迁徙停歇期鸻鹬类在崇明东滩潮间带的食物分布

崇明东滩是鸻鹬类在东亚-澳大利西亚迁徙路线上重要的迁徙停歇地,滩涂上的底栖动物为迁徙的候鸟提供了丰富的食物来源。采用圆筒取样法对崇明东滩潮间带的大型底栖动物群落进行了研究。研究表明,该区域的大型底栖动物主要有腹足类、双壳类、甲壳类、多毛类环节动物及昆虫幼虫等类群。其中以腹足类密度最高（（2805±360）个/m^2）,约占底栖动物总密度的80%。其次为双壳类,密度为（320±31）个/m^2。双壳类的生物量（湿重）为（51.4±7.8）g/m^2,腹足类（38.7±5.1）g/m^2,两者占底栖动物总生物量的90%以上。不同类群的底栖动物在潮间带的空间分布上有显著差异。腹足类主要分布在海三棱藨草带,双壳类在海三棱藨草外带至光滩区域分布较多。从空间分布来看,腹足类在崇明东滩的北部区域分布较多,在南部区域则明显减少。双壳类在南北各条样线上的平均密度没有显著差异。除双壳类在秋季迁徙期的密度高于春季迁徙期外（P〈0.001）,其他类群的底栖动物在春季和秋季迁徙期的密度均无显著差异（P〉0.05）。     

山东曲阜大沂河春季鸻鹬类的初步调查

2008年3月至5月初,采用样方法对山东曲阜大沂河流域的鸻鹬类进行了调查.共记录8种鸻鹬类,隶属3科4属.发现保留了天然地貌的河道比人工改造的河道更适宜鸻鹬类栖息;天然河道中,水面积比例为0.4和0.6的生境更吸引鸻鹬类,鸻鹬类数量随着青草覆盖率的增加而上升;人为干扰对鸻鹬类的数量有显著影响,充分的隐蔽条件会降低人为干扰对鸻鹬类的影响.保护大沂河的鸻鹬类多样性将为曲阜市的生态保护提供科学依据,并为南四湖流域的生物多样性保护提供有益经验.     

基于MaxEnt模型的渤海湾沿岸鸻鹬类栖息地适宜性评价

渤海湾沿岸是鸻鹬类迁徙路线的重要栖息地。由于自然和人为原因,栖息地面积减少,质量恶化。因此,开展渤海湾沿岸鸻鹬类栖息地适宜性评价,对湿地生物多样性保护有重要意义。基于鸻鹬类点位信息和环境因子数据,利用MaxEnt模型对渤海湾沿岸2000年和2015年鸻鹬类栖息地适宜性进行评价。结果表明:土地利用/覆被、NDVI、年均气温、坡向是影响鸻鹬类分布的主要因子;鸻鹬类适宜栖息地主要分布在河北唐山南部和天津滨海地区。研究时段内渤海湾沿岸适宜栖息地面积总体有所下降,河北适宜栖息地面积下降,天津和山东增加;栖息地适宜性增加地区主要集中于天津南部、山东东南部,下降地区主要分布在河北丰南、黄骅及天津宁河县。该研究可识别渤海湾沿岸鸻鹬类适宜栖息地的分布范围及变化趋势,对该区域鸻鹬类保护及栖息地管理具有重要参考意义。     

上海市南汇东滩围垦后海岸带湿地冬春季水鸟生境选择

2009年12月-2010年5月,对上海市南汇东滩围垦后城市湖泊湿地、实验修复湿地、抛荒湿地等三类人工湿地冬季雁鸭类群落和春季鸻鹬类群落展开调查,并对雁鸭类和鸻鹬类群落特征与相应生境因子进行相关分析.结果显示:三类湿地雁鸭类的种类无显著差异,但密度有显著差异:实验修复湿地是抛荒湿地的3.77倍,是城市湖泊湿地的6.03倍.鸻鹬类种类和密度:实验修复湿地分别是抛荒湿地的2.88和5.70倍.两者种类和密度差异均极显著.雁鸭类种类、密度、Shannon-Wiener多样性指数(H')与明水面面积显著正相关;种类、H'与植被面积显著负相关;种类、密度、H'均匀度与植被盖度显著负相关;H'与平均水位显著正相关.鸻鹬类种类、密度均与裸露浅滩面积显著正相关.建议对已围垦土地的利用以大中型鱼蟹塘、水田为主,以提供足够的明水面给越冬的雁鸭类栖息.通过割除植被等方法在春季提供一定的裸露浅滩面积供迁徙的鸻鹬类栖息.     

盐地碱蓬盐沼与相邻泥质滩涂湿地迁徙期鸻鹬类的群落组成及行为差异

盐地碱蓬(Suaeda salsa)盐沼湿地是黄渤海地区河口区域的重要湿地类型, 是水鸟迁徙停歇期的重要栖息地。本研究以辽河口国家级自然保护区为研究地点, 通过对盐地碱蓬盐沼湿地和相邻泥质滩涂两个固定样区连续三年的水鸟组成调查和行为观察, 分析盐地碱蓬盐沼湿地在鸻鹬类多样性维持和栖息地利用中的作用。共记录到鸻鹬类水鸟28种6,348只次, 其中盐地碱蓬湿地记录到4科13种, 泥质滩涂记录到4科27种, 泥质滩涂的物种多样性显著高于盐地碱蓬盐沼湿地。此外, 盐地碱蓬盐沼湿地与相邻的泥质滩涂的鸻鹬类鸟类群落组成存在较大差异, 盐地碱蓬盐沼湿地的鸟类群落组成以体型较大的大杓鹬(Numenius madagascariensis)、白腰杓鹬(N. arquata)、灰鸻(Pluvialis squatarola)等为主, 而泥质滩涂以环颈鸻(Charadrius alexandrinus)、黑腹滨鹬(Calidris alpina)等小型鸻鹬类为主, 这说明两种生境在鸟类多样性维持中具有不同的功能。行为分析发现, 泥质滩涂中栖息鸟类的主要行为为取食(58.71%-93.26%), 而盐地碱蓬盐沼湿地鸟类的行为既包括较大比例的取食, 也包括休息, 特别是在春季迁徙期。这进一步说明, 两种生境在水鸟的栖息地利用中具有一定的生态功能差异。尽管盐地碱蓬盐沼湿地记录到的鸟类物种数和数量均低于泥质滩涂, 但是, 两种生境中存在较大比例的共同分布物种, 这说明其生态功能具有较强的生态互补性, 二者作为一种独特的湿地景观组合, 在鸻鹬类迁徙停歇期的栖息地利用和物种多样性维持中发挥着不可替代的作用。     

洪泽湖冬春季鱼塘生境中鸻鹬类群落特征与栖息模式

2005年冬季和2006年春季及冬季对洪泽湖东部湿地自然保护区内淮河入洪泽湖河口处(33°06'～33°07'N,118°29'～118°30'E)人工鱼塘生境中鸻鹬类群落进行了研究.设置了4个样地,总面积157 hm2.共记录到鸻鹬类19种,其中冬季10种,春季15种.从数量上看,冬季鱼塘中的鸟类总数量远大于春季.在冬春季滞留期间,鸻鹬类种群数量变动比较剧烈,反映了其迁徙集中的特点.鸻鹬类主要在鱼塘生境中休息和觅食,对鱼塘内泥滩和浅水区小生境利用率最高.洪泽湖地区的鱼塘生境和渔业方式使鱼塘成为鸻鹬类冬、春季的重要栖息地.     

杭州湾及钱塘江河口水鸟群落组成、季节动态及种间相关性分析

2007年7月-2010年11月,对杭州湾曹娥江口至甬江口间潮间带及其附近海涂水库的水鸟群落进行定期监测,共记录9目18科128种.其中,候鸟119种,占总数的93％;而国家重点保护鸟类11种.对13种鸻鹬类和9种鸭类进行种群数量随时间变化的种间相关性分析,两个类群各有21对和23对显著相关.通过对水鸟季节动态及其迁徙模式分析,将其迁徙过程分为6个阶段,即:4月上旬-5月中旬、7月下旬-9月下旬(旅鸟迁徙高峰期)、2月下旬-3月下旬、10月上旬-12月中旬(冬候鸟迁徙高峰期)、12月下旬-次年2月中旬(越冬期)和5月下旬-7月中旬(繁殖期).种间吸引作用可能是影响该区域迁徙季节鸻鹬类和越冬地鸭类群落组成的重要原因,而该区域特殊地理位置和水鸟群落构成可能是造成鸻鹬类春秋季迁徙高峰数量巨大差异的主要因素.     

广西防城港东湾红树林湿地春季小型底栖动物丰度与生物量

于2019年春季在广西防城港东湾红树林湿地,设置4个断面共13个站位采集沉积物样品,对小型底栖动物的类群组成、丰度和生物量进行研究。共鉴定出11个以上的小型底栖动物类群,分别为自由生活海洋线虫、桡足类、多毛类、寡毛类、介形类、等足类、双壳类、涟虫、海螨类、腹足类、枝角类和其他未鉴定类群;小型底栖动物总平均丰度为(10364±8012) ind·10 cm-2;线虫是绝对优势类群,占小型底栖动物总丰度的95.38%,平均丰度为(9886±7746) ind·10 cm~(-2),其次为桡足类,占比为2.14%,平均丰度为(221±358) ind·10cm~(-2);小型底栖动物的总平均生物量为(10502±7894)μg·10 cm~(-2),各断面的生物量趋势依次为:断面3断面2断面1断面4。     

湄洲湾潮间带底栖生物多样性

为了了解福建省湄洲湾潮间带底栖生物的物种多样性、数量时空分布及群落结构现状,2005年11月和2006年4月在湄洲湾潮间带选择了灵川(Mch1)、苏厝(Mch2)、郭厝(Mch3)、东吴(Mch4)和东桥(Mch5)5条断面进行了调查。共鉴定潮间带底栖生物225种,其中多毛类、软体动物和甲壳动物占总种数的88.00%,三者构成潮间带底栖生物的主要类群。断面间比较,东桥断面种数较多,苏厝断面较少。季节比较,春季各断面种类较秋季多。平均生物量22.91g/m2,以软体动物居第一位,甲壳动物居第二位;平均栖息密度为388个/m2,以多毛类居第一位,软体动物居第二位。生物量以中潮区>低潮区>高潮区;栖息密度以低潮区>中潮区>高潮区。调查结果显示湄洲湾潮间带底栖生物物种多样性较高,群落结构相对稳定。     

流沙湾海草床重金属富集特征

海草床是一种重要的海洋湿地生态系统,首次研究了流沙湾海草床重金属(铜、铅、镉、锌)的富集特征,并评价其潜在生态危害.研究表明:水体和沉积物环境中的重金属含量很低,潜在生态危害轻微,但是海草床大型底栖生物(绿藻、海草、双壳类和腹足类)对这4种重金属具有富集作用,其中对镉的富集最显著.绿藻对铜、铅和锌的富集效应明显大于海草,腹足类对铜、铅和锌的富集效应明显大于双壳类;而对镉的富集效应,情况正好相反.双壳类生物体内铅和镉含量普遍超一类标准,超标程度较高.     

Sandpipers go with the flow: Correlations between estuarine conditions and shorebird abundance at an important stopover on the Pacific Flyway

Estuaries of major rivers provide important stopover habitat for migratory birds throughout the world. These estuaries experience large amounts of freshwater inputs from spring runoff. Understanding how freshwater inputs affect food supply for migrating birds, and how birds respond to these changes will be essential for effective conservation of critical estuarine habitats. We estimated trends over time in counts of Western Sandpiper (Calidris mauri) and Pacific Dunlin (Calidris alpina pacifica) during northward migration on the Fraser River estuary, British Columbia, Canada, where shorebirds feed extensively on intertidal biofilm and invertebrates. We also examined whether counts were correlated with a suite of environmental variables related to local conditions (precipitation, temperature, wind speed and direction, solar radiation, tidal amplitude, and discharge rates from the Fraser River) during a total of 540 surveys from 1991 to 2019. Counts of Western Sandpiper declined ~54% (−2.0% per annum) over the entire study period, and 23% from 2009 to 2019 (−0.9% per annum). Counts of Pacific Dunlin did not show a statistically significant change over the study period. Counts of shorebirds were lower when discharge from the Fraser River was high, which we propose results from a complex interaction between the abrupt changes in salinity and the estuarine food web related to the quantity or quality of intertidal biofilm. Counts were also higher when tidal amplitude was lower (neap tides), potentially related to longer exposure times of the mudflats than during spring tides. Effects of wind are likely related to birds delaying departure from the stopover site during unfavorable wind conditions. The negative trend in migrating Western Sandpipers is consistent with declines in nonbreeding areas as observed in Christmas Bird Counts. Understanding causes of population change in migratory shorebirds highlights the need for research on mechanistic pathways in which freshwater inputs affect food resources at estuarine stopovers.     

鸭绿江口及邻近海域生物群落的胁迫响应

利用ABC曲线法结合粒径谱理论对鸭绿江口近岸海域的生物群落特征、优势种演替、多样性水平、稳定性状况等进行了分析,并尝试构建了鸭绿江口近岸海域生物群落稳定性的评估模型.研究结果表明,鸭绿江口滨海湿地生物群落结构相对简单,优势种演替明显,受外界干扰较大.春、夏季浮游植物以r-对策者为主,群落数量偏离平衡点;秋季以r-对策者为主的微小型浮游植物逐渐被中大型k-对策者演替,群落完成反馈调节,恢复到平衡点.浮游动物由于较高的能量供应其幼体全年一直处于较高优势水平,但生态效率转换相对较慢.潮间带底栖生物群落结构相对简单,优势种演替明显,系统具有低多样性低密度的特点,群落在夏季受外界扰动较大.游泳生物群落主要以小型个体为主,已处于极不稳定状态.构建的群落稳定性评估模型测算结果与上述结论基本一致,这也验证了该评估模型具有一定的有效性与实用性.综合以上分析结果,说明鸭绿江口近岸海域生物群落稳定性较差,受外界干扰比较严重.     

Stopover decision during migration: physiological conditions predict nocturnal restlessness in wild passerines

During migration, a number of bird species rely on stopover sites for resting and feeding before and after crossing ecological barriers such as deserts or seas. The duration of a stopover depends on the combined effects of environmental factors, endogenous programmes and physiological conditions. Previous studies indicated that lean birds prolong their refuelling stopover compared with fat birds; however, the quantitative relationship between physiological conditions and stopover behaviour has not been studied yet. Here, we tested in a large sample of free-living birds of three European passerines (whinchats, Saxicola rubetra, garden warblers, Sylvia borin and whitethroats, Sylvia communis) whether the amount of migratory restlessness (Zugunruhe) shown at a stopover site depends on physiological conditions. An integrated measure of condition based on body mass, amount of subcutaneous fat and thickness of pectoral muscles strongly predicted the intensity of Zugunruhe shown in recording cages in the night following capture. These results provide novel and robust quantitative evidence in support of the hypothesis that the amount of energy reserves plays a major role in determining the stopover duration in migratory birds.     

Seasonal Variations in the Diet and Foraging Behaviour of Dunlins Calidris alpina in a South European Estuary: Improved Feeding Conditions for Northward Migrants

During the annual cycle, migratory waders may face strikingly different feeding conditions as they move between breeding areas and wintering grounds. Thus, it is of crucial importance that they rapidly adjust their behaviour and diet to benefit from peaks of prey abundance, in particular during migration, when they need to accumulate energy at a fast pace. In this study, we compared foraging behaviour and diet of wintering and northward migrating dunlins in the Tagus estuary, Portugal, by video-recording foraging birds and analysing their droppings. We also estimated energy intake rates and analysed variations in prey availability, including those that were active at the sediment surface. Wintering and northward migrating dunlins showed clearly different foraging behaviour and diet. In winter, birds predominantly adopted a tactile foraging technique (probing), mainly used to search for small buried bivalves, with some visual surface pecking to collect gastropods and crop bivalve siphons. Contrastingly, in spring dunlins generally used a visual foraging strategy, mostly to consume worms, but also bivalve siphons and shrimps. From winter to spring, we found a marked increase both in the biomass of invertebrate prey in the sediment and in the surface activity of worms and siphons. The combination of these two factors, together with the availability of shrimps in spring, most likely explains the changes in the diet and foraging behaviour of dunlins. Northward migrating birds took advantage from the improved feeding conditions in spring, achieving 65% higher energy intake rates as compared with wintering birds. Building on these results and on known daily activity budgets for this species, our results suggest that Tagus estuary provides high-quality feeding conditions for birds during their stopovers, enabling high fattening rates. These findings show that this large wetland plays a key role as a stopover site for migratory waders within the East Atlantic Flyway.     

On the use by birds of intertidal areas of the Tagus estuary: implications for management

The use of intertidal areas of the Tagus estuary by birds was re-analysed, based on data from 1990 to 1993, to describe (i) the temporal and spatial patterns of use of intertidal areas, (ii) the diet of birds during winter and (iii) the habitat selection patterns of feeding birds, during winter. The most common birds in the estuary were gulls, waders and ducks. Highest densities were recorded for most species in autumn and winter. The spatial distribution of birds in the intertidal areas of the estuary did not vary significantly across seasons, although broader distributions occurred when bird populations were present in high numbers. In autumn, use of intertidal areas was highly variable. Specific areas in the estuary were identified as holding important densities of birds, or having a high species richness. The most abundant species selected feeding areas according to sediment type, although the presence of channels, saltmarsh or humans also influenced the distribution of birds. The invertebrates Carcinus maenas, Hediste diversicolor and Scrobicularia plana were identified as key prey species. Plant material was important as food for ducks. Implications of these findings for the management of the estuary are discussed.     

迁徙鸟类中途停歇期的生理生态学研究

大多数候鸟的迁徙活动由迁徙飞行和中途停歇两个部分组成。在迁徙过程中,鸟类要多次交替经历消耗能量的飞行阶段和积累能量的中途停歇阶段。从鸟类在中途停歇时期的能量积累速度、体重变化模式以及迁徙飞行中的禁食或食物限制、食物种类的改变、中途停歇的能量快速积累过程对消化器官的影响等方面,对目前迁徙鸟类的生理生态学研究成果进行回顾,并提出有待解决的问题及今后的研究方向。     

Population‐wide body mass increment at stopover sites is an unreliable indicator of refuelling rates in migrating waders

Estimates of refuelling rates in migrating waders are best based on intra‐seasonal recaptures of individually marked birds. This method, however, has methodological problems associated with capture effects and difficulties in attaining sufficient sample sizes. An alternative method had been proposed whereby refuelling rates are approximated by the body mass increment from the slope of the regression between body masses of all birds caught at a site and date. We investigated the appropriateness of this indicator with a simulation study in non‐synchronized migratory species (i.e. arrivals and departures of individuals at the stopover site are not synchronized). Simulation results indicated that the mass increment across the population may be used as an approximation of refuelling rate only in populations with low turnover rates (percentage of birds arriving at/departing from stopover site per day <2%) and ideally with constant numbers of staging birds. The mass increment of non‐synchronized populations with moderate or high turnover rates (higher than 5%) depends mainly on body masses of arriving birds and is not indicative of the individual rate of refuelling. The results of the simulation study were confirmed with empirical data gathered from Wood Sandpiper Tringa glareola and Common Snipe Gallinago gallinago during their autumn migration at a stopover site in Poland. The population mass increment methods considerably underestimated refuelling rate obtained from the recapture‐based approach of individual birds in both species. As a consequence, we suggest that population mass increment should not be used as an indicator of refuelling rates in non‐synchronized stopover populations of migrating waders.     

Do systematic daily counts reflect the total number of birds using stopover sites during migration? A test with Eurasian Spoonbill

Many migratory waterbird populations are declining and wetland connectivity is a major conservation challenge. The importance of stopover sites has been typically assessed by peak counts of birds, which underestimate the total number of individuals using the site over a migratory season, especially in small wetlands. We analysed the accuracy of different daily count schemes to estimate the total number of Eurasian Spoonbill that stop over at two tidal wetlands during their autumn migration and compared them with the birds observed leaving the area each day. Total number of birds was obtained by combining numbers of each flock of birds leaving during the season. We obtained different accurate predictors for birds departing daily from each stopover area. Daily low-tide counts were the best predictor of the daily number of birds that stopover in a tidal wetland mainly used to refuel (staging site), whereas daily high-tide counts were best at a wetland mainly used to rest (stopover site). Each measure also accurately predicted annual trends for each area, respectively. Daily low-tide counts could be used as an easy census method to estimate the daily number of individuals using a staging site consistently during the entire migratory season, as well as indicating trends, without the necessity of estimating turnover rates. By contrast, daily high-tide counts would be especially suitable for determining the minimum relevance and the population trends of other tidal wetlands (especially the smaller ones), which regularly support moderate numbers of spoonbills during migration where birds use to stop over for less than one day. This method developed for the spoonbill, a flagship and umbrella species, could represent a first step in improving the conservation of other endangered migratory waterbird populations.     

Body fat influences departure from stopover sites in migratory birds: evidence from whole-island telemetry

Migration remains one of the great mysteries of animal life. Small migratory birds rely on refuelling stopovers after crossing ecological barriers such as deserts or seas. Previous studies have suggested that fuel reserves may determine stopover duration but this hypothesis could not be tested because of methodological limitations. Here, we provide evidence that subcutaneous fat stores determine stopover duration by measuring the permanence of migratory garden warblers (Sylvia borin) on a small Mediterranean island during spring migration with telemetry methods. Garden warblers with large amounts of fat stores departed the island significantly sooner than lean birds. All except one fat bird left the island on the same evening after capture, with a mean total stopover estimate of 8.8 hours. In contrast, the mean estimated total stopover duration of lean birds was 41.3 hours. To our knowledge, this is the first study that measures the true minimum stopover duration of a songbird during migration.     

福建沿海湿地鸻鹬类资源调查

1997年1月～2003年4月,采用直接计数法与航线调查法相结合的方法对福建省海岸湿地的涉禽进行了调查,共发现鸻鹬类43种及亚种计56386只。结合以往的调查记录,得知福建沿海鸻鹬类共53种及亚种,占全国该类群总种数的62％。冬候鸟和旅鸟是本地鸻鹬类中占优势的生态类群。目前沿海滩涂的围垦和鸟类食物的减少,是鸻鹬类所面临的主要威胁。尽快制定湿地保护与合理利用的规划,对福建沿海湿地鸟类的保护至关重要。闽江口湿地不仅是鸻鹬类集中分布的区域,同时也是世界珍禽黑脸琵鹭(Platalea minor)重要的停歇地,应尽快建立闽江口湿地自然保护区。