【作者】 桂小杰；

【导师】 魏美才；

【作者基本信息】 中南林业科技大学 ， 生态学， 2007， 博士

【摘要】 濒危物种保护是野生动物管理和生物多样性保护工作的重要内容与任务。就地保护(On site conservation)和迁地保护(Off site conservation)是物种保护的两种主要形式,其主要目标是恢复和保存野生种群,并通过关键物种的保护,保存和维持生物多样性,进而达到生态系统的恢复与保护。濒危物种保护成功与否取决于种群的遗传多样性和种群生存力(Population viability),并与人工种群(Captive breeding population)建立与管理、野生种群重建(Re-introduction of population)、栖息地管理(habitat management)、保护地规划(Protected areas planning)和保护计划(Conservation action plan)制定与实施密切相关。黄腹角雉(Tragopan caboti)为中国特有珍稀鸟类,是世界极度濒危物种之一,仅分布我国浙江、福建、江西、湖南、广东和广西等省(区),野生个体数量估计在4000只左右,栖息地呈现严重的“岛屿化”和“片段化”。目前我国在该物种的主要分布区建立了30多处自然保护区,开展了就地保护工作；在北京和湖南建立了两个人工种群,在迁地保护方面取得了初步进展。目前国内外对黄腹角雉的遗传多样性和种群生存力分析方面的研究未见报道。本论文根据湖南黄腹角雉人工种群研究工作,重点探索了黄腹角雉引种驯化、疾病防治、人工繁殖、生态群养等人工种群建立和管理关键技术；采用随机扩增多态DNA (RAPD)分子标记技术对黄腹角雉野生群体和子三代4个群体遗传多样性进行了分析,并检验了远交人工繁殖效果；应用种群生存力分析软件Vortex 9.51进行了种群生存力分析。根据上述研究结果,总结了黄腹角雉保护技术,并提出了保护策略。通过上述领域的研究,掌握了黄腹角雉人工种群建立的关键技术,建立了国际最大的黄腹角雉人工繁殖种群,为黄腹角雉迁地保护和重建野生种群积累了经验和技术、储备了种源、提供了数据,并为进一步的相关基础科学研究提供了基地及材料。主要研究结果如下：1、探索了黄腹角雉人工种群建立的关键技术,研究总结了黄腹角雉引种驯化、疾病防治等人工种群管理的技术,提出了黄腹角雉人工种群建立的整套技术标准和参数。通过对引种的野生个体进行寄生虫普查,发现了黄腹角雉的主要寄生虫疾病有球虫病、黑头病,并积累了有效的治疗方法,为建立黄腹角雉人工种群进行引种、检疫和治疗提供了经验。通过对黄腹角雉5种危险性疾病和7种常见疾病进行研究,发现黄腹角雉与鸡、鸭、鹅等家禽疾病有许多共同点,可以交叉传染,为有效防治新城疫(Newcatlle Disease)、禽出败Avian Pasteurella)和大肠杆菌(Escherichia coli)等疾病提供了科学依据。并采用琼脂凝胶免疫扩散试验(AGID),发明了检测新城疫病毒快速检测方法。首次治愈黄腹角雉肉毒梭菌中毒症(Botulism),填补了黄腹角雉人工种群和野生种群的疾病防治空白。2、研究了黄腹角雉繁殖行为。根据黄腹角雉繁殖行为特点和要求,进行了生态群体繁育模式的研究。通过生态群养和配对笼养技术的对比研究,证明黄腹角雉的群居程度、活动区大小、植被和隐蔽性与繁殖率有密切关系,群养、较大的活动空间、茂密的植被对提高繁殖率更有效,平均每只雌性产卵8.5枚,比传统对养方式提高产蛋率50%,提高受精率32.3%,达82.6%。通过对黄腹角雉饲料营养成分分析及对比实验,为黄腹角雉各生长时期筛选出了较为合理的营养搭配和饲料配方。根据黄腹角雉的特殊的生物学特性,在育雏过程中采用了日龄营养配方、定期免疫措施等,育雏成活率达到了91.3%。3、摸清了黄腹角雉繁殖规律。通过连续8年观察研究,发现黄腹角雉雄性较雌性发情早而明显。由于发情不一致,导致受精率下降,是该物种繁殖率低和致危的一个主要原因。在人工孵化研究中,发现黄腹角雉的应激反应强,其产卵数量比野生状态下增加3倍。黄腹角雉在野外年平均产卵3枚。在人工养殖条件下3月初即开始产卵,每只雌性平均年产卵量8.5枚。2002年H2号笼一只雌性年产卵19枚,是野外产卵量的6倍,说明该物种具有较大的存活潜力。研究发现雌性有25-30%的繁殖个体第二年即能产下受精卵,而且成功孵化出幼鸟,但未发现同龄雄性能成功繁殖,说明黄腹角雉的雄性比雌性性成熟更晚。4、进行了黄腹角雉人工繁育方案对比研究。通过采取1雄1雌、1雄多雌、多雄多雌等3类配比繁育方案研究,结果表明以多雄多雌效果为好,多雄多雌中又以雄性多于雌性最好,其受精率和孵化率分别为83.1%和89.2%,显著高于其他组别的相应指标。说明该物种的生存竞争策略倾向于K选择,即以较大的雄性比例来提高有效种群数量,进而控制整个种群的数量,以保证种群基因的杂合度。5、掌握了黄腹角雉人工孵化技术和关键技术指标。孵化临界温度控制在37.5℃,湿度控制在65-75%,出雏温度控制在36.5℃,湿度控制在65-100%,孵化率达到了89.2%。这些条件要求,特别是孵化温度和出雏湿度,与家鸡、环颈雉及基地同时养殖的红腹锦鸡、白颈长尾雉等雉类要求有很大的差别,孵化临界温度和出雏较上述雉类低,而湿度要求高。6、采用随机扩增多态DNA (RAPD)和微卫星(SSR)技术,首次对黄腹角雉野生群体和子四代5个群体遗传多样性进行了检测。检测结果显示,野生群体的遗传多样性高于人工繁殖群体,并随着世代更替,遗传多样性逐渐降低。7、分析了野生和人工繁殖四代5个群体遗传相似率和遗传距离。计算了黄腹角雉任意两个个体之间的遗传相似系数和遗传距离,构建出黄腹角雉遗传距离距阵,野生与人工繁殖群体的相似系数,随着世代更替递减,而遗传距离逐渐加大。子代F1、F2、F3、F4与亲本的遗传距离是逐渐增大的,逐代分化,并且分化程度逐代加大。8、对野生和人工繁殖群体遗传变异进行了研究。与遗传相似系数和遗传距离分析的结果一致,即随着世代更替,遗传相似系数逐渐降低,而遗传距离逐渐加大。遗传变异主要来自于群体内。9、对五个群体黄腹角雉的10个位点进行了哈迪-温伯格遗传平衡偏离指数(Hardy-Weinberg genetic equilibrium)分析。通过对各群体的多位点检测,野生群体和子一代中的平均哈迪—温伯格遗传平衡偏离指数显示过剩,在子二代、子三代和子四代中的平均哈迪—温伯格遗传平衡偏离指数显示缺失,且随着世代的更替缺失曾现递增趋势。本研究发现人工繁殖群体子二代、子三代和子四代在MCW330,、MCW29、MCW34三个座位杂合子严重缺失。10、检测了黄腹角雉人工种群生存力。应用旋涡模型(Vortex 9.51)软件,根据8年的连续观测研究数据,进行了50年100次模拟,结果表明,在考虑人为因素、近交压力和环境方差影响的前提下,假设容纳量为500±50(SD=0.1)只,在无收获(猎捕)、内禀增长率r为0.113(SD=0.238,PE=0.1)。在各种因素的综合作用下,种群达到环境容纳量之前的随机增长率为0.053(SD=0.238,PE=0.1)；在达到环境容纳量前的平均增长率为0.0458(SE=0.0035；SD=0.2401)。最后种群数量(包括现存和灭绝情形)平均为348.35只(SE=14.57,SD=145.72),在有灭绝情形下的最后种群数量平均为362.56(SE=13.23,SD=129.67)。种群的世代长度为4.85年,即平均每4.85年种群基因交换一次,其中雌性为4.16年,雄性为5.45年。周限增长率λ为1.12(倍/年),净增长率RO为1.604；成年雄性数量是成年雌性的1.259倍。每25次模拟中至少发生一次灭绝,在50年中有4次灭绝。11、进行了致危因子的敏感性分析。对黄腹角雉繁殖率、死亡率、性比、灾害、环境容纳量、初始种群数量和异质种群效应等影响种群动态因子进行了敏感性检测。通过研究分析,找出了影响黄腹角雉种群存活的关键因子。雌性繁殖率、幼鸟死亡率、环境容纳量、初始种群数量和亚种群数量为关键致危因子；致死基因当量的变化,对小种群作用明显,并确定了黄腹角雉最小存活种群(MVP)、重建野生种群初始种群大小和性比等关键技术参数。12、探讨了黄腹角雉种群特征。通过对黄腹角雉种群生存力分析和结合人工繁育方式研究结果,表明该物种对环境因子变化敏感,由多个亚种群构成的异质种群(Metapopulation)有利于保持较高的遗传多样性和抵御环境因子的影响；通过雄性比例高于雌性比例的策略,在保持遗传多样性的前提下,增加有效种群,验证了黄腹角雉在野生状态下呈现异质种群分布的特征,是该物种在保持遗传多样性的前提下所采取的竞争策略。在环境容纳量K分别为100、200、300、400和500只(SD=0.1)时,每个亚种群的数量N与回归方程N=5.6390+0.813991K有极大拟合性,决定系数达R=0.9997,确定系数为RR=0.9994。13、提出了具有针对性的黄腹角雉就地和迁地保护策略。根据目前黄腹角雉种群数量、遗传多样性、种群生存力、社会经济条件和物种保护工作的要求,按照黄腹角雉特有的生物学特性,应采取就地保护和迁地保护相结合的技术方式,应用比较成熟的人工种群管理技术,增建人工种群,保存遗传多样性,并采取在多点重建野生小种群的措施,保持野生种群的总体数量和存活概率,以抵御由于环境因子,特别是灾害性事件导致种群灭绝的影响。更多还原

【Abstract】 The conservation of endangered species constitutes the critical component and priority mission of both wildlife management and biodiversity conservation. On site conservation and off site conservation are the two dominant species conservation approaches. The objective is to restore and maintain the natural populations. Ultimately the ecosystem is revived and conserved through conservation of the key species, and through preservation and maintenance of biodiversity. The success or failure of the conservation of endangered species relies on both the genetic diversity and population viability. Needless to say, this is also pertinent to establishment and management of a captive breeding population, reintroduction of the population, habitat management, preparation and implementation of the protected area planning and conservation action plan.The rare bird species, Tragopan caboti, endemic to China, is among the critically endangered species globally. It is distributed in only such provinces (regions) as Zhejiang, Fujiang, Jiangxi, Hunan, Guangdong and Guangxi. Some 4,000 individuals of this species are estimated to be surviving in their natural habitat, however the population is seriously fragmented and isolated. So far upwards of 30 nature reserves, in the main distribution area of the species, have been established and on site conservation has been carried out. In addition, one captive breeding population each has been established in Hunan and Beijing respectively and initial headway made on off site conservation. So far there has been little documentation of the genetic diversity and population viability analyses in relation to Tragopan caboti, either at home or abroad.1. The key technique for establishment of a captive breeding population of Tragopan caboti was studied. This research distilled expertise for introduction, domestication, disease control and other management in relation to Tragopan coboti captive breeding population. Finally a set of technical standards and parameters was established. An inventory of the parasites infesting introduced natural individuals of Tragopan caboti demonstrated that dominant parasites included Coccidiosis and Histomoniasis and effective control measures against these diseases were gleaned, which provided experience for the introduction aimed at establishment of a captive breeding population, disease quarantine and control as well. Tests were made to prevent and control five dangerous and seven common diseases. The results indicated that the diseases infesting Tragopan caboti or poultry shared common grounds. Cross infestations were found between poultry and Tragopan caboti, which laid scientific foundation for effective cure approaches for such diseases as Newcastle Disease, Avian Pasteurella and Escherichia coli. Particularly a rapid test method, using AGID to testify Newcastle Disease, was found. The disease, caused by the bacterium, Botulism was cured for the first time, which filled the gap of disease control for both captive and natural populations of Tragopan caboti.2. The breeding behavior was studied. Taking into consideration the behavior characteristics and demands of Tragopan caboti, research on the reproduction pattern of the ecological population was conducted. The comparison between group-rearing under ecological conditions to couple-rearing in captive conditions showed that there was a close relationship between reproduction rate and size of the population, living space, vegetation and concealment. Generally group-rearing, larger living space, and abundant vegetation could improve the reproduction rate. Group-rearing can increase egg-laying by 50% and the average of individual egg-laying marked 8.5 eggs a-1, the fertilization ratio increased by 32.3%, reaching 82.6%. Nutrition elements and forage formula for different growth periods were screened for Tragopan caboti, through nutrition analysis and comparison researches. In addition nutrition formula, in light of bionomics of the birds, on the day-age basis during the nestling rearing periods, and regular immunity were adopted. As a result the survival rate of the nestlings peaked at 91.3%.3. The reproduction regularity of Tragopan caboti was understood. Consecutive research for seven years on reproduction showed that the estrus of the female was markedly earlier than that of the male. The discrepancy in the estrus led to a drop in fecundation, which was considered as the underlying cause of the low reproduction rate and status of being endangered. A study on artificial incubation indicated that the Tragopan caboti demonstrated strong emergency response and the number of eggs laid was three times of that under natural conditions. Under natural conditions the annual average of eggs laid per female was three eggs whilst under artificial condition it was 8.5 eggs. The initial egg-laying commenced in earlier March under the latter condition. For instance, up to 19 eggs were produced by one female from the cage H2 in 2002,6 times of the average under natural conditions, which implied that the survival potential of this species was adequately high. In addition, the research also showed that some 25%-30% of the reproductive individuals were able to produce fertilized eggs in the second year and culminated in nestlings. However the male individuals at the same age could not successfully produce progeny. This illustrated that the male sex maturation lagged behind the female. 4. Different mate combination patterns were examined. Such mate patterns as one male coupling one female, one male matching multi-female, and multi-male matching multi-female were tried and the results indicated that the last pattern was the best. Moreover, out of various options of multi-male matching multi-female, the option of the males outnumbering the females was the best, which generated 83.1% fecundation rate and 89.2% incubation rate, clearly higher than the other options. This implies that this species developed the ecological strategy of K-Selection. In other words, improving the number of viable population through larger proportion of males, and controlling the abundance of the entire population and securing the adequate gene heterozigosity of the population.5. The artificial incubation technique and relevant indicators were developed. The incubation rate reached 89.2%, at a critical temperature of 37.5℃, humidity of 65-67%, nestling emerging temperature of 36.5℃and emerging humidity of 65-100%. These development conditions differed greatly from that for the domestic chickens, Phasianus colchicus, Chrysolophus pictus, and Syrmaticus ellioti reared in the reproduction site, with lower critical temperature and emerging temperatures but higher humidity.6. Randomly amplified polymorphic DNA markers and Microsatellites analysis were applied to analyze the genetic diversity of the different group/populations, i.e. wild group, the captive breeding four groupsfirst filial generation.40 primers were used,and 10 loci were tested. The results reveal that captive breeding decreases the genetic diversity of the species. And these results also imply it is not proper to conserve species by captive breeding.7. The genetic similarity and distances of the different groups were analyzed by RAPD and SSR testing. The genetic similarity and distance for every two groups and individuals were calculated with a matrix of RAPD and SSR based. However, the genetic similarity declined gradually for wild and captive breeding groups, and genetic distance increased with each generation. The genetic variation that occurred distinctly increased with each generation for captive breeding groups.8. The genetic variation of wild and captive breeding groups was studied RAPD-based. The analysis results also showed that average heterozygosity(Hpop) by population was 0.1073 for whole groups, average heterozygosity (Hsp) by species was 0.1752, the average genetic variability by species (HPOP/Hsp) was 0.7331, and average genetic variability by population ((Hsp-Hpop)/Hsp) was 0.2668. This indicated that the most genetic variation was from groups, only 26.7% genetic variability was tested in different individuals. 9. Hardy-Weinberg genetic equilibrium was used to test genetic diversity for all the groups of Tragaopan caboti through ten loci, analysis revealed that heterozygosity excess and deficiency respectively in wild, first captive breeding groups and third, fourth, fifith captive breeding groups. Moreover, analysis detected that first captive breeding groups and third, fourth, fifith captive breeding group showed a remarkable genetic disequilibrium and heterozygosity distinct deficiency at loci MCW330,、MCW29、MCW34.10. The population viability of the captive breeding group of Tragopan caboti was examined with the software Vortex 9.51. About 100 simulations for 50 years were tested, on the basis of data collected for eight years in a row. Considering the human factor, inbreeding stress and impact of the environment variance, with assumption carrying capacity marking 500±50 (SD=0.1), under the condition of no harvesting, the determined rate of natural increase R was 0.113 birds (SD= 0.238, PE=0.1). Before reaching the carrying capacity ceiling, the stochastic increase rate was 0.053 (SD=0.238, PE=0.1) and the mean increase rate 0.0458 (SE=0.0035; SD= 0.2401), under the integrated impact of all factors. The ultimate population size (including existing and extinct populations) averaged 348.35 (SE=14.57, SD=145.72) or 362.56 (SE=13.23, SD=129.67), removing extinct populations. The length of the population generation lasted 4.85 years. In other words, the population gene would be reshuffled once every 4.85 years. The female’s reshuffle took 4.16 years whilst the male’s 5.45 years. The finite rate of increase (λ) was 1.12 (time/per year) and net increase (RO) 1.604. The number of the adult males was 1.259 times that of the adult females. At least one extinction occurred within 25 modelings and four extinctions happened within 50 years.11. The sensitivity of the lethal factors was analyzed. Specifically such factors affecting the population fluctuation factors as the reproduction rate, mortality, sex ratio, catastrophes, environmental carrying capacity, initial population size, and metapopulation effect were examined to understand their sensitivity. As a result, the key factors affecting the survival of the population were identified after analysis. The findings suggested that the reproduction rate of the females, chick mortality, carrying capacity, initial population size and the subpopulation size were the key lethal factors. The impact of the lethal loci on the small population was obvious. In addition the minimum viability population (MVP), the size and sex ratio of initial population for reintroduction, and parameters for key techniques were determined.12. The population features of Tragopan caboti were examined. The analysis of population viability and captive breeding showed that Tragopan caboti was very sensitive to environmental variance. Thus the metapopulation consisting of multi-subpopulations was conducive to maintaining relatively high genetic diversity and offseting the impact of environmental variance. More, effective population can be augmented through the strategy of raising the male proportion. This attests to the feature of metapopulation under natural conditions, a contest strategy adopted by this species under the precondition of retaining genetic diversity. Given the carrying capacity at 100,200,300,400, and 500 birds (SD=0.1), there existed a high correspondence between the number (N) of the subpopulation and the regression equation, i.e. N=5.6390+0.813991K, with R=0.9997 and RR=0.9994.13. Strategies for on site conservation and off site conservation, pertinent to the Tragopan caboti, were provided. Taking into consideration the quantity of the Tragopan caboti, genetic diversity, population viability, social economic conditions and the requirements of the species conservation, the approach of combining both on site conservation and off site conservation should be adopted. Also the established management techniques of captive breeding population should be applied and captive breeding populations augmented. At the same time, genetic diversity should be preserved. Particularly restoration of the natural population at more sites should be achieved to maintain the adequate quantity of natural population and survival probability so as to overcome the impact brought by environment factors, particularly the events of catastrophic proportion leading to population extinction.更多还原