Wetland Birds Research Articles

Slow development of woodland vegetation and bird communities during 33 years of passive rewilding in open farmland.

Passive rewilding is a potential tool for expanding woodland cover and restoring biodiversity by abandoning land management and allowing natural vegetation succession to occur. Land can be abandoned to passive rewilding deliberately or due to socio-economic change. Despite abandonment being a major driver of land use change, few have studied the long-term outcomes for vegetation and biodiversity in Western Europe. Studies are also biased towards sites that are close to seed sources and favourable to woodland colonisation. In this case-study, we reconstruct a time series of passive rewilding over 33 years on 25 ha of former farmland that had been subject to soil tipping, far from woodland seed sources. Natural colonisation by shrubs and trees was surveyed at three points during the time series, using field mapping and lidar. Breeding birds were surveyed at three time points, and compared with surveys from nearby farmland. Results showed that natural colonisation of woody vegetation was slow, with open grassland dominating the old fields for two decades, and small wetlands developing spontaneously. After 33 years, thorny shrub thickets covered 53% of the site and former hedgerows became subsumed or degraded, but trees remained scarce. However, the resulting habitat mosaic of shrubland, grassland and wetland supported a locally distinctive bird community. Farmland bird species declined as passive rewilding progressed, but this was countered by relatively more wetland birds and an increase in woodland birds, particularly songbirds, compared to nearby farmland. Alongside biodiversity benefits, shrubland establishment by passive rewilding could potentially provide ecosystem services via abundant blossom resources for pollinators, and recreation and berry-gathering opportunities for people. Although closed-canopy woodland remained a distant prospect even after 33 years, the habitat mosaic arising from passive rewilding could be considered a valuable outcome, which could contribute to nature recovery and provision of ecosystem services.

Ecological and faunal characteristics of helminths of wetland birds in North-Western Uzbekistan

The article studies some faunistic features of helminths of wetland birds in the ecological crisis zone in North-Western Uzbekistan. Parasites of wetland birds collected in the basin of the lower reaches of the Amu Darya during the hunting seasons of 2018–2022 were used as material for this work. 500 individuals of birds representing 39 species from 24 genera, 13 families and 9 orders were examined using the parasitological dissection method. The article discusses the distribution and ecology of the helminths in the studied groups of birds. A total of 112 helminth species were identified in the region – 28 species belong to the class Cestoda, the class Trematoda is represented by 57 species, Nematoda – 23 and Acanthocephala – 4 species. 92 species of heminths were identified in the study area for the first time. The work provides original data on the structure of the helminth fauna from 9 orders of wetland birds. Various paths of helminth transmission in the circulation of infection were specified. The researchers identified four ways parasites use to enter their definitive host: helminths penetrate the host’s body when the latter eats other organisms, intermediate or reservoir hosts of helminths, which are part of the definitive’s host’s diet; helminths enter the host as mechanical impurity to food or water; they make active efforts to penetrate their host; helminths are transmitted by the intermediate host when the latter forages on the definitive host. Most of intermediate hosts for representatives of the class Cestoda were crustaceans – inhabitants of different types of water bodies; Oligochaeta are also included here as second or reservoir hosts. The development of trematodes occurs with the participation of aquatic molluscs acting as the first intermediate host. Various species of insects, fish, amphibians, reptiles and small mammals were identified as the second hosts. Nematoda use a wider range of intermediate hosts (Oligochaeta, crustaceans, insects – aquatic and terrestrial). Fish and amphibians were registered as the second and reservoir hosts of nematodes. The food chains of individual orders of wetland birds largely determine the composition of helminths parasitising them and are the main factor in the formation of their helminth fauna. These processes undoubtedly occur in time and space under the strict control of environmental factors.

Eyebirds: Enabling the Public to Recognize Water Birds at Hand.

Enabling the public to easily recognize water birds has a positive effect on wetland bird conservation. However, classifying water birds requires advanced ornithological knowledge, which makes it very difficult for the public to recognize water bird species in daily life. To break the knowledge barrier of water bird recognition for the public, we construct a water bird recognition system (Eyebirds) by using deep learning, which is implemented as a smartphone app. Eyebirds consists of three main modules: (1) a water bird image dataset; (2) an attention mechanism-based deep convolution neural network for water bird recognition (AM-CNN); (3) an app for smartphone users. The waterbird image dataset currently covers 48 families, 203 genera and 548 species of water birds worldwide, which is used to train our water bird recognition model. The AM-CNN model employs attention mechanism to enhance the shallow features of bird images for boosting image classification performance. Experimental results on the North American bird dataset (CUB200-2011) show that the AM-CNN model achieves an average classification accuracy of 85%. On our self-built water bird image dataset, the AM-CNN model also works well with classification accuracies of 94.0%, 93.6% and 86.4% at three levels: family, genus and species, respectively. The user-side app is a WeChat applet deployed in smartphones. With the app, users can easily recognize water birds in expeditions, camping, sightseeing, or even daily life. In summary, our system can bring not only fun, but also water bird knowledge to the public, thus inspiring their interests and further promoting their participation in bird ecological conservation.

Aspects on the bird fauna's diversity in the sector Golăiești - Cotul Bran (Iași county, Romania)

The present study had followed to evaluate the bird fauna’s diversity and the seasonal dynamic of birds’ population in the sector of Golăiești – Cotul Bran, related to the common Jijia and Prut Rivers’ basin. We did our fieldwork in the years 2014 and 2015. The bird fauna’s list includes 117 bird species. The typically woodland bird species are dominant like diversity, but also through their effectives. The wetland bird species present small populations, appearing during the migration time. The breeding bird fauna include 77 certainly breeding species, other 6 species being irregular or probably breeding species in the area. During our study, we identified 21 bird species that appear in the Annex 1 of Birds’ Directive, respectively, 12 bird species included in the Romanian Red Book of Vertebrates.

Modeled distribution shifts of North American birds over four decades based on suitable climate alone do not predict observed shifts

As climate change alters the global environment, it is critical to understand the relationship between shifting climate suitability and species distributions. Key questions include whether observed changes in population abundance are aligned with the velocity and direction of shifts predicted by climate suitability models and if the responses are consistent among species with similar ecological traits. We examined the direction and velocity of the observed abundance-based distribution centroids compared with the model-predicted bioclimatic distribution centroids of 250 bird species across the United States from 1969 to 2011. We hypothesized that there is a significant positive correlation in both direction and velocity between the observed and the modeled shifts. We then tested five additional hypotheses that predicted differential shifting velocity based on ecological adaptability and climate change exposure. Contrary to our hypotheses, we found large differences between the observed and modeled shifts among all studied bird species and within specific ecological guilds. However, temperate migrants and habitat generalist species tended to have higher velocity of observed shifts than other species. Neotropical migratory and wetland birds also had significantly different observed velocities than their counterparts, which may be due to their climate change exposure. The velocity based on modeled bioclimatic suitability did not exhibit significant differences among most guilds. Boreal forest birds were the only guild with significantly faster modeled-shifts than the other groups, suggesting an elevated conservation risk for high latitude and altitude species. The highly idiosyncratic species responses to climate and the mismatch between shifts in modeled and observed distribution centroids highlight the challenge of predicting species distribution change based solely on climate suitability and the importance of non-climatic factors traits in shaping species distributions.

Study on Seasonal Variations of Wetland Birds in Karaivetti Bird Sanctuary, Ariyalur, Tamil Nadu, India

Study on Seasonal Variations of Wetland Birds in Karaivetti Bird Sanctuary, Ariyalur, Tamil Nadu, India

Better together? Assessing different remote sensing products for predicting habitat suitability of wetland birds

Diversity and DistributionsVolume 28, Issue 11 p. 2443-2443 CORRIGENDUMOpen Access Better together? Assessing different remote sensing products for predicting habitat suitability of wetland birds This article corrects the following: Better together? Assessing different remote sensing products for predicting habitat suitability of wetland birds Zsófia Koma, Arie C. Seijmonsbergen, Meiert W. Grootes, Francesco Nattino, Jim Groot, Henk Sierdsema, Ruud P. B. Foppen, W. Daniel Kissling, Yoan Fourcade, Volume 28Issue 4Diversity and Distributions pages: 685-699 First Published online: February 5, 2022 First published: 13 September 2022 https://doi.org/10.1111/ddi.13633AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat In the version of this paper originally published (Koma et al., 2022), the author would like to add the following sentence to the Data Availability Statement: “and the used bird observation dataset can be accessed from https://doi.org/10.5281/zenodo.6497349.” The corrected Data Availability Statement is as follows: Open Research DATA AVAILABILITY STATEMENT All scripts for processing the different remote sensing products, and the R scripts to reproduce the statistical analyses, are available on GitHub (https://github.com/komazsofi/LiDAR_Sentinel_birdsdm_wetlands). The calculated remote sensing metrics (raster layers) are available on Zenodo (https://doi.org/10.5281/zenodo.5772673), and the used bird observation dataset can be accessed from https://doi.org/10.5281/zenodo.6497349. REFERENCE Koma, Z., Seijmonsbergen, A. C., Grootes, M. W., Nattino, F., Groot, J., Sierdsema, H., Foppen, R. P. B., & Kissling, W. D. (2022). Better together? Assessing different remote sensing products for predicting habitat suitability of wetland birds. Diversity and Distributions, 28, 685– 699. https://doi.org/10.1111/ddi.13468 Volume28, Issue11November 2022Pages 2443-2443 ReferencesRelatedInformation

The impact of climate change and potential distribution of the endangered white winged wood duck (Asarcornis scutulata, 1882) in Indian eastern Himalaya

The White-Winged Wood duck (Asarcornis scutulata) is an endangered forest wetland bird currently on the verge of extinction due to an array of anthropogenic pressures. It has been reported that global climate change could affect the distribution of many bird species globally. Therefore, an understanding the potential distribution of the White-Winged Wood duck in future climate scenarios could facilitate the creation of immediate conservation plans and the mitigation of subsequent threats. This is the first ever study on the distribution of White-Winged Wood Duck (WWWD) where Representative Concentration Pathway (RCP) 8.5 scenario was used to forecast the distribution of the WWWD in the Indian Eastern Himalayan region in the 2050s and 2070s. The study revealed that 1.87 % of the total area of IEH has the high potential distribution of WWWD. The state of Assam alone includes 1.68 % of the highly potential habitat in the region. It was predicted that 436.61 km2 of highly potential habitat would be lost by 2070. Changes in the annual temperature range, precipitation in the wettest months (June to September), and precipitation decrease in the warmest quarter (October to December) would result in the loss of highly potential habitats. Under the influence of climate change, the habitat of WWWD in the eastern part of the region is likely to shift towards the western part. It was found that there will be a decline in potential habitat in the Indian states of Arunachal Pradesh, Assam, Nagaland, and Tripura located in the IEH under future climate scenarios. The potential of areas located at the Bhutan and Assam border would increase for supporting WWWD as this species' requires the average annual precipitation about 1000–1200 mm. However, the simultaneous anthropogenic activity would further destroy potential habitats in the future. The current study has provided baseline data on the potential distribution of WWWD in the IEH region for immediate conservation management plans.

Spatial drivers of wetland bird occupancy within an urbanized matrix in the Upper Midwestern United States

AbstractWetland birds are undergoing severe population declines in North America, with habitat degradation and wetland loss considered two of the primary causes. Due to the cryptic nature of many wetland bird species, the ecological conditions (e.g., matrix composition) that influence bird occupancy, and the relevant spatial scales at which to measure bird responses, remain unclear but may affect inference about wetland use and suitability. We conducted wetland bird surveys at 477 points across northeastern Illinois and northwestern Indiana within the highly urbanized landscape surrounding Chicago. Using remotely sensed land cover data, we built occupancy models for 10 wetland bird species (American Coot Fulica americana, Black‐crowned Night‐Heron Nycticorax nycticorax, Blue‐winged Teal Anas discors, Common Gallinule Gallinula galeata, Least Bittern Ixobrychus exilis, Marsh Wren Cistothorus palustris, Pied‐billed Grebe Podilymbus podiceps, Sora Porzana carolina, Swamp Sparrow Melospiza georgiana, and Virginia Rail Rallus limicola) to quantify their responses to wetland cover types (emergent wetland, forested wetland, riverine wetland, and freshwater pond) and urbanization at four spatial scales (200‐, 400‐, 800‐, and 2000‐m radial distances). We also included the distance to Lake Michigan as a covariate in occupancy models to account for ecological differences between coastal and inland wetlands. We found that relationships between land cover types and occupancy differed by species, as did the spatial scale of support. Generally, the presence of emergent wetlands or ponds at immediate (200 m) and local (400 m) spatial scales within the surrounding matrix was positively associated with wetland bird occupancy. Contrary to expectations, we did not find support for a negative relationship between urbanization and occupancy for most focal species, indicating that birds are using available wetland habitats despite surrounding development. While future research should evaluate management strategies at the watershed scale, our findings suggest that wetland conservation planning at immediate and local scales is likely to promote bird habitat use within highly modified landscapes of the Upper Midwestern United States.

Avifaunal diversity in unprotected wetlands of Ayodhya District, Uttar Pradesh, India

Nine unprotected wetlands of Ayodhya district, Uttar Pradesh, India were studied to assess the bird species composition and richness from March 2019 to February 2020 using point count method. A total of 105 species of birds belonging to 79 genera, distributed among 35 families and 12 orders were recorded. Passeriformes had the highest diversity with 25 species and 12 families. Anatidae was the most dominant family with 15 species, constituting 14.29% of the wetland bird community in the study area. These wetlands provided habitat for 62 residential species, 42 winter migrants and one vagrant. The carnivore guild was the most dominant with 46 species. The wetland sites under study were continuously used by humans mainly for land encroachment, fishing activities and livestock grazing apart from other minor uses. Out of the nine selected wetlands, three wetlands (˂2 ha) had very few bird species (≤3), therefore were excluded from further calculations. But the rest of the six selected wetlands (˃5 ha) provided habitat for 12 bird species of conservation importance (one Endangered species, five Vulnerable species, and six Near Threatened species) according to the IUCN Red list. These wetlands also supported 39 species of birds having a declining population trend globally. These findings highlight the role of medium and large-sized unprotected wetlands in providing critical habitat to the birds throughout the year in Ayodhya district. Future research must concentrate on understanding the key factors influencing the presence and absence of birds in such unprotected wetlands so that these wetlands can be managed effectively to secure the potential habitat of birds.

Quantifying effects of wetland restorations on bird communities in agricultural landscapes

Restoring wetlands to improve habitats for birds has become an important conservation tool as many wetlands have deteriorated and wetland bird populations declined. To what extent such restorations are effective is not well known because surveys usually either lack data before the restoration or means of correcting for background population trends. We identified wetland restorations made in agricultural landscapes in Sweden and retrieved all available Before-After survey data of breeding birds. From the resulting heterogeneous surveys, we quantified the effectiveness of restorations for eight bird groups comprising 72 bird species from 30 wetlands. We used national survey data to correct for background population trends. We estimated that island breeder populations have increased by between 62 % and 315 % (95 % confidence intervals) following restorations. Deep water foragers, shallow water foragers and short meadow breeders also mainly increased following restoration. The direction of effect was uncertain for tall meadow breeders, reed breeders and predators. Shrubland breeder populations declined between −55 % and −4 % following restorations. While restoration measures seemed to generally benefit about half of the breeding wetland bird community, estimated species- and site-specific responses varied greatly and were associated with large uncertainty. Such heterogeneity in responses can arise due to biotic and abiotic interactions, varying management actions and survey methods between wetlands. Thus, to improve the effectiveness of future wetland restorations, funding bodies and environmental agencies should require standardised Before-After bird surveys at both restored and non-restored reference sites. Such improved survey designs would facilitate the development of more efficient restoration efforts.

Active Surveillance and Genetic Characterization of Prevalent Velogenic Newcastle Disease and Highly Pathogenic Avian Influenza H5N8 Viruses Among Migratory Wild Birds in Southern Egypt During 2015-2018.

A total of 1007 samples (910 fecal droplets and 97 cloacal swabs) were collected from 14 species of migratory wild birds in most wetlands during 3 successive migration seasons from September to March (2015-2018) in Southern Egypt. The samples were propagated inembryonated chicken eggs and positive allantoic fluids by hemagglutination test were tested for Newcastle disease virus (NDV) and avian influenza virus (AIV) prevalence using RT-PCR and specific primers targeting the NDV fusion (F) and AIV matrix genes. Further subtyping of the AIV hemagglutinin (HA) and neuraminidase (NA) was conducted, and representative isolates were selected and sequenced for full F gene of NDVs and HA and NA genes of the AIV. Overall isolation rate of hemagglutinating viruses was 5.56% (56/1007), from them 5.36% (3/56) AIV, 85.71% (48/56) NDV and 8.93% (5/56) co-infection of NDV and AIV was detected. The sequences analysis of full F genes of 10 NDV isolates revealed that they have multi-basic amino acid motifs 111E/GRRQKR/F117 as velogenic strains with nucleotides and amino acids similarities of 96-100%. In addition, they phylogenetically clustered into groups and subgroups within genotype VII.1.1 and sub-genotype VIIj with a close relation to NDVs isolated from chickens in Egypt. The AIVH5N8 subtype was in clade 2.3.4.4b with a highly pathogenic nature and close relation to Egyptian domesticated H5N8 viruses rather than those from wild birds. The current data showed the contribution of migratory birds to the continuous circulation of virulent NDV and AIVH5N8 among domesticated chickens in Southern Egypt.

Bird dependence on wetlands determines functional responses to flood pulse in the Brazilian Pantanal

Hydrological regimes in floodplains are essential to support biodiversity that depend on wetlands, and understanding how these organisms are associated to this ecosystem could be useful, as they can act as important agents for the maintenance of diversity and natural processes. We aimed to assess the bird functional responses to the Pantanal flood pulse, considering the hydrological periods and three bird groups with different degrees of wetlands dependence. For this, bird survey was conducted in the Paraguay River floodplain system, covering the hydrological periods of the 2017–2018 cycle. We considered species richness, abundance, four functional diversity measures, and functional trait composition as ecological responses. Species richness was higher for bird group with lower degree of wetland dependence, mainly in drought and ebb periods. On the other hand, we found that the higher the degree of wetland dependence by birds, the higher the differences in the functional-trait values over periods. Abundance was affected by the variation of the hydrological periods for all bird groups. Bird groups had distinct niches, and functional traits associated with waterbirds were dominant in all periods. We found that degree of wetland dependence is driving the response of birds to changes in hydrological periods. Measuring only species richness may not reflect the inherent characteristics of this ecosystem. Bird groups such as waterbirds and wetland birds showed greater functional diversity throughout the hydrological periods, evidencing the importance of the flood pulse regime for species that are highly dependent on these environments and that perform many ecological services.

Dominated Taxonomic and Phylogenetic Turnover but Functional Nestedness of Wetland Bird Beta Diversity in North China

The decomposition of taxonomic, phylogenetic, and functional beta diversity into their turnover and nestedness components could provide novel insights into biodiversity conservation, e.g., provide implications for the Single Large Or Several Small reserves debate (SLOSS debate). Due to dramatic climate change and massive anthropogenic activities in recent decades in North China, the wetlands and the associated biodiversity in this region have declined significantly. This study applied the taxonomic, phylogenetic, and functional beta diversity decomposition for the first time in wetland bird communities in North China, aiming to propose scientific and comprehensive suggestions for bird diversity conservation in this region. A paired t-test was used to compare the differences between taxonomic, phylogenetic, and functional turnover, and their nestedness components. In addition, a spearman correlation analysis was used to assess the associations between each explanatory variable (differences in mean annual temperature and mean annual precipitation, as well as spatial distances) and each beta diversity index. A total of 546 bird species were found in 38 wetlands in North China, with three critically endangered species, 19 endangered species, 22 vulnerable species, and 61 near threatened species. The number of threatened species (critically endangered, endangered, and vulnerable) found in these lakes was about 30% of all threatened species in China. The results showed that taxonomic and phylogenetic beta diversity among wetland bird communities in North China was mainly dominated by turnover, while functional beta diversity was mainly dominated by nestedness. Importantly, the phylogenetic and functional results showed similar patterns even after controlling for the effects of taxonomic beta diversity. In addition, the taxonomic and phylogenetic turnover was more associated with both climate variables and spatial distances than other components. The contrasting patterns among the taxonomic, phylogenetic, and functional decompositions of wetland bird communities in North China indicate that distinctive conservation strategies should be considered for different biodiversity dimensions. Specifically, the conservation of taxonomic and phylogenetic bird diversity in this region should focus on multiple wetlands, while the conservation of bird functional diversity should focus on a single wetland with high functional diversity.

Importance of flood irrigation for foraging colonial waterbirds

AbstractFor a colonial‐nesting bird, like the white‐faced ibis (Plegadis chihi), the landscape surrounding the breeding colony can be important. White‐faced ibis must rely on areas outside their breeding colony for foraging, but this part of their life history has received little attention, and the management of this landscape even less so. To address this knowledge gap, we conducted road‐based driving surveys and a randomly selected, spatially balanced sample survey of agricultural fields within a 22‐km radius of the 2 largest white‐faced ibis breeding colonies in Idaho, USA: Market Lake Wildlife Management Area and Mud Lake Wildlife Management Area. Our study took place in 2012 and the primary objective was to quantify patterns of foraging habitat use of this marsh‐nesting species, particularly associations with specific irrigation practices and crop types. We documented the majority of foraging birds in flood‐irrigated and wheel‐line sprinkler‐irrigated agricultural fields (76%) and natural wetlands (13%), which were limited in our study area (3% of land cover). Even though 70% of the agricultural landscape included center pivot sprinkler irrigation, only 11% of foraging observations came from this irrigation type. Most agricultural fields (>85%) used by foraging ibis were flood‐irrigated and all had standing water or recent moisture at the time of use. Though ibis used many crop types when foraging in flooded agricultural fields, ibis use of alfalfa (58%) was greater than availability (38%). We also observed distinct distribution patterns around the 2 breeding colonies. Whereas birds foraged in all directions around Mud Lake (~80%) within a 12‐km radius from the colony, we observed over half of birds around Market Lake foraging within 12–22 km, and almost exclusively to the south and southeast of the colony, reflecting the distribution of flood‐irrigated agriculture in the area. The most common foraging distance (12–22 km) around Market Lake is greater than found in existing literature, suggesting that the foraging habitat is limited within 12 km of the colony and that the birds may need to travel farther to find adequate foraging habitat. Flood‐irrigated agriculture and natural wetlands provide foraging habitats for white‐faced ibis in eastern Idaho and should be considered in future management and conservation of wetland birds.

Invasive grass causes biotic homogenization in wetland birds in a Lake Erie coastal marsh

Invasive grass causes biotic homogenization in wetland birds in a Lake Erie coastal marsh

Stable isotope mixing models demonstrate the role of an invasive plant in wetland songbird food webs.

PremiseInvasive plants in wetlands are often ecosystem engineers, mediating changes in ecosystem functions like trophic support. We documented the impacts of Lepidium latifolium, an invasive plant, on the food web of omnivorous birds (Suisun song sparrows, Melospiza melodia maxillaris) in a tidal wetland of northern California, USA.MethodsWe used analysis of natural abundance stable isotopes of 13C and 15N in song sparrow blood, invertebrate food sources, L. latifolium seeds, and other marsh plant seeds to inform Bayesian, concentration‐dependent mixing models that predicted average song sparrow diets.ResultsSeason and plant phenology influenced food source incorporation and isotopic signatures. Song sparrows showed higher isotopic variability in the summer. The observed changes in song sparrow diets were driven by altered invertebrate communities related to seasonal L. latifolium presence and by shifts from seeds to consumption of invertebrate food sources during the breeding season in the spring and summer.DiscussionThis study used stable isotope tools and modeling to demonstrate two mechanisms of isotopic influence by L. latifolium on omnivorous song sparrows. This study can inform site‐ and species‐specific management strategies by demonstrating how changes to the plant community can impact entire trophic systems.

Influence of heavy metals on Saunders's Gull (Saundersilarus saundersi) reproduction in the Yellow River Estuary: risk assessment and bioaccumulation.

The heavy metal migration in the food chain exerted significant influence on the survival and reproduction of wetland birds and then disturbed and threatened the balance and health of the estuary ecosystem. In this study, the concentration of heavy metals (Cu, Cr, Fe, Mn, Cd, Ni, and Pb) in surface sediment of the Yellow River Estuary (YRE), the food sources of Saunders's Gull (Saundersilarus saundersi) nestlings, and the egg structure of birds were analyzed to determine the bioaccumulation and reproductive influence on wetland bird. The results indicated higher mean concentrations of sediment heavy metals than their corresponding background values in 2019, with the exception of Fe. Notably, the metal Cd exceeded geochemical background value by 1561.5% in 2018 and 1353.9% in 2019, resulting in severe contamination associated with Cd in the YRE (with geo-accumulation indexes of 3.44 and 3.23). Biomagnification factor (BMF) of heavy metals demonstrated that the concentrations of Cr, Ni, and Cu decreased with the trophic level rising while Cd, Mn, Pb, and Fe denoted bio-amplification in the food chain. The residual indexes showed that the food resources of Saunders's Gull were polluted by Cr, Pb, and Cu. Additionally, a higher enrichment of heavy metals was observed in the eggshell membrane. Metal concentrations had significant influences on the reproduction of Saunders's Gull, except for Cd, among which Ni, Pb, Cu, and Fe may have contributed to the reproductive success of birds, whereas the hatching failure of birds may be caused by Cr and Mn. It is of great importance to monitor the contamination of the wetland ecosystem and provide effective management and protection of the wildlife in the YRE.

Global warming and avifauna from the Argeş River dam basins (Southern Romania) – long term study case

An attempt to find a link between the global warming, manifested on local scale, and the dynamics of the winter avifauna recorded on the Vâlcele, Budeasa, Bascov, Piteşti and Goleşti Dam Basins from ROSPA0062 Lacurile de acumulare de pe Argeş was achieved in the paper. Based on the data collected between 1999 and 2020 during the MidWinter (the Winter Census of the Wetland Birds), some major conclusions were drawn: the climate change resulted from the analyse of the air temperature registered in the area and it was noticeable in some measure on the phenology of the birds; it influenced the dynamics of the avifauna, as total number of species and individuals, as well as the strength of every species; also, other local and extern elements, like the process of silting of the dam basins, the direct anthropogenic pressure, were involved here.

Evaluating the Vulnerability of Siberian Crane Habitats and the Influences of Water Level Intervals in Poyang Lake Wetland, China

The hydrological situations of wetlands are critical to the habitat qualities of wintering migratory birds. It is of great value to evaluate the habitat vulnerabilities within more precise intervals of water levels and quantitatively assess the influences of water level changes. The findings are advantageous for managing wetland ecosystems and for migratory bird habitat protection. This study identified the ideal habitats for wintering Siberian cranes in Poyang Lake wetland within 1-meter water level intervals (from 5 to 16 m) based on the Landsat thematic mapper (TM), enhanced thematic mapper plus (ETM+), and operational land imager (OLI) remote sensing images taken on multiple dates in the past 30 years. Three indicators—sustainability, stability, and variety—were used to evaluate the vulnerabilities of crane habitats within various water level intervals; the spatial variations and distribution patterns of the habitat vulnerabilities were further explored. The explanatory powers of water level intervals (and others) and their paired interactive effects on the habitat vulnerabilities were quantified using the geographical detector method. The results showed that crane habitat vulnerabilities were significantly sensitive to the water level changes of Poyang Lake; the habitat vulnerabilities and their spatial distribution patterns both exhibited specific tendencies with water level increases. A water level of 12 m was identified as the potential upper threshold for the maintenance of sustainable crane habitats and a water level interval of 9–10 m was expected to be the optimal interval for facilitating the aggregation features of crane habitats. The water level interval was identified as the most dominant factor in habitat vulnerability. It explained 14.46%, 42.89%, and 21.78% of the sustainability, stability, and variety of crane habitats; the numbers were expected to increase to 22%, 49.25%, and 25.84%, respectively, with water level intervals interacting with other factors. This article provides a novel perspective in evaluating the habitat vulnerabilities of wintering migratory birds and quantifying the responses to water level changes in wetlands; the proposed approaches are applicable and practicable for habitat vulnerability assessments of other wintering birds in other typical wetlands.