Waterbird Groups Research Articles

Distribution dynamics of waterbirds in Dongting Lake and surrounding lakes

Abstract Dongting Lake and the lakes surrounding it are spatially relatively independent, yet they form an inseparable integrated system for waterbirds. Understanding the changes in waterbird distribution pattern in Dongting Lake and surrounding lakes is important for waterbird conservation and management. Based on six surveys during the winter period of waterbird and habitat data, we studied the changes in distribution pattern of different functional group of waterbirds between Dongting Lake and surrounding lakes and explored the effect of habitat area in Dongting Lake on waterbird distribution. The results revealed that the habitat areas within Dongting Lake are larger but less stable, whereas those in the surrounding lakes are much smaller but more stable. During regular hydrology periods, waterbirds were mainly distributed in Dongting Lake, whereas most of the diving ducks and vegetation gleaners occurred in surrounding lakes; during extreme dry periods, many waterbirds shifted to surrounding lakes (e.g., dabbling ducks and gulls). The Percentage Similarity Index (PSI) of these groups, which reflects waterbirds’ distribution dynamics, exhibited negative correlations with changes in water area within Dongting Lake. The percentages of these water-dependent groups and water area in Dongting Lake exhibited a positive correlation. Water area in Dongting Lake could reflect the distribution pattern of waterbirds between Dongting Lake and surrounding lakes. Our results emphasize the importance of the overall protection of wetlands in the Dongting Lake region.

Threshold responses and relationships between waterbird distribution and habitat factors at Shengjin Lake, China

The wintering period is an essential part of the annual life history of waterbirds. The environmental conditions of habitats in winter directly affect the abundance and physical condition of waterbirds. Therefore, it is important to study the relationship between waterbird abundance and habitat factors. In this study, we conducted significance and threshold analyses between habitat factors and the waterbird community at Shengjin Lake, a Ramsar Site in China, using Redundancy Analysis (RDA), Spearman Correlation Analysis, and Threshold Indicator Taxa Analysis (TITAN). The results indicate that seven environmental variables significantly affected the abundance of waterbird communities, that is, fractional vegetation cover, degree of receding water, grassland area, mudflat area, shallow water area, deep water area, and distance to reeds. Waterbird communities exhibited significant threshold responses to all seven factors. The number of species significantly responding to different habitat factors varied among waterbird communities, with the highest number of species (15) responding to distance to reeds. Except for the deep water area and distance to reeds, waterbirds showed higher positive than negative thresholds for the remaining five factors. Different groups of waterbirds influenced the threshold responses of waterbird communities to habitat factors, and there were variations in how each waterbird group responded to these factors. The results of this study highlight the importance of habitat type, water recession degree, and shelter conditions in waterbird habitat selection. Minor differences in habitat structure can influence waterbird habitat preferences. Therefore, wetland management at Shengjin Lake should consider the specific habitat needs of different waterbird species.

Deteriorating habitat suitability and connectivity of waterbirds in the Bohai Sea Rim: Consequences of land use transformation

Wetlands in the Bohai Sea Rim play an indispensable role in maintaining the stability of waterbird populations on the East Asian-Australian flyway. However, motivated by economic development and urban expansion, coastal wetlands in this region have been extensively reclaimed, leading to a decline in the area and degradation of natural wetlands over the past two decades. We analyzed the temporal and spatial changes of suitable habitats of different groups of waterbirds and quantified habitat connectivity changes and the importance of different patches by using the Probability of Connectivity. The results show that the suitable habitat area of all the different groups of waterbirds decreased sharply from 2000 to 2020. In addition, the utilization ratio by waterbirds of artificial habitats increased. Land use is the primary environmental variable determining the distribution of suitable habitats. Meanwhile, the connectivity of habitats of different groups of waterbirds has also been declining. However, the patches of Tianjin and Hebei in Bohai Bay still have high importance for waterbirds, particularly shorebirds. Expanding existing protection areas to cover the above-mentioned patches is recommended. We also advocate stricter protection measures and necessary ecological restoration activities on both the natural and artificial wetlands.

Identifying research trends in avian migration tracking in Korea using text mining

Identifying avian migration routes and habitats is critical for species conservation and management. South Korea is an important region in the East Asian-Australasian flyway, inhabited by various migratory birds. In this study, previous research on avian migration routes in South Korea was systematically analyzed, and research trends and characteristics were determined. Among 64 peer-reviewed papers, the number of papers by year has gradually increased since the 2000s. Land birds were the most extensively studied, followed by wading birds, raptors, waterfowl, multiple waterbird groups, and shorebirds. Among the research methods, wildlife tracking devices were most commonly used (n = 32), followed by direct visual observation (n = 19), bird banding (n = 10), and stable isotope analysis (SIA; n = 3). Sinan-gun, a Korean island, received the greatest attention; several studies have been conducted across various regions throughout South Korea. Text mining showed that the following terms were frequently used and strongly correlated: ‘home’, ‘range’, ‘breeding’, ‘wintering’, ‘island’, ‘area’, and ‘habitat’. Based on our findings, we predict that, as technology advances, the number of studies on migration routes of a greater diversity of species using global positioning system (GPS) tracking and SIA will continue to increase.

Integrating suitable habitat dynamics under typical hydrological regimes as guides for the conservation and restoration of different waterbird groups

The operation of the Three Gorges Project (TGP) has influenced the wetland ecosystems downstream, thereby affecting the distribution of habitats suitable for waterbirds. However, dynamic studies on habitat distribution under different water regimes are lacking. Here, using data from three successive wintering periods representing three typical water regimes, we modelled and mapped the habitat suitability of three waterbird groups in Dongting Lake, which is the first river-connected lake downstream of the TGP, and a crucial wintering ground for waterbirds along the East Asian-Australasian Flyway. The results showed that the spatial pattern of habitat suitability varied among the wintering periods and waterbird groups. The analysis estimated the largest suitable habitat area for the herbivorous/tuber-eating group (HTG) and the insectivorous waterbird group (ING) under a normal water recession pattern, whereas early water recession had a more adverse effect. The suitable habitat area for the piscivorous/omnivorous group (POG) was higher under late water recession than under normal conditions. The ING was the most affected by hydrological changes among the three waterbird groups. Further, we identified the key conservation and potential restoration habitats. The HTG exhibited the largest key conservation habitat area compared to the other two groups, while the ING showed a potential restoration habitat area larger than its key conservation habitat area, indicating its sensitivity to environmental changes. The optimal inundation durations from September 1 to January 20 for HTG, ING and POG were 52 ± 7 d, 68 ± 18 d, and 132 ± 22 d, respectively. Therefore, the water recession starting in mid-October may be favourable for waterbirds in Dongting Lake. Altogether, our results can be used as guidance for prioritising certain management actions for waterbird conservation. Moreover, our study highlighted the importance of considering habitat spatiotemporal variation in highly dynamic wetlands when implementing management practices.

ORNITHOLOGICAL RESEARCH IN THE MID REACHES OF THE ARAKS RIVER IN ARMENIA

The Araks River is the main water artery in Armenia sharing a nearly 150 km border with Turkey. Its mid reaches historically served important passage grounds for migratory waterbirds. However, the left banks of the Araks River within its border strip have not been surveyed since the late 1960s due to restricted access. The research aimed to survey the species diversity of waterbirds and their habitats preferences along the river shoreline. In 2020 and 2021, a total of 55 waterbird species from 13 families have been observed. Their abundance peaked in summer and declined in midwinter which was due to reduced habitat availability during these seasons in the Ararat valley. The current research revealed that despite nesting grounds for waterbirds are limited along the length of the shoreline, the river continues to provide important stopover and foraging grounds for diverse groups of waterbirds before and during the periods of migration.

Impact of water level on spring bird assemblages in a natural river valley in central Europe

Water level appears to be crucial for waterbirds, especially in the changeable conditions prevailing in river valleys. One of the best preserved Central European rivers is the Biebrza in north-eastern Poland, which seasonally overflows in spring, creating optimal habitats for various waterbirds. We examined a number of environmental factors which could strongly influence different foraging groups and bird assemblages with respect to water surface area and depth. Number of waterbirds peaked during the second half of March, when a large wave of geese and ducks stopped over there. The species diversity was the greatest in the first half of April, when more species arrived from their wintering grounds. We did not find any relationship between water depth and total abundance, but the former did significantly influence the numbers of some ecological feeding groups of waterbirds, i.e. diving omnivores, diving carnivores and surface carnivores. We assume that higher water level in a river valley is favourable to birds during their spring passage, because it creates areas of shallow floodwater that are intensively used by many different aquatic species. Owing to the well-preserved hydrological conditions and its full protection as a national park, the Biebrza valley not only offers optimal conditions for migratory waterbirds, but is also a good research area for studies of the phenomena taking place in avian communities during their migratory staging.

STUDI META-ANALISIS KONDISI HUTAN MANGROVE TERHADAP KEANEKARAGAMAN HEWAN DI PULAU RAMBUT, KEPULAUAN SERIBU, DKI JAKARTA

<p><em>Mangrove forest is a form of a transitional ecosystem from land and sea so it has many roles and functions for the ecosystem, one of which is maintaining the biological stability of the waters. This study aims to determine the condition of the mangrove forest and its effect on the diversity of animal species found on Rambut Island. The method used in this study is a meta-analysis by combining some previous data through a literature study on the condition of mangrove forests and animal diversity on Rambut Island. The study results show that on Rambut Island 18 species of mangrove plants have been identified and in the last 10 years, there has been a decrease in the number of mangrove species to 6 species in 2021. The mangrove forest is dominated by Rhizophora mucronata species. Animal species found in mangrove forests are dominated by groups of water birds, such as the great egret (Egretta alba). The decrease in the number of mangrove plant species resulted in a decrease in the abundance and diversity of animal species on Rambut Island. This is because these animals lose mangrove vegetation which provides a place to find food and protection for the animals that live in them. Therefore, the mangrove forest is an area that must be preserved so that it can benefit the animals that live in it.</em></p>

Water Birds as Indicators of Ecological Conditions in a Ramsar Wetland (Sebkhet Bazer, East of Algeria)

Background: Wetlands are the highly complex ecosystems due to various interactions between the components, where, the most iconic of ecological changes are the water birds. The current study was aimed to examine the interactions between the water birds diversity, abundance and the abiotic factors in Sebkhet Bazer. Methods: The investigation was conducted between March 2013 and December 2014 in Sebkhet Bazer (Sétif, Algeria, 36°05'N and 5°45'E), by monitoring water birds abundance (grouped into 4: Anatidae, Rallidae, Phoenicopteridae and Shorebirds) and measuring the physico-chemical water parameters (depth, temperature, pH, salinity and vegetation cover). All statistical analysis was performed using the InfoStat software (2017), it was carried out in two steps, by testing of fixed linear models; first of the seasonal differences in water body variables and second of the seasonal differences in bird abundance for the 4 water bird groups. Result: The results showed that the physico-chemical parameters of water varied considerably from season to season. The four groups of birds reached their lowest abundance in summer, with Rallidae and Phonicopteridae being more abundant in spring, Anatidae in winter and Shorebirds in autumn, suggesting that this variation is attributed to changes in water body characteristics between the four seasons. Therefore, the abundance of the different water bird group could be used as an ecological indicator of this wetland’s characteristics. If these features are altered by climate change, the water bird community would be also affected.

Eneolithic pile dwellers captured waterfowl in winter: Analysis of avian bone remains from two pile dwellings in Ljubljansko barje (Slovenia)

AbstractThis study presents the results of an ornitho‐archaeological analysis of avian bones from Stare gmajne and Blatna Brezovica, two Eneolithic pile dwelling sites in the area of Ljubljansko barje, Slovenia. Avian bone remains, together with remnants of huts, tools, mammal bones and bones of other vertebrates, represent the material remnant of a pile dwelling culture from the second half of the fourth millennium BC.A total of 2091 avian bones or fragments thereof were excavated. The avifauna includes 682 taxonomically identified remains (NISP), assigned to 15 bird taxa. Taxonomically, species from the Anatidae group predominate (68.7% of NISP), mainlyBucephala clangula(40.3% of NISP). Also abundant isFulica atra(26.2% NISP) from the family Rallidae. In the ecological context, species inhabiting aquatic or marshy habitats prevail. Representatives of three ecomorphological groups of waterbirds were found: diving birds (Podicepssp.,Phalacrocorax carbo,Aythya fuligula,B. clangulaandMergussp.), waterbirds (Cygnussp.,Ansersp.,Anassp. andF. atra) and the marsh species group (Ardea cinerea).The absence of medullary bone and the abundance of wintering species in the area are consistent with the hypothesis that the birds were captured during the winter season. Taphonomic evidence (burned bones) suggests that the studied assemblages were human food waste. The abundance of avian bone remains supports the hypothesis that the native peoples were skilled hunters of aquatic birds.

Diet and Life-History Traits of Savannah Dwelling Waterbirds in Southern Africa: Implications for Their Conservation Status

This study evaluates the relative contribution of reproduction-based life history traits and diet to the population trends in waterbirds from southern Africa. Life history traits (clutch size, incubation period, fledging time, body mass and generation length), diet (prey weight, body lengths and number of taxa represented in its diet (NTD)) and conservation status (declining/not declining) of 163 waterbird species were reviewed. An index of diet generalism was created based on NTD. Cluster analysis was applied on life history traits to define groups of waterbirds. Binomial regressions were used to test if population trends were different across cluster groups and diet variables. Four clusters of waterbirds were defined, with most waterfowl clustering together. Species that feed on small and large prey had higher probabilities of declining (0.17 and 0.26, respectively) compared to those feeding on medium-sized prey (0.08). Amphibians, coleopterans, crustacea, molluscs and tunicates were used by species in all clusters, and the risk of waterbird populations declining further are high given the current dwindling of the prey base. The large proportions of declining species (61%) in waterbirds, which have constrained habitats, calls for continued efforts to mitigate disturbances to wetlands.

Which water bird groups need greater habitat conservation measures in a wetland ecosystem?

One important issue in wildlife conservation is the identification of the groups of species that need greater conservation measures. In this regard, maps of habitat degradation are useful tools. However, water bird habitat mapping in wetland ecosystem is difficult due to the large extent and complexity of wetlands and the narrow boundary between the habitats of different groups. In this paper, the capabilities of synthetic aperture radar (SAR) data were applied to overcome these limitations and to provide a practical scheme to conserve water bird habitats. The significance of this paper is the novel application of the SAR capabilities for water bird habitat conservation. These data were used to separate the habitat of the three water bird groups and to determine the destroyed habitats that should be protected for water birds in wetlands with unstable conditions. Using Sentinel-1 (S1) data, habitat maps for the water birds were created during the inundation period in the Hamoun-e-Hirmand. These habitats included the shrub swamps, flooded meadows, and open water. Based on the four-month flooded period of the wetland and the S1 image archive, habitat maps were created for six dates. The SAR backscattering coefficients of these three habitat classes were first analyzed to investigate the potential of the S1 images to differentiate between the habitat classes. A support vector machine (SVM) was then developed to separate the habitat classes. The accuracy of the six produced maps was calculated to be between 81% and 87.5%, which confirmed the ability of the S1 images to differentiate between water bird habitat classes. Based on the habitat degradation analysis, Anatidae, Charadriiformes, Ciconiiformes, Gruidae, Pelecanidae and the diving ducks need greater conservational measures in their feeding habitats (flooded meadow and open water). This paper introduced S1 data as an effective tool for mapping the habitats of each group of water birds in a wetland.

Bird diversity and waterbird habitat preferences in relation to wetland restoration at Dianchi Lake, south-west China

BackgroundRestoration projects have been implemented worldwide to mitigate the adverse effects of the loss and degradation of wetland habitats. Much research has been carried out on the impacts on birds of wetland restoration and management projects in China. Studies have mainly investigated central or coastal wetlands, while inland wetlands in remote areas have been much less studied. We focused on examining the response of wild birds to wetland restoration in Dianchi Lake, south-west China.MethodsThe line transect method was performed at 26 sampling plots. Three of these were in the city, and to acquire all wild bird data 23 plots were located every 2–8 km along the shore of Dianchi Lake, between December 2011 and November 2013. We collected all related bird records by searching the available literature, articles, newspapers and records of birdwatchers to compare species variation before and after implementation of wetland restoration. To measure the relationships between waterbird assemblages and habitat structures, we used canonical correspondence analysis (CCA) to pair the main matrix of bird assemblages with a second matrix of habitat variables.ResultsWe recorded 182 bird species belonging to 51 families and 17 orders. Of the species, 42 were new records for Kunming City and 20 were new records for Yunnan Province. Ten waterbird species were found to have disappeared from the shore of Dianchi Lake. CCA results indicated that waterbirds could be divided into four categories based on their habitat preference: synanthropic (wintering gulls), special habitat (shorebirds), semi-natural (wintering coots and ducks) and disturbance-tolerant (resident) species.ConclusionsOur study is the first to consider the entire wild bird community throughout the year and discuss the species variation before and after wetland restoration projects launched for Dianchi Lake. Distinct habitat requirements of different waterbird groups were detected in our study, suggesting different types of restoration and management should be implemented.

The Relative Importance of Agricultural and Wetland Habitats to Waterbirds in the Sacramento–San Joaquin River Delta of California

Biodiversity loss from agricultural intensification underscores the urgent need for science-based conservation strategies to enhance the value of agro-ecosystems for birds and other wildlife. California’s Central Valley, which has lost over 90% of its historical wetlands and currently is dominated by agriculture, still supports waterbird populations of continental importance. A better understanding of how waterbirds use available habitat is particularly needed in the Sacramento–San Joaquin Delta, an ecosystem under threat. From 2013 to 2015, we studied waterbird habitat associations in the Delta during fall migration and winter by conducting diurnal counts at random locations in key waterbird habitats throughout the Delta. Waterbird use of cover types (agricultural crops and managed wetlands) varied substantially among waterbird groups, by season, and among geographic sub-regions of the Delta. Overall, wetlands were particularly important to waterbirds in fall. In winter, wetlands and flooded rice and corn were important to many waterbird groups, and non-flooded corn and irrigated pasture to geese and cranes. The factors that influenced waterbird abundance and distribution also varied substantially among groups and differed at various geographic scales. In both seasons, most groups had a positive association at the field level with flooded ground and open water, and a negative association with vegetation. Given the great uncertainty in the future extent and pace of habitat loss and degradation in the Delta, prioritizing the conservation actions needed to maintain robust waterbird populations in this region is urgent. For the Delta to retain its importance to waterbirds, a mosaic of wetlands and wildlife-friendly crops that accounts for the value of the surrounding landscape must be maintained. This includes restoring additional wetlands and maintaining corn, rice, alfalfa, and irrigated pasture, and ensuring that a substantial portion of corn and rice is flooded in winter.

The Relative Importance of Agricultural and Wetland Habitats to Waterbirds in the Sacramento–San Joaquin River Delta of California

Biodiversity loss from agricultural intensification underscores the urgent need for science-based conservation strategies to enhance the value of agroecosystems for birds and other wildlife. California’s Central Valley, which has lost over 90% of its historical wetlands and currently is dominated by agriculture, still supports waterbird populations of continental importance. A better understanding of how waterbirds use available habitat is particularly needed in the Sacramento–San Joaquin Delta, an ecosystem under threat. From 2013 to 2015, we studied waterbird habitat associations in the Delta during fall migration and winter by conducting diurnal counts at random locations in key waterbird habitats throughout the Delta. Waterbird use of cover types (agricultural crops and managed wetlands) varied substantially among waterbird groups, by season, and among geographic subregions of the Delta. Overall, wetlands were particularly important to waterbirds in fall. In winter, wetlands and flooded rice and corn were important to many waterbird groups, and non-flooded corn and irrigated pasture to geese and cranes. The factors that influenced waterbird abundance and distribution also varied substantially among groups and differed at various geographic scales. In both seasons, most groups had a positive association at the field level with flooded ground and open water and a negative association with vegetation. Given the great uncertainty in the future extent and pace of habitat loss and degradation in the Delta, there is an urgency to prioritize conservation actions needed to maintain robust waterbird populations in this region. For the Delta to retain its importance to waterbirds, it will be necessary to maintain a mosaic of wetlands and wildlife-friendly crops that accounts for the value of the surrounding landscape. This includes restoring additional wetlands and maintaining corn, rice, alfalfa, and irrigated pasture, and ensuring that a substantial portion of corn and rice is flooded in winter.

Waterbird counts on large water bodies: comparing ground and aerial methods during different ice conditions.

The aerial and ground methods of counting birds in a coastal area during different ice conditions were compared. Ice coverage of water was an important factor affecting the results of the two methods. When the water was ice-free, more birds were counted from the ground, whereas during ice conditions, higher numbers were obtained from the air. The first group of waterbirds with the smallest difference between the two methods (average 6%) contained seven species: Mute Swan Cygnus olor, Whooper Swan Cygnus cygnus, Greater Scaup Aythya marila, Tufted Duck Aythya fuligula, Common Goldeneye Bucephala clangula, Smew Mergellus albellus and Goosander Mergus merganser; these were treated as the core group. The second group with a moderate difference (average 20%) included another six species: Mallard Anas platyrhynchos, Eurasian Wigeon Mareca penelope, Common Pochard Aythya ferina, Great Crested Grebe Podiceps cristatus and Eurasian Coot Fulica atra. The third group with a large difference (average 85%) included five species, all of the Anatini tribe: Gadwall Mareca strepera, Northern Pintail Anas acuta, Northern Shoveler Spatula clypeata, Eurasian Teal Anas crecca and Garganey Spatula querquedula. During ice conditions, smaller numbers of most species were counted from the ground. The exception here was Mallard, more of which were counted from the ground, but the difference between two methods was relatively small in this species (7.5%). Under ice-free conditions, both methods can be used interchangeably for the most numerous birds occupying open water (core group) without any significant impact on the results. When water areas are frozen over, air counts are preferable as the results are more reliable. The cost analysis shows that a survey carried out by volunteer observers (reimbursement of travel expenses only) from the land is 58% cheaper, but if the observers are paid, then an aerial survey is 40% more economical.

Distribution and Long-Term Population Trends of Wintering Waterbirds in Poyang Lake, China

Although total wintering waterbirds have increased in Poyang Lake, some groups or species might have declined. Identifying declining groups and species will help to optimize conservation strategies. In addition, knowledge of waterbird distribution is required to identify priority areas for protection. In this study, we aimed to explore long-term population trends of waterbird groups and species and to investigate waterbird distribution in Poyang Lake by integrating survey data from 1996/1997 to 2014/2015. Poyang Lake Nature Reserve, Duchang and Nanji Wetland Nature Reserve had high waterbird richness and abundance and high proportion of IUCN endangered species, thus they are important areas for waterbird protection. An important limitation to waterbird protection in the three areas is lack of management rights of most sub-lakes. Most waterbird groups in Poyang Lake have grown, but ducks have declined. Hunting and the decline of aquatic vegetation might be driving the duck declines. In addition, White-naped Crane (Grus vipio), Spot-billed Duck (Anas poecilorhyncha) and Northern Lapwing (Vanellus vanellus) have declined. While we believe the data presented here indicate general trends in groups and species, the analyses suffered from variation in methods used in different surveys. We advocate long-term waterbird monitoring using standardized methods to better understand waterbirds’ population dynamics.

Goose-like birds survived the dino wipeout

They looked like loons, and are kin to a group of birds that includes geese and chickens. Meet the Vegaviidae, a newly named group of waterbirds that may have lived through the mass extinction that took out the dinosaurs. The Vegaviidae no longer exist, but they are the first bird group known to have survived the extinction, says Federico Agnolin at the Bernardino Rivadavia Argentine Museum of Natural Sciences in Buenos Aires. At the end of the Cretaceous 66 million years ago, a mass extinction--probably caused by an asteroid impact--wiped out many species, including all non-avian dinosaurs. Birds survived, but which groups has been unclear.

A long-term macroecological analysis of the recovery of a waterbird metacommunity after site protection.

We used the so called “land-bridge island” or “nested-subsets” theory to test the resilience of a highly fragmented and perturbated waterbird metacommunity, after legal protection of 18 wetlands in the western Mediterranean. Sites were monitored during 28 years and two seasons per year. The metacommunity was composed by 44 species during breeding and 67 species during wintering, including shorebirds, ducks, herons, gulls and divers (Podicipedidae). We identified a strong nested pattern. Consistent with the fact that the study system was to a large extent a spatial biogeographical continuous for thousands of years, fragmented only during the last centuries due to human activities. Non-random selective extinction was the most likely historical process creating the nested pattern, operated by the differential carrying capacity (surface-area) of the remaining sites. We also found a positive temporal trend in nestedness and a decreasing trend in species turnover among sites (β-diversity), indicating that sites are increasingly more alike to each other (i.e. increased biotic homogenization). This decreasing trend in β-diversity was explained by an increasing trend in local (α) diversity by range expansion of half the study species. Regional (γ) diversity also increased over time, indicating that colonization from outside the study system also occurred. Overall our results suggest that the study metacommunity is recovering from historical anthropogenic perturbations, showing a high long-term resilience, as expected for highly vagile waterbirds. However, not all waterbird groups contributed equally to the recovery, with most breeding shorebird species and most wintering duck species showing no geographical expansion.

Impact Of Coastal Wetland Restoration Strategies In The Chongming Dongtan Wetlands, China: Waterbird Community Composition As An Indicator

This paper aims to evaluate the success of coastal wetland restoration by quantifying the waterbird community composition at three restored sites and on one natural coastal wetland, which served as a reference site, from September 2011 to May 2012 in the Chongming Dongtan wetlands in China. The Shannon–Wiener diversity index was calculated to describe habitat diversity in the four study sites. Significant differences in habitat heterogeneity and species group diversity, richness, and waterbird density were observed in the sites, but a significant difference among three seasons was observed only in the waterbird density. Significant interactions between site and season were noted for species group diversity, richness, and waterbird density. The densities of four dominant waterbird groups exhibited significant differences in the four sites, and the density of Anatidae and Ardeidae exhibited significant differences among three seasons. Significant interactions were noted between site and season for the densities of Charadriidae, Anatidae, and Ardeidae. In conclusion, the restored coastal wetlands served as a suitable habitat for waterbirds to some extent, although not all restored wetlands were used equally by waterbirds. The restored wetlands with higher habitat heterogeneity supported a greater abundance of waterbirds. However, the same restored wetland was not used equally by waterbirds among different seasons. Multi-functional restored wetlands could be created for different seasons to attract a diverse group of waterbirds to forage and roost in the coastal wetlands of Yangtze River during their migration from Australia to Siberia.