有助于制定远景目标和确保有益计划的长期可持续进行。在俄亥俄洲实施CRP的土地上,对植被和土壤物理特性进行定量分析、记录产卵期鸟类受到干扰的时间和范围、测定鸟类对这些环境的利用情况、以及与土地特性相关的鸟类对土地利用情况参数,结果发现由于在产卵季节（5～6月）割草,引起一半以上的样地受到干扰。在这些样地中居住了43种鸟,几种依赖于草地的鸟类对CRP地块的利用与由田地提供的草场面积和相邻的草地有关。然而,所有种类的丰富度与永久覆盖植被的年限和田地的大小关系不大。在这类生境中,于繁殖季节消除对植物覆盖的干扰对野生动物是非常有益的。制定增大草地面积或营造类似现存草地的草被层等政策,将有助于草地鸟类的繁衍生息。     

扬州市禽流感风险评估模型的研究进展探析

扬州水网分布密集而广泛,养殖以水禽鸭、鹅为主,同时扬州处在候鸟东部迁徙线上,境内的高邮湖、邵伯湖是候鸟的重要栖息地,也是候鸟和家禽的交汇点。因此,禽流感入侵扬州市的风险很大。基于此,针对扬州市特定的生态系统和养殖环境,通过文献分析和专家建议,确定了扬州市禽流感发生的风险因子,采用层次分析法建立扬州市高致病性禽流感传播风险评估模型,以期实现扬州市禽流感疫情发生风险的定量评估。     

山西省中条山区鸟类群落结构分析

从中条山区自然环境条件入手，在分析鸟类区系特征的基础上，揭示了不同栖息环境中鸟类的群落组成，中条山鸟类区系属古北界，人类活动对鸟类群落组成具有显著影响，鸟类分布随垂直自然带不同而变化。     

陇东黄土高原塬区冬小麦越冬期土壤水分损耗规律浅析

通过分析陇东塬区冬小麦越冬期土壤水分损耗,以及决定越冬土壤水分损耗的关键气象要素,指出在秋季降水充沛、土壤收墒充足、冬季气温偏高、降水明显偏少的年型,越冬期土壤水分损耗是不可忽视的,其中有一半年份,越冬期土壤水分损耗占冬小麦生长季节自然降水的10%～22%。尤其是入冬前土壤含水量充沛,而返青以后生长期降水相对较少的年份,越冬期麦田土壤水分损耗相当于返青到成熟期降水量的44%。     

儋州市新英湾红树林开发保护问题及对策分析

红树林是指以红树科植物为主的常绿灌木和小乔木群落.这类植物的枝干内富含单宁酸,如果暴露在空气中就会被氧化变成红色,使受伤的树干呈现鲜艳的红色,所以这类植物被称为红树林.为了有效保护红树林资源,促进我国沿海地区社会、经济、环境稳定持续发展,分析了海南省儋州市新英湾红树林目前开发保护中存在的主要问题,提出"尽快划定保护区和...     

Long-term population declines in Afro-Palearctic migrant birds

We present the first continent-wide analysis of the population trends of European breeding birds to show that populations of Afro-Palearctic migrant birds have shown a pattern of sustained, often severe, decline. The mean trend of inter-continental migrants was significantly negative between 1970 and 1990 and non-significantly so between 1990 and 2000. Mean population trends were positively correlated between periods, suggesting little change in the trajectory of most migrant species’ populations over this 30-year period. In both periods, trends of inter-continental migrants were significantly more negative than those of short-distance migrants or residents. This negative trend appeared to be largely, although not entirely, due to declines in species wintering in dry, open habitats in Africa. Analyses of trends of 30 closely related pairs of species, one a long-distance migrant and the other not, indicated significantly more negative trends in the former, irrespective of breeding habitat. Conservation action to address these declines is required under the Convention on Migratory Species and the Pan-European Biological and Landscape Diversity Strategy, to which most European countries are signatories and which aim, respectively, to conserve migratory species and to halt the loss of biodiversity by 2010. Our results indicate that more conservation action may be required outside Europe to achieve these targets. Further research is needed to assess whether the declines are caused by factors operating on the birds’ wintering grounds, breeding grounds or on migration routes, and to identify ways to reverse them.     

Protected areas do not fulfil the wintering habitat needs of the trans-Saharan migratory Montagu’s harrier

Populations of migratory birds can be affected by events happening at both breeding and wintering grounds. The Sahel is a vast region holding a large number of wintering trans-Saharan migratory European birds, and current land-use changes there may represent a threat for these species. We used satellite tracking data from the migratory Montagu’s harrier to evaluate habitat use of the species during the wintering season, and whether the current network of protected areas is effective to provide their habitat needs during that season. We also developed an ecological niche model for the species in Western-Central Sahel to check if the most suitable sites are included within current protected areas. Tracked harriers occupied a large region encompassing a total of eight countries. The most preferred habitats during winter were croplands and some natural vegetation habitats, especially grasslands. Protected areas only covered a small proportion of the overall wintering grounds of tracked harriers and the most suitable areas for the species in Western-Central Sahel. Increasing the extent of preferred natural habitats within protected areas should benefit the conservation of this and probably other insect-eating raptors. However, substantial increases in extent and number of protected areas in sub-Saharan Africa are very unlike to occur. Conservation actions in the region should therefore be mostly focused on improving land use planning and management outside protected areas, specially enhancing agricultural practices to make biodiversity conservation compatible with poverty alleviation. These can be chiefly targeted at an area of <20,000 km² of very suitable habitat for these species.     

Status, distribution and long-term changes in the waterbird community wintering in Doñana, south-west Spain

The Guadalquivir Marshes or Doñana wetland complex is the most important wintering site for migratory waterbirds in the Mediterranean region. However, there is a lack of previous information on the status of different species in this area. Using monthly aerial counts conducted from 1978 to 2005, we analysed the size of wintering populations of 21 waterbird species, their distribution within the Guadalquivir Marshes, and their long-term population trends. We used Underhill indices to replace missing values and to correct for flocks of unidentified ducks. Based on long-term means, we identified 16 species whose populations at Doñana exceed 1% of the biogeographical flyway population. For at least 1 month of the year, mean counts were around 10% of the flyway population for six species. The natural, temporary marshes of Doñana National Park were particularly important for Anatidae, ricefields for gulls, white storks and grey herons, fish ponds for flamingos, cormorants and avocets, and salt pans for shelduck. Four Anatidae species have undergone long-term declines and eight non-Anatidae have undergone long-term increases. Population trends were related with trophic guild, migratory status and habitat use. Winter visitors and herbivorous species showed more negative trends than resident, omnivorous-carnivorous species. Those species concentrated in strictly-protected natural marshes have tended to decline. The surface area of ricefields and fish ponds has increased over the study period, and bird species concentrated in these artificial wetlands have tended to increase. This raises questions about the value of waterbirds as flagship or umbrella species for wetland conservation.     

The potential importance of migratory stopover sites as flight feather molt staging areas: a review for neotropical migrants

The decline of many species of Neotropical migrants has prompted increased research on their ecology on their breeding and wintering grounds. However, studies of their ecology during migration are relatively few. Despite documentation of molt-migration in at least six Neotropical passerine species, this phenomenon has been ignored in current conservation strategies for Neotropical migrants. In this review paper, we suggest that molt studies need to be done as a way to refine and improve conservation plans for Neotropical migrants. We identify three important questions that merit further study: (1) which Neotropical migrant species undergo flight feather molt at migratory-stopover sites; (2) where are molt-migration stopover sites geographically located; and (3) why are these sites preferred as stopover sites during molt? Finding answers to these questions will allow us to protect molt staging areas occupied by Neotropical migrants during migration as many wetland and nearshore oceanic habitats have been protected for molting waterfowl, shorebirds, and seabirds.     

Life-history and ecological correlates of population change in Dutch breeding birds

Predicting relative extinction risks of animals has become a major challenge in conservation biology. Identifying life-history and ecological traits related to the decline of species helps understand what causes population decreases and sets priorities for conservation action. Here, we use Dutch breeding bird data to correlate species characteristics with national population changes. We modelled population changes between 1990 and 2005 of all 170 breeding bird species using 25 life-history, ecological and behavioural traits as explanatory variables. We used multiple regression and multi-model inference to account for intercorrelated variables, to assess the relative importance of traits that best explain interspecific differences in population trend, and to identify the environmental changes most likely responsible. We found that more breeding birds have increased than decreased in number. The most parsimonious models suggest that ground-nesting and late arrival at the breeding grounds in migratory birds are most strongly correlated with decline. Increasing populations are mainly found among herbivores, sedentary and short-distance migrants, herb- and shrub-nesting birds and large species with a small European range. Declines in ground-nesting and late arriving migrant birds suggest that agricultural intensification, eutrophication and climate change are most likely responsible for changes in Dutch breeding bird diversity. We illustrate that management strategies should primarily focus on the traits and causes responsible for the population changes, in order to be effective and sustainable.     

Acacia, cattle and migratory birds in southeastern Mexico

Acacia pennatula groves in mid-elevation valleys of southern Mexico supported both the highest density and diversity of migratory birds compared to other habitats in the region. In addition, we found the highest numbers for over half of the common migratory species. Despite the high degree of leaf loss during the late winter, acacia groves do not experience greater declines in insectivorous migratory bird populations than other local habitats. Color-marked individuals of canopy species had a strong tendency to remain resident within a single acacia grove throughout the winter. Management of native acacias on subtropical rangelands for wood products, fodder, and soil improvement would probably directly and indirectly benefit migratory song bird populations. Neotropical acacia woodland is primarily associated with grazing land for livestock which might discourage some from considering acacia management a viable option for migratory bird conservation. However, acacias were probably widespread in recent geologic time under drier conditions with heavy browsing and seed dispersal by a now extinct megafauna. Two observations suggest a foraging advantage for acacia use: the higher density of migratory birds in acacia is a result of higher numbers of canopy insectivores; and acacias are selected by migrants when they occur in mixed habitat. We hypothesize that plant investment in mechanical defenses (thorns) reduces energy available for chemical defenses effective against insect herbivores.     

Challenging conservation of migratory species: Sahelian rainfalls drive first-year survival of the vulnerable Lesser Kestrel Falco naumanni

In the context of attested global changes, accurate estimation of whether climatic fluctuations impact on population demographic parameters is needed for adequate management, especially for migratory species. We present a capture-recapture analysis linking survival rates of the vulnerable Lesser Kestrel (Falco naumanni) to annual rainfalls in the Sahel region, considered as a proxy of climatic conditions on wintering grounds. Recapture data were obtained from field observations of individuals ringed and sexed as juveniles over a 14-year monitoring period (1994-2007). We addressed a common but problematic situation in birds where: (i) sex is known with certainty for first-summer or older birds but only suspected for juveniles, and (ii) a large proportion of individuals never return to the study population (e.g. transient behavior). Transient behavior and unknown sexes were explicitly integrated considering a two age class in a multistate capture-recapture model. Survival was time-varying for juveniles (geometric mean: 0.499 ± 0.021) but constant - and higher - for adults (0.718 ± 0.013). Yearling survival probabilities were strongly correlated with rainfalls in the Sahel, suggesting a high dependence of juvenile upon the wintering conditions. While taking sex uncertainty into account, we detected no sex-dependence in survival. Incorporating the sensitivity of survival of wintering migratory birds to climatic variables such as precipitations in arid Sahelian ecosystem may allow to model conservation scenarios with a greater realism. Finally, we encourage the development of international management strategies for migratory species on wintering areas in addition to the existing conservation actions on summering Mediterranean grounds.     

Conservation of seed-dispersing migrant birds in Mediterranean habitats: Shedding light on patterns to preserve processes

Migratory frugivorous birds disperse the seeds of many plant species, forming mutualistic associations that render frugivores a priority for conservation in many habitats worldwide. We analysed the distribution of seed-dispersing frugivorous passerines in southern Spain, which is an important area for the conservation of European birds during winter. Frugivorous birds showed similar regional abundance and richness during four winters, although fruit availability changed among years. However, the spatial distribution of frugivorous birds in the area changed among years. These changes were principally determined by annual variation in the distribution of fruits in the area, revealing a clear ability of birds to track the distribution of fruits. The unpredictable distribution of fruits each year suggests that regional fruit crops, rather than selected habitat patches, need to be protected for the long-term conservation of frugivorous bird populations in wintering grounds. Remarkably, the distribution of frugivores was independent of forest development or general cover of shrubs, which helps to reconcile the protection of fruiting shrubs with forest cleaning, an usual management to prevent devastating summer fires that is destroying fleshy-fruited plant communities in many areas of southern Spain. Thus, leaving a part of the fruiting shrubs untouched when cleaning forest undergrowth will allow the settlement of frugivorous birds. Interestingly, both abundance and richness of frugivores decreased with elevation, probably as a consequence of impaired climatic conditions at high altitude, revealing the importance of lowland shrublands as wintering grounds for frugivorous birds. These habitats deserve special conservation efforts, as they are seriously threatened by the ongoing encroachment of agricultural and urban areas along the Mediterranean coasts.     

The conservation value of urban riparian areas for landbirds during spring migration: Land cover, scale, and vegetation effects

Urbanization changes bird community structure during the breeding season but little is known about its effects on migrating birds. We examined patterns of habitat use by birds at the local and landscape level during 2002 spring migration at 71 riparian plots along an urban gradient in Cincinnati, Ohio, USA. Using linear regression, we examined variation in relative density, species richness, and evenness of four migratory guilds associated with natural land covers and building area at four scales (50, 100, 250, 500 m radial buffers). We also examined the influence of local vegetation using multiple regression models. As building area increased, riparian forests tended to be narrower and have fewer native trees and shrubs. In general, native birds were positively associated with tree cover (within 250-500 m of stream) and native vegetation, and negatively with building area (within 250 m); exotic species responded inversely to these measures. Short-distance migrants and permanent residents displayed the weakest responses to landscape and vegetation measures. Neotropical migrants responded strongest to landscape and vegetation measures and were positively correlated with areas of wide riparian forests and less development (>250 m). Resident Neotropical migrants increased with wider riparian forests (>500 m) without buildings, while en-route migrants utilized areas having a wide buffer of tree cover (250-500 m) regardless of buildings; both were positively associated with native vegetation composition and mature trees. Consequently, developed areas incorporating high native tree cover are important for conserving Neotropical migrants during stopover.     

Partial migration and philopatry of Yellowstone pronghorn

Spring migration may facilitate survival and recruitment in mammals by reducing predation risk and increasing access to higher-quality forage. The Yellowstone pronghorn Antilocapra americana population (<250 animals) retains one of only two pronghorn migrations remaining in the greater Yellowstone region of the western United States. We used 5743 telemetry locations of 44 adult, female pronghorn during June 1999-August 2005 to determine migration patterns, seasonal distributions, and individual fidelity to migratory strategies. Yellowstone pronghorn were partially migratory, with >70% of the pronghorn population migrating 15-50 km to 4 contiguous summering areas and <30% remaining year-round on the winter range. Most radio-collared pronghorn showed fidelity across years to their migration strategy and summer use area, but approximately 20% migrated in some years, but not others. This behavioral flexibility is consistent with the hypothesis that migration in Yellowstone pronghorn is a conditional strategy and likely contributed to dynamic and rapid changes in the proportion of migrants from 80% to 20% and back to 70% during 1967-2005. All migrant pronghorn traveled 10 km over a topographic bottleneck (Mt. Everts) separating the winter and summer ranges, primarily using grassland-sagebrush pathways through conifer forest. We recommend continued protection of this corridor because increased mortality and a decreasing proportion of migrants may be as important a threat to the persistence of partially migratory populations as habitat fragmentation, especially when local resources for non-migrants are inadequate to sustain the entire population.