Grus Grus Research Articles

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

Миграции красавки (Anthropoides virgo) и тибетского серого журавля (Grus grus korelovi) в Казахстане

Modern data on the migration of the Demoiselle Crane (Anthropoides virgo), nesting in Kazakhstan and adjacent territories in Russia, and the Tibetan Common Crane (Grus grus korelovi), inhabiting the Central Tien Shan in southeastern Kazakhstan, are presented. On the basis of remote tracking, flyways of the Demoiselle Crane have been clarified, and key territories have been identified in the premigration period and on the flyways. The features of the Tibetan common crane migration have been established, and a wintering ground on the Muzart River in China has been identified.

Clade 2.3.4.4b H5N8 Subtype Avian Influenza Viruses Were Identified from the Common Crane Wintering in Yunnan Province, China.

The seasonal migration of wild aquatic birds plays a critical role in the maintenance, transmission, and incursion of the avian influenza virus (AIV). AIV surveillance was performed during 2020-2021 in two national nature reserves with abundant wild bird resources in Yunnan, China. Four H5N8 AIVs isolates from the common crane were identified by next-generation sequencing. Phylogenetic analysis demonstrated that all eight gene segments of these H5N8 AIVs belonged to clade 2.3.4.4b high-pathogenic AIV (HPAIV) and shared high nucleotide sequence similarity with the strains isolated in Hubei, China, and Siberia, Russia, in 2020-2021. The H5N8 HPAIVs from common cranes were characterized by both human and avian dual-receptor specificity in the hemagglutinin (HA) protein. Moreover, possessing the substitutions contributes to overcoming transmission barriers of mammalian hosts in polymerase basic 2 (PB2), polymerase basic protein 1 (PB1), and polymerase acid (PA), and exhibiting the long stalk in the neck region of the neuraminidase (NA) protein contributes to adaptation in wild birds. Monitoring AIVs in migratory birds, at stopover sites and in their primary habitats, i.e., breeding or wintering grounds, could provide insight into potential zoonosis caused by AIVs.

Using computer vision, image analysis and UAVs for the automatic recognition and counting of common cranes (Grus grus)

Long-term monitoring of wildlife numbers traditionally uses observers, which are frequently inefficient and inaccurate due to their variable experience/training, are costly and difficult to sustain over time. Furthermore, there are other inhibiting factors for wildlife counting, such as: inhabiting inaccessible areas, fear of humans, and nocturnal behavior. There is a need to develop new technologies that will automatically identify and count wild animals in order to determine the appropriate management protocol. In this study, an advanced and accurate method for automatically calculating the number of cranes (Grus grus), using thermal cameras at night and visible light (RGB) cameras during the day onboard unmanned aerial vehicles (UAVs), based on image analysis and computer vision, was developed. The cranes congregate at night in a large communal roost, making it possible to count the birds while they are relatively static and all together. Each bird was counted individually by creating a standardized tool to determine population numbers for management, using image analysis and automatic processing. A dedicated algorithm was developed that aimed to identify the cranes based on their spectral characteristics (typical temperature, shape, size) and to effectively separate the cranes from the typical background. The automatic segmentation and counting of roosting common cranes using UAV nighttime thermal images had an Overall Accuracy (OA) of 91.47%, User's Accuracy (UA) of 99.68%, and Producer's Accuracy (PA) of 91.74%. The computer vision and machine learning algorithm based on the YOLO v3 platform of daytime RGB UAV images of common cranes at the feeding station yielded an overall loss accuracy level of 2.25%, with a mean square error of 1.87, OA of 94.51%, UA of 99.91%, PA of 94.59%. These results are highly encouraging, and although the algorithms were developed for the purpose of counting cranes, they could be adapted for other counting purposes for wildlife management.

Comparing invasive and noninvasive faecal sampling in wildlife microbiome studies: A case study on wild common cranes.

In ecological and conservation studies, responsible researchers strive to obtain rich data while minimizing disturbance to wildlife and ecosystems. We assessed if samples collected noninvasively can be used for faecal microbiome research, comparing microbiota of noninvasively collected faecal samples to those collected from trapped common cranes at the same sites over the same periods. We found significant differences in faecal microbial composition (alpha and beta diversity), which likely did not result from noninvasive sample exposure to soil contaminants, as assessed by comparing bacterial oxygen use profiles. Differences might result from trapped birds' exposure to sedatives or stress. We conclude that if all samples are collected in the same manner, comparative analyses are valid, and noninvasive sampling may better represent host faecal microbiota because there are no trapping effects. Experiments with fresh and delayed sample collection can elucidate effects of environmental exposures on microbiota. Further, controlled tests of stressing or sedation may unravel how trapping affects wildlife microbiota.

Balancing structural complexity with ecological insight in Spatio‐temporal species distribution models

Abstract The potential for statistical complexity in species distribution models (SDMs) has greatly increased with advances in computational power. Structurally complex models provide the flexibility to analyse intricate ecological systems and realistically messy data, but can be difficult to interpret, reducing their practical impact. Founding model complexity in ecological theory can improve insight gained from SDMs. Here, we evaluate a marked point process approach, which uses multiple Gaussian random fields to represent population dynamics of the Eurasian crane Grus grus in a spatio‐temporal species distribution model. We discuss the role of model components and their impacts on predictions, in comparison with a simpler binomial presence/absence approach. Inference is carried out using Integrated Nested Laplace Approximation (INLA) with inlabru, an accessible and computationally efficient approach for Bayesian hierarchical modelling, which is not yet widely used in SDMs. Using the marked point process approach, crane distribution was predicted to be dependent on the density of suitable habitat patches, as well as close to observations of the existing population. This demonstrates the advantage of complex model components in accounting for spatio‐temporal population dynamics (such as habitat preferences and dispersal limitations) that are not explained by environmental variables. However, including an AR1 temporal correlation structure in the models resulted in unrealistic predictions of species distribution; highlighting the need for careful consideration when determining the level of model complexity. Increasing model complexity, with careful evaluation of the effects of additional model components, can provide a more realistic representation of a system, which is of particular importance for a practical and impact‐focused discipline such as ecology (though these methods extend to applications for a wide range of systems). Founding complexity in contextual theory is not only fundamental to maintaining model interpretability but can be a useful approach to improving insight gained from model outputs.

Comparative Analysis of the Gut Microbiota of Three Sympatric Terrestrial Wild Bird Species Overwintering in Farmland Habitats.

The gut microbiota of wild birds are affected by complex factors, and cross-species transmission may pose challenges for the host to maintain stable gut symbionts. Farmland habitats are environments strongly manipulated by humans, and the environmental characteristics within a large area are highly consistent. These features provide the ideal natural conditions for conducting cross-species comparative studies on gut microbiota among wild birds. This study aimed to investigate and compare the gut microbiota of three common farmland-dependent bird species, Great Bustard (Otis tarda dybowskii), Common Crane (Grus grus), and Common Coot (Fulica atra), in a homogeneous habitat during the wintering period. The results indicated that under the combined action of similar influencing factors, the gut microbiota of different host species did not undergo adaptive convergence, maintained relatively independent structures, and exhibited host-driven signals. In addition, we also detected various pathogenic genera that may cause outbreaks of periodic infections among sympatric migratory birds. We conclude that phylosymbiosis may occur between some wild birds and their gut microbiota. Usage of non-invasive methods to monitor the changes in the gut microbiota of wild bird fecal samples has important implications for the conservation of endangered species.

The Eurasian crane (Grus grus) as an ecosystem engineer in grasslands: Conservation values, ecosystem services, and disservices related to a large iconic bird species

AbstractLarge bird species, such as cranes are involved in human‐wildlife conflicts as they often forage in croplands. The Eurasian crane (Grus grus) is a large bird species, protected across Europe, which, thanks to conservation programmes and its ability to utilise croplands for foraging, shows a strongly increasing population trend. This exaggerates the existing conflicts between crop farmers and cranes and is spilling over to natural habitats, where foraging by large flocks can lead to land degradation. No studies have evaluated the effects of foraging cranes on grasslands, despite the fact that these habitats provide important feeding grounds for cranes across their whole range. To fill this knowledge gap, we evaluated the ecosystem engineering effect of foraging Eurasian cranes on the vegetation of dry grasslands in Hungary. We used indicators of vegetation naturalness, forage quality, and floral resource provision to evaluate the ecosystem state from multiple aspects. We sampled 100 quadrats in disturbed patches and 100 in undisturbed grasslands in two seasons and 2 years (800 observations). Cranes created distinct vegetation patches with different species composition from undisturbed areas. We identified important trade‐offs between the positive and negative effects of the foraging activity of cranes on different structural and functional components of the ecosystems. The crane‐disturbed early‐successional patches increased plant diversity and floral resources but decreased the area of undisturbed grasslands. Although crane‐disturbed patches could provide forage for livestock early in the season, the forage quality became poor later in the year. We highlight the importance of monitoring the landscape‐level extent of the disturbed areas.

The 46th Annual Report of the California Bird Records Committee: 2020 Records

From its last report through 2020, the California Bird Records Committee reached decisions on 206 records involving 195 individuals of 67 species and two species groups, endorsing 180 records of 169 individuals. Especially notable records detailed in this report include those of California’s third Common Crane (Grus grus), third Bristle-thighed Curlew (Numenius tahitiensis), third Marsh Sandpiper (Tringa stagnatalis), third Eurasian Skylark (Alauda arvensis), fourth Chuck-will’s-widow (Antrostomus carolinensis), and fourth Fork-tailed Flycatcher (Tyrannus savanna).

Winners and losers of land use change: A systematic review of interactions between the world's crane species (Gruidae) and the agricultural sector.

While agricultural intensification and expansion are major factors driving loss and degradation of natural habitat and species decline, some wildlife species also benefit from agriculturally managed habitats. This may lead to high population densities with impacts on both human livelihoods and wildlife conservation. Cranes are a group of 15 species worldwide, affected both negatively and positively by agricultural practices. While eleven species face critical population declines, numbers of common cranes (Grus grus) and sandhill cranes (Grus canadensis) have increased drastically in the last 40 years. Their increase is associated with higher incidences of crane foraging on agricultural crops, causing financial losses to farmers. Our aim was to synthesize scientific knowledge on the bilateral effects of land use change and crane populations. We conducted a systematic literature review of peer‐reviewed publications on agriculture‐crane interactions (n = 135) and on the importance of agricultural crops in the diet of cranes (n = 81). Agricultural crops constitute a considerable part of the diet of all crane species (average of 37%, most frequently maize (Zea mays L.) and wheat (Triticum aestivum L.)). Crop damage was identified in only 10% of all agriculture‐crane interactions, although one‐third of interactions included cranes foraging on cropland. Using a conceptual framework analysis, we identified two major pathways in agriculture‐crane interactions: (1) habitat loss with negative effects on crane species dependent on specific habitats, and (2) expanding agricultural habitats with superabundant food availability beneficial for opportunistic crane species. The degree to which crane species can adapt to agricultural land use changes may be an important factor explaining their population response. We conclude that multi‐objective management needs to combine land sparing and land sharing strategies at landscape scale. To support viable crane populations while guaranteeing sustainable agricultural production, it is necessary to include the perspectives of diverse stakeholders and streamline conservation initiatives and agricultural policy accordingly.

Изучение позвоночных животных Барабинской и Ишимской лесостепей и Кулундинской степи для подготовки третьего издания Красной книги Омской области

The article presents the results of monitoring of the conditions of vertebrate populations included in the Red Book of the Omsk Region (2015) in the territories of the Azov German National, Gorkovsky, Kalachinsky, Kormilovsky, Nizhneomsky, Okoneshnikovsky, Omsk, and Cherlaksky municipal districts within the area of ​​24 000 square km. 97 respondents with an average experience of observing animals and working in nature for 27 years were interviewed. 67 key sites were surveyed by scientific methods. Monitoring was carried out to search for all 107 species recorded in the Red Book (2015) in the mentioned area and species left in that area by 2021. 79 species of animals were found. After examining its entire territory, it is proposed to exclude the following species from the Red Book of the Omsk region: siberian loach, siberian sculpin, common crane, black woodpecker and the gray shrike. The status of protection of the savka and bustard should be changed to the first category, the little bittern, white-eyed pochard and the Eurasian hoopoe - to the second category, the red-necked grebe, Siberian salamander and the gray-cheeked grebe, Siberian salamander and the greater spotted eagle - to the fifth category of rarity status.

Species diversity, spatial distribution and protection strategies of wintering waterbirds after extreme summer flood in Lake Poyang

鄱阳湖是我国最大的淡水湖，也是具有国际意义的候鸟越冬地. 近年来，鄱阳湖水文情势异常使得候鸟越冬环境更加复杂. 本文以2020年鄱阳湖出现夏季极端水位为背景，基于2019和2020年鄱阳湖越冬水鸟同步调查数据，探讨了夏季极端水位对越冬水鸟丰富度和空间分布的影响. 研究结果表明：夏季极端水位条件下鄱阳湖越冬水鸟的总数量、群落结构和优势物种组成相对稳定，水鸟数量由597307只下降至572358只，主要是鸭科、鸥科、鹳科、鸬鹚科和鹮科鸟类数量明显下降；食块茎、食种子和食鱼集团水鸟数量均有所下降. 水鸟的整体空间分布格局变化不大，主要栖息地仍为鄱阳湖保护区和上饶湿地的碟形湖及人控湖汊，越冬水鸟向人工湿地扩散加剧. 2019年在人工湿地主要记录到灰鹤926只、白鹤3只；2020年则记录到白鹤2215只、灰鹤7294只、白头鹤88只、白枕鹤378只、豆雁550只、鸿雁3100只、灰雁3200只和小天鹅1543只. 2020年冬季人工湿地中的越冬水鸟数量比2019年增加显著. 鄱阳湖夏季极端水位导致沉水植物群落崩溃，造成植食性水鸟在天然湿地中的越冬食物短缺，从而导致种群空间分布格局出现明显变化，这也是鹤类和雁类水鸟前往人工湿地觅食的主要原因. 因此，在夏季洪水频发的背景下加强人工湿地管理，是当前解决越冬水鸟天然湿地食物资源短缺的重要措施.;Lake Poyang is the largest freshwater lake in China and has been an important wintering ground for migratory birds. In recent years, the abnormal hydrological regime of Lake Poyang deteriorated the quality of this wintering ground for migratory birds. In summer of 2020, Lake Poyang experienced extreme water level, which maybe affect the waterbird community structure and waterbird distribution. We compared the wintering waterbird species diversity, abundance and spatial distribution between winter of 2019 and 2020 to understand the impact of extreme water level on wintering waterbirds. The results showed that the total number, community structure and dominant species composition of wintering waterbirds were relatively stable after extreme summer water level. The total number of waterbirds decreased from 597307 to 572358, among which the number of Anatidae, Laridae, Ciconiidae, Phalacrocoracidae and Threskiornithidae obviously decreased. The abundances of tuber eaters, seed eaters and fish eaters were declined. The overall spatial distribution pattern of waterbirds showed little change. Waterbirds mainly inhabited the sub-lakes and controlled lake branches in the Lake Poyang National Nature Reserve and Shangrao wetland. However, waterbirds spread more severely from Lake Poyang nature wetlands to artificial wetlands nearby Lake Poyang. In 2019, 926 common cranes and 3 Siberian cranes were recorded in rice paddies and lotus ponds; In 2020, 2215 Siberian cranes, 7294 common cranes, 88 hooded cranes, 378 white-napped cranes, 550 bean geese, 3100 swan geese, 3200 greylag geese and 1543 tundra swans occurred in these artificial wetlands. The wintering waterbirds in artificial wetlands in winter of 2020 was significantly more abundant than that in winter of 2019. The extreme water level in summer led to the collapse of submerged plant community, resulting in the shortage of wintering food for herbivorous waterbirds in the natural wetlands, which drove cranes and geese dispersed into the artificial wetlands. Therefore, it is necessary to strengthen the management of artificial wetlands under the condition of frequently higher flood in Lake Poyang for wintering waterbirds conservation.

Long-term monitoring data reveal effects of age, population density, and environmental aspects on hatching success of Common Cranes (Grus grus)

Facing climate and land use change, a species’ ability to successfully adapt to changing environments is crucial for its survival. Extensive drainage and intensification of agriculture and forestry set wetlands and associated species at risk of population declines. The population of Common Cranes (Grus grus) has experienced considerable fluctuations over the last century. Despite increasing population numbers, hatching success seemed to have decreased over the last years. The aim of this study was to identify factors influencing hatching success and nest survival of Common Cranes based on analyses of long-term individual-based monitoring data from northeastern Germany and evaluate the species ability to adapt to changing environments. Hatching success decreased over the course of the study period from 0.75 to 0.55. Surprisingly, nest survival and hatching success did not vary across different nesting habitats, whereas factors such as female age, timing of nest initiation and breeding pair density were found to have significant effects on hatching success. Older females showed higher hatching success, even though the proportion of unhatched eggs was highest in females aged 20 years or older. Early nest initiation had a positive effect on hatching success. Water levels are more favorable early in the nesting season, whereas increasing evaporation with time causes water levels to decrease, granting easier access for predators. Independently of female age, hatching success decreased with increasing numbers of breeding pairs within a 2-km radius around a nesting site. High population densities intensify competition for resources and promote intraspecific interactions, affecting reproductive outcome negatively. This study gives first insights into mechanisms behind population regulation in Common Cranes, highlighting the importance of population dynamics and individual features. We suggest to further investigate density dependent effects including landscape and habitat features as well as reproductive success in terms of chick survival, since successfully raising juveniles is crucial for a species survival.

Сharacteristics of visible autumn migrations of the common crane Grus grus (Linnaeus, 1758) in NNP "Prypiat-Stokhid" in 2012-2017

The vіsіble mіgratіons of bіrds were study of the terrіtory of national nature park at left bank of the Prypіat Rіver near Svalovychі vіllage іn Kamin-Kashyrsk dіstrіct, Volyn regіon of Ukraіne іn September and October 2012-2017. There were 2737 individuals of the Common Crane counted at the one observation point during this time. Almost all birds migrated in flocks. Several lone birds were observed also, apparently lagging behind their flocks. There are from 2 to 222 individuals in one flock, on average – 39,0±5,12 (n=70). The main passage lasted from the 3rd decade of September to the middle of the 2nd Decade of October. The majority of them flew in the 5 last hours of observations (77,9% of all counted birds during 6 years). Most birds of this species were observed on passage at altitudes above 250 m (61,2%), less – between 100 and 250 m (36,1%), and the predominant directions of their migration were SW (48,5%) and S (40,7%).

Automatic Segmentation and Counting of Roosting Common Cranes (Grus Grus) Using Uav Thermal Images, Computer Vision, and Machine Learning in the Hula Valley, Israel

Automatic Segmentation and Counting of Roosting Common Cranes (Grus Grus) Using Uav Thermal Images, Computer Vision, and Machine Learning in the Hula Valley, Israel

Birds as Plastic Dispersers from Terrestrial to Aquatic Ecosystems: The Case of the Common Crane (Grus Grus) and the Lesser Black-Backed Gull (Larus Fuscus) in Temporary Lakes of Central Spain

Birds as Plastic Dispersers from Terrestrial to Aquatic Ecosystems: The Case of the Common Crane (Grus Grus) and the Lesser Black-Backed Gull (Larus Fuscus) in Temporary Lakes of Central Spain

Seasonal Migration and Daily Movement Patterns of Sympatric Overwintering Black-Necked Cranes (Grus nigricollis) and Common Cranes (Grus grus) in Caohai, Guizhou, China

Wintering Black-necked (Grus nigricollis) and Common (G. grus) cranes occur sympatrically in Caohai Wetland, Guizhou, China. Seasonal migration dynamics, daily movement patterns, and diurnal activity budgets of the two crane species were investigated in Caohai Wetland, in order to characterize their wintering activity differences and the mechanism of interspecific coexistence, during October - April 2014 - 2017. Black-necked Cranes wintered in Caohai for 147 ± 8 days, and Common Cranes for 169 ± 8 days. Common Cranes generally arrived in Caohai 11.4 ± 3.28 days earlier and departed 11.00 ± 3.20 days later than Black-necked Cranes. During winter in Caohai Wetland, the behavioral activities of both the Black-necked and Common cranes were strongly influenced by circadian rhythms. However, there were significant differences in daily temporal patterns between them in percent time spent in specific behaviors. Common Cranes left their roosting sites 20 min. earlier than Black-necked Cranes and returned 32 min. later. Common Cranes also spent more time foraging and being vigilant than Black-necked Cranes.

Common Crane as a species indicating the conservation importance of wetlands

The relevance of the study is determined by the high importance of wetlands in the ecological frameworks of territories and the need for methodological approaches to identify wetlands of high conservation importance. The paper is aimed to demonstrate the indicator role of the Common crane to determine the conservation importance of wetlands on the example of the Nizhny Novgorod region. Objectives: to estimate the number of the common crane in existing and reserved protected areas; to analyze the presence of wildlife species listed in the Red Data Book of the Nizhny Novgorod region in these protected areas. The results of many years of surveys as well as data from the Red Data Book of Nizhny Novgorod region are analyzed. It is shown that within 93 protected areas of the total area 491870 ha 135598.4 ha of wetlands are protected, where 830 territorial pairs of cranes (about 60% of the regional population of the species) inhabit. Along with the common crane, these areas serve to protect almost all (91%) obligate wetland wildlife species listed in the Red Data Book of Nizhny Novgorod region, 82% of rare species associated with wetlands and 53% of species not associated with wetlands. Our calculations showed a high correlation of the number of rare wildlife species with the wetland area (correlation coefficient 0.75). The correlation of the number of rare species with the number of common crane was higher (correlation coefficient 0.82). Quantitative correlations of the number of rare wildlife species with the area of wetlands and the number of common cranes were also calculated. The obtained conclusions allow using the number of the common crane for substantiation of importance of wetlands for nature protection and establishment of protected areas.

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.

New observations of four waterbird species in Algerian Sahara

AbstractThe range mapping and phenological status of four waterbird species was studied in Ghardaïa and El‐Ménéa regions between 2017 and 2021. Seasonal waterbird censuses were conducted throughout Ghardaïa and El‐Ménéa by individual counts or visual estimation. During these counts, four species were reported for the first time in this region, three passage visitors, European golden plover Pluvialis apricaria, black stork Ciconia nigra and Western Reef Heron Egretta gularis, and one winter stopover, common crane Grus grus. Observations on the species in Ghardaïa and El‐Ménéa regions are new for southern Algeria.