Grus Vipio Research Articles

Integrated Assessment of Survival, Movement, and Reproduction in Migratory Birds: A Study on Evaluating Reinforcement Success.

Conservation managers increasingly employ reinforcement techniques to bolster declining populations by reintroducing non-wild individuals born in captivity into natural habitats, but success rates remain modest. In this study, the success is evaluated of reinforcement efforts using satellite tracking and field observation data collected between 2010 and 2021. It focuses on 13 non-wild individuals, as follows: seven red-crowned cranes Grus japonensis, two white-naped cranes Antigone vipio, and four demoiselle cranes Anthropoides virgo, as well as five wild individuals including two red-crowned cranes and three white-naped cranes. The assessment criteria included survival, movement, and reproduction, utilizing a comprehensive scoring method. The scoring process indicates that more timely field observation records and the movement pattern scoring combining models and trajectories can improve the accuracy of estimation. From the results, although wild individuals generally achieve higher scores across these metrics, statistical differences were not significant possibly due to limited sample size. Notably, non-wild individuals frequently displayed residence, nomadic, or abnormal migration. In addition, field observations underscored the benefits of pairing non-wild individuals with their wild counterparts to enhance migration success. So in order to enhance migration success, it is advisable to release non-wild individuals approaching sexual maturity in proximity to wild subadult flocks during the breeding or summering periods. Additionally, during the overwintering phase, these individuals should be released in areas where wild populations are concentrated.

Migratory birds modulate niche tradeoffs in rhythm with seasons and life history

Movement is a key means by which animals cope with variable environments. As they move, animals construct individual niches composed of the environmental conditions they experience. Niche axes may vary over time and covary with one another as animals make tradeoffs between competing needs. Seasonal migration is expected to produce substantial niche variation as animals move to keep pace with major life history phases and fluctuations in environmental conditions. Here, we apply a time-ordered principal component analysis to examine dynamic niche variance and covariance across the annual cycle for four species of migratory crane: common crane (Grus grus, n = 20), demoiselle crane (Anthropoides virgo, n = 66), black-necked crane (Grus nigricollis, n = 9), and white-naped crane (Grus vipio, n = 9). We consider four key niche components known to be important to aspects of crane natural history: enhanced vegetation index (resources availability), temperature (thermoregulation), crop proportion (preferred foraging habitat), and proximity to water (predator avoidance). All species showed a primary seasonal niche "rhythm" that dominated variance in niche components across the annual cycle. Secondary rhythms were linked to major species-specific life history phases (migration, breeding, and nonbreeding) as well as seasonal environmental patterns. Furthermore, we found that cranes' experiences of the environment emerge from time-dynamic tradeoffs among niche components. We suggest that our approach to estimating the environmental niche as a multidimensional and time-dynamical system of tradeoffs improves mechanistic understanding of organism-environment interactions.

Flightless Molt Period and Habitat Selection of White-Naped Cranes (Antigone vipio) Revealed by Satellite Tracking

Flightless Molt Period and Habitat Selection of White-Naped Cranes (Antigone vipio) Revealed by Satellite Tracking

Optimizing Water Level Management Strategies to Strengthen Reservoir Support for Bird’s Migration Network

Migratory waterbirds depend on a complex network of wetlands globally for their life cycles. However, habitat loss and degradation pose risks to these networks’ sustainability, potentially impacting wetland habitat availability. This study investigates the impact of water level changes in Beijing’s Miyun Reservoir on white-naped cranes’ (Antigone vipio) habitat use. We utilized satellite imagery from 2000–2021 and monthly data from 2018–2023 to observe changes in the reservoir’s water and land areas. Additionally, the study tracked 32 cranes using GSM-GPS loggers, yielding insights into their movement patterns and habitat preferences. Our findings emphasize the significant influence of reservoir water levels on habitat availability for these cranes. Notably, our results indicate that the decrease in suitable migratory bird habitats in the reservoir is primarily attributed to high-water level management strategies. This study highlights the necessity for balanced management of aquatic and terrestrial areas in reservoir ecosystems to preserve migratory waterbird habitats.

Satellite Tracking Reveals an Exploration of Migration Routes by White-Naped Cranes (Antigone vipio)

Satellite Tracking Reveals an Exploration of Migration Routes by White-Naped Cranes (Antigone vipio)

Effects of Habitat Change on the Wintering Waterbird Community in China’s Largest Freshwater Lake

Poyang Lake wetland in the middle and lower Yangtze River floodplain provides important wintering sites for migratory waterbirds. Extreme climatic events and human activities have resulted in the degradation and redistribution of habitat over the last few decades. However, the effects of habitat changes on the abundance of waterbirds remain unclear. We used long-term waterbird monitoring data and Landsat remote-sensing data to characterize changes in abundance and the relationship between habitat variation and abundance. A total of 113 waterbird species were recorded in the wintering period between 1999 and 2021, including 23 globally threatened species. Greater White-fronted Goose (Anser albifrons), Swan Goose (Anser cygnoides), Bean Goose (Anser fabalis), and Tundra Swan (Cygnus columbianus) were the dominant species. A total of 46 species with more than 6 annual surveys and average abundance >100 were recorded between 1999 and 2021. For most species, the mean abundance across all sub-lakes was higher in the first year than in the last year, and no obvious changes were observed over the last 20 years. The mean abundances of the vulnerable species Hooded Crane (Grus monacha) and White-naped Crane (Grus vipio) significantly declined between 1999 and 2021. No significant changes in the mean abundance of all foraging groups were observed. The area of water bodies increased, and the area of mudflats decreased. For most species with significant changes in abundance, habitat change did not greatly contribute to variation in mean abundance. The reduction in the area of mudflats greatly contributed to declines in the mean abundance of the gray heron (Ardea cinerea) and gadwall (Anas strepera).

Avian species survey with citizen-science data in Janghang Wetland, Goyang, Republic of Korea.

Monitoring of avian populations in Janghang Wetland, Goyang, Republic of Korea (ROK) is based on citizen science (also called community-based monitoring). This monitoring data can be used to track avian density, population status and waterbird census at local, national and regional levels. The Ministry of Environment (MoE) ROK has surveyed since 1999, including Odusan Unification Tower to Ilsan Bride, which connects the cities of Gimpo and Goyang along the Han River estuary. However, it has not covered Janghang Wetland, which is located in the Han River estuary at the transboundary between the two Koreas. The Janghang Wetland is a protected wetland in the Demilitarized Zone (DMZ) between the two Koreas. In 2019, Janghang Wetland was designated as a Flyway Network Site by Goyang City and the East Asian-Australasian Flyway Partnership. This Network site is a voluntary collaboration and includes many internationally significant wetlands for waterbirds that still lack formal national protection. In addition, it was designated as a Ramsar site in 2021. The wetland currently supports wintering population of White-naped Crane (Grusvipio), species listed as vulnerable and Tundra Bean Goose (Ansercygnoides), spring-autumn migration population of Swan Goose (Ansercygnoid), species listed as vulnerable and a breeding population of Black-faced Spoonbill (Plataleaminor), species listed as endangered in summer. We provide data that the Janghang Wetland is a significant area for migration and breeding for waterbirds; and that Han River estuary is also internationally important for waterbirds during the migratory bird season. We observed 14 orders, 42 families and 132 species. The surveys also observed the critically-endangered Black-faced Spoonbill (Plataleaminor), Swan Goose (Ansercygnoides), White-naped Crane (Grusvipio), Whooper Swan (Cygnuscygnus) and Peregrine Falcon (Falcoperegrinus). We also observed the Black-faced Spoonbill, Great Egret, Little Egret, Great Cormorant, Eastern Spot-billed Duck, Pheasant and Brown-eared Bulbul at the sensor camera point and White-naped Crane, Hooded Crane, Bean Goose, White-fronted Goose, Snow Goose, Swan Goose, Great Cormorant and Eastern Spot-billed Duck at the closed-circuit television camera point from the camera-trap surveys. Based on the species recorded, the survey area is of clear importance for biodiversity conservation.

Strong call to safeguard traditional agriculture as habitat for threatened crane species

This Scientific Impact Paper summarizes the changes in policy and practice of crane conservation that have occurred since our 2019 research in the Cheorwon Basin located in the Civilian Control Zone (CCZ) of the Republic of Korea (ROK). Changes in National Policy as well as increased engagement of conservation NGOs have led to more engagement of farmers in safeguarding crane habitat in their fields. Yet the current system of low-intensity rice farming is dependent on military land-use restrictions. The Cheorwon Basin in the Civilian Control Zone (CCZ) of the Republic of Korea (ROK) hosts the most important wintering site of two threatened crane species, the white-naped crane (Grus vipio) and the red-crowned crane (Grus japonensis). Both species predominately use harvested rice paddy fields as foraging sites (Kim et al., 2016). In 2019, we carried out a stakeholder analysis (Jin et al., 2021) revealing that local initiatives had successfully engaged farmers in conserving crane habitat on their fields, in part through the provision of direct and indirect financial incentives. Yet it proved challenging to engage stakeholders critical of crane conservation in our research (e.g., the military or firms interested in agricultural/ industrial development of the area). Here we summarize the changes in policy and practice of crane conservation that have occurred in the three years following our initial research. We report these insights based on expert interviews conducted in 2022 with a local farmer representative (I#1), and a local and international crane conservation specialist (I#2, I#3). At national level, the Biological Diversity Act (2002) was revised in 2019 allowing for the possibility of the private sector to co-finance the ROK government's system of Payment for Ecosystem Services (PES). The National Nature Trust owns a legal foundation to operate PES and has expressed interest in extending the payments to crane conservation (I#3). While the system of PES was already in place in other regions of ROK, enhanced funding by the local government and the Ministry of Environment allowed for its initiation in the Cheorwon Basin. Farmers now receive government payments for specific biodiversity-friendly methods. These include the restricted use of pesticides, leaving leftover grains on the field and keeping rice fields flooded throughout winter in order to provide foraging and roosting habitat for cranes (I#2). According to a local farmer representative, the process of engaging in interviews for our initial publication and thereby expressing diverse opinions increased trust relations, and respect among members of the Crane Coordinating Committee. Yet communication with stakeholders outside the committee is still perceived as challenging. (I#1). The International Crane Foundation has started a new project centered upon Cheorwon with the major components being citizen science, outreach to stakeholders and policy-makers, strengthening networks for crane conservation and education, and awareness raising for example, by initiating a local crane festival which can attract tourists to the region (I#2). The Cheorwon Basin is the only area in the ROK, in which low-intensity rice farming is still practiced and crucial roosting and foraging habitat for cranes are secured. Plans to protect the site and the traditional farming practices by establishing a nature reserve have not yet been successful (Kim et al., 2011). This means that the current state of successful cooperation between farmers and crane conservation largely depends on military land-use restrictions that have become less strict in recent years. The size of the CCZ has decreased (Figure 1) and even within the remaining area, greenhouses and ginseng farms have rapidly expanded while the pressure for further economic development persists. Karoline Hemminger: Conceptualization (lead); Conducting Interviews, Interview Analysis (lead); Writing-original draft (lead); Writing-review and editing (lead). Hyeyeon Sarah Jin: Conducting Interviews (lead); Writing-review and editing. Spike Millington, Jongsoo Choi: Writing-review and editing. Kisup Lee: Visualization; Writing-review and editing. Claudia Sattler: Conceptualization, Visualization (lead), Writing-review and editing. The authors declare that there is no conflict of interest. Open Access funding enabled and organized by Projekt DEAL. The interview transcripts are not available because they include clear names of individuals mentioned during the interview conversations as well as sensitive information which may allow to guess the identity of the interviewees.

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.

Young, wild, and free—Subadult White-naped Crane (Antigone vipio) exhibit wider home range movements than breeding adults during the summering period

Young, wild, and free—Subadult White-naped Crane (Antigone vipio) exhibit wider home range movements than breeding adults during the summering period

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

The content of heavy metals in the habitat of birds, Zeya-Bureya plain

From 2019 to 2021, the content of heavy metals in the components of the aquatic ecosystem, which is the habitat of birds on the territory of the Zeya-Bureya plain, was studied (water, sediments, macrophytes, bird feathers). High levels of iron and manganese were found in the water of small rivers. Due to heavy rains and floods, heavy metals were washed out of the surface layers of soil in agricultural fields into rivers. High concentrations of copper and lead were found in the bottom sediments of small rivers. Agricultural pollution of aquatic ecosystems affected the accumulation of lead and manganese in macrophytes. Bird feathers contained the highest amounts of iron, zinc, copper, and manganese, and the lowest amounts of cobalt and cadmium. The feathers of protected bird species such as Swan Goose, Red-crowned Crane, Hooded Crane and Daurian white-naped Crane contained lead 13.5 -38.2 mg/kg, cadmium 0.17 - 0.51 mg/kg. The elements in the feathers of birds were of exogenous origin. Birds are bioindicators of anthropogenic pollution. Researches in this direction are necessary for an estimation of ecological risk of environment and acceptance of measures on its protection.

Comparative analysis of intestinal flora between rare wild red-crowned crane and white-naped crane.

Animal intestines are extremely rich in microbial ecosystems. Numerous studies in different fields, such as epidemiology and histology, have revealed that gut microorganisms considerably mediate the survival and reproduction of animals. However, gut microbiology studies of homogeneously distributed wild cranes are still rare. This study aimed to understand the structural composition of the gut microbial community of wild cranes and elucidate the potential roles of the microorganisms. We used high-throughput sequencing to analyze the gut microbial community structure of wild cranes in the Zhalong Nature Reserve. A total of 1,965,683 valid tags and 5248 OTUs were obtained from 32 fecal samples. Twenty-six bacteria phyla and 523 genera were annotated from the intestinal tract of the red-crowned crane. Twenty-five bacteria phyla and 625 genera were annotated from the intestine of the white-naped crane. Firmicutes, Proteobacteria, and Bacteroidetes are the dominant bacterial phyla in the intestinal tract of red-crowned cranes, while Catellicoccus, Lactobacillus, Neisseria, and Streptococcus were the dominant genera. The dominant bacterial phyla in the intestinal tract of white-naped cranes were Firmicutes, Proteobacteria, Bacteroidetes, Epsilonbacteraeota, Actinobacteria, and Fusobacteria. However, the dominant genera were Catellicoccus, Lactobacillus, Neisseria, Campylobacter, Streptococcus, Anaerobiospirillum, Romboutsia, Turicibacter, Haemophilus, and Lautropia. Firmicutes had significantly higher relative abundance in the intestine of the red-crowned than white-naped cranes (P < 0.05). However, the relative abundance of Actinobacteria and Bacteroidetes was significantly higher (P < 0.05) in the intestines of white-naped than red-crowned cranes. The diversity of the intestinal flora between the two crane species was significantly different (P < 0.05). Besides, the alpha diversity of the intestinal flora was higher for white-naped than red-crowned cranes. Eight of the 41 functional pathways differed in the gut of both crane species (P < 0.05). Both species live in the same area and have similar feeding and behavioral characteristics. Therefore, host differences are possibly the main factors influencing the structural and functional differences in the composition of the gut microbial community. This study provides important reference data for constructing a crane gut microbial assessment system. The findings have implications for studying deeper relationships between crane gut microbes and genetics, nutrition, immunity, and disease.

Breeding and migration performance metrics highlight challenges for White-naped Cranes

Globally, habitat loss has been deemed a major threat to wetland bird populations. However, the underlying mechanism of population declines and variations in the birds’ vulnerability throughout their annual cycle is challenging to determine, yet critical for development of targeted conservation strategies. Over seven years, landscape water availability explained occupancy of breeding territories best when breeding performance, migratory performance, and annual survival of the White-naped Crane (Grus vipio) population in eastern Mongolia were studied. Also, the hatching success of eggs was positively correlated with water availability in addition to plant productivity. High ambient temperatures and large numbers of herder families (and hence more livestock) negatively affected hatching success. High water availability at Luan, a major stopover site increased migration speed during the cranes’ northbound migration to their breeding grounds. In contrast, when water conditions were favorable, the birds stayed longer at the stopover site during southbound migration. Increased human density reduced the use of the stopover site during northbound migration. Finally, cranes arrived early at the breeding grounds when ambient temperature was high in northeast Mongolia. Combining these findings with historical trends in key environmental factors on their breeding grounds explains the general decline observed in this population of cranes in recent decades. Extrapolating our findings with future climate predictions, the outlook seems poor unless urgent action is taken. Knowledge of the mechanisms underlying White-naped Crane population decline in eastern Mongolia identified in this paper should improve the effectiveness of these actions.

Gene Pool Homogeneity of Western and Eastern Populations of the White-Naped Crane Antigone vipio in Different Flyways

Gene Pool Homogeneity of Western and Eastern Populations of the White-Naped Crane Antigone vipio in Different Flyways

Reintroduction of Parent-Reared and Semi-Wild Chicks of Red-Crowned Grus japonensis and White-Naped Cranes Antigone vipio in Russia: Lessons from 29 Years of Experience

Red-crowned Grus japonensis (IUCN status: Endangered) and White-naped Antigone vipio (IUCN status: Vulnerable) cranes are both rare, with wild populations of ∼3,000 and ∼6,000 individuals, respectively. Since 1991, the Rare Bird Reintroduction Station at the Khingansky State Nature Reserve, Russia, has been rearing and reintroducing chicks of both species to bolster wild populations. The station uses two different chick-rearing methods: (1) the “parent-reared” method, in which chicks are raised in enclosures by natural parents and stay with them until their release into the wild, and (2) the “semi-wild” method, a modification of hand-rearing, in which cohorts of 2–7 chicks spend most of their time together in an enclosure but are guided on daily excursions outside the enclosure, under supervision of a keeper from a distance of 30–50 m. We have assessed and compared apparent survival of crane chicks reared under these methods. Of the 165 juveniles released into the wild from 1991–2019 (104 Red-crowned; 61 White-naped), no difference was found between apparent survival of parent-reared and semi-wild chicks. Six-month apparent survival of Red-crowned Cranes was 84.2% (95% confidence interval: 75.3–90.3%); for White-naped Cranes –89.5% (95% CI: 83.9–93.3%). Both parent-reared and semi-wild chicks were later observed in mated pairs with their own offspring (17 chicks in total), coupling with either other reintroduced birds or with wild individuals. We conclude that both the parent-reared and semi-wild methods had similar outcomes with respect to apparent survival. However, since the semi-wild method is less costly with respect to time (i.e., more juveniles can be released annually using this method) we recommend that it be used whenever possible to bolster these Endangered and Vulnerable populations.

The Impacts of a Large Water Transfer Project on a Waterbird Community in the Receiving Dam: A Case Study of Miyun Reservoir, China

As natural wetlands are degrading worldwide, artificial wetlands can operate as a substitute to provide waterbirds with refuge, but they cannot replace natural wetlands. Reservoirs, one of the most common artificial wetlands in China, can be of great importance to waterbirds. Miyun reservoir in Beijing, China, has undergone a process similar to a natural lake being constructed in a reservoir. In this study, we surveyed waterbird community composition and evaluated the corresponding land cover and land use change with satellite and digital elevation model images of both before and after the water level change. The results showed that in all modelled scenarios, when the water level rises, agricultural lands suffer the greatest loss, with wetlands and forests following. The water level rise also caused a decrease in shallow water areas and a decline in the number and diversity of waterbird communities, as the components shifted from a shallow-water preferring group (waders, geese and dabbling ducks) to a deep-water preferring group (most diving ducks, gulls and terns). Miyun reservoir ceased to be an important waterbird habitat in China and is no longer an important stopover site for white-naped cranes. A similar process is likely to occur when a natural lake is constructed in a reservoir. Therefore, we suggest that policymakers consider the needs of waterbirds when constructing or managing reservoirs.

Habitat selection and food choice of White-naped Cranes (Grus vipio) at stopover sites based on satellite tracking and stable isotope analysis

By combining satellite tracking, land-cover extracted from Landsite 8 images, and the traditional stable isotope analysis, we studied the habitat selection and food preference of a vulnerable migratory waterbird, the White-naped Crane (Grus vipio), in one of its key stagging sites, the Shandian River Basin in the semi-arid northern China, to provide knowledge that is critical for its conservation in the Anthropocene. Our results showed that the White-naped Cranes used both uplands and natural wetlands in the stopover site. While the cranes used farmland and natural land cover equally as night-time roosting grounds, they spent most daytime foraging at farmlands. Despite the extensive usage of croplands as their foraging ground, the Bayesian mixing models based on stable isotopic analysis revealed that crop residues after harvesting, such as Maize (Zea mays) and Naked Oat (Avena chinensis), were only a small fraction of the White-naped Cranes’ diet (∼19%), and their diet composited mainly natural plants, such as Allium ledebourianum, Potentilla anserina, and P. tanacetifoli. Moreover, more than 20% of the total wetlands in the region were modelled as home range of the cranes. On contrast, less than 10% of croplands and about 1% of the unused uplands were identified as home range. In addition, the entire core habitats were located in natural wetlands. Our findings demonstrated the importance of natural wetlands for the survival of the threatened crane. However, the satellite-derived land cover data showed that croplands increased rapidly in the last decade in this area, at the expense of natural wetlands. With the sharp decrease of White-naped Crane population in China, the conservation of stopover sites becomes imperative. Based on our analysis, we recommend the following management actions: conserving adequate natural wetland area, regulating anthropogenic pressures such as the use of herbicides, expanding the duration and extent of current conservation regulations, establishing a comprehensive monitoring program, and initiating basin-scale ecological restoration, for effective conservation of this threatened species. These integrated conservation strategies for migratory waterbirds are necessary, considering the rapid land-cover changes and agricultural expansion that have been occurring in East Asian-Australasian Flyway, especially in the semi-arid temperate zone.

Winter coexistence in herbivorous waterbirds: Niche differentiation in a floodplain, Poyang Lake, China.

The classical niche theory supports the idea that stable coexistence requires ecological differences between closely related species. However, information on waterbirds coexistence in the entirely landlocked freshwater system of Poyang Lake is not well understood, especially when the available biomass of their food in the area decreases. In this study, we tested the ecological segregation mechanisms in the 2015/2016 and 2016/2017 wintering periods among eight herbivorous waterbirds (including the Siberian crane Grus leucogeranus, hooded crane Grus monacha, white‐naped crane Grus vipio, common crane Grus grus, greater white‐fronted goose Anser albifrons, bean goose Anser fabalis, swan goose Anser cygnoides, and tundra swan Cygnus columbianus) at Poyang Lake. Using field observations and species niche and foraging habitat selection models, we investigated the abundance, distribution, and food sources of these eight waterbird species to quantify and compare their habitat use and ecological niches. Our results showed that niche segregation among the waterbirds, with respect to food types, time, and spatial location, allow them to coexist and use similar resources. The water level gradually receded in the sub‐lakes of the Poyang Lake, which could provide food sources and various habitats for wintering herbivorous waterbirds to coexist. We demonstrated that the differences in habitat use could mitigate interspecific competition, which may explain the mechanism whereby waterbirds of Poyang Lake coexist during the wintering period, despite considerable overlap in the dietary niches of herbivorous waterbirds.

Combining Tracking and Remote Sensing to Identify Critical Year-Round Site, Habitat Use and Migratory Connectivity of a Threatened Waterbird Species

We tracked 39 western flyway white-naped cranes (Antigone vipio) throughout multiple annual cycles from June 2017 to July 2020, using GSM-GPS loggers providing positions every 10-min to describe migration routes and key staging areas used between their Mongolian breeding and wintering areas in China’s Yangtze River Basin. The results demonstrated that white-naped cranes migrated an average of 2556 km (±187.9 SD) in autumn and 2673 km (±342.3) in spring. We identified 86 critical stopover sites that supported individuals for more than 14 days, within a 100–800 km wide migratory corridor. This study also confirmed that Luan River catchment is the most important staging region, where white-naped cranes spent 18% of the annual cycle (in both spring and autumn) each year. Throughout the annual cycle, 69% of the tracking locations were from outside of the currently protected areas, while none of the critical staging areas enjoyed any form of site protection. We see further future potential to combine avian tracking data and remote-sensing information throughout the annual range of the white-naped crane to restore it and other such species to a more favourable conservation status.