内蒙古中生代有尾两栖类一新种：道虎沟辽西螈

有尾两栖类化石在中生代十分稀少且多数残破,我国近期报道了5属5种保存骨架化石的中生代有尾类，因而引起国际同行的重视。它们都产自下白垩统热河群或略低的层位中，与世界其他地区有尾类相比，我国种类具有时代早、化石较完整以及分异度大等特点，对研究有尾两栖类的起源、早期演化和散布具有特别意义。在我国已知中生代有尾类化石点中，内蒙古道虎沟的化石材料最为丰富，已报道了奇异热河螈和天义初螈2属2种，但道虎沟化石层的时代争论很大，有3种不同观占。     

早期鸟喙研究获进展

正根据5月3日《自然》发表的一篇论文,新发现的一组保存极其完好的早期有喙鸟类化石表明,恐龙向鸟类的过渡比预期的更复杂。鸟类的头骨与其恐龙祖先的头骨存在明显差异。现代鸟类鸟喙较大,没有牙齿,脑壳也较大,闭颌肌肉较弱,头骨铰接更明显,拥有活动上颚和悬颌。但是,一直以来人们却难以确定这些特征是如何形成的,以及是按什么顺序形成的;原因之一就是鸟类头骨化石一般都保存不佳。     

红胸秋沙鸭分布新记录

红胸秋沙鸭(Mergus serrator Linnaeus)郑作新在《中国鸟类分布名录》第一版(1955)、第二版(1976)以及《中国鸟类系统检索》(1964)中均记载在长白山地区有分布,为非繁殖鸟,但未具体到省区。吉林省鸟类学者在几十年的鸟类考察和研究中均未在长白山地区和吉林省内发现,     

基于层次结构监测方案鉴别农田鸟类栖息地需求(英文)

农田景观在生物多样性保护中发挥着重要作用,很多农田地区最重要的指示性鸟类物种的数量已呈下降趋势。然而,有关二者间确切的因果关系却鲜有报道,有时也难下定论,特别是目前的监测数据只是基于鸟种调查和个体计数。鉴于确定栖息地偏好是保护农田鸟类的前提,我们设计并验证了一套可同步搜集和分析鸟类及土地利用数据的监测方案。为了能在不同空间尺度、不同的土地利用方式及作物种类水平上将鸟类种类与土地特征相关联,我们采用了层次结构取样设计。将空间尺度分为"农田景观"、"农田景观类型"、"农作物及其他栖息地"和"植被结构"。这些尺度合为一个新的概念,即"栖息地矩阵(HM)"。利用领域标图方法,我们在29块1 km2的样地上监测了繁殖鸟类的丰富度。在这些样地周边分别增加100 m宽的缓冲带,并记录栖息地的大小和位置以及研究区域内所有耕地上植被的高度、盖度和密度。这一监测方案便于分析农田鸟类栖息地特征与鸟类丰富度之间在空间尺度上的关系。我们以黍鹀(Emberiza calandra)、云雀(Alauda arvensis)和草原石鵖(Saxicola rubetra)3种农田鸟类为例进行了验证。结果表明,这3种鸟类的繁殖领域在"农田景观"、"农田景观类型"和"农作物"尺度上有较大不同。在整个繁殖季内,鸟类丰富度因作物种类和植被发育情况(高度、盖度及密度)的不同而发生变化。栖息地矩阵分析可以用于分析农田景观中某一鸟种偏好的栖息地的详细状况。综上所述,这一套方法在设计分析景观配置、土地利用方式及土地利用变化与农田鸟类栖息地适宜度及鸟类丰富度间关系的监测方案上具有很大的潜力。     

鸟类羽毛演化秘密揭开

我国科学家发现了一种世界上迄今为止最原始的反鸟,这种命名为“原羽鸟”的鸟类具有一种我们前所未知的羽毛类型,为科学家对鸟类羽毛的早期演化研究提供了非常重要的依据。羽毛一直被认为是鸟类所特有的结构,它把鸟类从所有其它脊椎动物区分开来。但是人们对鸟类羽毛的起源问题知之甚少,在该问题的一个基本认识就是“鸟类羽毛与爬行动物的鳞片同源”或“羽毛起源于爬行动物的鳞片”。近年来在我国热河生物群发现的带“毛”的恐龙化石,使鸟类的羽毛起源问题成为国际古生物学研究的一个热点。     

研究发现1.2亿年前鸟类已有嗉囊

现生鸟类大都有嗉囊,那么鸟类最早是什么时候开始有嗉囊的呢?中国科学院古脊椎动物与古人类研究所研究员周忠和、张福成,山东天宇自然博物馆馆长郑晓廷教授以及美国学者近日在美国《国家科学院学报》上发表研究结果称,在辽宁省出土的朝阳会鸟化石和高冠红山鸟化石中寻找到迄今最早的鸟类嗉     

中国传统名贵笼鸟

中国人民驯鸟、养鸟和赏鸟具有悠久的历史，而且驯养鸟的种类逐渐增多，在中国悠久的驯鸟、养鸟、赏鸟的历史发展过程中，笼鸟的饲养管理和调教经验不断丰富，对每一种鸟都形成了一定的标准和特定的饲养方法，而且逐渐形成了具有中国特色的笼鸟饲养与观赏体系。１中国笼鸟种类概况地球上现存鸟类９２００余种，而中国就有１２６０种，其中适合家庭饲养的观赏笼鸟仅是少数。目前，我国饲养的笼鸟涉及近２０种鸟类，约１００多个物种，从分类学上说，除少数属于鹦形目、佛法僧目和鸽形目外，其它均是雀形目的鸟类（主要是百灵科、椋鸟科、鸦科…     

我国引进的笼养鸟

我国为了发掘笼养鸟养殖业的潜力,减少对野生鸟类的捕捉,加强野生鸟类资源的保护,提高笼养鸟产量,丰富养殖品种,广泛运用现代科学技术,使传统笼养鸟业向高产、高效、优质方面发展,对笼养鸟种类的选择,除了注重本国的优质鸟类资源开发利用外,近年来还从国外引进了许多"名、特、优"的笼养鸟类到国内饲养.     

恐龙今何在 翱翔蓝天上

１４０多年前，年轻的科学家赫胥黎向世人公布假说：鸟类是由小型兽类恐龙演化而来。其根据是从世界各地的恐龙化石研究，发现恐龙有３０多个特征与鸟类完全一样。至８０年代，美国耶鲁大学教授奥斯特隆在对德国始祖鸟、美颌龙和美洲恐爪龙进行解剖学研究后，肯定赫胥黎是对的，乌肯定是由恐龙演变而来的。但是，由于没有恐龙演变到鸟的过渡性生物的化石标本佐证，人们对奥斯特隆这位权威人士的“肯定”还是将信将疑。 中国科学家。中国地质博物馆馆长季强从辽宁的一位农民于 １９９６年８月 １２日送交的７５ ｃｍ长， ５０ ｃｍ宽的恐龙化…     

春季三种鹀类媒鸟鸣叫声对其集群行为的影响

鸟鸣是一种非常重要的鸟类行为。目前我国各地鸟类环志站为了提高鸟类环志数量,媒鸟引诱方法是环志工作中常用的方法,但是该方法也具有其局限性。2007年3～5月,笔者对黑龙江省帽儿山鸟类保护环志站春季常见的3种鹀科鸟类田鹀、黄喉鹀和灰头鹀,通过媒鸟鸣叫声音吸引其他同种鸟的方法,研究对鸟类集群行为的影响,以找出不同迁徙阶段以及每日不同时间段其鸣声对集群行为的影响,其结果将对增加鸟类环志数量具有一定的意义。研究表明:鸟类的鸣叫声音对于鸟类迁徙不同阶段的集群行为有不同的影响,在每天的不同时间段鸟鸣叫声音对其集群也是有一定的影响。对于旅鸟如田鹀等,媒鸟对于同种鸟的集群行为有明显的作用。当地繁殖的夏候鸟如灰头鹀,在迁到后期则不能使用媒鸟来提高环志量,因为它起的作用可能是完全相反的。各种鸟每日不同时间段媒鸟所起的作用也有较大的差异。对于夏候鸟而言,迁来早期早晨媒鸟有吸引的作用,而迁来中晚期则作用相反。     

Feathered dinosaurs from China and the evolution of major avian characters

Recent discoveries of feathered dinosaurs from Early Cretaceous deposits in Liaoning, China, have not only lent strongest support for the dinosaurian hypothesis of bird origins, but have also provided much‐needed information about the origins of feathers and avian flight. Preliminary analysis of character evolution suggests that the major avian osteological characters were acquired during the early evolution of maniraptoran dinosaurs. The available evidence also suggests that the first feathers with a filamentous morphology probably evolved in basal coelurosaurs and pennaceous feathers (including those with aerodynamic features) were developed in non‐avian maniraptorans, indicating that feathers evolved before the origin of birds and their flight. An evolutionary model is proposed here to describe the major stages of feather evolution, a process characterized by a combination of both transformational and innovative modifications. This model is different from some recent developmental models, which suggest that feathers are evolutionary novelties without a homologous relationship to reptilian scales. Although non‐avian theropods are traditionally regarded as distinctly cursorial animals, recent discoveries suggest that the closest relatives of birds might be arboreal theropods. Many bird features, such as the furcula and pennaceous feathers, evolved in a terrestrial context, whereas others, such as some pedal modifications, may have evolved in an arboreal context. Consequently, arboreality may have also contributed to the origin of avian flight.     

More than eating dirt: a review of avian geophagy‡

Geophagy, the ingestion of earth varying in particle size from stones to soils rich in clay, is a relatively widespread behaviour across avian taxa. We reviewed its occurrence in birds and its hypothesised adaptive functions in birds. Of the ～30 avian orders, 23 exhibit geophagy. However, it has only been documented in ～260 species (～2% of birds) and therefor is relatively uncommon. Ingestion of stones and other large particles (grit) is recorded in 54 extant families across the avian phylogeny and appears to be ancient in birds and has evolved several times. Clay ingestion is recorded in 14 phylogenetically scattered families and might have evolved repeatedly. Furthermore, at least nine families exhibit both clay and grit ingestion. Six hypothesised functions of avian geophagy involve digestion and nutrition. Ingested grit might provide (1) essential minerals, particularly sodium or calcium, but it appears to primarily (2) improve mechanical digestion of food in the gizzard, where ingested stones and sand particles are known as gastroliths. Consistent with this gastrolith hypothesis, ～86% of species ingesting grit consume “hard” food: seeds, leaves, insects or other animals. In contrast, ingested clay appears to be for sodium or other nutrient intake and/or protecting birds from ingested plant secondary compounds, by (3) protecting the digestive tract and (4) adsorbing these compounds. Consistent with this, ～88% of species ingesting clay eat fruit that is often rich in secondary compounds and low in sodium, and clay ingestion is associated with frugivory in a representative sample of genera of which many have been shown to source sodium. The other two hypotheses are buffering gastric pH (5) and acquiring antidiarrheal agents (6), but no documentation of this in birds was found. We suggest additional tests of these hypotheses and additional investigation of these proposed benefits of geophagy in birds.     

KAv-1 is Better Suited to Chick Fibroblast Culture than DMEM or 199 Media

Cultured cells are a useful resource for poultry scientists, since these cells allow scientists to evaluate biological responses to conditions such as infectious diseases in vitro while mimicking the whole-body response in birds. However avian cell culture requires an optimized basal medium, and there are currently relatively few options for this basal medium (medium 199 and KAv-1). This means that there is still room for the development of an optimal basal medium for avian cell culture. Here we compare KAv-1 medium, Dulbecco''s modified Eagle medium (DMEM) and medium 199 during the culture of chick fibroblasts and determine that KAv-1 remains the optimal medium for these assays. Our results show that DNA damage is reduced in fibroblasts cultured in the KAv-1 medium, when compared to both DMEM and Medium 199 and that these cells also display improved growth dynamics in KAv-1 medium when compared to both DMEM and medium 199. To the best of our knowledge, this is the first study to describe a comparative analysis of culture media for avian cells, which would provide useful information for poultry scientists.     

Host range of avian influenza virus in free-living birds

Isolation of avian influenza virus (AIV) has been reported from 12 orders and 88 species of free-living birds. Most isolations are reported from species in the orders Anseriformes and Charadriiformes and it is recognized that species in Anseriformes represent important reservoirs of AIV. Morbidity and mortality among free-living birds attributable to AIV infection are rare, but differences in prevalence of AIV occur within and between avian species. Seasonal variation has been reported from free-living and sentinel ducks with peak AIV infection occurring in late summer and early fall. Prevalence of AIV is age-related, with highest isolation rates reported from juvenile birds. Differences in susceptibility to AIV infection among species have been demonstrated under experimental conditions. The dynamics and epidemiology of species-related variation in populations of free-living birds require further study.     

Prevalence and relevance of avian Toxoplasma gondii infections in Europe

Toxoplasma (T.) gondii is a parasitic protozoon whose life cycle includes a definite and an intermediate host. Besides a wide range of mammals also birds are suitable intermediate hosts. There are a high number of case reports, prevalence data and experimental studies regarding avian toxoplasmosis. In many domestic, wild and zoo bird species which are relevant in Europe the susceptibility for T. gondii infection could be demonstrated though susceptibility for clinical disease often seems to be low, especially in gallinaceous birds. Comprehensive Europe-wide studies concerning the occurrence of avian toxoplasmosis have not been conducted so far. The general infestation ratio of birds on European free-range poultry farms seems to be relatively high. The European wild bird population represents a significant reservoir for the pathogen. When evaluating the seroprevalence it has to be considered that sensitivity and specificity of the detection methods for T. gondii specific antigens which are used frequently in mammals often are not satisfying in birds.     

First record of avian Plasmodium DNA from mosquitoes collected in the Yaeyama Archipelago, southwestern border of Japan

We studied the prevalence of avian Plasmodium in 509 mosquitoes of 9 species collected from the Ishigaki and Iriomote islands in the Yaeyama Archipelago, located southwest from the mainland of Japan. Two identical avian Plasmodium lineages were detected from Culex (Culiciomyia) nigropunctatus. Detected lineages were phylogenetically classified into different clade to avian Plasmodium lineages from birds and mosquitoes in the mainland of Japan but identical to a lineage detected from a resident bird, White-breasted Waterken (Amaurornis phoenicurus). This is the first detection of avian Plasmodium DNA from mosquitoes in the Yaeyama Archipelago and suggested that resident birds might have been infected with an avian Plasmodium lineage specific to the studied area and C. nigropunctatus could be the candidate vector mosquito species.     

Physiology, diagnosis, and diseases of the avian reproductive tract.

Disorders of the reproductive system represent a large portion of both large and small domestic animal medicine. Although some disorders of this system have been extensively studied in birds, this science is still in its infancy, when compared to mammalian reproductive medicine. This may be due to several reasons, but the simple fact that birds are oviparous renders knowledge of mammalian reproductive anatomy, histology, physiology, and disease process, inapplicable to avian patients. Nevertheless, several specific diseases or conditions affecting the reproductive system of birds have been described. By integrating information about the comparative anatomy and physiology of birds, reports of the most common reproductive diseases of birds and utilizing the latest diagnostic techniques, especially videoendoscopy, the avian practitioner should be able to diagnose and properly treat a high percentage of the avian reproductive diseases.     

Comparison of Chinese field strains of avian leukosis subgroup J viruses with prototype strain HPRS-103 and United States strains

Eight Chinese field strains of subgroup J avian leukosis viruses (ALV-J) were isolated from broilers or parent stocks during January 1999 to April 2001. One strain, SD9902, was an acute transforming virus, able to induce typical myelocytomatosis in 22-38 days after inoculation of 1-day-old meat-type chicks. The envelope protein and 3'-untranslated region (UTR) of the eight field strains were compared with the U.K. prototype HPRS-103 and several U.S. field strains isolated in 1993-97. All Chinese strains shared an almost identical deletion with the U.S. strain 4817 in the E element region of 3'-UTR when compared with the prototype HPRS-103, indicating that they have a very close phylogenic relationship. Every year, China has to import grandparent stocks of meat-type chickens, mainly from the United States. Chinese isolates should represent a part in the phylogenic tree of U.S. ALV-J evolution. Envelope protein gp85 amino acid sequence analysis demonstrated that, interestingly, all recent Chinese isolates were more closely related to HPRS-103 and the earliest U.S. isolates but not to the late U.S. isolates. The result implies that envelope gp85 may not have diverged from prototype and older strains. It is also possible that some recently imported birds could have been infected by the older viruses that were introduced in the late 1990s.     

基于家禽产业链视角分析广东珠三角地区H7N9禽流感传播途径

珠三角地区H7N9禽流感传播途径具有复杂性和特殊性。为进一步明确传播途径,基于家禽产业链视角,在H7N9禽流感最为严重的广州市、深圳市、佛山市,采用分层抽样法选取有代表性且能反映整体情况的养殖场、批发市场、屠宰场、农贸市场,调查H7N9禽流感的动物防疫和个人防护情况。结果显示:养殖场的生物安全隔离仍不完善,存在活禽接触候鸟感染禽流感的风险;批发市场和屠宰场防疫水平高,人感染风险较低;农贸市场的动物防疫条件和个人防护不充分,易扩散病毒;最有可能的传播途径是与候鸟接触后携带病毒的活禽,通过"养殖—批发—零售"产业链蔓延。该结论在明确"禽传人"、"活禽市场环境暴露"观点上深化了产业链各环节间的传播路径。因此,珠三角地区H7N9禽流感的防控重点要加强养殖环节的生物安全隔离,并做好零售环节中活禽与人之间的防控。