Hydrology‐driven responses of herbivorous geese in relation to changes in food quantity and quality

East Dongting Lake is a Ramsar site and a particularly important wintering ground for herbivorous geese along the East Asian‐Australasian Flyway. The operation of the Three Gorges Dam has changed the water regime and has a significant impact on wetland ecosystems downstream. We studied the responses of two sympatric herbivorous goose species, the Lesser white‐fronted goose Anser erythropus and Bean goose Anser fabalis, to habitat change by investigating their food conditions, habitat selection, and diet composition in the wintering periods of 2016/2017 and 2017/2018, which had early and late water recession, respectively. It was expected that the contrasting water regimes would result in different food conditions and geese responses. The results showed that the food quality and quantity differed significantly between winters. As responses to the high‐quantity/low‐quality food during 2016/2017, more geese switched to feeding on mudflat and exploited plants such as dicotyledons and moss. The tall swards of Carex spp. (dominant plants in the meadow) that developed during the first growing season decreased the food accessibility during the second growing season and hindered the exploitation of newly generated shoots by the geese, which was further confirmed by our clipping control experiment. Nearly all the geese chose to feed on meadow, and Carex spp. made up the majority of their diet in 2017/2018 when there was more low‐quantity/high‐quality food. Compared with the globally vulnerable Lesser white‐fronted geese, the larger‐sized Bean geese seemed to be less susceptible to winter food shortages and exhibited more stable responses. We concluded that the food quality–quantity condition was the external factor influencing the geese responses, while morphological and physiological traits could be the internal factors causing different responses between the two species. This study enhanced the understanding of the influence that habitat change exerts on herbivorous geese in their wintering site in the context of the Three Gorges Dam operation. We suggested that regulating hydrological regime was important in terms of wetland management and species conservation.     

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.     

Spring migration patterns,habitat use,and stopover site protection status for two declining waterfowl species wintering in China as revealed by satellite tracking

East Asian migratory waterfowl have greatly declined since the 1950s, especially the populations that winter in China. Conservation is severely hampered by the lack of primary information about migration patterns and stopover sites. This study utilizes satellite tracking techniques and advanced spatial analyses to investigate spring migration of the greater white‐fronted goose (Anser albifrons) and tundra bean goose (Anser serrirostris) wintering along the Yangtze River Floodplain. Based on 24 tracks obtained from 21 individuals during the spring of 2015 and 2016, we found that the Northeast China Plain is far‐out the most intensively used stopover site during migration, with geese staying for over 1 month. This region has also been intensely developed for agriculture, suggesting a causal link to the decline in East Asian waterfowl wintering in China. The protection of waterbodies used as roosting area, especially those surrounded by intensive foraging land, is critical for waterfowl survival. Over 90% of the core area used during spring migration is not protected. We suggest that future ground surveys should target these areas to confirm their relevance for migratory waterfowl at the population level, and core roosting area at critical spring‐staging sites should be integrated in the network of protected areas along the flyway. Moreover, the potential bird–human conflict in core stopover area needs to be further studied. Our study illustrates how satellite tracking combined with spatial analyses can provide crucial insights necessary to improve the conservation of declining Migratory species.     

Flyway structure in the circumpolar greater white‐fronted goose

Dispersal and migratory behavior are influential factors in determining how genetic diversity is distributed across the landscape. In migratory species, genetic structure can be promoted via several mechanisms including fidelity to distinct migratory routes. Particularly within North America, waterfowl management units have been delineated according to distinct longitudinal migratory flyways supported by banding data and other direct evidence. The greater white‐fronted goose (Anser albifrons) is a migratory waterfowl species with a largely circumpolar distribution consisting of up to six subspecies roughly corresponding to phenotypic variation. We examined the rangewide population genetic structure of greater white‐fronted geese using mtDNA control region sequence data and microsatellite loci from 23 locales across North America and Eurasia. We found significant differentiation in mtDNA between sampling locales with flyway delineation explaining a significant portion of the observed genetic variation (~12%). This is concordant with band recovery data which shows little interflyway or intercontinental movements. However, microsatellite loci revealed little genetic structure suggesting a panmictic population across most of the Arctic. As with many high‐latitude species, Beringia appears to have played a role in the diversification of this species. A common Beringian origin of North America and Asian populations and a recent divergence could at least partly explain the general lack of structure at nuclear markers. Further, our results do not provide strong support for the various taxonomic proposals for this species except for supporting the distinctness of two isolated breeding populations within Cook Inlet, Alaska (A. a. elgasi) and Greenland (A. a. flavirostris), consistent with their subspecies status.     

Genetic structure among greater white‐fronted goose populations of the Pacific Flyway

An understanding of the genetic structure of populations in the wild is essential for long‐term conservation and stewardship in the face of environmental change. Knowledge of the present‐day distribution of genetic lineages (phylogeography) of a species is especially important for organisms that are exploited or utilize habitats that may be jeopardized by human intervention, including climate change. Here, we describe mitochondrial (mtDNA) and nuclear genetic (microsatellite) diversity among three populations of a migratory bird, the greater white‐fronted goose (Anser albifrons), which breeds discontinuously in western and southwestern Alaska and winters in the Pacific Flyway of North America. Significant genetic structure was evident at both marker types. All three populations were differentiated for mtDNA, whereas microsatellite analysis only differentiated geese from the Cook Inlet Basin. In sexual reproducing species, nonrandom mate selection, when occurring in concert with fine‐scale resource partitioning, can lead to phenotypic and genetic divergence as we observed in our study. If mate selection does not occur at the time of reproduction, which is not uncommon in long‐lived organisms, then mechanisms influencing the true availability of potential mates may be obscured, and the degree of genetic and phenotypic diversity may appear incongruous with presumed patterns of gene flow. Previous investigations revealed population‐specific behavioral, temporal, and spatial mechanisms that likely influence the amount of gene flow measured among greater white‐fronted goose populations. The degree of observed genetic structuring aligns well with our current understanding of population differences pertaining to seasonal movements, social structure, pairing behavior, and resource partitioning.     

Central European Greylag Geese Anser anser show a shortening of migration distance and earlier spring arrival over 60 years

Global climate change can cause pronounced changes in species? migratory behaviour. Numerous recent studies have demonstrated climate‐driven changes in migration distance and spring arrival date in waterbirds, but detailed studies based on long‐term records of individual recapture or re‐sighting events are scarce. Using re‐sighting data from 430 marked individuals spanning a 60‐year period (winters 1956/1957 to 2015/2016), we assessed patterns in migration distance and spring arrival date, wintering‐site fidelity and survival in the increasing central European breeding population of Greylag Geese Anser anser. We demonstrate a long‐term decrease in migration distance, changes in the wintering range caused by winter partial short‐stopping, and the earlier arrival of geese on their breeding grounds. Greylag Geese marked on central Europe moulting grounds have not been recorded wintering in Spain since 1986 or in Tunisia and Algeria since 2004. The migration distance and spring arrival of geese indicated an effect of temperature at the breeding site and values of the NAO index. Greylag Geese migrate shorter distances and arrive earlier in milder winters. We suggest that shifts in the migratory behaviour of Central European Greylag Geese are individual temperature‐dependent decisions to take advantage of wintering grounds becoming more favourable closer to their breeding grounds, allowing birds to acquire breeding territories earlier.     

Effects of agricultural change on abundance, fitness components and distribution of two arctic-nesting goose populations

Intensification of agriculture since the 1950s has enhanced the availability, competitive ability, crude protein content, digestibility and extended growing seasons of forage grasses. Spilled cereal grain also provides a rich food source in autumn and in winter. Long‐distance migratory herbivorous geese have rapidly exploited these feeding opportunities and most species have shown expansions in range and population size in the last 50 years. Results of long‐term studies are presented from two Arctic‐breeding populations, the Svalbard pink‐footed goose and the Greenland white‐fronted goose (GWFG). GWFGs have shown major habitat shifts since the 1950s from winter use of plant storage organs in natural wetlands to feeding on intensively managed farmland. Declines in local density on, and abandonment of, unmodified traditional wintering habitat and increased reproductive success among those birds wintering on farmland suggest that density‐dependent processes were not the cause of the shift in this winter‐site‐faithful population. Based on enhanced nutrient and energy intake rates, we argue that observed shifts in both species from traditionally used natural habitats to intensively managed farmland on spring staging and wintering areas have not necessarily been the result of habitat destruction. Increased food intake rates and potential demographic benefits resulting from shifts to highly profitable foraging opportunities on increasingly intensively managed farmland, more likely explain increases in goose numbers in these populations. The geographically exploratory behaviour of subdominant individuals enables the discovery and exploitation of new winter feeding opportunities and hence range expansion. Recent destruction of traditional habitats and declines in farming at northern latitudes present fresh challenges to the well being of both populations. More urgently, Canada geese colonizing breeding and moulting habitats of white‐fronted geese in Greenland are further affecting their reproductive output.     

安徽沿江浅水湖泊越冬水鸟群落的集团结构

长江中下游湖泊是越冬水鸟的重要栖息地,随着湖泊渔业养殖强度的不断加大,湖泊湿地严重退化,水鸟的越冬生态受到影响。为揭示长江中下游浅水湖泊越冬水鸟对湿地资源的利用特征,2008年12月至2009年3月,通过扫描取样法采集安徽省长江沿江升金湖、菜子湖和武昌湖3个浅水湖泊30种越冬水鸟的取食行为百分比数据,利用聚类分析法对越冬水鸟进行集团划分,并采用无倾向对应法(DCA)分析越冬水鸟的取食特征。聚类分析结果表明,安庆沿江湖泊越冬水鸟群落可分为4个集团,即深水取食集团G1、挖掘和啄取集团G2、浅水取食集团G3和泥滩拾取集团G4。G2集团的鸟种最多,共有13种,优势种为鸿雁(Anser cygnoides)、豆雁(Anser fabalis);G3集团次之,共6种,优势种为小天鹅(Cygnus columbianus)、白琵鹭(Platalea leucorodia);G4集团共5种,优势种为黑腹滨鹬(Calidris alpina)、鹤鹬(Tringa erythropus)和红脚鹬(Tringa totanus);G1集团水鸟种类有6种。这些水鸟的觅食生境主要在湖泊滩涂和浅水区域,其食物资源的可利用性和觅食对策共同决定群落组成结构。DCA分析表明,取食方式及取食时运动方式组成的觅食对策决定了集团食物资源的分割,草滩中取食鸟类主要采用静止取食和啄取方式,泥滩取食集团主要采取拾取及奔-停取食,深水区取食集团则主要采用潜水方式取食,因此,维持湖泊不同区域的丰富食物资源对于保护湖泊丰富的水鸟资源具有重要意义。     

Internal transport of alien and native plants by geese and ducks: an experimental study

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极端洪水作用下升金湖消落带生境变化对越冬水鸟群落结构的影响

水鸟是湿地生境质量的重要指示性动物类群,可敏感地反映湿地环境变化。浅水通江湖泊消落带具有复杂多样的生境和丰富的食物资源,是水鸟特别是越冬水鸟的重要聚集区,其食物资源的丰富度和可获得性受水文节律影响。在极端洪水作用下,消落带生境变化对越冬水鸟群落结构及其多样性的影响是一个值得关注的水鸟及湿地生态学问题。选择了具有典型消落带生境的升金湖作为研究区域,对2019年(正常水位)和2020年(异常水位)两个越冬季水鸟的数量、种类进行调查统计,分析了消落带的生境变化情况对越冬水鸟群落结构的影响。2019年越冬期,记录到水鸟(50984.20±9595.71)只(n=5),隶属7目13科51种;2020年越冬期,记录到水鸟(27923.00±13808.47)只(n=5),隶属7目12科53种。整个越冬季消落带的水鸟种类略增但数量减少,2019年游禽中的优势种为豆雁,2020年游禽中的优势种增加为豆雁和斑嘴鸭,但涉禽中的优势种由白琵鹭、反嘴鹬、凤头麦鸡转变为苍鹭、大白鹭和反嘴鹬。洪水导致的草滩-水域混合区生境面积减小使湿生植物退化,可能是导致以豆雁为主的食苔草水鸟数量大幅度减少的重要原因;因湖水延迟...     

Foraging Patch Selection and Departure by Non-Omniscient Foragers: A Field Example in White-Fronted Geese

Animals often face great uncertainty as to the quality of foraging patches. There have been a number of theoretical studies investigating how non‐omniscient predators, i.e. predators that are unable to assess foraging patch quality prior to patch exploitation, should forage in a heterogeneous environment, but empirical studies, especially in the field, are scarce. This paper describes the way in which white‐fronted geese Anser albifrons forage on harvest remains of rice, focusing on the processes of patch selection and departure. Not only in autumn, but also in spring when rice depletion has progressed, patch rice density showed no positive effect on patch selection by geese, indicating the incapability of geese to select the most profitable patch. Instead, the geese tended to select patches with a large proportion of rice fields that were near the roost and a previously visited patch and bordered by a small number of windbreaks only. The rice consumption volume by geese increased with increasing initial rice density, while giving‐up density was independent of initial rice density and was positively correlated to the mean rice density of the habitat. This suggests that the geese could compensate their lack of information on patch quality at the moment of patch selection by leaving less profitable patches earlier. We discuss the necessity of predictive models based on random patch selection and an appropriate departure rule to explain the distribution of individuals of species with limited information on patch quality.     

A preliminary analysis of the diet composition of overwintering Bean geese (Anser fabalis) and greater white-fronted geese (A. albifrons) in Korea using PCR on fecal samples

Bean geese (Anser fabalis) and Greater white-fronted geese (Anser albifrons) are the dominant wintering waterfowl in South Korea. Although they are commonly observed in estuaries and rice fields during the winter, the diet composition of the geese during the winter has rarely been studied. In this study, we provide the results from preliminary analyses on the diet of these two geese species overwintering in Daebu Island of South Korea. We used a total of 13 fecal samples from Bean geese (n?=?4) and Greater white-fronted geese (n?=?9), and performed a BLAST search for the sequences obtained from 87 clones (n?=?36 for Bean geese and n?=?51 for Greater white-fronted geese). The diet of Bean geese consisted of five families of plants: Caryophyllaceae (75.0%), Poaceae (13.9%), Asteraceae (5.5%), Polygonaceae (2.8%) and Cucurbitacea (2.8%). On the other hand, the diet of Greater white-fronted geese consisted of 6 families of plants: Poaceae (74.5%), Caryophyllaceae (9.8%), Solanacea (5.9%), Portulacaceae (3.9%), Lamiaceae (3.9%) and Brassicaceae (2.0%). We found that plants of the rice family (Poaceae) are important in the diet of wintering geese, especially for Greater white-fronted geese. This knowledge can be used to establish conservation strategies of the geese overwintering in South Korea.     

鄱阳湖越冬雁类食源植被适宜取食时间窗口

雁类是长江中下游越冬水鸟的优势种群,以苔草(Carex spp)等湿生植被为主要食物来源。作为长江中下游仅存的通江湖泊之一,鄱阳湖显著受到水文波动的影响,湿地植被的生长发育与洲滩淹没和出露时间密切相关。雁类对食物资源具有高度的选择性,建立雁类取食植被的特征和苔草生长过程之间的关系,是刻画适宜栖息地时空分布范围,开展雁类及其食物资源保育的关键。选择鄱阳湖典型子湖泊常湖池作为研究区,对苔草春季生长期开展了原位观测试验,对4个高程梯度的苔草株高和生物量等关键生长因子进行了12次野外监测和采样。同时,结合遥感影像、气温数据及实地观测记录,确定了4个高程梯度洲滩的出露时间和苔草有效生长时间。在此基础上,建立了基于Logistic方程的苔草株高和生物量的生长过程曲线。并根据实地观测的雁类觅食苔草的特征,反推得到雁类适宜取食苔草的时间窗口。结果表明:苔草株高与地上生物量显著正相关,水文条件和气温是影响苔草生长的关键因素,而退水时间的推迟,会导致生长期缩短和低温限制下的有效生长时间减少,影响雁类食物资源的分布。苔草在秋季生长期出露达到12—28 d,而在春季生长期出露达到83—182 d时适宜雁类取食。研究提出了确定越冬雁类苔草适宜取食时间窗口的方法,证实洲滩退水时间推迟超过20 d,苔草生长节律将难以匹配雁类数量峰值期觅食的需要。本研究对鄱阳湖湿地水文调控和湿地资源管理具有重要意义。     

No evidence for sex bias in winter inter‐site movements in an Arctic‐nesting goose population

Understanding movement of individuals between sites is necessary to quantify emigration and immigration, yet previous analyses exploring sex biases in site fidelity among birds have not evaluated remigration (the return of marked birds that moved to alternative areas from the site at which they were marked). Using novel Bayesian multistate models, we tested whether between‐winter emigration, remigration and survival rates were sex‐biased among 851 Greenland White‐fronted Geese Anser albifrons flavirostris marked at Wexford, Ireland. We found no evidence for sex biases in emigration, remigration or survival. Thus, sex biases in winter site fidelity do not occur in any form in this population; these techniques for modelling sex‐biased movement will be useful for a better understanding of site fidelity and connectivity in other marked animal populations.     

Relationship between wild greylag and European domestic geese based on mitochondrial DNA

The origins of the European domestic goose are uncertain. The available information comes from archaeological findings and historical literature, but genetic evidence has hitherto been scarce. The domestic goose in Europe is derived from the greylag goose (Anser anser), but it is not known where the initial domestication took place and which of the two subspecies of greylag goose was ancestral. We aimed to determine the amount and geographical distribution of genetic diversity in modern populations of greylag geese as well as in different breeds of the domestic goose to make inferences about goose domestication. We studied DNA sequence variation in the mitochondrial control region of greylag geese from multiple populations across Europe and western Asia as well as specimens of domestic geese representing 18 modern breeds and individuals not belonging to any recognised breed. Our results show notable differences in genetic diversity between different greylag goose populations and the presence of six mitochondrial haplogroups which show a degree of geographical partitioning. The genetic diversity of the domestic goose is low, with 84% of sampled individuals having one of two major closely related haplotypes, suggesting that modern European domestic geese may derive from a narrow genetic base. The site of domestication remains unresolved, but domestic geese in Turkey were unusually diverse, indicating the importance of further sampling in the vicinity of the eastern Mediterranean and the Near East. There appears to be past or ongoing hybridisation between greylags and domestic geese in particular areas, consistent with field observations.     

Close relatedness between mitochondrial DNA from seven Anser goose species

The phylogenetic relationships of seven goose species and two of the subspecies representing the genus Anser were studied by approximately 1180 bp of mitochondrial DNA tRNAglu, control region and tRNAphe sequences. Despite obvious morphological and behavioural affinities among the species, their evolutionary relationships have not been studied previously. The small amount of genetic differentiation observed in the mitochondrial DNA indicates an extremely close evolutionary relationship between the Anser species. The sequence divergences between the species (0.9–5.5%) are among the lowest reported for avian species with speciation events of Anser geese dating to late Pliocene and Pleistocene. The species grouped into four mtDNA lineages: (1) snow and Ross’ goose, (2) greylag goose, (3) white‐fronted goose, and (4) bean, pink‐footed and lesser white‐fronted goose. The phylogenetic relationships of the most closely related species, bean, pink‐footed and lesser white‐fronted goose, indicate a period of rapid cladogenesis. The poor agreement between morphological relationships and the phylogenetic relationships indicated by mtDNA sequences implies that either ancestral polymorphism and lineage sorting, hybridization and introgression or convergent evolution has been involved.     

Evaluating behavioral responses of nesting lesser snow geese to unmanned aircraft surveys

Unmanned aircraft systems (UAS) are relatively new technologies gaining popularity among wildlife biologists. As with any new tool in wildlife science, operating protocols must be developed through rigorous protocol testing. Few studies have been conducted that quantify the impacts UAS may have on unhabituated individuals in the wild using standard aerial survey protocols. We evaluated impacts of unmanned surveys by measuring UAS‐induced behavioral responses during the nesting phase of lesser snow geese (Anser caerulescens caerulescens) in Wapusk National Park, Manitoba, Canada. We conducted surveys with a fixed‐wing Trimble UX5 and monitored behavioral changes via discreet surveillance cameras at 25 nests. Days with UAS surveys resulted in decreased resting and increased nest maintenance, low scanning, high scanning, head‐cocking and off‐nest behaviors when compared to days without UAS surveys. In the group of birds flown over, head‐cocking for overhead vigilance was rarely seen prior to launch or after landing (mean estimates 0.03% and 0.02%, respectively) but increased to 0.56% of the time when the aircraft was flying overhead suggesting that birds were able to detect the aircraft during flight. Neither UAS survey altitude nor launch distance alone in this study was strong predictors of nesting behaviors, although our flight altitudes (≥75 m above ground level) were much higher than previously published behavioral studies. Synthesis and applications: The diversity of UAS models makes generalizations on behavioral impacts difficult, and we caution that researchers should design UAS studies with knowledge that some minimal disturbance is likely to occur. We recommend flight designs take potential behavioral impacts into account by increasing survey altitude where data quality requirements permit. Such flight designs should consider a priori knowledge of focal species’ behavioral characteristics. Research is needed to determine whether any such disturbance is a result of visual or auditory stimuli.     

Spring snow goose hunting influences body composition of waterfowl staging in Nebraska

A spring hunt was instituted in North America to reduce abundance of snow geese (Chen caerulescens) by increasing mortality of adults directly, yet disturbance from hunting activities can indirectly influence body condition and ultimately, reproductive success. We estimated effects of hunting disturbance by comparing body composition of snow geese and non-target species, greater white-fronted geese (Anser albifrons) and northern pintails (Anas acuta) collected in portions of south-central Nebraska that were open (eastern Rainwater Basin, ERB) and closed (western Rainwater Basin, WRB; and central Platte River Valley, CPRV) to snow goose hunting during springs 1998 and 1999. Lipid content of 170 snow geese was 25% (57 g) less in areas open to hunting compared to areas closed during hunting season but similar in all areas after hunting was concluded in the ERB. Protein content of snow geese was 3% (14 g) less in the region open to hunting. Greater white-fronted geese had 24% (76 g; n = 129) less lipids in the hunted portion of the study area during hunting season, and this difference persisted after conclusion of hunting season. We found little difference in lipid or protein content of northern pintails in relation to spring hunting. Indirect effects of spring hunting may be considered a collateral benefit regarding efforts to reduce overabundant snow goose populations. Disrupted nutrient storage observed in greater white-fronted geese represents an unintended consequence of spring hunting that has potential to adversely affect reproduction for this and other species of waterbirds staging in the region. © 2012 The Wildlife Society.     

Food constraints explain the restricted distribution of wintering Lesser White‐fronted Geese Anser erythropus in China

More than 90% of the Lesser White‐fronted Geese Anser erythropus in the Eastern Palearctic flyway population winter at East Dongting Lake, China. To explain this restricted distribution and to understand better the winter feeding ecology and habitat requirements of this poorly known species, we assessed their food availability, diet and energy budgets at this site through two winters. Lesser White‐fronted Geese maintained a positive energy budget when feeding on above‐ground green production of Eleocharis and Alopecurus in recessional grasslands in autumn and spring to accumulate fat stores. Such food was severely depleted by late November and showed no growth in mid‐winter. Geese fed on more extensive old‐growth Carex sedge meadows in mid‐winter where they were in energy deficit and depleted endogenous fat stores. Geese failed to accumulate autumn fat stores in one year when high water levels prevented the Geese from using recessional grassland feeding areas. Fat stores remained lower throughout that winter and Geese left for breeding areas later in spring than in the previous year, perhaps reflecting the need to gain threshold fat stores for migration. Sedge meadows are widespread at other Yangtze River floodplain wetlands, but recessional grasslands are rare and perhaps restricted to parts of East Dongting Lake, which would explain the highly localized distribution of Lesser White‐fronted Geese in China and their heavy use of these habitats at this site. Sympathetic management of water tables is essential to maintain the recessional grasslands in the best condition for Geese. Regular depletion of fat stores whilst grazing sedge meadows in mid‐winter also underlines the need to protect the species from unnecessary anthropogenic disturbances that enhance energy expenditure. The specialized diet of the Lesser White‐fronted Goose may explain its highly restricted winter distribution and global rarity.     

Optimising hydrological conditions to sustain wintering waterbird populations in Poyang Lake National Natural Reserve: implications for dam operations

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