鄱阳湖越冬小天鹅在高水位年份的昼间时间分配和活动节律

2011年1～2月,采用焦点动物观察法对鄱阳湖康山湖候鸟自然保护区内越冬小天鹅种群进行了时间分配和日间活动节律的研究。通常认为小天鹅是典型的游禽,冬季大部分时间都在水中游动。我们的研究结果表明,93.2%的个体在湿地洲滩生境内活动。2010年鄱阳湖持续高水位导致的水体生境中食物短缺,可能是迫使小天鹅主要在湿地洲滩生境活动的主要原因。取食是小天鹅越冬期间最主要的行为,占52.6%,其次为警戒18.2%、运动10.6%、休息10.0%和理羽8.6%。取食、警戒、运动、休息和理羽行为发生的持续时间存在显著差异,休息行为持续最长,平均为48.4s±2.9s,警戒行为的持续时间最短,平均持续时间为9.5s±0.6s。小天鹅在水域生境和湿地洲滩生境中时间分配存在显著差异,在水域生境以休息为主,在湿地洲滩生境以取食为主。除理羽行为与休息行为发生节律存在显著的负相关,其他行为没有显著的相关性。     

基于卫星跟踪的洞庭湖越冬小天鹅迁徙路线研究

掌握洞庭湖越冬小天鹅Cygnus columbianus的迁徙行为和规律,明确迁徙路线和停歇地,是小天鹅栖息地恢复研究及保护的基础。2014—2017年,在湖南东洞庭湖国家级自然保护区对18只小天鹅进行卫星跟踪,收集了38 882条定位数据。本研究确定了小天鹅西线、中线和东线3条迁徙路线,其中,新发现的西线沿我国湖北、河南、山西、陕西、内蒙古,以及蒙古国、哈萨克斯坦,抵达俄罗斯亚马尔-涅涅茨自治区北部靠近喀拉海的北极苔原。西线春季迁徙距离为6 715 km,平均迁徙速度为21.52 km·h~(-1),秋季迁徙距离为7 467 km,平均迁徙速度为32.75 km·h~(-1)。中线春季迁徙距离为2 083 km,平均迁徙速度为28.93 km·h~(-1)。东线春季迁徙距离为5 965~6 351 km,平均迁徙速度为(28.71±0.95)km·h~(-1),秋季迁徙距离为5 101~5 331 km,平均迁徙速度为(29.15±3.65)km·h~(-1)。小天鹅春季迁徙进程慢于秋季,迁徙途中的最大飞行速度达133.3 km·h~(-1)。内蒙古自治区的黄河湿地和大兴安岭两侧河谷湿地是迁徙途中的重要中转站,小天鹅在此停歇15 d以上。本研究有助于了解小天鹅对栖息环境的偏好及迁徙路线选择策略,为禽流感等疾病传播和防控提供科学依据。     

基于MODIS的洞庭湖湿地面积对水文的响应

利用MODIS影像数据集提取了2000-2010年间的洞庭湖水面面积。结合城陵矶水位数据分析了10月-翌年5月洞庭湖水体湿地和洲滩湿地的面积变化。研究结果表明,洞庭湖水体湿地呈现明显减小的趋势。2010年2月、10月、12月较2000年2月、10月、12月相比,分别有29.98%、26.76%和9.02%水体湿地转化为洲滩湿地。城陵矶在24-26 m水位涨落的时序变化较大,使东洞庭湖草滩湿地提前出露。推迟淹没,洲滩湿地裸露时间延长,亦将导致低海拔的草滩湿地向芦苇滩湿地的演变。洞庭湖湿地面积的变化是三口、四水来水减少、降雨减少等多方因素共同作用的结果,而三峡在9-10月间蓄水,将进一步加重湿地洲滩化的趋势     

鄱阳湖围垦区藕塘生境小天鹅与白鹤的种间关系

鄱阳湖是小天鹅（Cygnus columbianus）和白鹤（Leucogeranus leucogeranus）极为重要的越冬地,它们均主要以沉水植物苦草（Vallisneriaspp.）冬芽为食,且通过觅食空间生态位分化减少种间竞争。近年来,鄱阳湖苦草冬芽锐减导致大量小天鹅和白鹤由自然生境转移到南昌五星白鹤保护小区的藕塘觅食。大量小天鹅和白鹤集中在小片藕塘觅食可能导致种间竞争强度增加。因此,本研究以五星白鹤保护小区藕塘为研究地点,于2021年11月10日至25日,采用瞬时扫描法和焦点动物法调查了藕塘与白鹤混群和不与白鹤混群时小天鹅的日间行为、单次取食时间和每分钟摄食成功频次,并采用单因素方差分析或Mann-WhitneyU检验对数据进行统计分析。结果表明,小天鹅日间行为主要以觅食（45.59%）、运动（17.05%）和休息（15.92%）为主。小天鹅和白鹤混群时的觅食行为比例和单次觅食时间显著高于不混群时,表明小天鹅主要通过增加觅食时间以应对种间竞争的负面影响,满足能量需求。小天鹅混群时的每分钟摄食成功频次显著高于不混群时,这可能是由于小天鹅通过摆动脚蹼或者扁平喙啄食的方式较难取食...     

野化放归丹顶鹤活动节律、家域特征和栖息地选择

了解野放丹顶鹤的运动模式、家域和栖息地选择的时间节律特征对丹顶鹤种群保护和栖息地管理尤为重要。基于GPS-GSM跟踪数据,综合运用3S技术、动态布朗桥模型、栖息地选择指数,研究了盐城海滨湿地野放丹顶鹤在不同生活周期的活动节律、家域的面积和重叠指数,以及栖息地选择。结果表明：(1)丹顶鹤日活动节律具有明显的周期性特征。丹顶鹤活动强度：育成期>越冬期>孵化期>育雏期,孵化期和育雏期日间活动强度平稳,育成期和越冬期呈“双峰”模式。(2)丹顶鹤95%家域面积均值介于(111.18±22.15)hm²—(621.28±105.77)hm²,育成期((621.28±105.77) hm²)>育雏期((226.83±54.86) hm²)>孵化期((112.40±7.72) hm²)>越冬期((111.18±22.15) hm²);核心家域面积均值介于(0.53±0.26)—(45.78±6.66) hm²,育成...     

越冬水鸟对升金湖周边间歇性湿地氮磷的影响

近年来,由于升金湖湖区食物资源的匮乏,一些在此越冬的水鸟会到周边间歇性浅水农田、草滩去摄食和栖息。为了解水鸟活动对这类湿地环境N、P营养盐的影响,本文以安徽升金湖小鹭咀以西3块有小天鹅和豆雁活动的浅水农田、草滩为对象,于2016—2017年水鸟越冬季早、中、晚期分别采集表层水样并分析其中的N、P营养盐浓度变化,结合鸟粪中N、P含量及鸟类数量观测结果,研究了小天鹅和豆雁活动对间歇性湿地营养盐的影响。结果表明:整个研究时间段内草滩水体TN和TP浓度最高,且均显著高于对照(沟渠,其水源与农田和草滩一致),表明受豆雁活动影响强烈;早期农田1水体TN和TP浓度均显著高于对照,表明受小天鹅活动影响强烈,其余月份与对照则差异不明显;农田2水体TN和TP浓度与对照无显著差异,表明受小天鹅活动影响不明显;N、P其他形态含量与对照之间呈现不同的规律,反映了它们受到水鸟活动强度变化和鸟粪分解等多重影响。本研究表明,越冬水鸟的栖息、摄食活动对升金湖小鹭咀周边浅水湿地中的N、P营养盐产生了不同程度的影响。     

食块茎水鸟及水位对沙湖沉水植物冬芽分布的影响

分别于2012—2013、2013—2014年度越冬期候鸟越冬前(10月份)与越冬后(4月份)采用样方法调查沙湖沉水植物冬芽的种类、密度及生物量,分析不同水位条件的2个年度鄱阳湖碟形子湖沉水植物冬芽的分布及其对食块茎水鸟食物贡献的差异性,探讨越冬水鸟取食与水位变化对沉水植物冬芽分布的影响。结果表明:刺苦草(Vallisneria spinulosa)和罗氏轮叶黑藻(Hydrilla verticillata var.rosburghii)2种沉水植物的冬芽同域分布。2013年10月2种植物冬芽的密度与生物量均显著低于2012年同期,主要原因是鄱阳湖水位年际间变化剧烈,并对水质有显著影响:与2012年相比,2013年丰水期(4—9月)沙湖与主湖区连通的时间和日平均水深显著减小,但水体浊度显著增加,不利于沉水植物生长发育。2012—2013年度越冬水鸟迁出后2种冬芽的密度和生物量均明显下降,而2013—2014年度越冬期水鸟迁出后与迁入前相比两种植物冬芽的密度和生物量均无显著变化,很可能与食块茎水鸟的取食活动和高水位对食物可利用性的负面影响有密切关系。湖泊剧烈的水位变化导致越冬水鸟的食源具有年际波动的特征,而食块茎水鸟对鄱阳湖子湖的食物利用率受越冬季冬芽丰富度和食物可及性(accessibility)的共同影响。研究结果对鄱阳湖乃至长江中下游流域沉水植被恢复、越冬水鸟保护以及生态系统功能评估具有指导意义。     

鄱阳湖藕田越冬期小天鹅和鸿雁能量支出与取食行为比较

2016年12月—2017年2月和2017年12月—2018年3月,采用瞬时扫描法和焦点动物法,对鄱阳湖畔藕田生境中小天鹅(Cygnus columbianus)和鸿雁(Anser cygnoides)越冬期昼间行为的能量支出和取食行为进行观察。结果表明:小天鹅和鸿雁主要行为是休息(小天鹅:36.01%;鸿雁:28.02%)、取食(32.71%; 17.44%)和运动(17.26%; 30.61%);小天鹅和鸿雁昼间能量支出较多的行为也是取食(小天鹅:354. 1 kJ·d-1;鸿雁:144. 88kJ·d-1)、休息(275.22 kJ·d-1; 164.35 k J·d-1)和运动(219.79 kJ·d-1; 299.22 kJ·d-1);小天鹅在藕田中取食行为的能量支出和总能量支出均显著高于鸿雁;小天鹅和鸿雁一天中的能量支出无显著差异;藕田生境中小天鹅主要采取表面取食和头颈浸入水体的取食方式,鸿雁则主要采取表面取食和挖掘食物,这与藕田生境中水深、食物组成以及自身形态有关;小天鹅和鸿雁通过不同的取食方式和取食水深,减少种间竞争。     

鄱阳湖越冬雁鸭类的种群动态与时空分布

2014年10月—2015年4月,采用样点法对鄱阳湖5个区域的47个样点中越冬雁鸭类数量与分布进行了调查。共记录雁鸭类18种,包括国家Ⅱ级重点保护动物小天鹅Cygnus columbianus和白额雁Anser albifrons。豆雁Anser fabalis的累计数量最多,其次为小天鹅、白额雁、鸿雁Anser cygnoides和罗纹鸭Anas falcata;斑嘴鸭Anas poecilorhyncha出现频次最高,其次为豆雁、小天鹅、鸿雁和白额雁;斑嘴鸭、豆雁和小天鹅出现湖泊数最多。浅水湖泊、草洲和泥滩是多数越冬雁鸭类偏好的生境。鄱阳湖国家级自然保护区集中了最多、最全的雁鸭类。     

三峡工程运行后对洞庭湖湿地的影响

长江三峡工程建成运行后,其下游第一个大型通江湖泊——洞庭湖的水文、水质以及湿地环境等均发生了很大变化。三峡工程已经开始影响到洞庭湖的泥沙淤积、水位波动、水质以及植被演替等。以三峡水库调度运行方案、河湖交互作用和洞庭湖湿地植被分布格局为基础,从长江三峡工程对洞庭湖水文、水质以及湿地植被演替等方面综述了三峡工程对洞庭湖湿地的综合影响。三峡工程减缓了长江输入洞庭湖泥沙的淤积速率,对短期内增加洞庭湖区调蓄空间、延长洞庭湖寿命有利。总体上减少了洞庭湖上游的来水量,改变了洞庭湖原来的水位/量变化规律。给洞庭湖水环境质量造成了直接或间接的影响,对其水质改变尚存一定争议,但至少在局部地区加剧了污染。水位变化和泥沙淤积趋缓协同改变了洞庭湖湿地原有植被演替方式,改以慢速方式演替,即群落演替的主要模式为:水生植物—虉草或苔草—芦苇—木本植物。展望了今后的研究趋势与方向,为三峡工程与洞庭湖关系的进一步研究提供参考。     

不同水位下拟建鄱阳湖水利枢纽对食块茎鸟类栖息地适宜性的影响研究

鄱阳湖为亚洲最大的候鸟栖息地,近十余年发生了枯水期提前且延长及湖区生态环境日益恶化的问题,对于此问题江西政府提出了一种科学的工程措施--鄱阳湖水利枢纽（简称枢纽）。然而,枢纽对越冬候鸟栖息地的影响尚无定量研究。以鄱阳湖食块茎鸟类--白鹤（Grus leucogeranus）、白枕鹤（Grus vipio）和小天鹅（Cygnus columbianus）的栖息地为研究对象,利用3S技术结合生态学知识,在ArcGIS平台上搭建了食块茎鸟类栖息地适宜性评价模型,使用二维水动力模型联合适宜性评价模型,生成鄱阳湖在兴建枢纽前、后的食块茎鸟类栖息地适宜性分布图。选取工程调度时期水位相对稳定时段,以鄱阳湖无枢纽状态下星子水位为基础,探究鄱阳湖在不同水位时,有拟建枢纽和无拟建枢纽状态下食块茎鸟类的栖息地适宜性的变化,定量分析拟建枢纽对候鸟栖息地适宜性造成的影响。研究发现：枢纽的调度规则具有一定的科学性,水位调度方案对湖泊食块茎鸟类越冬初期栖息产生的影响较小,但会牺牲一部分越冬后期适合食块茎鸟类栖息的区域。拟建枢纽选址处至都昌站的食块茎鸟类栖息地适宜性受枢纽的负面影响最为显著,各级自然保护区之中,北部省级候鸟自然保护区受其负面影响最大,此保护区将减少18.01-39.80 km²适合食块茎鸟类栖息的面积。但是枢纽的运行能增加湖泊土壤水含量,使食块茎鸟类更易于觅食,且能增加喜食块茎鸟类的食物丰富度。本研究可为为今后鄱阳湖湖区水环境规划和水生态管理维护提供一定的科学参考。     

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.     

Influence of migrant tundra swans (Cygnus columbianus) and Canada geese (Branta canadensis) on aquatic vegetation at Long Point, Lake Erie, Ontario

Numerous studies have shown that large, herbivorous waterfowl can reduce quantity of aquatic plants during the breeding or wintering season, but relatively few document herbivory effects at staging areas. This study was done to determine if feeding activities of tundra swans (Cygnus columbianus columbianus) and Canada geese (Branta canadensis) had a measurable additive influence on the amount of aquatic plants, primarily muskgrass (Chara vulgaris), wild celery (Vallisneria americana), and sago pondweed (Potamogeton pectinatus), removed during the fall migration period at Long Point, Lake Erie, Ontario. Exclosure experiments done in fall 1998 and 1999 showed that, as compared to ducks and abiotic factors, these two large herbivorous waterfowl did not have any additional impact on above or below ground biomass of those aquatic plants. As expected, however, there were substantial seasonal reductions in above-ground and below-ground biomass of aquatic plants in wetlands that were heavily used by all waterfowl. We suggest that differences in large- and small-scale habitat use, feeding activity, and food preferences between tundra swans and other smaller waterfowl as well as compensatory herbivory contributed to our main finding that large waterfowl did not increase fall reductions of Chara spp, V. Americana, and P. pectinatus biomass.     

Population Structure of Tundra Swans Wintering in Eastern North America

ABSTRACT Our objective was to determine whether there were subpopulations within the eastern population of tundra swans (Cygnus columbianus columbianus) wintering along the mid-Atlantic coast. Movement rates between regions were substantial enough to result in continual mixing of wintering birds. Thus, we were unable to identify distinct subpopulations based on exclusive use of specific wintering areas. These birds should therefore be monitored, and their harvest managed, as if they were one population.     

Changes in habitat suitability influence non‐breeding distribution of waterbirds in central Europe

Waterbird species have different requirements with respect to their non‐breeding areas, aiming to survive and gain condition during the non‐breeding period. Selection of non‐breeding areas could change over time and space driven by climate change and species habitat requirements. To help explain the mechanism shaping non‐breeding area selection, we provide site‐specific analyses of distributional changes in wintering waterbirds in central Europe, located at the centre of their flyways. We use wintering waterbirds as a highly dynamic model group monitored over a long‐time scale of 50 years (1966–2015). We identified species habitat requirements and changes in habitat use at the level of 733 individual non‐breeding (specifically wintering) sites for 12 waterbird species using citizen‐science monitoring data. We calculated site‐specific mean numbers and estimated site‐specific trends in numbers. The site‐specific approach revealed a general effect of mean winter temperature of site (seven of 12 species), wetland type (all species) and land cover (all species) on site‐specific numbers. We found increasing site‐specific trends in numbers in the northern and/or eastern part of the study area (Mute Swan Cygnus olor, Eurasian Teal Anas crecca, Common Pochard Aythya ferina, Great Cormorant Phalacrocorax carbo and Eurasian Coot Fulica atra). Common Merganser Mergus merganser, Great Cormorant, Grey Heron Ardea cinerea, Common Pochard, Eurasian Coot and Common Moorhen Galinulla chloropus increased their site‐specific numbers on standing industrial waters with traditionally low fish stock. The site‐specific dynamics of bird numbers helped us to identify general preference for sites reducing winter harshness (warmer areas, running waters and more wetlands in the site vicinity), as well as indicating climate‐driven changes in spatial use of wintering sites (northern/north‐eastern range changes and changes in preference for industrial waters). This fine‐scale (site‐specific) approach can reveal large‐scale range and distribution shifts driven by climate and environmental changes regardless of the availability of large‐scale datasets.     

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...     

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.     

鄱阳湖湖岸带景观变化

湖岸带是水陆生态系统过渡带,是人类活动最集中的区域之一,也是生态系统较为脆弱的区域。湖岸带具有重要的生态功能,湖岸带研究对于湖泊湿地生态系统保护具有重要意义。利用1995年,2000年,2005年和2010年4个时期的同水位条件下鄱阳湖湿地湖岸带遥感影像,对鄱阳湖湖岸带的景观进行了研究,结果表明,鄱阳湖湖岸带各种景观类型的面积变化显著,2010时期的水体面积较1995年、2000年和2005年时期减少近100km~2,绿地面积2010年较1995年减少近500km~2,建设用地和裸地面积2010年较1995年增加700km~2以上。景观指数变化明显,景观斑块数量逐年上升,最大斑块面积逐年减小,周长面积分形指数逐年加大,辛普森和香浓景观多样性指数逐年增大,表明湖岸带景观破碎化程度逐年加强。通过遥感影像解译结果综合分析,鄱阳湖湖岸带建设用地和裸地增加主要表现在沙化土地面积、交通建设用地面积和居民建筑建设用地的增加有关。