Leucogeranus Research Articles

Double jeopardy: global change and interspecies competition threaten Siberian cranes.

Anthropogenic global change is precipitating a worldwide biodiversity crisis, with myriad species teetering on the brink of extinction. The Arctic, a fragile ecosystem already on the frontline of global change, bears witness to rapid ecological transformations catalyzed by escalating temperatures. In this context, we explore the ramifications of global change and interspecies competition on two arctic crane species: the critically endangered Siberian crane (Leucogeranus leucogeranus) and the non-threatened sandhill crane (Grus canadensis). How might global climate and landcover changes affect the range dynamics of Siberian cranes and sandhill cranes in the Arctic, potentially leading to increased competition and posing a greater threat to the critically endangered Siberian cranes? To answer these questions, we integrated ensemble species distribution models (SDMs) to predict breeding distributions, considering both abiotic and biotic factors. Our results reveal a profound divergence in how global change impacts these crane species. Siberian cranes are poised to lose a significant portion of their habitats, while sandhill cranes are projected to experience substantial range expansion. Furthermore, we identify a growing overlap in breeding areas, intensifying interspecies competition, which may imperil the Siberian crane. Notably, we found the Anzhu Islands may become a Siberian crane refuge under global change, but competition with Sandhill Cranes underscores the need for enhanced conservation management. Our study underscores the urgency of considering species responses to global changes and interspecies dynamics in risk assessments and conservation management. As anthropogenic pressures continue to mount, such considerations are crucial for the preservation of endangered species in the face of impending global challenges.

Response of Siberian Cranes (Grus leucogeranus) to Hydrological Changes and the Availability of Foraging Habitat at Various Water Levels in Poyang Lake.

To assess the Siberian crane (Grus leucogeranus)'s response to changing water levels and habitat quality at Poyang Lake, we analyzed the lake's hydrological trends over the past two decades with the Mann-Kendall and Sen slope methods. Additionally, we explored the link between the crane population size and hydrological conditions at the lake from 2011 to 2019. Meanwhile, five environmental factors, including habitat type, distance from shallow lakes, human footprint index, elevation and normalized vegetation index were selected, and the distribution patterns of suitable habitats for the Siberian crane under 10 water level gradients with intervals of about 1 m (5.3-14.2 m) were simulated by using an improved habitat suitability index model that determines the weights of evaluating factors based on the MaxEnt model. The results showed that the overall trend of the inundated area in Poyang Lake was shrinking in the last 20 years, with a significant increase in the area of exposed floodland during the early wintering period (Z = -2.26). The prolonged drought resulting from this will force vegetation succession, thereby diminishing the food resources for cranes in their natural habitat. The mean inundated area in June demonstrated a significant negative correlation with the population of Siberian cranes in natural habitats (r = -0.75, p = 0.02). Shortage of the Siberian crane-preferred Vallisneria tuber due to June flooding was the primary driver of the crane's altered foraging strategy and habitat shift. In years with relatively normal June inundation, indicating abundant Vallisneria resources, the relationship between the inundated area during the dry season and the crane population fit well, with a quadratic curve (R2 = 0.92, p = 0.02). The dry season's inundated area primarily affected the crane population and distribution pattern by influencing the availability of food resources, and both excessive and insufficient inundation areas were unfavorable for crane survival. The modeling results for habitat suitability indicated that as the water level decreased, the trend of the area of good habitat for the Siberian crane showed an inverted bell shape, peaking at a water level of 8.8 m, with optimal conditions occurring between 8 and 10 m. The combined effects of climate and human activities have made the shortage of food resources in Poyang Lake the new normal. The degradation of natural habitats has led to a decline in the quality of Siberian crane habitats, and artificial habitats can only be used as refuges to a certain extent. Thus, formulating strategies to restore natural habitats and enhance the management of artificial habitats is crucial for the conservation efforts of Siberian cranes.

Первая регистрация стерха (Grus leucogeranus) в Магаданской области

The first case of meeting a Siberian White Crane in Magadan Oblast has been documented. Observations of a single bird were made outside the nesting range, during the breeding season.

Modern Trends in Populations of the Siberian Crane (Grus leucogeranus) and the Sandhill Crane (Grus canadensis) (Gruidae, Gruiformes) on the Tundra of Yakutia and Chukotka Based on Aerial Surveys

Modern Trends in Populations of the Siberian Crane (Grus leucogeranus) and the Sandhill Crane (Grus canadensis) (Gruidae, Gruiformes) on the Tundra of Yakutia and Chukotka Based on Aerial Surveys

Wetlands dynamics analysis: a case study of Keoladeo National Park (India), the wintering grounds of West Siberian white crane population

The work is devoted to the study of the dynamics of the wetlands area in the Keoladeo National Park (Bharatpur province, Rajasthan, India) over the past decades in connection with changes in climatic parameters to assess the wintering conditions of the endangered West Siberian White Crane population (Leucogeranus (=Grus) leucogeranus Pallas, 1773). The article presents the results of a statistical analysis of the main meteorological parameters (average maximum and minimum temperatures of the surface layer of the atmosphere in 1971–2022, average precipitation per year and from October to March (the wintering period of West Siberian White Crane) in 1958–2021); the results of an analysis of the ratio of areas of different types of habitats according to remote sensing data in 1972–2022; the results of statistical analysis of the volume of water entering the park from the Ajahn Bund reservoir in 1980–2010. During the study period, a significant increase in the average maximum and minimum temperatures of the winter period was revealed, which, along with the absence of a significant trend towards an increase in the average amount of precipitation and an increase in the number of dry years, indicates a warming climate with an increase in its aridity. A statistically significant reduction in the area of habitats suitable for West Siberian White Crane has been established. This indicates a significant decrease in the water level in the Keoladeo wetlands, both due to increased evaporation and a significant reduction in the volume of water entering the park from the reservoir. The results of the study show that in the conditions of observed climate changes, the main regulators of the water level and the state of the ecosystem of the Keoladeo wetlands are agricultural users, whose water consumption increases with increasing aridity of the climate.

POPULATION MONITORING AND MAJOR THREATS TO DEMOISELLE CRANE(GRUS VIRGO) AT LASBELA COAST, BALOCHISTAN, PAKISTAN

The Demoiselle Crane (Grus virgo) is one of the most threatened bird species in the world as it is indicated as “Least Concern” under the IUCN and Bird Life International category. To evaluate the current status and threats to G. virgo from Lasbela coast, two field stations were selected i. e, Siranda lake and Sonmiani area. Data were based on daily observation monitored during February, March, April, September, October, November, and December during 2020-2021. The line transit method and questionnaire-interview based survey was used to estimate the bird population and threats to birds population. Total of 322,143 numbers of cranes were observed in which 142700 in autumn and 179443 during spring season. Area wise distribution of cranes were detected at 271701 from Sarinda lake while, 50442 cranes were observed from Sonmiani area. It was also noted that during autumn overall 136850 cranes were observed in flying mode while 5850 were observed at resting stage, however in Spring 167330 were in flying and 12113 were at resting. Overall, high population was observed during spring season at 55.7% while population during autumn was observed at 44.29%. It was also noted that during present study the percentage of flying cranes are higher than the resting cranes and higher numbers were observed from Sarinda lake compared to Sonmiani area. This maybe because the Sarinda lake is far from city area so cranes prefer to rest compare to Sonmiani area. The hunting information was collected from local community, government agencies and personal visits at local areas. It was noted that total of 116 numbers of cranes were hunted during the study period from which 74 cranes were hunted using gunshot and 42 cranes were caught alive. Most of the hunting cranes were operated during March. We may assume that these sites (study area) are short term stay for these guest birds. However, due to certain reasons it may also be noted that flying cranes are higher than the resting cranes which shows that these sites also indicate the threats to the cranes. It may also suggest that hunting must be prohibited and Sarinda lake should be declared as Ramsar site for the conservation of migratory birds. Key words: Sarinda lake, Siberian crane, Endangered, Hunting, Lasbela, Pakistan

Illegal Wildlife Trades and Ecological Consequences: A Case Study of the Bird Market in Fereydunkenar, Iran

ABSTRACT Illegal bird hunting in and around the Fereydunkenar International Wetland in Iran has a long history but one with serious ecological consequences. Such hunting has involved the mass killing of critically endangered species – such as Siberian cranes, white-headed ducks, geese, lapwings and wintering raptors – and has caused damage to regional ecosystems. The outcome has been described by conservationists and regional news commentators as a “bird genocide.” This study addresses some of the significant problems created by the illegal bird market of Fereydunkenar and explores the reasons for both the actors’ participation and the market’s resilience. The paper draws on original fieldwork – data from qualitative, in-depth interviews with 21 participants actively involved in this bird market. Actors provided various justifications and explanations for their activities, such as food and income, the ineffectiveness of formal controls alongside the supportiveness of informal social norms, and the ability to create an enterprise and attract capital based on simple commodification of nature. The case study illuminates how a traditional practice and a narrowly-focused set of behaviors persist despite the impact of related cascade effects causing harm to ecosystems that push some species to the edge of extinction. The paper therefore serves as an interdisciplinary contribution to green criminology and conservation criminology, as well as to ecological sciences, more generally.

Responses of the Siberian crane population to temporal and spatial hydrological variations in stopover sites in northeast China

The Siberian crane (Grus leucogeranus), a critically endangered species, is used as an indicator species for ecosystem stability because of its sensitivity to the environment. The distribution of Siberian cranes has shown dramatic fluctuations on an order of magnitude at the main stopover site (Jilin Momoge National Nature Reserve) since the present century, which poses a great challenge to the conservation of endangered species. Research on the threshold values of key factors of the Siberian crane in stopover habitats and the relationship between the Siberian crane and hydrological temporal and spatial fluctuations can promote endangered species conservation. The response of population changes and distribution patterns of Siberian cranes to hydrological temporal and spatial patterns of wetlands was analyzed from 1984 to 2020. The results showed that population changes and distribution patterns of Siberian cranes were highly correlated with hydrological temporal and spatial patterns in the study area, and their variation trend was the same. However, there were obvious stage migration changes in the core activity area of the Siberian crane (1984–2000, 2001–2010 and 2010–2020). The habitat characteristics of fragmentation, dispersion and complex shape of water bodies changed from steady to dramatic fluctuations and then leveled off in the core activity area of Siberian cranes during the 37 years of migration transit. This was closely related to the early agricultural reclamation and the later ecological water replenishment project in the study area. In addition, the trend of the water pattern index of the spatial distribution of Siberian crane active habitat was also closely related to their habitat selection preference. When the perimeter area fractal dimension of water (1.27–1.40), landscape division index (0.73–0.95) and aggregation index (80.97–91.36) are within a certain stable threshold, the stopover habitat of the Siberian crane is suitable. This study will provide scientific guidance for the conservation of the Siberian crane population and the development of wetland restoration projects.

Projection of the potential distribution of suitable habitats for Siberian crane (Grus leucogeranus) in the middle and lower reaches of the Yangtze River basin

Introduction: The middle and lower reaches of the Yangtze River basin (hereafter MLYRB) are one of the most important wintering grounds for waterbirds along the East Asian-Australasian Flyway (EAAF). Climate change and human activities have greatly altered the habitats of waterbirds in this region.Methods: The potential distribution of suitable habitats for the Siberian crane (Grus leucogeranus) in the MLYRB was projected using Maximum Entropy Models (MaxEnt) and three Global Climate Models (GCMs). Additionally, estimations for temperature and precipitation before 2060 were made using CMIP6 multi-model and multi-scenario data.Results: 1) the MaxEnt model was highly applicable (AUC = 0.939) for analyzing the suitable habitat distribution and climatic suitability of Siberian cranes in the study area; 2) Precipitation of the driest quarter and altitude were the main factors affecting the potential suitable habitat distribution of Siberian cranes, accounting for 40% of the total contribution rate each; 3) The climatically suitable areas for the distribution of suitable habitats of Siberian cranes in the study area was mainly concentrated in parts of Poyang Lake, Dongting Lake, Taihu Lake, and the mainstream of the Yangtze River; 4) In the BCC-CSM2-MR, CanESM5, and CNRM-CM6-1 models, the suitable habitat area for Siberian cranes is expected to decrease under different SSP scenarios from 2021 to 2060 compared to 1970–2000.Discussion: The BCC-CSM2-MR model’s SSP2-4.5 scenario shows the most significant decline in the suitable habitat area for Siberian cranes, with a maximum decrease of approximately 35.7%, followed by a maximum decrease of about 26.2% and 16.4% under the CNRM-CM6-1 and CanESM5 models’ SSP2-4.5 scenario, respectively. In general, the suitable habitat areas for Siberian cranes are projected to decline, indicating the need for comprehensive evaluation and uncertainty research using more models.

Maximizing the potential for living cell banks to contribute to global conservation priorities.

Although cryobanking represents a powerful conservation tool, a lack of standardized information on the species represented in global cryobanks, and inconsistent prioritization of species for future sampling, hinder the conservation potential of cryobanking, resulting in missed conservation opportunities. We analyze the representation of amphibian, bird, mammal, and reptile species within the San Diego Zoo Wildlife Alliance Frozen Zoo® living cell collection (as of April 2019) and implement a qualitative framework for the prioritization of species for future sampling. We use global conservation assessment schemes (including the International Union for Conservation of Nature (IUCN) Red List of Threatened Species™, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the Alliance for Zero Extinction, the EDGE of Existence, and Climate Change Vulnerability), and opportunities for sample acquisition from the global zoo and aquarium community, to identify priority species for cryobanking. We show that 965 species, including 5% of all IUCN Red List "Threatened" amphibians, birds, mammals, and reptiles, were represented in the collection and that sampling from within existing zoo and aquarium collections could increase representation to 16.6% (by sampling an additional 707 "Threatened" species). High-priority species for future cryobanking efforts include the whooping crane (Grus americana), crested ibis (Nipponia nippon), and Siberian crane (Leucogeranus leucogeranus). Each of these species are listed under every conservation assessment scheme and have ex situ populations available for sampling. We also provide species prioritizations based on subsets of these assessment schemes together with sampling opportunities from the global zoo and aquarium community. We highlight the difficulties in obtaining in situ samples, and encourage the formation of a global cryobanking database together with the establishment of new cryobanks in biodiversity-rich regions.

Suitable overwintering habitat simulation and the drivers of their population expansion for Siberian cranes (Grus leucogeranus) in China.

To gain a more comprehensive understanding of habitat preferences, potential wintering area distribution and drivers of population expansion of Grus leucogeranus, we selected 70 geographical distribution points and 11 environmental variables in its wintering period from 2015-2022. We modeled suitable habitat patterns for G. leucogeranus in China using MaxEnt model, and analyzed the relationship between suitable habitat distribution and environmental factors. The results showed that the dominant factors affecting the overwintering distribution of G. leucogeranus were distance to mudflats, elevation, average precipitation in February, distance to water sources, minimum temperature in December, and land use type, with a cumulative contribution rate of 94.6%. The wintering ground of G. leucogeranus in China was mainly distributed in the middle and lower reaches of the Yangtze Plain and the Yellow River Delta of the North China Plain. In these regions, the area of high-, medium- and low-suitability habitat were 17685, 60787 and 60747 km2, respectively. A total of 40 protected areas had been established in the high-suitability wintering range of G. leucogeranus in China, whereas 12 high-suitability wetlands such as Qili Lake in Anhui, Liangzi Lake in Hubei and Chenjia Lake in Jiangxi were still unprotected. The wintering grounds had shown a trend of expansion to the northeast and southeast since 2015. Considering the large-scale habitat shifts of G. leucogeranus in recent years and the frequent new wintering records in various places, we suggested that the shortage of food resources in natural habitats was the main factor driving the expansion of G. leucogeranus' wintering range. To protect G. leucogeranus more effectively, we should strengthen the restoration of natural habitats and the management of farmland habitats.

Prediction of overwintering crane population in Poyang Lake wetland based on RS and regression Model, China

Reasonable prediction of the crane population that arrives at Poyang Lake Reserve for overwintering every year is of great significance to protect cranes and to provide data about reserve planning. In this paper, considering the time-lag effect of landscape index on crane population, the Landsat satellite images of Poyang Lake wetland in 19 winter periods from 2001 to 2019 were selected. The land-use types of the images were classified by support vector machine to acquire the landscape pattern index. In addition, the Pearson test was adopted to examine the correlation between crane population dynamics and landscape pattern index during overwintering. Finally, the regression model of the crane population was obtained by multivariate linear regression analysis. The results showed that the landscape index had a delayed impact on the crane population, which was significantly correlated with the crane population in the following five years. This effect on different crane population was disparate. The number of siberian cranes and white-naped crane populations showed a downward trend, while that of hooded cranes and common crane populations showed an upward trend. Furthermore, the landscape index affects the crane population to a certain extent, but the landscape pattern has diverse effects on different crane populations. It is suggested that corresponding protection measures be taken for different crane populations to provide a better habitat for cranes in Poyang Lake.

Siberian Crane Migration: Individuals Repeat Timing and Route in Spring Migration

Stopover habitats in long-distance migrants such as Siberian Cranes (Leucogeranus leucogeranus) are subject to dynamic changes, both seasonally and spatially. Due to the difficulty in conserving stopover habitats across vast geographies, it is necessary to clarify the timing and route patterns of stopover sites in order to take practical measures to protect habitats. From 2014 to 2018, we successfully tracked n = 10 Siberian Cranes by satellite tracking and obtained data for n = 26 complete migrations. We obtained the annual cycle of cranes and analyzed the repeatability between seasons and individuals. According to tracking data, Siberian Cranes started and ended autumn migration on 23 September and 19 November, respectively. Spring migration started on 8 April and ended on 4 June. The migration routes between seasons showed spatial similarity but less repeatability. There is significant repeatability in migration routes from 48°N to 58°N (Russian areas) between individuals in spring. Our results provide support for some seasonal plasticity in the timing of migration and flexibility in routes taken by migrating Siberian Cranes. Other than rigid patrol and guardianship for the entire spring, we also propose strengthening monitoring and protection in the identified stopover areas from the end of March to the beginning of May each year.

Annual Dynamics of Bird Community at a Coastal Wetland and Their Relation to Habitat Types: The Example of Beidagang Wetland, Northern China

In order to provide more scientific guidance for wetland bird protection, this study addressed the dynamics of the bird community sorted by ecotypes, classifications and threat categories from 2015 to 2019, and non-metric multidimensional scaling analysis, generalized additive models and the Mantel test were used to examine the relationships between bird communities and habitat types. The results showed that: (1) The abundance of birds peaked in 2017 at 88,258 individuals and then declined. Moreover, there was an inverse trend between species richness and abundance of birds, meaning greater abundance is associated with fewer species. (2) Swimming birds were dominant ecotypes and Anseriformes possessed the highest abundance. It was noteworthy that the abundance of critically endangered birds (Aythya baeri and Grus leucogeranus) and the species richness of endangered birds increased. (3) Building land and farmland had dominant impacts on the composition of bird community. Wading birds and birds in Gruiformes were significantly impacted by building land and farmland, and near threatened species were substantially influenced by farmland. Therefore, maintaining good connectivity between protected areas and surrounding areas is one of the best ways to effectively manage biodiversity of the target area. This research may provide a broader insight for coastal wetland bird habitat management and bird diversity preservation.

MODERN RENDS IN THE POPULATIONS OF THE SIBERIAN CRANE (<i>GRUS LEUCOGERANUS</i>) AND THE SANDHILL CRANE (<i>GRUS CANADENSIS</i>) (GRUIDAE, GRUIFORMES) IN THE TUNDRA OF YAKUTIA AND CHUKOTKA, BASED ON AERIAL SURVEYS

The Sandhill crane has become a common to abundant breeding species in the tundra of northeastern Yakutia, with the ranges of both Sandhill and Siberian cranes presently overlapping widely. Further range expansion of the Sandhill crane to the west and a population increase can assist competition to the stenotopic Siberian crane which is classified as a Critically Endangered species by the IUCN. To assess the dynamics of the Siberian and Sandhill crane populations, we repeated the historical aerial surveys of 1993–1995 along the Arctic coast of Yakutia and Chukotka in 2020 to 2021. Novel methods of our survey included the use of a photo-camera in addition to a voice recorder and a GPS navigator. The survey data were processed using QantumGIS 3.16.5 software. The overlapping area of both crane species expanded significantly in 2020 to 2021 as compared to 1993–1995. The local densities correlate negatively: in those areas where the density of the Sandhill crane increased, the density of the Siberian crane decreased or the latter one disappeared. The Siberian crane disappeared from the western part of the Kolyma Lowland and the Kolyma Delta, where a peak population density of the Sandhill crane has recently been reported. Our data show some concentration of the Siberian crane range in the Yana-Indigirka Lowland. Areas of the maximum density of the two species do not coincide, the distance between their centers amounting to 400 km. The center of the maximum density of the Sandhill crane has shifted to the west by 400 km from the Chaun Lowland to the Kolyma Delta over 28 years, while the numbers remain almost stable. They increased 1.22 times between the aerial surveys and can be estimated at 41,930 individuals in the areas under survey. The density of the Siberian crane increased 5.3 times over the same years, the population numbering 2.086 individuals in the surveyed areas.

ON THE RISKS OF SIBERIAN CRANE (<i>LEUCOGERANUS LEUCOGERANUS </i>PALLAS 1773, GRUIDAE, GRUIFORMES) REINTRODUCTION

The reintroduction of Siberian Cranes reared from the Oka Crane Breeding Center of the Oka State Nature Reserve goes on for 30 years. During this time, 47 eggs were placed into Eurasian Crane nests, and 190 juveniles were released into the wild, including 57 in Eurasian Crane staging areas. In order to optimize the methods of captive breeding and to mitigate the risks for releasing Siberian Cranes, it is necessary to take into account the results of the reintroduction of Whooping and Red-crowned cranes, as well as the features of Eurasian Crane biology.

长江中下游湿地大型水鸟种群动态和幼鸟比例研究

PDF HTML阅读 XML下载 导出引用 引用提醒 长江中下游湿地大型水鸟种群动态和幼鸟比例研究 DOI: 10.5846/stxb202106011446 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31970433，31870369）；中国生物多样性监测网（SinoBON） Population dynamics and age ratio of large-bodied waterbird species in the wetlands of the Yangtze River floodplain Author: Affiliation: Fund Project: National Natural Science Foundation of China (No.31970433; No.31870369), China Biodiversity Monitoring Network (Sino BON) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:迁徙水鸟保护对生物多样性保护具有重要意义。开展水鸟种群数量和幼鸟比例监测，对科学评估其种群变化趋势、制定长期保护策略具有重要价值。长江中下游湿地是东亚-澳大利西亚迁徙路线上重要的水鸟越冬区之一。本研究采用野外同步调查等方法对该区域87个湿地的亟需保护和具有代表性的10种大型越冬水鸟，其中雁形目6种，分别是鸿雁Anser cygnoides、豆雁A. fabalis、灰雁A.grus、白额雁A.albifrons、小白额雁A.erythropus和小天鹅Cygnus columbianus；鹤形目4种，分别是白鹤Leucogeranus leucogeranus、白枕鹤Antigone vipio、灰鹤Grus grus和白头鹤G.monacha，进行了长期监测（2003-2019年冬季），并结合相关文献，评估其种群变化趋势、幼鸟比例和死亡率。研究结果如下：（1）2005-2019年3种水鸟（豆雁、灰雁和灰鹤）的种群数量呈上升趋势，7种水鸟（鸿雁、白额雁、小白额雁、小天鹅、白鹤、白枕鹤和白头鹤）种群数量呈下降趋势；（2）种群趋势下降组（N=7）和上升组（N=3）的幼鸟比例均值在2016-2019年中，分别为0.168与0.173，两组间无显著差异（P=0.601）；（3）种群趋势下降和上升水鸟的死亡率均值在2016-2019年中，分别为0.245与0.125，两组间有显著差异（P=0.006）。本研究表明，导致长江越冬水鸟种群趋势下降的主要因素是高死亡率，而不是低繁殖成功率。建议未来加强对7个下降种群的保护，并进一步研究死亡的时间、地点和原因。 Abstract:Migratory waterbirds protection is essential for biodiversity protection. It is particularly important to clarify the population dynamics based on the monitoring of population size and age ratio, so as to scientifically evaluate its population trend and formulate long-term protection strategies. Wetlands in the Yangtze River floodplain are one of important winterings for waterbird species on the East Asian-Australasian flyway. In this study, the overwintering waterbird species in 87 wetlands were monitored for a long time (in each winter from 2003 to 2019) by the field investigation and literature review, and the age ratio and the mortality of 10 large-bodied waterbirds (6 geese and swans species, Swan Goose Anser cygnoides, Bean Goose A. fabalis, Greylag Goose A. grus, Greater White-fronted Goose A. albifrons, Lesser White-fronted Goose A. erythropus, and Bewick's Swan Cygnus columbianus; 4 cranes species, Siberian Crane Leucogeranus leucogeranus, White-naped Crane Antigone vipio, Common Crane Grus grus, and Hooded Crane G. monacha) were evaluated. The results are as follows:(1) the population size of 7 species of waterbirds (Swan Goose, Greater White-fronted Goose, Lesser White-fronted Goose, Bewick's Swan, Siberian Crane, White-naped Crane, and Hooded Crane) decreased, 3 species of waterbirds (Bean Goose, Greylag Goose, and Common Crane) increased; (2) In 2016-2019, the average age ratio of the declining (N=7) and rising (N=3) groups were 0.168 and 0.173, with no significant difference between the two groups (P=0.601); (3) In 2016-2019, the average mortality of the declining and rising group were 0.245 and 0.125, with significant difference between the two groups (P=0.006). This study showed that the main factor leading to the decline of overwintering waterbird species population in the Yangtze River is high mortality, not low reproductive success rate. It is suggested to strengthen the protection of the 7 declined waterbirds in the future, collect the time, place and the cause of death, and further study the factors caused high mortality. 参考文献 相似文献 引证文献

Effects of diet shift on the gut microbiota of the critically endangered Siberian Crane

Wetlands worldwide have suffered from serious degradation and transformation, leading to waterbirds increasingly dependent on agricultural fields for feeding. Although gut microbiota is an essential component of host health, the impacts of agricultural feeding on gut microbial community and pathogen transmission remain poorly understood. To fill this knowledge gap, we used 16S rRNA sequencing to characterize the fecal bacterial community of the Siberian Crane (Grusleucogeranus), a Critically Endangered species, that recently has shifted its foraging from largely Vallisneria tubers in Poyang Lake natural wetlands to crops (i.e., rice seeds and lotus rhizomes) in agricultural fields. We compared the bacterial communities between tuber foraging cranes and crop foraging cranes. Our results indicate that diet shift greatly modified the gut microbiota diversity, composition and function. Crop foraging cranes had higher microbiota diversity than tuber foraging cranes. The alteration in microbiota composition and function were correlated with change in food nutrition. Tuber (i.e., high in fiber) foraging cranes were enriched in Clostridiaceae with fiber digestion ability, and crop (i.e., high in carbohydrate) foraging cranes were enriched in bacterial taxa and functions related to carbohydrate metabolism. The flexibility of gut microbiota might enhance Siberian Cranes’ ability to adapt to novel diet and environment. However, many enriched families in crop foraging cranes were pathogenic bacteria, which might increase the susceptibility of cranes to pathogenic infection. Special caution should be taken to agricultural feeding waterbirds in Asia, where the widespread poultry-keeping in over-harvested rice fields might increase the transmission probability of pathogenetic bacteria among wild birds, domestic poultry and humans.

Prediction of Climate Change Effects on Siberian Crane (Grus leucogeranus) Habitat Suitability by Using Ensemble Modeling in Asia Wetlands

The Siberian Crane (Grus leucogeranus) is the third rarest and the most endangered crane species in the world. This study aimed at predicting the effect of climate change on Siberian Crane habitat suitability of breeding range and wintering range in Asia Wetlands by using ensemble modeling under future climate scenarios before the year 2050. In this regard, we used 4 modeling methods, Surface Range Envelop (SRE), Random Forest (RF), Classification Tree Analysis (CTA) and Flexible Discriminant Analysis (FDA) to determine the relationships between the species occurrence and bioclimatic variables under the ensemble framework by using Biomod2 and R software. The results showed that the AUC values were greater than 0.9 and functioning of all models was excellent. The Temperature Seasonality and Temperature Annual Range in the breeding range and Temperature Seasonality and Mean Temperature of Coldest Quarter in the wintering range had the most important role for habitat suitability of this species and respectively 105.64% and 136.27% changes was justified in Siberian Crane habitat suitability. Under RCP2.6 and RCP8.5 climate scenario for Siberian Crane breeding and wintering range, it is possible that climate change will cause a 100% loss of suitable habitat in West Sibera, and a 25.28% loss in Iran and China by 2050. The results of this study can be used in planning and conservation of crane species.

Using Tracking Data to Identify Gaps in Knowledge and Conservation of the Critically Endangered Siberian Crane (Leucogeranus leucogeranus)

The critically endangered Siberian crane (Leucogeranus leucogeranus) is the world’s third most endangered species of crane. Despite the enhanced conservation actions in recent years, there are pieces of evidence that suggest that its population is continuously decreasing. To gain insights into the possible causes of the population decline, we tracked nine Siberian cranes in Russia and Mongolia using GPS transmitters. We obtained migration episodes based on over 0.31 million subsequent locations from 3283 bird days between June 1995 and December 2021. Siberian cranes migrated an average of 5604 ± 362 km in spring from wintering to breeding areas and a mean of 5265 ± 454 km from breeding to wintering areas. We identified 35 staging sites along the migration corridor, including 17 critical staging sites at which birds staged for >14 days and 18 stopover sites that supported individuals for more than two days within a ca. 200 km-wide migratory corridor. Of the areas used by the tagged cranes, 77% of the breeding areas in Russia, 55% of the staging areas, 99% of the non-breeding summering area in Mongolia, and 50% of the wintering areas in Poyang Lake in China lay outside the current protected area network. Although we should be prudent about interpreting the conservation gaps of the entire population from only a few tracked birds, these results strongly suggest that the current protection network for this numerically rare species is inadequate, requiring urgent review.