Shallow sub-lakes are essential for sustaining the successful wintering of waterbirds in Poyang Lake,China

For migratory waterbirds,the quality of wintering habitat is related to spring migration and successful breeding in the next year.The availability of food resources in the habitat is critical and varies within water levels.Although the water-level fluctuations in Poyang Lake have been extremely variable interannually in recent years,the wintering waterbird populations have remained relatively stable.Hence,the mechanism of maintaining the stability is worth exploring.This study aimed to compare the distribution of vegetation and herbivorous wa-terbirds in 2015-2016 and 2016-2017,focusing on three shallow sub-lakes and one main lake are.The results showed that the emergence of tubers and the growth of Carex spp.provided a continuous food supply and habitat for wintering waterbirds with a gradual decline in the water level.Shallow sub-lakes supported almost all of the tuber-eating waterbirds(1.42-1.62×10^(5))and most geese(1.34-1.53×10^(6)).However,the main lake area,covered with Persicaria hydropiper,did not provide adequate and accessible food.This resulted in almost no distribution of tuber-eating waterbirds,with only a few geese congregating in early winter.Our results demonstrated that the shallow sub-lakes under human control provided a different environment from the main lake and are key to sustaining the successful wintering of hundreds of thousands of migratory waterbirds in Poyang Lake.Therefore,we recommend refining the anthropogenic management of the shallow sub-lakes to regulate the water level to ensure the carrying capacity of Poyang Lake.

River width and depth as key factors of diurnal activity energy expenditure allocation for wintering Spot-billed Ducks in the Xin'an River Basin

Rivers are important habitats for wintering waterbirds.However,they are easily influenced by natural and human activities.An important approach for waterbirds to adapt to habitats is adjusting the activity time and energy expenditure allocation of diurnal behavior.The compensatory foraging hypothesis predicts that increased energy expenditure leads to longer foraging time,which in turn increases food intake and helps maintain a constant energy balance.However,it is unclear whether human-disturbed habitats result in increased energy expenditure related to safety or foraging.In this study,the scan sample method was used to observe the diurnal behavior of the wintering Spot-billed Duck(Anas poecilorhyncha) in two rivers in the Xin’an River Basin from October 2021 to March 2022.The allocation of time and energy expenditure for activity in both normal and disturbed environments was calculated.The results showed that foraging accounted for the highest percentage of time and energy expenditure.Additionally,foraging decreased in the disturbed environment than that in the normal environment.Resting behavior showed the opposite trend,while other behaviors were similar in both environments.The total diurnal energy expenditure of ducks in the disturbed environment was greater than that in the normal environment,with decreased foraging and resting time percentage and increased behaviors related to immediate safety(swimming and alert) and comfort.These results oppose the compensatory foraging hypothesis in favor of increased security.The optimal diurnal energy expenditure model included river width and water depth,which had a positive relationship;an increase in either of these two factors resulted in an increase in energy expenditure.This study provides a better understanding of energy allocation strategies underlying the superficial time allocation of wintering waterbirds according to environmental conditions.Exploring these changes can help understand the maximum fitness of wintering waterbirds in response to nature and human influences.

Seasonal dynamics of wintering waterbirds in two shallow lakes along Yangtze River in Anhui Province

The shallow lake wetlands in the middle and lower Yangtze River floodplain are important wintering and stopover habitats for migratory waterbirds on the East Asia-Australia Flyway.With increasing fishery practices in recent years,however,the wetlands have deteriorated significantly and now threaten wintering waterbirds.To gain insight into the influence of deteriorating wetlands on waterbirds,we conducted a survey of wintering waterbird species,population size,and distribution across 11 belt transects in Caizi Lake and Shengjin Lake,two shallow lakes along the Yangtze River in Anhui Province from November 2007-April 2008 and from November 2008-April 2009,respectively.The impacts of different fishery patterns on the distribution of waterbirds were also analyzed.A total of 43 waterbirds species belong to 7 orders of 12 families were counted during the surveys,of which 38 were found in Caizi Lake with a density of 8.2 ind./hm2,and 42 in Shengjin Lake with a density of 3.5 ind./hm2.Geese（Anser cygnoides）,bean geese（Anser fabalis）,tundra swan（Cygnus columbianus）,and dunlin（Calidris alpina） were the dominant species in the two shallow lakes.Species number and individual assemble reached maximum at the end of December and in early January of the following year,without coincidence of the largest flock for different ecological groups.Based on waterbird diversity across the 11 belt transects and the fishery patterns,habitats could be divided into three groups.Gruiformes,Anseriformes and Charadriiformes had relatively higher densities in the natural fishery zones and lower densities in the cage fishery zones;whereas,the density of Ardeidae showed little change across all lake zones.It is important to develop sustainable fishery patterns in shallow lakes along the middle and lower Yangtze River floodplain to better protect resources of wintering waterbirds.

Habitat utilization and resource partitioning of wintering Hooded Cranes and three goose species at Shengjin Lake

The loss and degradation of wetlands have adversely affected waterbirds, which depend on wetland habitats. Interspecific competition has an important effect on habitat utilization of wintering waterbirds. Resource utilization, including partitioning, in degraded wetlands has become a hot issue in ecological studies of wintering waterbirds. In order to have an insight into the habitat utilization and resource partitioning between a Hooded Crane(Grus monacha) population and the guild of three goose species, i.e., Anser fabalis, A. albifrons and A. erythropus wintering in lake wetlands, we carried out a study at Shengjin Lake National Nature Reserve from November 2011 to April 2012. We surveyed the Hooded Cranes and goose guild foraging in various habitats during the wintering periods with a combined method of fixed route searching and fixed site observations. Resource partitioning was studied by means of calculating habitat utilization rates and the width and overlap of spatial niches. The results showed that the habitat utilization rate and the width of spatial niches of the Hooded Crane population and goose guild shifted with the season. The habitat utilization rates of the cranes in grasslands were high at all three wintering stages. The habitat utilization rates were 0.454, 0.435 and 0.959 respectively for the Hooded Cranes and 0.627, 0.491 and 0.616 for the goose guild. This suggests that the overlap in grasslands was higher between cranes and goose guild. Most habitats were accessible at the middle stage, so the width of the spatial niche of the cranes(1.099) and goose guild(1.133) both reached their peak at this stage. The greatest niche overlap was 0.914 for these two groups at the late stage, followed by 0.906 at the middle stage and the smallest was 0.854 at the early stage. Ecological response to the changes in habitats of wintering waterbirds was clearly shown in the dynamic variations of the niche of both the Hooded Cranes and the three goose species. Coexistence among waterbirds was achieved by regulation of niche width to reduce niche overlap and relieve interspecific resource partitioning.

Wintering ecology of the Black Stork (Ciconia nigra) in Beijing

The Black Stork (Ciconia nigra) is a new winter resident in Beijing due to temperature changes.To understand the wintering ecology of this species better, a field survey covering the number of birds of this population, habitat selection, feeding activity and grouping behavior was conducted at the Shidu Nature Reserve from January 2004 to March 2009. The results show that the Black Stork selected the Juma River at this nature reserve as their new winter habitat. The number of birds in this population decreased from 28 in the 2004/2005 winter to 17 in the 2007/2008 winter with a subsequent recovery to 23 the following year. The wintering flock was formed in mid-November and dispersed in mid-March, but the date changed with seasonal temperature fluctuations. The storks exhibited feeding habitat fidelity and the main food type was fish (＞ 92.4%). There was no significant variation in food composition between adults and sub-adults (Mann-Whitney U test, U = 1.00, p = 0.44). Feeding activity occurred in the morning and at noon during early winter, but concentrated in the afternoon during mid winter, divided into dawn and dusk in late winter. Daily fish intake was 538 g for adults and 449 g for sub-adults if the period of foraging reached six hours in the wild, which was similar to the level under artificial feeding. Agonistic behavior among feeding birds was observed among group members in late winter. The main negative factor for wintering Black Stork was a reduced feeding habitat resulting from increased water depth due to damming of the river to benefit tourism and to wetland exploitation.

Effect of Water Level Fluctuations on Wintering Goose Abundance in Poyang Lake Wetlands of China

The Poyang Lake is a Ramsar site and is the important over-wintering site for migratory waterbirds along the East Asian-Australasian Fly way. Examining the effects of water level fluctuations on waterbird abundance and analyzing the influencing mechanism is critical to waterbird protection in the context of hydrological alteration. In this study, the effect of water level regime on wintering goose abundance was examined and the influencing mechanism was interpreted. Synchronous waterbirds survey data, hydro- logical data, Moderate Resolution Imaging Spectroradiometer-Normalized Difference Vegetation Index （MODIS-NDVI） data and habi- tat data derived from Landsat TNUETM data and HJ/CCD data were combined. The satellite-derived Green Wave Index （GWI） based on MODIS-NDVI dataset was applied to detect changes in goose food resources. It was found that habitat size and vegetation conditions are key factors determining goose abundance. Geese numbers were positively correlated with habitat area, while intermediate range of vegetation productivity might benefit the goose abundance. Water level affects goose abundance by changing available habitat areas and vegetation conditions. We suggested that matching hydrological regime and exposed meadows time to wintering geese dynamics was crucial in the Poyang Lake wetlands. Our study could provide sound scientific information for hydrological management in the context of waterbird conservation.

Effects of variation in food resources on foraging habitat use by wintering Hooded Cranes(Grus monacha)

Background:The ideal habitat use of waterbirds can be considered to be fixed,but current habitat use depends on environmental conditions,especially those of food characteristics,considered crucial to their use of habitats.Understanding how waterbirds respond to variation in food availability at degraded wetland sites and change their habitat use patterns over spatial and temporal scales should direct future conservation planning.The objectives of this study were to identify these spatial-temporal foraging habitat use patterns of Hooded Cranes(Grus monacha)and their relationship with food characteristics in the severely degraded wetlands of the Shengjin and Caizi lakes along with the Yangtze River floodplain.Methods:We investigated the changes in food characteristics,relative abundance and density of Hooded Cranes in various habitat types across three winter periods from November 2012 to April 2013.We examined the effect of these winter periods and habitat types on the pattern of use by the cranes and explored the relationship between these patterns and food characteristics using linear regression.Results:The food characteristics and habitat use clearly changed over spatial-temporal scales.In the early and mid-winter periods,the most abundant,accessible and frequented food resources were found in paddy fields,while in the late period the more abundant food were available in meadows,which then replaced the paddy fields.There were fewer effects of winter periods,habitat types and their interactions on habitat use patterns except for the effect of habitat types on the relative abundance,determined as a function of food abundance,but independent of food depth and sediment permeability.Conclusions:In response to the degradation and loss of lake wetlands,the cranes shifted their habitat use patterns by making tradeoffs between food abundance and accessibility over spatial-temporal scales that facilitated their survival in the mosaic of these lake wetlands.

Contribution of citizen science towards cryptic species census： “many eyes” define wintering range of the Scaly-sided Merganser in China's Mainland

Background: Citizen science has tremendous potential in advancing scientific knowledge and improving natural resource management.To detect the wintering distribution of the endangered species Scaly-sided Merganser(Mergus squamatus), national wintering surveys were organized by China Birdwatching Association.Methods: The surveys of M.squamatus were conducted in three successive winters from 2014 to 2016.A total of 2019 people from 102 organizations participated in the surveys.With three groups of 13 environmental variables, species distribution model for its wintering distribution of each year was developed using random forest.Schoener's D index was used to compare the distribution of M.squamatus in 3 years.Results: Totally, 441, 634 and 1138 individuals of M.squamatus were recorded in 2014, 2015 and 2016 respectively.Two main sites in Dabie Mountain and East Qinling mountains were verified and the wintering range of M.squamatus was defined.The wintering range was found to be highly identical for the 3 years.Conclusions: The highly overlapped distribution range among years suggested that the wintering range of M.squamatus was relatively stable.Well organized and coordinated citizen science can be used to define distribution range and improve species conservation.

Autumn migration routes and wintering areas of juvenile Chinese Egrets(Egretta eulophotes)revealed by GPS tracking

Background:The vulnerable Chinese Egret(Egretta eulophotes)is a long-distance migratory waterbird whose migration and wintering information is poorly understood.This study aims to identify the autumn migration routes and wintering areas of juvenile Chinese Egrets and determine the migration movement traits of this species.Methods:Thirty-nine juvenile Chinese Egrets from the Fantuozi Island,an uninhabited offshore island with a large breeding colony of Chinese Egrets in Dalian,China,were tracked using GPS/GSM transmitters.Some feathers from each tracked juvenile were collected for molecular identification of sex in the laboratory.The GPS locations,recorded at 2-h intervals from August 2018 to May 2020,were used for the analyses.Results:Of the 39 tracked juveniles,30 individuals began their migration between September and November,and 13 successfully completed their autumn migration between October and November.The juveniles migrated southward via three migration routes,coastal,oceanic and inland,mainly during the night.The migration duration,migration distance,flight speed,and stopover duration of the 13 juvenile egrets that completed migration averaged 5.08±1.04 days,3928.18±414.27 km,57.27±5.73 km/h,and 23.08±19.28 h,respectively.These juveniles wintered in the coastal wetlands of Southeast Asia including those in the Philippines,Vietnam,and Malaysia,and only one successfully began its spring migration in June 2020.Conclusions:This study newly finds that the oceanic route taken by juvenile Chinese Egrets,suggesting that the juveniles are able to fly over the Pacific Ocean without a stopover.Moreover,our novel data indicate that coastal wetlands along the East Asian-Australasian Flyway are important areas for both autumn migration stopover and the wintering of these juveniles,suggesting that international cooperation is important to conserve the vulnerable Chinese Egret and the wetland habitats on which it depends.

Temporal-spatial patterns of intestinal parasites of the Hooded Crane(Grus monacha) wintering in lakes of the middle and lower Yangtze River floodplain

Background: Parasites have adverse effects on the life and survival of many migratory waterbirds, especially birds on the endangered species list. Hooded Cranes are large migratory colonial waterbirds wintering in wetlands,which are prone to parasite infection, thus monitoring the diversity of parasites is important for sound wetland management and protection of this species.Methods: From November 2012 to April 2013, we collected 821 fresh faecal samples from the three lakes(Poyang,Caizi and Shengjin Lake) in the lower and middle Yangtze River floodplain, and detected with saturated brine floating and centrifugal sedimentation methods. Parasite eggs were quantified with a modified Mc Master's counting method.Results: In this study, 11 species of parasites were discovered, i.e., two coccidium(Eimeria gruis, E. reichenowi), five nematodes(Capillaria sp., Strongyloides sp., Ascaridia sp., Trichostrongylus sp., Ancylostomatidae), three trematodes(Echinostoma sp., Echinochasmus sp., Fasciolopsis sp.) and one cestode(Hymenolepis sp.). About 57.7% of the faecal samples showed parasitic infection. All species of parasites were found at the three sites except Hymenolepis which was not found at Poyang Lake. While most samples were affected by only one or two species of parasites, infection by Eimeria spp. was the most common(53.1%). From One-Way ANOVA analysis of the three lakes, parasite species richness index(p = 0.656), diversity index(p = 0.598) and evenness index(p = 0.612) showed no significant difference. According to the statistical analysis of our data, there were no significant difference in parasite species richness index(p = 0.678) and evenness index(p = 0.238) between wintering periods, but a strong difference in diversity index(p < 0.05).Conclusions: Our study suggests that in the wintering Hooded Crane populations, parasite diversity is more sensitive to changes in the overwintering periods than to locations. This also indicates that with the limitations of migration distance, the parasites may not form the differentiation in Hooded Crane populations of the three lakes.

Number and distribution of cranes wintering at Poyang Lake,China during 2011-2012

Poyang Lake is a very important wintering place for cranes in China and East Asia.Two crane surveys were conducted at Poyang Lake during the 2011/2012 winter,the first on 18-19 December 2011 and the second on 18-19 February 2012.The survey covered the entire Poyang Lake basin,as well as two main lakes in Jiujiang (Saicheng Hu and Chi Hu),i.e.,a total of 85 sub-lakes were surveyed.Both surveys recorded four species of cranes.The first survey on 18-19 December 2011 recorded 4577 Siberian Cranes (Grus leucogeranus),mostly in Bang Hu,Sha Hu and Dahu Chi,302 Hooded Cranes (G.monacha),885 White-naped Cranes (G.vipio) and 8408 Eurasian Cranes (G.grus),for the most part in the center of the lake basin.The second survey on 18-19 February 2012 recorded 3335 Siberian Cranes (mostly in Poyang Lake National Nature Reserve (PLNR) and its surrounding areas),110 Hooded Cranes (largely in PLNR and its surrounding areas),283 White-naped Cranes (86％ in Bang Hu) and 2205 Eurasian Cranes (particularly in Duchang and Nanjishan NNR).The number of Siberian Cranes enumerated in December was 1000 more than the second count in February 2012.It is not possible to rule out double counting due to the close proximity of the main sites of the Siberian Cranes.During winters from 1998 to 2009,the average of the highest counts each winter was 3091,ranging from 2345 in 1996 to 4004 in 2002.By comparison with counts taken at other times,we therefore estimate a wintering population of Siberian Cranes of ～3800-4000 at Poyang Lake.Additional evidence will be needed to raise the world population estimate.Our more recent surveys indicate a continuing decline in the number of White-naped Cranes and an increase in Eurasian Cranes.

Changes in wintering Hooded Cranes and their habitats at Chongming Dongtan over the past 20 years

The Hooded Crane(Grus monacha)is listed as a Vulnerable species in the IUCN red list.Tidal wetland(tideland),the major habitat for wintering Hooded Cranes at East China’s Chongming Dongtan,has dramatically changed in the past two decades,but there is limited knowledge about the population and habitat changes of the Hooded Cranes.This study investigated the population size and distribution of wintering Hooded Cranes at Chongming Dongtan from 2000 to 2021.We used remote sensing images combined with a vegetation classification algorithm to analyse the distribution of saltmarsh vegetation.The quadrat method was used to investigate the density and weight of the underground corms of Sea Bulrush(Scirpus mariquter),the main food on tideland for the Hooded Cranes.From 2000 to 2021,the population number of wintering Hooded Cranes at Chongming Dongtan remained stable at approximately 100.In 2000,the area of Scirpus spp.and Common Reed(Phragmites australis)accounted for approximately half of the total saltmarsh area at Chongming Dongtan,respectively.The invasive Smooth Cordgrass(Spartina alterniflora)rapidly expanded on tideland in the 2000s while the Scirpus spp.was competed out and thus significantly reduced in area.After the implementation of an ecological project to control Smooth Cordgrass and to restore Scirpus spp.in the 2010s,the area of the Smooth Cordgrass decreased considerably while the area of Scirpus spp.increased.The corms of Sea Bulrush decreased on the southeastern tideland during the study period,which might be the cause of the northward movement of the foraging Hooded Cranes on tideland.We also found Hooded Cranes foraged crops in the nearby farmland in mid-winter,causing human-bird conflicts in the recent decade.Our results found that changes in habitat and food conditions on tideland impacted wintering Hooded Cranes.Foraging in farmland with human disturbance in the recent decade might be related to insufficient food on tideland.We suggest active intervention to accelerate the restoration of Sea Bulrush on tideland and reduce human disturbance in farmland to improve the habitat quality of the wintering Hooded Crane at Chongming Dongtan.

Migration and wintering of vulnerable adult Chinese Egrets(Egretta eulophotes)revealed by GPS tracking

Knowledge of migratory bird requirements is critical to developing conservation plans for vulnerable migratory species.This study aimed to determine the migration routes,wintering areas,habitat uses,and mortalities of adult Chinese Egrets(Egretta eulophotata).Sixty adult Chinese Egrets(31 females and 29 males)on an uninhabited offshore breeding island in Dalian,China were tracked using GPS satellite transmitters.GPS locations recorded at2 h intervals from June 2019 to August 2020 were used for analysis.A total of 44 and 17 tracked adults completed their autumn and spring migrations,respectively.Compared with autumn migration,tracked adults displayed more diverse routes,higher number of stopover sites,slower migration speed,and longer migration duration in the spring.Results indicated that migrant birds had different behavioral strategies during the two migratory seasons.The spring migration duration and stopover duration for females were significantly longer than those for males.A positive correlation existed between the spring arrival and spring departure dates,as well as between the spring arrival date and stopover duration.This finding indicated that the egrets that arrived early at the breeding grounds left the wintering areas early and had a shorter stopover duration.Adult birds preferred intertidal wetlands,woodlands,and aquaculture ponds during migration.During the wintering period,adults preferred offshore islands,intertidal wetlands,and aquaculture ponds.Adult Chinese Egrets showed a relatively low survival rate compared with most other common ardeid species.Dead specimens were found in aquaculture ponds,indicating human disturbance as the main cause of death of this vulnerable species.These results highlighted the importance of resolving conflicts between egrets and human-made aquaculture wetlands and protecting intertidal flats and offshore islands in natural wetlands through international cooperation.Our results contributed to the hitherto unknown annual spatiotemporal migration patterns of adult Chinese Egrets,thereby providing an important basis for the conservation of this vulnerable species.

Influences of the Weather and Climate on Wintering Migratory Bird in Dongting Lake

[Objective] The research aimed to study influences of the weather and climate on wintering migratory bird in Dongting Lake. [Method] Bird analysis data provided by East Dongting Lake National Nature Reserve and wintering migratory bird monitoring data in big and small west lakes in recent 5 years were used. By combing water level data and various meteorological factors in Chenglingji, wintering migratory bird in Dongting Lake was analyzed. [Result] Abnormal precipitation led to drought or flood in Dongting Lake, causing significant adverse effect on the birds. Abnormal climate was important reason for that wintering migratory bird greatly reduced, such as high temperature and later going south of the strong cold air. Extreme weather and climate events led that some birds in Dongting Lake significantly reduced. Meteorological element had certain influence to bird survey. We should select a reasonable investigation time based on weather and climate. In Birding Festival, weather had little effect on bird species observation. In the migratory season of bird, we could see many birds in fine cold weather after a strong cold air, which suitable for observing bird. When it was low temperature or less rain in autumn, and was high temperature or more rain and sunshine in early winter, it was suitable for migratory birds wintering in Dongting Lake. Ardea cinerea, Anser fabalis and Anser erythropus were more in sunny days while Phalacrocorax carbo was more in rainy weather. Grus grus was more in heavy wind weather while Recurvirostra avosetta was more in small wind weather. [Conclusion] The research provided scientific basis for studying migratory bird in east Dongting Lake.

Morphometric Characterization of the Grasshopper Sparrow (<i>Ammodramus savannarum</i>) and Baird’s Sparrow (<i>Ammodramus bairdii</i>) during the Wintering Season

Grassland bird populations have declined more than any other group of bird species in North America. Some species such as the grasshopper (Ammodramus savannarum) and Baird’s sparrows (Ammodramus bairdii) are of particular conservation concern, since they have shown negative trends in their population over the last 50 years. Their winter ecology has only begun to be studied recently and information is limited. The purpose of this study is to achieve the morphometric characterization of these two grassland species during the wintering season. The study is conducted in the Rancho Santa Teresa located in Villa Hidalgo, Durango, Mexico and the Ecological reserve “El Uno”, located in Janos, Chihuahua, Mexico. During winter 2013-2014, 135 birds were captured;banded and zoometric measurements were taken such as total body weight, wing chord, tail length, culmen, and beak depth and width. Two indices of body condition (BCI) are also calculated. All measurements and indices are compared per species and per sex. Both species are sexed with molecular techniques, determining 20 females and 18 males for A. bairdii and 41 females and 56 males for A. savannarum. All variables are significant different between species (p < 0.05). Beak measurements are not significantly different when comparing birds of different sexes (same species), with the exception of beak width of A. bairdii (p < 0.05). Male’s weight, wing chord, tail length, as well as one of the body condition indices (BCI2) are significantly higher (p < 0.05) than females’ for both species. BCI1 shows significant differences (p < 0.05) between species and sexes in A. bairdii. The biometric data obtained in this study can be used as reference values wintering populations of both species.

Effects of Meteorological Factors on Overwintering Ability,Yield and Quality of Forage Rape

In order to investigate the effects of meteorological factors on rape overwintering ability,forage yield and quality of rape in the North China plain,Brassia campestris L.and Brassica napus L.were used in this study.The results showed that compared with the B.napus L.varieties,the growth period of B.campestris L.was shortened by 10-15 d,the overwintering rate(WR)increased by 50.6%,and the density after winter(PD)increased by 41.5%.The fresh forage yield(FFY)and dry forage yield(DFY)of the B.campestris L.type significantly increased by 40.9%and 38.1%compared with the B.napus L.type.,respectively,while the forage quality of the B.napus L.type rape was significantly better than that of the B.campestris L.type.Compared with the B.campestris L.type,the crude protein(CP),fat,ash and total fatty acid(TFA)contents of the B.napus L.type of rape increased by 27.6%,42.9%,23.9%and 52.3%,respectively,and the milk productivity(HM),relative forage value(RFV)and relative forage quality(RFQ)increased by 14.0%,16.2%and 42.1%,respectively.The light and heat resources before wintering increased the WR and PD(P<0.05),and were positively correlated with FFY and DFY(P>0.05),and lower temperature during the wintering period led to lower WR(P<0.01).The light and heat resources during the overwintering period and after regreening were negatively correlated with FFY and DFY(P>0.05).The contents of CP,fat and TFA of rape had an extremely significant negative correlation with the temperature and sunshine hours before wintering,but an extremely significant positive correlation with the temperature during the wintering period and after regreening,as well as the sunshine hours and rainfall during the wintering period;and HM had an extremely significant positive correlation with the temperature,sunshine hours and rainfall during the wintering period,while RFV and RFQ were only extremely significantly positively correlated with the maximum temperature and rainfall.In summary,in the North China Plain,for autumn sowing rape,the B.campestris L.type can be selected to improve the wintering rate,and the B.napus L.type should be the main choice to improve the forage quality of rape.Therefore,the B.napus L.variety HYZ62 can be selected for autumn sowing in the North China Plain.

In Search of Identity in Language and Irish Geography：On Seamus Heaney＇s Wintering. Out

Seamus Heaney in his lifespan of 74 years is lauded not only for his great accomplishment in the field of poetry, butalso for his translation, editing and literary criticism. Yet, when it comes to socio-political affairs, the poet is not aunanimous favorite. Far from being an influential political activist sometimes anticipated by his friends andcountrymen in Ireland, Heaney resorted to his search for identities and for answers to his nation＇s predicament inthe world of words. As a poetic collection published during the political unrest in the seventies, Wintering Outdiscloses Heaney＇s composition of the dialectic between the aesthetic and the historical. In this essay, the authorwill look into Heaney＇s four poems in the collection, in which the poet＇s linguistic as well as geographical survey ofhis hometown is indispensible for readers who intend to discern his attitude in the critical period of his artisticformation。

Size matters: wintering ducks stay longer and use fewer habitats on largest Chinese lakes

Background:Evidence suggests that wintering waterbirds have become conspicuously more concentrated at two largest lakes of the Yangtze River Floodplain,East Dong Ting Lake(Hunan Province,29°20′N,113°E)and Poyang Lake(Jiangxi Province,29°N,116°20′E),relative to other lakes,despite the establishment of reserves elsewhere.While this relationship is likely due to greater extent of undisturbed habitats in larger lakes,we understand little of the drivers affecting individual behaviours behind this tendency.Methods:We tracked wintering movements of three duck species(Eurasian Wigeon Mareca penelope,Falcated Duck M.falcata and Northern Pintail Anas acuta)using GPS transmitters,examining differences between the two largest lakes and other smaller lakes in ducks’habitat use,duration of stay at each lake and the daily distances moved by the tagged birds while at these sites.Results:The Eurasian Wigeon and Falcated Duck stayed five times longer and almost exclusively used natural habitat types at the two large lakes(91‒95%of positions)compared to length of stay time at smaller lakes,where they spent 28‒33 days on average(excluding the capture site)and exploited many more different habitats(including c.50%outside lakes).Conclusions:Our study is the first to show that shorter length of stay and more varied habitat use by ducks at small lakes may contribute to explaining the apparent regional concentration of numbers present of these and other species at the largest lakes in recent years.This compares with their declining abundance at smaller lakes,where habitat loss and degradation has been more manifest than on the larger lakes.

Number and distribution of Black-necked Cranes wintering in Zhigatse Prefecture,Tibet

We surveyed all known wintering areas of the Black-necked Crane (Grus nigricollis) in Zhigatse Prefecture of the Tibet Autonomous Region during three winters.Our surveys confirm that Zhigatse Prefecture is the most important wintering area for the species,accounting in some years for as much as 39％ of the estimated world population.Counts ranged from a high of 4240 cranes in January 2007 to a low of 2636 in February 2009.Chick recruitment (chicks/100 cranes) ranged from 8.2 (January 2010) to 11.3 (January 2007).The highest concentration of cranes during all three surveys occurred on the 60 km stretch of the Yarlung Tsangpo (River) between Lhaze and Phuntsoling.To evaluate potential impacts of the Xietongmen Copper Mine,we monitored wintering crane numbers prior to mine installation in an intensive study area located between the Shab Chu Valley and the city of Zhigatse.Our surveys recorded on average 820 ± 83 cranes (SE; n =8) in this area.With the installation of the mine at a location ～50 km west of Zhigatse,increased traffic and development on the north side of the Yarlung River will likely result in a shift in crane distribution away from the north side,to nearby suitable habitats.Based on our survey results,we recommend three areas hosting high numbers of cranes in the vicinity of the mine be added to the Yarlung Tsangpo Middle Reaches Black- necked Crane Nature Reserve.These areas are Nierixiong and Jiaqingze Villages in Nierixiong Xiang and the Shab Chu Valley.

Response of wintering waterbird diversity to reclamation history and post-reclamation habitat along Yellow Sea coast

Waterbird diversity is one of the most important indicators for monitoring wetland quality.However,the increasing intensity of reclamation activities in recent decades caused the change of habitat landscape along coasts,which could affect the diversity of wintering waterbirds.Our study tried to investigate how reclamation history and postreclamation habitats influence the species richness,species abundance,and Shannon–Wiener diversity of wintering waterbirds along Yancheng coastal wetlands.A total of 68 waterbird species were recorded and the abundance pattern of wintering birds changed from 2009 to 2013.Species richness and abundance of wintering waterbirds varied in the different reclamation histories.Most importantly,the general linear mixed model highlighted the importance of reclamation history,post-reclamation habitat type,and their interactions for shaping both species abundance and Shannon–Wiener diversity of wintering waterbirds,but these variables did not affect the species richness of waterbirds.Furthermore,the random forest results also showed a positive association between reclamation history with species richness,species abundance,and Shannon–Wiener diversity of wintering waterbirds.Moreover,three post-reclamation habitat types,Suaeda glauca,bare flat,and fish pond,played important roles for wintering birds.Our results highlighted that reclamation history,post-reclamation habitats,and their interactions determined waterbird diversity.Given the growing threats to wetland ecosystems from reclamation activities,further research should find a balance between coastal reclamation and waterbird biodiversity conservation.