Extrinsic and endocrine factors are important mechanisms influencing the timing of spring bird migration. Whooper swans (Cygnus cygnus), including 122 adults and subadults over one year old and 98 juveniles under one year old, were satellite tracked to obtain detailed locational data at a wintering ground from 2015 to 2020. We assessed the effects of temperature, wind, photoperiod, available food resources, and sex hormones on age-related timing of spring migration. Our results suggested that both photoperiod and temperature had the greatest impacts on the timing of spring migration of adults, subadults and juveniles when food resources and wind conditions were favourable. With increasing photoperiod and temperature, the peak sex hormone concentrations of adults and subadults occurred one month earlier than that of juveniles, which corresponded to the peak of their departure time. Our study showed the synergistic impact of photoperiod and temperature and their variation among adults, subadults and juveniles on the initiation of spring migration. Compared with juveniles, adults and subadults with spring migration experience and reproductive needs could adjust their behaviours more quickly before departure based on changes in environmental conditions.

[目的]大天鹅(Cygnus cygnus)广泛分布于东亚地区,被认为是H5亚型禽流感病毒的易感鸟类.揭示大天鹅迁徙对H5N2病毒在东亚传播中所起的潜在作用,为研究H5N2病毒的重组和传播提供科学依据.[方法]2018年12月和2019年1月,在三门峡库区采集越冬大天鹅新鲜粪便共1866份;2018和2019年春季和秋季,沿着大天鹅的迁徙路线采集其它野生水鸟新鲜粪便样品共6351份并进行了检测.[结果]分离出14株H5N2亚型禽流感病毒,其中H5蛋白裂解位点处的序列均为PQRETR↓GLF,属于低致病性禽流感病毒.14株病毒8个基因片段的同源性均?≥?99.8％,这表明分离到的14株病毒基本一致.系统发育分析结果表明,14株分离株均属于欧亚谱系,在地理位置上均呈现出以亚洲为主的特点,涉及到的主要国家包括蒙古国、韩国、孟加拉国以及中国南部地区,与大天鹅等雁鸭类迁徙路线相吻合.[结论]H5N2分离株可能是由不同地点不同亚型的低致病性禽流感病毒重组而来,这些地点包括大天鹅越冬地、停歇地和繁殖地等.该病毒随着大天鹅的长距离迁徙进行传播,并且存在着传播至中国西部进行重组与进化成高致病性禽流感病毒的潜在风险.

Extrinsic factors, endocrine mechanisms, and behavioral indicators of migratory restlessness were studied in wintering whooper swans (Cygnus cygnus) in the Sanmenxia Swan National Wetland Park in western Henan Province, central China. First, the fecal glucocorticoid metabolite (FGM) concentration was established and related to mean air temperature or photo period (day length) using simple linear or non-linear regression models. After a model selection procedure, the best fitted model revealed that an increase of FGM concentration was associated with an increase in the squared mean air temperature (R-2=0.88). Other models showed an increasing FGM concentration to correspond with increasing values of day length, squared day length, and mean air temperature-however without statistical support. In a second step, behavioral frequencies of seven behaviors were condensed into three behavioral principal components (PCs) using principal components analysis. Behavioral PCs largely corresponded to three activity phases described for wintering whooper swans in central China and were correlated with the FGM concentration using Spearman's rank-order correlations. Results revealed a significant correlation between FGM and behavioral PC2 (positive factor loadings from vigilance and preening, negative loading from foraging). Finally, we tested for an effect of behavioral PCs on changes in winter home range size using a set of multiple linear regression models. Results of averaged model parameter estimates showed only the behavioral PC3 (positive factor loadings from fighting and calling, negative loading from locomotion) had a marginal significant effect on home range size. Results confirmed findings of previous studies on migratory restlessness in whooper swans. However, due to the small sample size (N=15 weeks) the effect of PC3 on home range size was weak and should be viewed with caution.

候鸟春季迁徙时间与其能否顺利完成迁徙过程,以及对繁殖地的成功选择和繁殖成效密切相关,通过对大天鹅越冬地和停歇地的春季迁徙时间选择原因及其影响因素进行分析,有助于深入理解候鸟春季迁徙时间策略和栖息地保护状况。2015年2月和12月,在河南三门峡湿地捕捉了60只越冬大天鹅并佩戴卫星跟踪器,获取了详细的大天鹅在越冬地和停歇地的春季迁徙时间等信息,并进一步分析了春季迁徙时间与气候因子的相关性。结果表明,大天鹅主要在夜间22:00—0:00和0:00—1:59迁离越冬地。大天鹅迁离越冬地的日期与温度呈显著性正相关,迁离时多选择顺风且风速较小的天气。大天鹅迁离越冬地后主要是在夜间飞行,而迁离停歇地后主要是在日间飞行。越冬地的温度越高,越有利于植物的生长,大天鹅可以快速地积累能量,提前开始春季迁徙。野外调查表明,内蒙古黄河中上游作为迁徙的重要停歇地,春季两岸捕鱼、农耕和放牧等为活动较多,因此大天鹅多选择在夜间觅食补充能量,在日间迁离。最后,针对黄河流域大天鹅栖息地的保护现状,提出了禁止经济开发项目、建立保护区和开展宣传教育等保护建议。

环境温度变化通过影响鸟类的行为进而使其活动区也发生变化,探讨三者之间的关联性有助于理解鸟类是如何通过行为调整以适应周围环境的变化,来满足自身的生理需求.本研究通过卫星跟踪的方法获得了在河南三门峡湿地越冬的31只大天鹅(Cygnus cygnus)详细位点数据,在ArcGIS和R语言中采用核密度估计法计算大天鹅的活动区面积,在SPSS中采用Spearman分析平均温度与活动区面积的相关性;并利用瞬时扫描法获得大天鹅越冬行为观察数据,采用非参数Kruskal Wallis检验对大天鹅行为的差异性进行分析,探讨了环境温度与大天鹅越冬行为和活动区三者之间相互作用的模式.研究表明,从越冬初期至后期,随着环境温度的先下降后升高,大天鹅的取食、运动、静息等主要行为发生了较大的变化,静息和取食行为先增加后减少,运动行为则先减少后增加.越冬不同时期的核心区和活动区面积与温度呈显著性正相关.大天鹅在不同时段的活动区面积大小整体上均呈现出先减少后增加的趋势.随着环境温度的变化,大天鹅的越冬行为也随之发生了调整,进而使活动区面积发生改变,主要体现在越冬初期大天鹅通过增加活动区面积及时补充能量增加体能,越冬中期减少活动保持能量需求,越冬后期增加盘旋飞行使得活动区面积增大等.大天鹅这一系列行为和活动区的调整都是为了更好地满足越冬不同时期的生理需求.

近年来黄河中游人类活动日益增加,大天鹅(Cygnus cygnus)的适宜越冬栖息地不断减少.三门峡天鹅湖国家城市湿地公园大天鹅种群密度较高,空间分布不尽合理,对大天鹅健康形成威胁,改善现有栖息地和寻找潜在的栖息地十分迫切.本文利用遥感和GIS技术进行适宜性分析,从影响大天鹅栖息地的食物、水源和周围生态环境3个方面选取7个环境变量,结合记录的大天鹅位点,构建最大熵模型,分析栖息地选择的主要环境变量及影响机制,并预测湿地公园内大天鹅适宜栖息地概率分布.结果显示:投食点距离、改进归一化水体指数(MNDWI)、道路距离和植被指数(NDVI)等4个环境变量为主要影响因素,投食点距离和NDVI值越大,大天鹅分布的概率越低;MNDWI和道路距离值越大,分布概率越高.参照联合国粮食及农业组织(Food and Agriculture Organization of the United Na-tions,FAO)土地适宜性分级标准,将公园内大天鹅栖息地适宜性概率分布划分为5个等级,最适宜栖息地面积0.41 km2,土地利用类型为坑塘水面.研究结果可用于天鹅湖内栖息地改造和在黄河中游寻找潜在越冬栖息地并开展湿地修复.大天鹅易于选择远离道路干扰的开阔水域作为越冬栖息地,冬季食物匮乏,前期可投食玉米引导大天鹅种群合理分布.

Surveillance of whooper swan migration is important for monitoring avian influenza transmission risk potential from east to west China between the East Asian-Australasian and Central Asian flyways.Here, we characterised the evolutionary and reasssortment history of H5N2 viruses isolated from 1866 fresh faeces samples of wintering whooper swans collected in the Sanmenxia Reservoir area, China.This was combined with information on the migration routes of whooper swans in Eastern Asia to elucidate the role of whooper swans in spreading the virus.All segments of the new H5N2 isolates belong to the Eurasian avian-like lineage and are closely related to wild-bird viruses from China, Korea and Mongolia covering the wintering, stopover and breeding grounds in migration routes of whooper swans.We further found that the temporal-spatial migration process of whooper swans was identical with the virus transmission and reassortment pathway in Eastern Asia particularly.

冬季幼鸟与成鸟面临着不同的生存压力,成鸟负责照顾幼鸟使其获得最大的生存率,这使得它们的行为选择不同.2016年12月-2017年3月,在河南省三门峡湿地,采用瞬时扫描法记录了成、幼大天鹅Cygnus cygnus的行为类型,并对越冬期成、幼大天鹅昼间行为选择的差异进行了分析.结果 表明,在整个越冬期,成鸟占比最高的行为是警戒(29.1％),并高于幼鸟(18.5％);幼鸟占比最高的行为是运动(22.7％),并高于成鸟(18.2％).对不同越冬阶段的行为差异分析表明,成鸟在越冬初期占比最高的行为是警戒(27.6％),幼鸟的是觅食(26.5％).在越冬初期,幼鸟经过长时间的迁徙,急需补充能量,因此觅食行为占比最高,此时成鸟为保护幼鸟的安全,在警戒上的时间较其他行为更多;进入越冬中期,成、幼鸟的警戒行为均有所增加(成鸟:32.3％;幼鸟:20.8％),占比最高,此时湖面结冰,大天鹅受到天敌攻击的几率增加,因此成、幼鸟警戒行为均有所增加,且此时天然食物减少,成、幼鸟的觅食行为有所下降(成鸟:8.8％;幼鸟:13.5％),并增加了休息时间,以减少能量消耗来抵御严寒;到了越冬后期,成鸟的警戒行为(27.2％)仍是占比最高的行为,但与前期、中期相比,后期有所下降,幼鸟占比最高的行为是运动(26.3％),如飞行等,此时春季迁徙即将来临,幼鸟需要增加运动来锻炼飞行能力;成鸟此时也需积累能量,因此警戒行为与其他2个时期相比有所下降.在整个越冬阶段,成鸟警戒的比例都是最高的,表明成鸟始终以减少觅食和休息时间来保证幼鸟的安全作为首要任务.

The spread of highly pathogenic avian influenza (HPAI) H5N1 virus is associated with wild fowl migration in East Asian-Australasian (EA) and Central Asian (CA) flyways. However, the spread of H5N1 virus between the two flyways is still unclear. Here, the movements of wild waterfowl were obtained from satellite tracking data covering seven bar-headed geese and three great black-headed gulls breeding in the Qinghai Lake area (along the EA flyway), and 20 whooper swans wintering in the Sanmenxia Reservoir area (at the CA flyway). From the 2688 samples that were screened from wild birds at Qinghai Lake after an outbreak of HSN1 in July 2015, four genomes of HSN1 virus were obtained from bar-headed geese. The results of phylogenetic analysis indicated that these H5N1 viruses belonged to Glade 2.3.2.1c and their gene fragments were highly homologous with A/whooper swan/Henan/SMX1/2015 (HSN1) virus (ranging from 99.76% to 100.00%) isolated from a dead whooper swan from the Sanmenxia Reservoir area along the EA flyway in January 2015. Furthermore, the coincidental timing of the HSN1 outbreak with spring migration, together with phylogenetic evidence, provided new evidence of the east-to-west spread of HPAI H5N1 between the EA and CA migratory flyways of China. [GRAPHICS] .

Home range and habitat use are the central components of avian ecology, and studies on these aspects will be helpful for the conservation and management of avian populations. Sixty-seven swans were global positioning system tagged at Sanmenxia Wetland of Henan Province to obtain detailed location data in winter from 2015 to 2016. The home range size of swans was the largest in the middle wintering period and followed by the early period and late period, and sizes were significantly different among the three wintering periods. There were significant differences in habitat use among the different wintering periods. In the early period, the swans mainly used the aquatic grasses and emergent plants zones, and they mainly relied on artificial supplementation because of a lack of natural feeding habitats in the middle period. In the late period, the swans mainly used the newly emerged terrestrial grasses zone. Except for the deep water, the use of other water levels was significantly different among the different wintering periods. In the early wintering period, the swans tended to prefer the low and high water level areas; in the middle period, they were mainly in the intermediate and high water level areas and they used all the water level areas except the deep water level in the late wintering period. It was concluded that some plants are preferred by the swans, such as reeds, cattails and barnyard grass, and that water depth should be suitable for the swans, with the water levels varying over a gradient.

大天鹅,又称白天鹅或鹄,是一种大型游禽,也是一种水禽,通常在浅水中栖息,属于雁形目鸭科天鹅属,分布在北欧、亚洲北部,越冬在中欧、中亚及中国等地.中国是大天鹅越冬主要栖息地之一,国内主要分布于黄河三门峡库区、黄河中下游、山东荣成、青海湖等地,其繁殖地主要在蒙古、俄罗斯等地.据调查,每年在中国越冬的大天鹅数量有15 000只左右,其中在三门峡市黄河湿地公园越冬的8 600只,而在三门峡市天鹅湖国家城市湿地公园越冬的有6 400多只.因此,三门峡市天鹅湖国家城市湿地公园成为大天鹅在中国最集中的区域.

采用粪便显微分析法,2014年11—12月、2015年11月对大天鹅粪便中的植物残片与27种植物进行对比、 分类、 统计,得到结果:大天鹅越冬初期食物比例中,小麦最多,占40.44％;玉米粒占17.23％,芦苇3.03％、 菵草2.02％、 苍耳1.41％、 牵牛1.21％、 酸模叶蓼1.04％、 睡莲0.95％、 多花水苋0.66％、 苘麻0.61％、 早熟禾0.58％、 红鳞扁莎和齿果酸模均为0.52％.大天鹅取食具有广泛性,且对小麦有取食偏好.大天鹅取食的植物中占比最大的是禾本科植物,占63.57％,其次是蓼科1.56％,菊科1.41％,旋花科1.21％.

药剂防治试验结果表明,在松大蚜发生初盛期用48％乐斯本乳油1 500倍液+1.8％阿维菌素乳油3 000倍液对松大蚜有较好的防治效果,根据松大蚜的生物学特性和虫态结构,在化学防治时应连防2～3次,间隔7～10d,为提高药液的沾着性,建议配置药液时加入0.1％的中性肥皂液或中性洗衣粉.

2019年3月5日16:30时在河南三门峡市天鹅湖湿地的双龙桥(111°08′E,34°46′N,海拔330m)附近湖边发现1只灰色的雁混杂在大天鹅(Cygnus cygnus)群中一起取食.该灰色雁头顶部白而头后有两道黑色条纹,喉部白色延伸至颈侧(图1),查阅相关工具书(约翰·马敬能等2000),鉴定为斑头雁(Anser indicus).观察期间发现该个体还飞到青龙湖大坝附近浅滩上取食和休息.3月6日继续在双龙桥附近观察到1只斑头雁,推测应为同一个体,至3月7日以后再也没有观察到斑头雁.根据郑光美(2017)对斑头雁分布的记录,未见该鸟种在河南有分布记录.检索“中国观鸟记录中心”(www.birdreport.cn)的观鸟记录,亦未发现斑头雁有在河南分布的记录.由此确认斑头雁为河南鸟类分布新记录种.

研究结果表明,松大蚜在河南省三门峡地区一年发生多代,一代平均历时18d,以受精卵在针叶上、1～2年生嫩枝上越冬;每年发生高峰期在8月中下旬;保护和利用天敌对松大蚜具有较好的控制效果.

2016年12月-2017年2月,对黄河三门峡库区大天鹅越冬期栖息地选择进行了研究,野生环境与人工环境下共记录到大天鹅夜栖地样方31处,觅食地样方23处.利用独立样本T检验和Mann Whitney U检验比较了大天鹅夜栖地与对照组的差异性.结果表明:植被高度、水深和距干扰源距离在夜栖地样方与对照组间差异显著(P<0.05),这3个因子是影响大天鹅夜栖地选择的主要因子.大天鹅觅食地样方与对照组的比较发现,植被盖度、距食源地距离和植被高度在觅食地样方与对照组间差异显著(P<0.05),这3个因子是影响大天鹅觅食地选择的主要因子.31处夜栖地和23处觅食地的主成分分析表明,安全因素是影响大天鹅夜栖地和觅食地选择的主要因素.

In late 2014, a highly pathogenic avian influenza (hereafter HPAI) H5N1 outbreak infected whooper swans Cygnus cygnus wintering at the Sanmenxia Reservoir area, China, and raised concerns about migratory linkages between wintering and breeding grounds of whooper swans. In this study, 61 swans were satellite tracked from 2013 to 2016 to determine the spatial association of their migration routes and H5N1 outbreaks, and 3596 fecal samples were collected along the migration routes for virology testing. Swans departed the wintering grounds and migrated along the Yellow River, and flew over the Yin Mountains in China. The Brownian bridge movement model showed there was a high degree of spatiotemporal overlap between the core use area along the spring migration pathway and historical H5N1 events in China and Mongolia from 2005 to 2015. The H5N1 strain was isolated and phylogenetic analyses confirmed that the HA gene sequence generated is genetically similar to that of the epidemic strain at a previous wintering site (the Sanmenxia Reservoir area) along its flyway. Our results identified a previously unknown migratory link of whooper swans in central China with Mongolia and confirmed that the swans could carry the HPAI H5N1 virus during migration, resulting in long-distance transmission.

人类活动对越冬大天鹅(Cygnus cygnus)栖息地的负面影响日益加剧,以黄河三门峡水库为例,由于越冬大天鹅缺少可利用的栖息地,大天鹅越冬时过高的种群密度导致了禽流感疫情的发生,直接威胁着越冬大天鹅的生存和繁衍.大天鹅栖息地选择研究是其栖息地修复和种群分布研究的基础.从影响越冬大天鹅选择栖息地的水源、食物、干扰、隐蔽物4方面选择了10个可能因子,探讨越冬大天鹅栖息地选择机制.利用2015年11月至2016年2月越冬大天鹅分布实测数据,考虑到大天鹅分布的“1-0”型特点,采用Logistic回归模型,开展研究.利用遥感和GIS空间分析技术,提取变量,经显著性检验,最终筛选出用于建立模型的7个变量,其贡献率水平从高到低依次为与投食点的距离、与水体的距离、与小麦地的距离、与道路的距离、土地利用类型、归一化植被指数和坡度.通过建立不同土地利用类型的回归模型,预测越冬大天鹅出现概率的空间分布,与观测值建立误差错判矩阵,得到的Kappa系数为0.78.在三门峡水库,由于冬季食物匮乏,大天鹅在越冬期多选择靠近人类投食点和种植冬小麦的区域,其主要越冬栖息地的土地利用类型为植物覆盖较少、坡度较缓的开阔坑塘水面、滩地和洪泛湿地.

To establish baseline information about the spring migration of waterbirds,we conducted surveys on the current status and habitats of whooper swans (Cygnus cygnus) and other waterbirds along the upper and middle reaches of the Yellow River in Inner Mongolia,ranging from Dengkou County to Tumed Right Banner based on distributions of vegetation types and the river stream in March 2015 and April 2016.Day and night home ranges for tracking whooper swans were determined using kernel density estimation (KDE) at levels of 90％ and 50％.Enhanced vegetation index (EVI) of these two levels were calculated and compared.A total of 25671 waterbirds were recorded,belonging to 37 species,of which swans and ducks accounted for 89.6％.The whooper and tundra swan (C.columbianus) were predominant.According to GPS-tracking data,the upper and middle reaches of Yellow River were important stopover sites for spring migratory whooper swans,where the most swans stayed for long periods ((24.74± 9.38) d).Their diurnal and night movements were roughly similar.The EVI at the upper and middle reaches of Yellow River were very low.Compared with that of the 90％ level of KDE,the home range size of the 50％ level and corresponding EVI were much lower from Dengkou County to Tumed Right Banner.During our field surveys,we discovered that these stopover sites were located on farmland around the Yellow River,providing abundant food and better shelter habitats for whooper swans and other waterbirds.

2015年初,黄河三门峡库区发生了大天鹅(Cygnus cygnus)等野鸟感染高致病性禽流感病毒的疫情,我们通过对三门峡大天鹅越冬种群的监测和环志回收的分析,了解大天鹅的越冬种群现状和活动状况,希望研究结果有助于我国对大天鹅种群的保护.调查表明,近些年来大天鹅越冬种群数量呈上升趋势,特别是三门峡天鹅湖由2010年410只增加到2014年6 317只,大天鹅种群数量在12月中旬至翌年1月达到高峰,2月下旬陆续离开,至3月下旬全部北迁.根据彩色颈环标记的回收结果,大天鹅对三门峡库区作为越冬地的选择是较为稳定的,不同个体在库区内的各地点之间还存在游荡行为,此外,还观察到带有彩色颈环的119只个体,已经被证实是由蒙古北部和中部的19个湖泊迁徙而来.三门峡湿地公园大天鹅越冬种群数量增加较快,是由于湖泊水质改善且人为大量投食玉米饲料,吸引了众多大天鹅前来越冬.蒙古环志的大天鹅连续多年在三门峡库区越冬也间接反映了这里有良好的栖息环境和丰富的食物资源.然而,初步推测,2015年这次大天鹅感染禽流感病毒可能与种群密度过高有较大的关系,建议当地政府合理投食补饲,不要盲目追求较多的种群数量;同时采取合理有效的措施促进大天鹅种群扩散,如在附近建立适宜的栖息地,这对于大天鹅种群保护具有重要意义.