首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
Genetic information can be critical in identifying conservation priorities and developing conservation strategies. There is an urgent need for noninvasive genetic tools to study the wild populations of Asian colobine monkeys. The majority of these species are threatened with habitat destruction, population reduction and even extinction, but generally lack information on their genetic diversity and population structure. Genetic sampling and tissue collection have been scarce in these species owing to strict regulations on manipulation of endangered species, and the difficulties and risks associated with capturing these arboreal and fast‐moving monkeys in the challenging environments that they inhabit. These difficulties have hindered the development of molecular genetic markers, which are usually derived from tissues or blood. In this study, we present a method for de novo microsatellite isolation and genotyping using DNA from noninvasive origins of a critically endangered Asian colobine, the white‐headed langur (Trachypithecus leucocephalus). Genomic DNA isolated from hair was shown to be sufficient for microsatellite enrichment and isolation, with similar isolation efficiencies as from tissue DNA. We identified and characterized 20 polymorphic microsatellite loci, and evaluated their amplification success and genotyping reliability with 86 field‐collected fecal samples. These results show that this panel of loci can produce reliable genotypes from fecal samples, and represent a useful tool for noninvasive investigation of genetic structure, individual identification and kinship assessment in this highly endangered species. Our approach can be applied to conservation genetic studies of other wild species that lack sequence information and tissue samples.  相似文献   

2.
This study reports the results of a survey of Coronado National Forest grazing permittees about their attitudes regarding the Endangered Species Act (ESA) and the management of threatened and endangered (T&E) species on grazing allotments in southeastern Arizona. A majority of respondents perceived negative impacts from ESA implementation. However, the degree of impact remained independent of the number of listed species on allotments and of the potential for restrictions on those allotments. Perceptions of negative impact and attitudes toward T&E species policies were more related to attitudes toward federal regulation. Permittees broadly supported the idea of species conservation and expressed willingness to work with federal agencies but did not perceive the federal agencies as having the same responsiveness to their concerns. A more proactive agency strategy with science-based, focused recovery objectives coupled with economic incentives could improve support for species recovery efforts.  相似文献   

3.
Threatened species typically have a small or declining population size, which make them highly susceptible to loss of genetic diversity through genetic drift and inbreeding. Genetic diversity determines the evolutionary potential of a species; therefore, maintaining the genetic diversity of threatened species is essential for their conservation. In this study, we assessed the genetic diversity of the adaptive major histocompatibility complex (MHC) genes in an endangered and narrowly distributed amphibian species, Leptobrachium leishanense in Southwest China. We compared the genetic variation of MHC class I genes with that observed in neutral markers (5 microsatellite loci and cytochrome b gene) to elucidate the relative roles of genetic drift and natural selection in shaping the current MHC polymorphism in this species. We found a high level of genetic diversity in this population at both MHC and neutral markers compared with other threatened amphibian species. Historical positive selection was evident in the MHC class I genes. The higher allelic richness in MHC markers compared with that of microsatellite loci suggests that selection rather than genetic drift plays a prominent role in shaping the MHC variation pattern, as drift can affect all the genome in a similar way but selection directly targets MHC genes. Although demographic analysis revealed no recent bottleneck events in L. leishanense, additional population decline will accelerate the dangerous status for this species. We suggest that the conservation management of L. leishanense should concentrate on maximizing the retention of genetic diversity through preventing their continuous population decline. Protecting their living habitats and forbidding illegal hunting are the most important measures for conservation of L. leishanense.  相似文献   

4.
Cryobanking of gametes in combination with artificial insemination is an essential option to support conservation programmes for endangered and threatened species. About two-thirds of the felid species are classified as ‘near threatened’, ‘vulnerable’ or ‘endangered’ ( www.cites.org ), and mostly, epididymal sperm are collected from euthanized or castrated male felids and cryopreserved. However, epididymal compared with ejaculated and cryopreserved compared with fresh sperm have a limited potential to fertilize if vaginal non-surgical insemination is applied in feline species. Missing or highly diluted seminal fluid in epididymal and cryopreserved sperm, as well as a potential interference of extender ingredients with the natural interactive properties of sperm in the female genital tract is discussed as potential drawback which hampers a proper sperm transit and fertilization besides the limited longevity of cryopreserved feline sperm. Individual components in seminal fluid as well as cryoextenders may adversely alter sperm properties and have a different impact on fertility and preservation success. The identification and investigation of beneficial as well as detrimental components is a precondition to deduce options for improving the process of cryopreservation in felids, particularly, if only epididymal sperm are available.  相似文献   

5.
The first comprehensive evaluation of more than 10 000 species in China based on the IUCN Red List Criteria and Regional Guidelines is complete. More than 100 experts have been involved in this evaluation, which covers a wide range of species, including invertebrates, vertebrates, gymnosperms and angiosperms. The present paper summarizes the major conclusions of the project. The number of threatened species in China was found to be much high than previously expected. In the past, the estimated percentages of species in each phylum that were endangered was 2‐30%. In this comprehensive evaluation, the percentages of threatened species were found to be 7.4‐100%. Compared with the status of threatened species worldwide (IUCN Red List 2006), groups such as fish, mammals and gymnosperms face much higher levels of threat in China then they do globally, and other groups, such as crustaceans, reptiles and birds, face lower levels of threat. Given the dire conclusions of this study, we recommend that more research be done on the threats faced by those groups of organisms that are most threatened.  相似文献   

6.
Red‐crowned cranes (Grus japonensis) were classified as an endangered species by the International Union for Conservation of Nature, but recently, their population has decreased dramatically. For the purpose of conserving this endangered species, 18 microsatellite markers were developed, including 12 newly isolated ones from a genomic library and 6 modified from another crane species. The markers were characterized in 26 red‐crowned cranes. As a result, these markers displayed 3–13 alleles, and the observed and expected heterozygosities ranged from 0.462 to 1.000 and from 0.483 to 0.884, respectively. The marker suite averaged 6.390 alleles per locus with an average polymorphic information content of 0.631. The combined exclusion probability (PE‐1) was 0.9985, and the combined exclusion probability (PE‐2) was 0.9999. Three of the 18 microsatellite loci presented significant deviations from Hardy–Weinberg Equilibrium (P < 0.05), likely due to sampling bias and unknown founder relatedness in a semi‐free population. Our results show that microsatellite loci can provide a standard protocol for genetic information in red‐crowned crane populations upon which strategies for effective conservation and management may be based.  相似文献   

7.
Rangeland management strategies impact biodiversity, the quality and quantity of ecosystem services, and overall rangeland resiliency. Previous management strategies, coupled with climate change, have led to widespread invasion by Kentucky bluegrass (Poa pratensis; bluegrass) in the Northern Great Plains, United States. Bluegrass invasions are expected to have detrimental impacts on biodiversity conservation and ecosystem services provided by rangelands. Yet none have investigated how bluegrass invasions influence pollinator populations, which are a prominent conservation concern and provide ecosystem services. We measured the impact of bluegrass invasion on mixed-grass prairie forb and butterfly communities. Obligate grassland butterflies, those that rely on grasslands, decreased as bluegrass cover increased, including the threatened Hesperia dacotae. Conversely, the abundance of facultative grassland butterflies, those found in grasslands but not fully dependent on them for their life history, increased as bluegrass increased. Moreover, plant species diversity and flowering forb species richness decreased as bluegrass cover increased. Overall, bluegrass invasion led to butterfly and plant community simplification, signaling a loss of biodiversity and potentially ecosystem services. Our research is the first to quantify how grassland butterflies and the floral resources they depend on are negatively impacted by bluegrass invasion. Resource managers should adopt management strategies that reduce bluegrass cover and improve nectar and host resources for obligate grassland butterflies. Management choices that removed disturbance regimes inherent to the Northern Great Plains (i.e., fire and grazing) led to bluegrass dominance in the region. Therefore, restoring disturbance regimes may be one way to reduce bluegrass and benefit pollinator populations.  相似文献   

8.
圈养金丝猴饲养管理刍议   总被引:1,自引:0,他引:1  
唐珞  王洁  许锋 《野生动物》2007,28(2):22-24
迁地保护是挽救濒危野生动物的重要手段,加强圈养金丝猴饲养管理,对扩大种群和拯救这个物种有着重要意义。本文对成都动物园金丝猴的饲养管理进行了阐述,旨在改进圈养金丝猴的饲养管理和改善生活条件,加强保护。  相似文献   

9.
A total of 2441 invertebrate species were evaluated using the IUCN Red List Criteria and Regional Guidelines. Approximately 30 experts were involved in this project, which covered a wide range of species, including jellyfish, corals, planarians, snails, mollusks, bivalves, decapods, benthic crustaceans, arachnids (spiders, scorpions), butterflies, moths, beetles, sea cucumbers, sea urchins, sea stars, acorn worms and lancelets. In general, invertebrate species in China were found to be severely threatened, with 0.9% being critically endangered, 13.44% endangered and 20.63% vulnerable. All species of hermatypic corals and planarians are threatened. More than 80% of evaluated species face serious threat due to habitat destruction by coral collection, logging, non‐woody vegetation collection, timber plantations, non‐timber plantations, extraction and/or livestock. Other threats are intrinsic factors, harvesting by humans, alien invasive species and pollution. The main intrinsic factors contributing to the high levels of threat are limited dispersal and restricted range. No conservation measures have been taken for 70% of the threatened invertebrates evaluated. Existing conservation measures include: strengthening of national and international legislation (Convention on International Trade in Endangered Species of Wild Fauna and Flora), increasing public awareness, studying population trends/monitoring, and establishment of protected areas. The major conservation measure employed is strengthening of policies. Relative to the situation worldwide (2006 IUCN Red List), there is little information available about invertebrate extinctions in China.  相似文献   

10.
畜禽遗传资源受威胁程度评价   总被引:31,自引:2,他引:29  
本文用群体遗传学、保护生物学原理,建立了畜禽遗传资源受威胁评价方法,并对我国231个畜禽遗传资源进行了分析。结果表明,有16个畜禽遗传资源为严重威胁资源,建议由国家采取保种场方式进行紧急保护;9个遗传资源为受威胁资源,必须采取相应措施进行保护,可采取保种场或划定保护区的方式进行保护;17个遗传资源为最低威胁资源,需视具体情况有必要进行保护,可采取由省、市、县级进行保护;57个遗传资源为潜在受威胁资源,需进行特别关注,要求在生产和利用过程中,密切监测群体的动态和性能变化;132个遗传资源为安全遗传资源。  相似文献   

11.
畜禽遗传资源受威胁程度评价   总被引:9,自引:0,他引:9  
本文用群体遗传学、保护生物学原理,建立了畜禽遗传资源受威胁评价方法,并对我国231个畜禽遗传资源进行了分析。结果表明,有16个畜禽遗传资源为受严重威胁资源,建议由国家采取保种场方式进行紧急保护;9个遗传资源为受威胁资源,必须采取相应措施进行保护,可采取保种场或划定保护区的方式进行保护;17个遗传资源为最低威胁资源,需视具体情况有必要进行保护,可采取由省、市、县级进行保护;57个遗传资源为潜在受威胁资源,需进行特别关注,要求在生产和利用过程中,密切监测群体的动态和性能变化;132个遗传资源为安全遗传资源。  相似文献   

12.
Livestock production contributes not only to national economies, but also to sustainability and profitability of agriculture, as well as to the fabric of local societies. Efficient and viable animal production systems are dependent upon the effective management of animal reproduction. Similar arguments can be made in support of the importance of reproduction for companion and performance animals, whereas its key role in preserving endangered species is indisputable. Despite such considerations, the widespread dissemination of current and credible information regarding animal reproduction faces challenges, not only in the developing world, but also in developed countries, where animal reproduction education is apparently in decline. This review will examine these issues, as well as various ways in which animal reproduction education and knowledge transfer is currently being pursued throughout the world. It will conclude with suggested avenues and opportunities for improvement.  相似文献   

13.
Our knowledge of diseases in New Zealand wildlife has expanded rapidly in the last two decades. Much of this is due to a greater awareness of disease as a cause of mortality in some of our highly threatened species or as a limiting factor to the successful captive rearing of intensely managed species such as hihi (Notiomystis cincta), kiwi (Apteryx spp.) and kakapo (Strigops habroptilus). An important factor contributing to the increase of our knowledge has been the development of new diagnostic techniques in the fields of molecular biology and immunohistochemistry, particularly for the diagnosis and epidemiology of viral and protozoan diseases. Although New Zealand remains free of serious exotic viruses there has been much work on understanding the taxonomy and epidemiology of local strains of avipox virus and circoviruses. Bacterial diseases such as salmonellosis, erysipelas and tuberculosis have also been closely investigated in wildlife and opportunist mycotic infections such as aspergillosis remain a major problem in many species. Nutritional diseases such as hyperplastic goitre due to iodine deficiency and metabolic bone disease due to Ca:P imbalance have made significant impacts on some captive reared birds, while lead poisoning is a problem in some localities. The increasing use of wildlife translocations to avoid the extinction of threatened species has highlighted the need for improved methods to assess the disease risks inherent in these operations and other intensive conservation management strategies such as creching young animals. We have also become more aware of the likelihood of inbreeding suppression as populations of many species decrease or pass through a genetic bottleneck. Climate change and habitat loss, however, remain the greatest threats to biodiversity and wildlife health worldwide. Temperature changes will affect our wildlife habitats, alter the distribution of disease vectors and wildlife predators, or directly harm threatened species in vulnerable localities.  相似文献   

14.
According to the International Union for Conservation of Nature Red List, 41% of the world's amphibian species are threatened with extinction, making them more threatened than any other vertebrate group nowadays. Given the global amphibian crisis, comprehensive understanding of demographics and population trends of declining and threatened species is essential for effective management and conservation strategies. Counting egg spawns is widely used to assess population abundance in pond breeding anurans. However, it is unknown how such counts translate into robust population size estimations. We monitored the breeding activity of the Natterjack toad (Epidalea calamita), combining egg string counts and individual photo-identification with Capture-Mark-Recapture population size and operational sex ratio estimation. Male Natterjack toads were identified by the pattern of natural markings with repeated ID of the same individual confirmed for 10% of the samples using genetic fingerprinting. We identified 647 unique individuals within a closed study population at Caherdaniel, Co Kerry. Population estimates derived from egg string counts estimated a breeding population of 368 females (95% CI 353–384) and Capture-Mark-Recapture estimated a breeding population of 1698 males (95% CI 1000–2397). The female:male sex ratio was conservatively estimated at 1:5 (95% CI 1:3–1:6) where 62% ± 6% of females were assumed to spawn. These substantially departed from any priori assumption of 1:1 which could have underestimated the breeding population by up to 72%. Where amphibian absolute population size estimation is necessary, methods should include empirical survey data on operational sex ratios and not rely on assumptions or those derived from the literature which may be highly population and/or context-dependent.  相似文献   

15.
In recent years wildlife diseases (infectious and non-infectious) have played a relevant role in both wildlife conservation and public health. Global environmental changes have determined a bimodal evolution of wildlife. On one side a huge loss of biodiversity has been observed leading to the increasing of threatened or endangered species. In contrast few opportunistic taxa increased their aboundances and ranges. The above scenarios claim the intervention of wildlife veterinarians. In conservation the understanding of the ecological role of the host parasite relationship and the perturbations on the host population dynamics have to be assessed and eventually modified. In public health the increased overlapping among wildlife, livestock, pets and human beings represents a risk for diseases spread (no matter in which directions). Serious limits are, still now, observed in the acceptance of this 'new world' by veterinary academics. As a consequence curricula often fail in providing adequate skill at both undergraduate and graduate levels. An addressed approach towards wildlife diseases should be promoted as an essential component of environmental management.  相似文献   

16.
Biodiversity is increasingly threatened by intensive agriculture, environmental pollution, extinction of natural habitats and several other factors. Several mammalian species including ungulates have disappeared or are threatened by extinction. However, ungulates play an important role both in the ecosystem and in the economy. In general, species or breeds are considered endangered if their population does not exceed 1,000 individuals. In these cases conservation programmes should be initiated in order to maintain or even increase their number. This review deals with the possibilities and limitations of assisted reproductive technologies (ART) in the conservation of ecologically valuable wild, rare and indigenous ungulates. The methods discussed here are artificial insemination, cryopreservation of semen and embryos, embryo recovery and transfer, in vitro production of embryos, as well as micromanipulation techniques including sperm injection, assisted hatching and cloning. Some of these procedures are already being exploited in the breeding of farm ungulates, but more basic information about the reproductive patterns of wild, rare and indigenous animal species is needed before the routine use of ARTs.  相似文献   

17.
Morphological information on the reproductive system allows the understanding of ecological and behavioural aspects of different species as well as supports the development of conservational strategies. Unfortunately, for many species, not enough relevant and precise information is available. In the present study, we describe for the first time the macroscopic and histological aspects of female genital organs and external female genitalia of Saimiri macrodon, Saimiri cassiquiarensis and Saimiri vanzolinii. We perform a comparison between these three peripatric species and investigate the possibility of their reproductive morphology to act as a factor of reproductive isolation. We have found that these species share many similarities in most of the analysed organs. Although some important differences were identified that may play an important role in the evolution of the components of the reproductive system of these species, those differences are not enough to compose a mechanism of reproductive isolation for these three species of Saimiri. The results of this study may be used to support the development of biotechnological approaches of reproduction and strategies for conservation programmes and management of threatened species of this genus, particularly S. vanzolinii, considered to be a vulnerable species to extinction.  相似文献   

18.
Following significant developments in technology, alternative devices have been applied in fieldwork for animal and plant surveys. Thermal‐image acquisition cameras installed on unmanned aerial vehicles (UAVs) have been used in animal surveys in the wilderness. This article demonstrates an example of how UAVs can be used in high mountainous regions, presenting a case study on the Sichuan snub‐nosed monkey with a detection rate of 65.19% for positive individual identification. It also presents a model that can prospectively predict population size for a given animal species, which is based on combined initial work using UAVs and traditional surveys on the ground. A great potential advantage of UAVs is significantly shortening survey procedures, particularly for areas with high mountains and plateaus, such as the Himalayas, the Qinghai–Tibet Plateau, Hengduan Mountains, the Yunnan‐Gui Plateau and Qinling Mountains in China, where carrying out a traditional survey is extremely difficult, so that species and population surveys, particularly for critically endangered animals, are largely absent. This lack of data has impacted the management of endangered animals as well as the formulation and amendment of conservation strategies.  相似文献   

19.
China lies at the heart of the global center of freshwater crab diversity in tropical Asia, where the 2 most diverse families occur: Potamidae (505 species, 95 genera) and Gecarcinucidae (344 species, 59 genera). China stands out as the country with the highest species richness of freshwater crabs globally. Its fauna comprises 243 species in 37 genera and in 2 families, and species discovery is still progressing at a rapid pace. The vast majority of the species are distributed in southwest, south central and eastern China in the Oriental zoogeographical region. China also stands out as having a highly endemic freshwater crab fauna at the species level (96%) and at the genus level (78%). Although the recent International Union for the Conservation of Nature (IUCN) red list conservation assessment found only 6 out of 228 species (2%) to be threatened (5 potamids and 1 gecarcinucid), the majority (more than 75%) of Chinese species are regarded as data deficient, so the number of threatened species is likely to be a serious underestimate. Threats from increasing habitat destruction and pollution are a major concern due to the rapidly growing economy and massive developments taking place in China. There is therefore an urgent need for increased species exploration and for the development of a conservation strategy for China's threatened (and potentially threatened) endemic freshwater crab species.  相似文献   

20.
The giant panda (Ailuropoda melanoleuca David, 1869) is an iconic species for global conservation, yet field research has only recently advanced to the point where adaptive management is possible. Here, we review recent developments in giant panda conservation science and propose a strategic plan for moving panda conservation forward. Because of scientific, funding, political, and logistical hurdles, few endangered species management programs have embraced adaptive management, wherein management decisions are shaped iteratively by targeted scientific research. Specific threats, such as habitat destruction, anthropogenic disturbance and fragmented nonviable populations, need to be addressed simultaneously by researchers, managers and policy‐makers working in concert to understand and overcome these obstacles to species recovery. With the backing of the Chinese Government and the conservation community, the giant panda can become a high‐profile test species for this much touted, but rarely implemented, approach to conservation management.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号