江西省中华秋沙鸭越冬种群现状调查与胁迫因素分析

于2009年2月对江西省五大水系:赣江、抚河、信江、饶河和修水的越冬中华秋沙鸭种群展开专项调查,分析了江西省越冬中华秋沙鸭种群的数量、性比、空间分布格局、生境特征及其胁迫因素.主要采用样线法在五大水系的主要河道展开同步调查,调查样线总长度400 km.结果发现,江西省越冬中华秋沙鸭有26个生活群255只个体,雌雄性比为119:117,其生活群雌雄性比也多接近1:1.江西省五大水系中,除赣江外,在其他4个水系均发现有中华秋沙鸭越冬群体.除了在曾有中华秋沙鸭越冬记录的婺源、贵溪、弋阳、浮梁、修水发现其越冬群体外,还首次在江西省境内的宜黄、武宁和龙虎山地区发现有较大的中华秋沙鸭越冬群体,而且龙虎山泸溪河段分布有本次调查中个体数量最大的有53只个体的群体.人类采砂活动、水质污染、非法捕鱼和家禽饲养是目前影响该种群生存的主要胁迫因素.     

江西鄱阳湖流域中华秋沙鸭越冬期间的集群特征

2010年11月—2011年3月,采用样线法对江西鄱阳湖流域8个河段的中华秋沙鸭Mergus squamatus的集群特征进行了研究。中华秋沙鸭的集群类型包括雄性群、雌性群、混合群、雌性孤鸭和雄性孤鸭5种类型。越冬期间共记录到89群次,432只次中华秋沙鸭。其中,混合群是最多的一种集群方式,孤鸭也是越冬期间出现频次较高的一种特殊的集群方式。集群类型存在时间变化(P<0.01)。混合群中,大多数群体中雌性个体数多于雄性个体或者是一雌一雄。89群次中,孤鸭和2—8只群占总群数的87.64%,提示中华秋沙鸭主要以集小群分散活动。中华秋沙鸭越冬期间的群体大小是(4.85±4.97)只/群。不同集群类型的群体大小差异较大。集群大小可能与采砂、捕鱼、食物的丰富度等环境因子有关。调查结果显示,中华秋沙鸭越冬期间的性比是1∶0.74(n=432)。中华秋沙鸭群体大小与性比有一定的关系。     

中华秋沙鸭在中国的近期越冬分布与数量

中华秋沙鸭(Mergus squamatus)以往在我国广有越冬记录,但分布点零散,且多为小群或零星个体,很少在同一地点见到10只以上的个体记录。20世纪90年代以来在个别地点虽发现有中华秋沙鸭的越冬群体,但缺少持续性观察结果。21世纪初在赣东北的弋阳、婺源相继发现中华秋沙鸭的较大越冬群,总数量至少超过100只,且数量和分布地点相对保持稳定。两地记录到的最大数量分别超过该种全球总量的1%,应当加强保护。     

天目溪中华秋沙鸭生态习性研究

中华秋沙鸭Mergus squamatus是全球濒危物种。2015—2018年在浙江省杭州市临安区天目溪开展了该物种越冬种群的监测研究。调查累计发现25群中华秋沙鸭,计106只次,平均每群4. 24只±0. 98只,性比为1∶3. 82,主要集成3～6只/群,分为3个类群,即孤雌群、雌性群和混和群。中华秋沙鸭主要栖息于开阔的河道,河宽30～60 m,附近有沙洲;水体较浅,水深40～60 cm;水流平缓,水流速度为0. 3～0. 5 m·s~(-1)。中华秋沙鸭对人为活动十分敏感,其栖息地远离居民点,距公路的距离可至30 m以内,但这种生境需要茂密的乔灌木或竹林隔离。     

江西宜黄、武宁发现中华秋沙鸭越冬群体

中华秋沙鸭(Mergus squamatus)属雁形目(Anseriformes)鸭科(Anatidae),分布地狭窄,繁殖地主要在俄罗斯东南部、北朝鲜和中国东北地区,越冬地主要在中国的中部和南部地区,少量越冬个体曾见于日本、南朝鲜和台湾,以及缅甸、泰国和越南北部地区(郑作新,1987;何芬奇等,2006).目前全球仅存约1 000～2 499只中华秋沙鸭成体,濒临灭绝(BirdLife International,2008),被世界自然保护联盟(IUCN)红皮书列为濒危种;我国也将中华秋沙鸭列为国家I级重点保护野生动物.     

中华秋沙鸭繁殖习性初报

2005年和2006年的4～5月在黑龙江省伊春市带岭碧水自然保护区对中华秋沙鸭(Mergussquamatus)的繁殖习性进行了初步研究,采用直接观察法观测了4个鸭巢.记录了巢的特征值、巢周围的环境因子以及中华秋沙鸭繁殖期的活动情况.结果表明,中华秋沙鸭每年的3月下旬至4月上旬陆续到达永翠河流域,9月末至10月下旬陆续迁离,居留时间210 d左右.其对栖息环境要求较高,行为方式独特,营巢树种皆为老龄榆树(Ulmus propinqua)或杨树(Populus ussuriensis),一般距河流和道路较近,两巢相距最近距离大于1.6 km.最大距离10 km,各巢洞口方向视野皆很开阔,巢址附近的植被相对稀疏.孵化期雌鸭用于孵化的时间占85.3%,取食仅占14.7%,雄鸭不参与孵化和育雏,用于觅食和取食的时间占24.4%.     

普通秋沙鸭

正中国有4种秋沙鸭,即白秋沙鸭(斑头秋沙鸭)、中华秋沙鸭、红胸秋沙鸭和普通秋沙鸭,其中普通秋沙鸭是秋沙鸭中个体最大、数量最多、分布最广的一种。普通秋沙鸭体长54~68厘米,成年个体体重可达1~2千克。别看普通秋沙鸭名字无奇,可是给它起名的人,却大有来头。1758年瑞典博物学家林奈第一次描述了普通秋沙鸭。普通秋沙鸭繁殖于北美洲北部和欧亚大陆,南下到美国南部和中国中部过冬。冬季和迁徙期间在中国东部和长江流域是常见的,而且种群数量较大,遍布于各种湖泊、山区溪流和低地。     

鄱阳湖保护区白琵鹭越冬种群分布

2007年10月至2010年3月3个冬季的调查显示,鄱阳湖国家级自然保护区白琵鹭(Platakakucorodia)种群数量在12月或1月达到峰值,3个越冬期最大种群数量分别为4 757只、10 385只和7 268只.大湖池、沙湖、常湖池是白琵鹭主要的栖息地,每个越冬期在这3个湖泊栖息的白琵鹭种群数量占保护区总数量的...     

中华秋沙鸭冬季生态习性的初步观察

2008年11～12月,在龙虎山国家级风景区对中华秋沙鸭的越冬生态进行了观察.包括居留情况、种群大小、性比、食性、栖息地、鸣叫、行为等.     

性别和温度对中华秋沙鸭越冬行为的影响

2011年11月至2012年3月,在江西婺源采用瞬时扫描法探讨性别和温度对中华秋沙鸭行为的影响.中华秋沙鸭越冬期的主要行为是取食、休息、游泳和修整.时间分配方面,雌雄中华秋沙鸭仅社会行为[雌:(2.13±1.40)％和雄:(3.24±1.55)％]存在显著性差异(t＝-2.258,df＝34,P＜0.05),其他行为差异不显著(P＞0.05).原因有:(1)非繁殖期雌雄中华秋沙鸭主要任务均为生存;(2)雌雄个体大小差异不大,对能量的需求量相似.日活动节律方面,雌雄的取食和休息行为均存在显著的节律性变化,分别为雌:取食(F(10,165)＝5.19,P＜0.05)、休息(F(10,165)＝ 2.56,P＜0.05)和雄:取食(F(10,165)＝ 7.55,P＜0.05)、休息(F(10,165)＝ 3.48,P＜0.05),其他行为节律均不显著(P＞0.05).温度对中华秋沙鸭越冬行为的影响较大,时间分配方面,在＜10℃月份环境下,取食(t＝-2.166,df＝ 16,P＜0.05)行为显著高于＞10℃月份,而游泳(t＝5.096,df＝ 16,P＜0.05)行为则相反,其他行为差异不显著(P＞0.05).这一结果表明,平均温度降低时,中华秋沙鸭需要摄取更多的食物以补充寒冷天气能量的消耗,并减少游泳行为降低耗能.日活动节律方面,＞10℃月份中华秋沙鸭日活动节律,仅警戒(F(10,77)＝1.96,P＜0.05)行为存在显著的节律性变化,其他行为的节律性变化不显著(P＞0.05).＜10℃月份中华秋沙鸭取食(F(10,86)＝ 5.93,P＜0.05)和休息( F(10,86)＝ 3.42,P＜0.05)行为存在显著的节律性变化,其他行为的节律性变化不显著(P＞0.05).研究结果表明,温度可以改变中华秋沙鸭的日活动节律,低温使中华秋沙鸭在夜间消耗较多能量,因此中华秋沙鸭在上午花更多的时间取食来补充能量.休息行为在＞10℃月份,中午和傍晚均有一个小的高峰,而在＜10℃月份从11:00开始(除13:00-13:59)均保持较高的水平.中华秋沙鸭采取这种对策,可能是＜10℃月份,晚上和下午温度较低,为了减少消耗,从下午就开始增加休息行为.低温条件下,中华秋沙鸭增加修整和休息行为,这一结果支持“鸟类在低温环境下通过减少行为活动以降低能量消耗和热量损失”这一观点.     

中华秋沙鸭越冬行为时间分配及日活动节律

2007年12月-2008年1月和2008年11-12月,在江西省境内4条主要河流及其支流对中华秋沙鸭(Mergus squamatus)越冬期的各种行为活动节律及时间分配进行了实地调查研究。结果表明:中华秋沙鸭越冬期的主要行为有取食、游泳、理羽、静息、睡眠、游戏、飞行和观察。其中取食、游泳、理羽、静息呈明显的节律性变化,且取食与静息呈相反的节律变化;睡眠、飞行、游戏和观察没有明显的节律性变化。取食在7:00-8:00、10:00-11:00、12:00-13:00有明显的峰值,峰值平均间隔2.3h,其它时段具相近取食频次,且上午高于下午。睡眠和静息下午发生频次明显高于上午,并呈现节律性变化,对应3个取食高峰表现为低频次。行为时间分配如下:取食(46%),游泳(23%),理羽(9%)、静息和睡眠(各占8%)、飞行(4%)、游戏(2%)和观察(0.5%)。越冬期中华秋沙鸭大量时间用于取食,意图是为了积累能量。相关分析表明:取食与睡眠的发生呈显著负相关(R=-0.73,df=8,P0.05);取食与飞行的发生呈显著正相关(R=0.70,df=8,P0.05);理羽与静息的发生呈极显著正相关(R=0.88,df=8,P0.01);其他各种行为之间无显著相关性。     

安徽沿江两个浅水型湖泊越冬水鸟的季节动态(英文)

安徽沿江浅水型通江湖泊湿地是东亚-澳大利亚迁徙水鸟的重要越冬地和停歇地。近年来,高强度的渔业养殖使湿地严重退化,对越冬水鸟构成威胁。为了解湿地变化对越冬迁徙水鸟的影响,2007年11-2008年4月和2008年11月-2009年4月,对安徽菜子湖和升金湖11个样带内越冬水鸟的种类、数量及空间分布进行了调查,并分析了湖泊渔业模式对水鸟分布的影响。两个湖泊共统计到越冬水鸟7目12科43种。其中,菜子湖群38种,密度为8.2ind./hm2;升金湖42种,密度为3.5ind./hm2,优势种为鸿雁(Anser cygnoides)、豆雁(Anser fabalis)、小天鹅(Cygnus columbianus)和黑腹滨鹬(Calidris alpina)。越冬水鸟种类和数量在12月底-次年1月上旬达到最大值,但不同类型越冬群最大数量出现的具体时期有所不同。根据水鸟组成的聚类分析,可将水鸟栖息地分为三组。水鸟的分布与渔业模式有关,在自然捕捞区,鹤类、雁鸭类和鸻鹬类密度较大,在围网养殖区密度较小,而鹭类的密度在各湖区变化都较小。本研究结果提示,发展可持续渔业对于长江中下游浅水湖泊湿地越冬水鸟资源的保护具有重要意义。     

广东海丰鸟类自然保护区黑脸琵鹭越冬种群现状

黑脸琵鹭(Platalea minor)是全球性濒危鸟类,广东海丰鸟类自然保护区作为新发现的重要越冬地,具有全球保护意义.2004~2007年对保护区内黑脸琵鹭越冬种群的调查结果表明,该越冬种群数量逐年增加(27~72只),占全球总数比例也相应增加(2.2%~4.1%).其主要分布在红树林、沿海滩涂和人工养殖塘3种生境,其中,沿海滩涂累计记录到的个体数最多,达217只;人工养殖塘记录剑最大集群,为52只.需积极采取有效措施保护该越冬种群及其生境.     

Agricultural ponds as alternative habitat for waterbirds: spatial and temporal patterns of abundance and management strategies

The progressive lost of natural wetlands as a consequence of human activities has lead to the use of new habitats by the species linked to water presence. In Southeast Spain, thousands of irrigation ponds have been lately constructed to store water for agriculture and are used by waterbirds as an alternative habitat. For this study, breeding and wintering waterbirds were counted in a subset of irrigation ponds between 2002 and 2007. Breeding communities were more abundant than wintering communities, but they presented a similar richness and diversity. The ponds were selected by waterbirds according to their characteristics, and breeding communities were more selective than wintering communities. Our results enhance the importance of pond size (area), connectivity (distance to the nearest wetland) and habitat quality (resource offer and construction material) in the pond selection process. The presence and design of these impoundments could be playing a crucial role for some waterbirds species. Therefore, the long-term information provided here can be useful for establishing management strategies for these artificial wetlands.     

云南纳帕海湿地越冬黑鹳种群动态和迁徙

掌握种群动态以及迁徙习性对濒危候鸟的保护至关重要。2004~2005、2007~2008、2008~2009年的冬季(10月~次年4月),采用夜栖地直接计数法对云南省纳帕海湿地黑鹳(Ciconia nigra)的种群数量进行了监测。结果表明,在2004~2005、2007~2008、2008~2009年冬季,纳帕海湿地越冬黑鹳种群平均数量分别为39.6、128.6、181.8只,呈逐年增加的趋势;通常黑鹳10月下旬迁来,至次年3月中下旬迁离;纳帕海同时也是繁殖于蒙古国的黑鹳迁往印度越冬地的重要停歇地,过境时间集中在 11月中上旬。纳帕海湿地已经成为国内最为重要的黑鹳越冬地和迁徙停歇地,建议当地管理部门加强湿地管理,维持适当的浅水区域作为黑鹳的觅食地,另外需加强旅游管理,减少游客对黑鹳的干扰。     

Broad wintering range and intercontinental migratory divide within a core population of the near‐threatened pallid harrier

Aim To identify the migration routes and wintering grounds of the core populations of the near‐threatened pallid harrier, Circus macrourus, and highlight conservation needs associated with these phases of the annual cycle. Location Breeding area: north‐central Kazakhstan; Wintering areas: Sahel belt (Burkina Faso to Ethiopia) and north‐west India. Methods We used ring recovery data from Kazakhstan and satellite tracking data from 2007 to 2008 on six adults breeding in north‐central Kazakhstan to determine migration routes and locate wintering areas. In addition, one first‐year male was tagged in winter 2007–2008 in India. Results Data evidenced an intercontinental migratory divide within the core pallid harrier population, with birds wintering in either Africa or India. The six individuals tagged in north‐central Kazakhstan followed a similar route (west of the Caspian Sea and Middle East) towards east Africa, before spreading along the Sahel belt to winter either in Sudan, Ethiopia, Niger or Burkina Faso. Spring migration followed a shorter, more direct route, with marked interindividual variation. The bird tagged in India spent the summer in central Kazakhstan. Half of the signal losses (either because of failure or bird mortality) occurred on the wintering areas and during migration. Main conclusions Our study shows that birds from one breeding area may winter over a strikingly broad range within and across continents. The intercontinental migratory divide of pallid harriers suggests the coexistence of distinct migratory strategies within the core breeding population, a characteristic most likely shared by a number of threatened species in central Asia. Conservation strategies for species like the pallid harrier, therefore, require considering very large spatial scales with possibly area‐specific conservation issues. We highlight urgent research priorities to effectively inform the conservation of these species.     

Tunisian man‐made wetlands as alternative habitats for waterbirds and their role for conservation

The distribution of wintering waterbirds within some Tunisian artificial wetlands (AW) was studied during the 2004–2007 stable wintering periods. The survey has regarded 88 wetlands including 27 large dams, 25 hill dams and 36 hill lakes. We identified 42,840 individuals representing seven orders, eleven families, 37 species and six functional groups: dabbling ducks, grazing waterfowl, fish‐eaters, deep‐water foragers, shoreline foragers and waders. The population structure analysis showed an absolute dominance of the deep‐water foragers with approximately 82% of observed waterbirds. The total abundance survey showed a fluctuation of population sizes and richness, from thousands to few individuals and from 1 to 25 species, respectively. Analysis results showed that the species distribution is governed by several ecological factors and there was a significant correlation between species abundance and richness and some habitat variables such as area, depth, age, plant cover and hunting disturbance. Investigated AW revealed a significant carrying capacity and refuge serving for the conservation of numerous wintering and endangered waterbird species of high nature conservation value, the White‐headed Duck Oxyura leucocephala that has been observed with relatively high numbers representing more than 40% of the assessed Tunisian–Algerian population.     

Wintering Habitat Model for the North Atlantic Right Whale (Eubalaena glacialis) in the Southeastern United States

The coastal waters off the southeastern United States (SEUS) are a primary wintering ground for the endangered North Atlantic right whale (Eubalaena glacialis), used by calving females along with other adult and juvenile whales. Management actions implemented in this area for the recovery of the right whale population rely on accurate habitat characterization and the ability to predict whale distribution over time. We developed a temporally dynamic habitat model to predict wintering right whale distribution in the SEUS using a generalized additive model framework and aerial survey data from 2003/2004 through 2012/2013. We built upon previous habitat models for right whales in the SEUS and include data from new aerial surveys that extend the spatial coverage of the analysis, particularly in the northern portion of this wintering ground. We summarized whale sightings, survey effort corrected for probability of whale detection, and environmental data at a semimonthly resolution. Consistent with previous studies, sea surface temperature (SST), water depth, and survey year were significant predictors of right whale relative abundance. Additionally, distance to shore, distance to the 22°C SST isotherm, and an interaction between time of year and latitude (to account for the latitudinal migration of whales) were also selected in the analysis presented here. Predictions from the model revealed that the location of preferred habitat differs within and between years in correspondence with variation in environmental conditions. Although cow-calf pairs were rarely sighted in the company of other whales, there was minimal evidence that the preferred habitat of cow-calf pairs was different than that of whale groups without calves at the scale of this study. The results of this updated habitat model can be used to inform management decisions for a migratory species in a dynamic oceanic environment.     

Northern range shift may be due to increased competition induced by protection of species rather than to climate change alone

Few long‐term, large‐scale studies have been conducted about the factors likely to explain changes in species abundance and distribution in winter. Range shifts are generally attributed to the climate change or land use. This study shows that other factors such as species protection and the ensuing increasing numbers of individuals and competition could be involved. It details the progressive conquest of France, the most important European wintering area for great cormorant, in three decades as its legal protection by the EU Birds Directive. It is based on 13 exhaustive national counts. Cormorants first occupied the farthest areas (Atlantic and Mediterranean lagoons, then larger rivers) from the main‐core European breeding area, with only progressive occupancy of the northeastern part later. This strategy mainly resulted from competition for optimal available feeding areas. Suboptimal areas (smaller wetlands harboring smaller night roosts, colder northeastern French areas) and progressive fragmentation of large night roosts into smaller, better located ones minimized flight costs. The coldest areas were occupied last, once other areas were saturated. Their occupancy was favored locally by the global climate change, but it played a minor role in these strategies. Both factors induced only a small NNE shift of the weighted centroid range of the wintering population (2.6 km/year) which mainly resulted from competition (buffer effect). Only the 2009 cold wave decreased the total number of wintering cormorants at the national scale, once the population had probably reached the carrying capacity of the country, while the previous cold waves had a minor effect. Comparatively, there was a greater SSE range shift of the weighted centroid of the breeding population (4.66 km/year). Range shifts of other recently protected species have been attributed to the sole climate change in the literature, but competition due to the saturation of usual wintering or breeding areas should be considered too.