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.

Effect of water level fluctuations on temporal-spatial patterns of foraging activities by the wintering Hooded Crane(Grus monacha)

Background:The Yangtze River floodplain provides important wintering habitats for Hooded Cranes(Grus monacha) in China.Fluctuations in the water level change foraging habitat and food availability,affecting their temporal-spatial patterns of foraging activities.It is of considerable importance to investigate the effect of these fluctuations on food availability for wintering Hooded Cranes and their foraging response to these changes.Understanding their behavior patterns is beneficial in protecting the wintering crane population and restoring their wintering habitats.Methods:A field survey of the winter behavior of cranes was carried out at Shengjin Lake from November in 2013 to April in 2014.Habitat variables,as well as the spatial distribution and behavior patterns of wintering cranes at their foraging sites during five stages of water level fluctuation were collected.Based on this data we analyzed the relationship of foraging behavior relative to water level fluctuations and habitat types.Results:The foraging habitats used by Hooded Cranes varied at the different water level stages.As the water level decreased,the use of meadows and mudflats increased.When the water dropped to its lowest level,the use by the Hooded Crane in the mudflats reached a peak.There were statistically significant differences in time budget in the three types of habitats over the five stages of the water level.In the mudflats,the foraging behavior and maintenance behavior varied significantly with the water level,while the alert behavior showed little variation.Analysis of a generalized linear model showed that the five water level stages and three habitat types had a significant effect on foraging behavior,while the combined effect of these two variables was significant on the foraging time budget and the length of foraging activity of the Hooded Crane.Conclusions:With the decrease in the water level,the use of mudflats by Hooded Cranes increased correspondingly.Food availability in different habitats was affected by changes in the water level.The Hooded Crane adjusted its foraging patterns and made full use of the three available types of habitat in order to acquire enough food in response to fluctuations in the water level.

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.

笼养白头鹤(Grus monacha)行为及空间利用研究

2014年4月～2015年4月,在长春市动植物园,采用目标取样法研究了1对年白头鹤(Grus monacha)的采食、游走、护理、站立、休息、繁殖等行为。结果表明:白头鹤全年主要行为活动时间分配比例为采食12.21%,游走24.14%,刻板9.58%,护理20.51%,站立26.36%,休息1.41%,繁殖5.79%,其他行为0.09%。白头鹤笼舍划分为4个区:A区域:采食区;B区域:中央区域;C区域:巢区;D区域:边缘区域。白头鹤对笼舍内各个区域的单位面积利用率差异不显著。春季白头鹤对A采食区的单位面积利用率为1.08%,B区域为1.83%,C巢区域单位面积利用率为2.75%,D^1区为13%,最低利用区域为D^2区,占1%。进入夏季后,对A区域的单位面积利用率显著升高,占整个区域的2.92%;B中央区为1.83%;对C巢区单位面积利用率依旧较高为2.25%;D^1区单位面积利用率为7.5%;D^2区仅占0.5%。秋季时亲鹤需要照顾雏鹤,所以对中央区域B区等开阔地的利用率增加,增至2.25%;A采食区2.25%,C巢区1.58%,D^1区11%,D^2区2.5%。由于冬季白头鹤从室外笼舍转移至室内笼舍,所以冬季空间利用性不作比较。

Annual spatio-temporal migration patterns of Hooded Cranes wintering in Izumi based on satellite tracking and their implications for conservation

Background: The Hooded Crane(Grus monacha) is listed as a vulnerable species by IUCN. Knowledge about the migration of the Hooded Crane is still limited. Here we reported the spatio-temporal migration patterns of Hooded Cranes wintering in Izumi, Japan, as well as important stopover areas for their conservation.Methods: Four adult and five subadult cranes, all wintering in Izumi, Japan, were fitted with satellite transmitters(GPS–GSM system) at their stopover sites in northeastern China in 2014 and 2015. We analyzed the time and duration of adults and subadults in spring and autumn migration, as well as the time and duration they stayed in breeding and wintering ground. In addition, we analyzed the land use of the cranes in stopover areas.Results: Adult cranes took much longer time to migrate both north in spring(mean days) compared with subadult cranes(15.3 and 5.2 days, respectively). H= 44.3 days) and south in fall(mean = 54.0 owever, the subadults had longer wintering(mean = 149.8 days) and nomadic(breeding season for adults) seasons(mean d with adults(133.8 and 122.3 days, respectively). Three important stopover areas have been= 196.8 days) compare identified: the region around Muraviovka Park in Russia, the Songnen Plain in China, and the west coast of South Korea, where cranes spent most of their migration time(62.2 and 85.7% in spring and autumn, respectively). During migration, nomadic period and winter, Hooded Cranes usually stay in croplands for resting and feeding. In non-wintering season, less than 6% of stopover sites were located within protected areas.Conclusion: Overall, our results contribute to understanding the annual spatio-temporal migration patterns of Hooded Cranes in the eastern flyway, and planning conservation measures for this species.

小兴安岭白头鹤繁殖习性初报

Hooded crane Grus monacha is listed as an endangered species by China red data book,and was listed as a vulnerable species by IUCN,and listed AppendixⅠof CITES.The population of hooded crane is about 9 500 individuals worldwide and breeding is limited to remote eastern Siberia in Russia and Xiaoxing’an mountains marsh in China.The species winters in in southern Japan,and the south coastline of Korea,and middle-lower reaches of Yangtze River in China.Because little is known about their breeding biology,we conducted this study to provide a scientific basis of future protection in China.We conducted our study in the Xiaoxing’an mountains Zhanhe valley of Heilongjiang Province between spring in 2003 and spring in 2004.We located nests erected a tent 10-30 meters from the nest.We observed hooded crane or the nest from the tent and documented behaviour by video and still camera throughout the day.When migration justly or moving in breeding site of hooded crane,we had taken investigation and recording by binoculars and long-focus camera and photo-camera,and during sorted out the records,we checked continually and made accurateness just by video information and photos. The study revealed that hooded crane migrated to the breeding site in early April yearly,mated in middle April,and laid eggs in late April or early May.The average egg was 93.4×58.4 mm in size and weighed 159.4 g.Male and female of hooded crane hatched together after incubating 30.5 days.Hooded crane build nests in the marshy forests or small swamp,and the average nest was 900×900 mm in size with no obvious interior diameter.The nest was 130-180 mm above water and the water depth around the nest was 120-300 mm.Adult hooded crane fed chicks with earthworms and polliwogs,etc.Comparing the habitats of hooded crane nest with Russia,breeding of hooded crane in Zhanhe where there are more trees and greater concealment.We recorded large-billed crow Corvus macrorhynchos,black kite Milvus migrans,golden eagle Aquila chrysaetos that threatened the hooded crane.During the hatching period,hooded crane showed anxiousness to great spotted woodpecker Picoides major.Breeding of hooded crane in Xiaoxing’an mountains mainly fed on Heilongjiang brown frog Rane amurensis,Siberian salamander Hynobius keyserlingii,leech,loach Misgurnus mohoity,predaceous diving beetle Cybister spp.,perch sleeper Percottus glehni,lake minnow Phoxinus percnurus and wheat seeds.

黑龙江流域白头鹤繁殖栖息地选择模型预测

白头鹤是中国国家Ⅰ级重点保护野生动物,世界自然保护联盟（IUCN）将其列为易危物种。目前仅知道白头鹤繁殖于中国黑龙江流域和俄罗斯西伯利亚东南部,但对其繁殖栖息地的具体研究尚不完善。为了掌握这一物种在东北亚地区的繁殖栖息地的分布及特征,更好地对该物种及其栖息地实施保护,2011—2013年在小兴安岭对白头鹤繁殖栖息地进行了调查,除新近采集的数据,还通过调查收取了过去近10年（2001—2010年）的白头鹤繁殖数据。本研究采用Salford Predictive Modeler、R等数据分析软件对收集到的繁殖数据建立模型（随机森林模型）进行预测,并使用地理信息系统（GIS）对预测的白头鹤繁殖区绘图,得到直观的繁殖分布预测图。结果表明：在景观尺度下,影响白头鹤繁殖栖息地的主要因素有3个,分别是海拔、坡度和坡向。进一步分析后得出结论：中等海拔（300～500 m）、朝向东北且平缓（坡度小于2.4°）的泰加林区域是白头鹤最为适宜的繁殖区。由此结论以及研究区域内的GIS数据分析表明：在本研究区域内,白头鹤最适宜繁殖区（分布概率高于0.8）面积为6 832 km2,只占研究区面积的0.18%,估计能容纳2 000～3 000对白头鹤繁殖。绘图显示：只有少量的最适宜繁殖区（仅784 km2）在保护区范围内,并且在白头鹤的繁殖分布地中存在大量的农田和水利设施。保护区面积的不足和严重的人为干扰是白头鹤在繁殖区内面临的主要问题。

小兴安岭白头鹤繁殖地种群数量初步调查

2004年通过地面和航空调查等方法,对繁殖于小兴安岭沾河流域的白头鹤(Grusmonacha)种群进行了数量调查,共统计到白头鹤30只。发现了3对鹤的巢;2对以及2只单只的个体,虽然没有发现巢,但根据其保护领域的行为,可以确定其为繁殖个体。同时统计到13只没有参加繁殖的个体,以及3只不能判明是否参加繁殖的个体。通过本次调查表明,小兴安岭沾河流域的森林沼泽是我国白头鹤的重要繁殖地。

白头鹤国内圈养种群现状分析

对中国白头鹤圈养种群的统计学和遗传学结果进行了相关分析,并对种群数量、年龄结构、性比情况、基因多样性、近交系数以及未来100 a种群的发展趋势进行了重点研究。结果表明:截止到2013年12月31日,中国圈养白头鹤种群共有存活个体76只,分别饲养于15家单位,其中建立者的数量为16只,潜在建立者的数量为41只。圈养白头鹤种群中育龄个体充足,但幼龄个体数量不足,种群年龄结构不是很合理。白头鹤种群保留了野生个体92.9%的基因多样性,平均近亲系数为0,是一个没有任何近亲繁殖的优质种群。通过分析发现,虽然白头鹤圈养种群的数量呈逐年递增的趋势,但多数都是野外救助的个体,圈养出生数近10 a没有明显的增加。根据现状分析结果,建议将潜在建立者集中饲养在几家技术能力比较强的单位,解决饲养中的配对等繁殖难题,完善个体标识和完成性别鉴定工作,从而最大限度地增加白头鹤的圈养种群数量。

崇明东滩越冬白头鹤食性的研究

采用粪便显微组织分析法和直接观察法对崇明东滩越冬白头鹤进行食性研究.结果表明:崇明岛东滩越冬白头鹤的觅食地在98堤外滩涂,主要位于海三棱草群落外带和中间带的潮沟附近,内带是白头鹤在大潮高潮时的觅食地及休息地.白头鹤的越冬食性分析,占总重量99%的食物成分为海三棱草的地下球茎和根茎(根状茎),对地下球茎特别偏爱,很少食用海三棱草的种子.潮汐冲刷作用使潮沟附近海三棱草球茎和根茎裸露,为白头鹤取食带来便利条件.白头鹤与小天鹅食性相似,但两者具有明显的生态隔离.由于白头鹤大部分时间在滩涂自然湿地上活动和觅食,因此崇明东滩对于保护白头鹤非常重要.但目前人类活动特别是围垦对白头鹤及其栖息地带来严重干扰.