Wintering Period Research Articles

Impact of mixed groups on the gut bacterial structure of herring gull (Larus argentatus) and common shelduck (Tadorna tadorna) on Binzhou Seashell Island in Wudi, China

Abstract The cross-species transmission of intestinal bacteria caused by mixed-group contact in animals is currently an issue of concern. Herring gulls (Larus argentatus) and common shelducks (Tadorna tadorna) often forage in mixed groups, a process which is known as sympatric mixed foraging. This study sought to explore how mixed foraging affects the gut bacteria structure in herring gulls and common shelducks on Binzhou Seashell Island, China. Illumina high-throughput sequencing was employed to analyze the intestinal bacteria of these birds during their wintering period, with the goal of understanding the impact of mixed-species interactions on gut microbiota diversity. The results showed that alpha diversity of intestinal flora in common shelducks was higher than that in herring gulls, and there was no significant difference in beta diversity between the two species. The similarity ratio of the top five abundances of bacteria at the phylum classification level reached 42.86%. Judging from the results, there is resemblance in the structure of the intestinal flora between the two species. The study not only enhances our understanding of the adaptive strategies and interactions of these two avian species within the ecosystem, but also establishes a crucial foundation for bird resource management and disease prevention and control in this region. It holds significant scientific and practical implications for fields such as ecological conservation and biodiversity.

Functional diversity dynamics of waterbird communities driven by water levels at Shengjin Lake, a small river-connected shallow lake in the middle and lower Yangtze River floodplain.

Gate-controlled activities in lakes can directly or indirectly influence the assembly of waterbird communities. Shengjin Lake, a Ramsar site, is a typical river-connected and gate-controlled shallow lake in the lower and middle Yangtze River floodplain in China, comprising three sub-lakes (upper, middle, and lower) based on topographical features. We surveyed wintering waterbirds at Shengjin Lake from October 2022 to March 2023. We divided the winter water level period into nine phases based on the characteristics of water level changes. By measuring functional diversity, we aimed to provide insights into the differences in waterbird communities among the three sub-lakes under different water level conditions. Multiple linear regression was used to analyze the relationship between habitat factors and functional diversity. We further explored the relationship between specific functional traits and habitat factors through a combination of the R-mode linked to the Q-mode and the trait-environment correlation matrix (fourth-corner analyses) to explain the mechanism underlying waterbird community assembly. When the water level fluctuated in the range of 10.43-10.74 m (Huanghai elevation), the three sub-lakes had significant habitat differences and high habitat heterogeneity, increasing functional richness and functional dispersion of the upper and lower lakes, both of which significantly differed from those of the middle lake. Habitat heterogeneity and mudflat habitats have positive effects on functional diversity. The difference in functional diversity was primarily determined based on the foraging traits and strata of waterbirds. Habitat filtering of particular traits is a major driving force underlying the assembly of waterbird communities. Overall, we suggest that the minimum water level in the wintering period at Shengjin Lake should be regulated between 10.43 and 10.74 m. These findings provide reasonable suggestions for water level regulation and a theoretical basis for conserving waterbird diversity at Shengjin Lake.

Gut fungi of black-necked cranes (Grus nigricollis) respond to dietary changes during wintering

BackgroundMigratory birds exhibit heterogeneity in foraging strategies during wintering to cope with environmental and migratory pressures, and gut bacteria respond to changes in host diet. However, less is known about the dynamics of diet and gut fungi during the wintering period in black-necked cranes (Grus nigricollis).ResultsIn this work, we performed amplicon sequencing of the trnL-P6 loop and ITS1 regions to characterize the dietary composition and gut fungal composition of black-necked cranes during wintering. Results indicated that during the wintering period, the plant-based diet of black-necked cranes mainly consisted of families Poaceae, Solanaceae, and Polygonaceae. Among them, the abundance of Solanaceae, Polygonaceae, Fabaceae, and Caryophyllaceae was significantly higher in the late wintering period, which also led to a more even consumption of various food types by black-necked cranes during this period. The diversity of gut fungal communities and the abundance of core fungi were more conserved during the wintering period, primarily dominated by Ascomycota and Basidiomycota. LEfSe analysis (P < 0.05, LDA > 2) found that Pyxidiophora, Pseudopeziza, Sporormiella, Geotrichum, and Papiliotrema were significantly enriched in early winter, Ramularia and Dendryphion were significantly enriched in mid-winter, Barnettozyma was significantly abundant in late winter, and Pleuroascus was significantly abundant in late winter. Finally, mantel test revealed a significant correlation between winter diet and gut fungal.ConclusionsThis study revealed the dynamic changes in the food composition and gut fungal community of black-necked cranes during wintering in Dashanbao. In the late wintering period, their response to environmental and migratory pressures was to broaden their diet, increase the intake of non-preferred foods, and promote a more balanced consumption ratio of various foods. Balanced food composition played an important role in stabilizing the structure of the gut fungal community. While gut fungal effectively enhanced the host’s food utilization rate, they may also faced potential risks of introducing pathogenic fungi. Additionally, we recongnized the limitations of fecal testing in studying the composition of animal gut fungal, as it cannot effectively distinguished between fungal taxa from food or soil inadvertently ingested and intestines. Future research on functions such as cultivation and metagenomics may further elucidate the role of fungi in the gut ecosystem.

Current water pollution status at an important wintering site of the black-faced spoonbill Platalea minor in Xinghua Bay, south China

Xinghua Bay is one of the largest wintering sites of the black-faced spoonbill Platalea minor in mainland China. The ecosystem of Xinghua Bay has shown a deteriorating trend with the increasing pressure of economic development in recent decades. To understand the current conservation status of the wintering spoonbills in Xinghua Bay, we collected water samples along the coast of Xinghua Bay and important spoonbill habitats during the wintering period to analyze the pollution degree of 7 target heavy metals and organics. The Nemerow pollution index (NPI), heavy metal pollution index (HPI) and contamination degree (CD) were used to assess the heavy metal pollution levels. The ecological risk index of a target heavy metal (Efi) and potential ecological risk index of all target heavy metals (RI) were used to assess the ecological risk of heavy metals levels in Xinghua Bay. Positive matrix factorization (PMF) was used to determine the sources of heavy metals in coastal waters with the EPA PMF5.0 model. The results showed that there was moderate to very heavy pollution by heavy metals and moderate associated ecological risks in Xinghua Bay, in which Hg and Cd were the major heavy metal pollution sources, and the level of organic pollution was of serious concern. The use of fertilizers for cultured shellfish and aquaculture in and around the bay were the major cause of the excessive nitrogen and phosphorus levels, and factories surrounding Xinghua Bay were the major sources of heavy metals and organic pollution. We propose conservation measures to increase black-faced spoonbill population and enhance its habitats.

Оңтүстік-Шығыс Қазақстанның ағаш жартылай қаттықанаттыларының (Hemiptera, Heteroptera) биологиясы мен экологиясы

As a result of the study of arboreal hemipterans of South-Eastern Kazakhstan, 35 species belonging to 8 genera were identified. Among them are the Miridae family (9 species), the Pentatomidae family (8 species), the Anthocoridae family (7 species), and 1-3 species are known from the remaining 5 families. According to the habitat, arboreal hemipterans are divided into dendrobionts (22 species), dendro-tamnobionts (2 species), dendro-tamno-hortobionts (4 species), dendro-hortobionts (6 species). Arboreal hemipterans are divided by trophic relationship into zoophages (14 species), zoophytophages (6 species), phytophages (12 species) and mycetophages (3 species). Arboreal hemipterans of South-East Kazakhstan are divided into 4 groups according to the number of generations they give per year: monovoltine (27 species), bivoltine (1 species), polyvoltine (4 species), acyclic (3 species). The species in the study area are ecologically mesophilic. In many species of Hemiptera, the wintering period takes place in the adult stage (20 species), the egg stage (10 species), the adult and larval stage (4 species), and the larval stage (1 species).

Wetlands dynamics analysis: a case study of Keoladeo National Park (India), the wintering grounds of West Siberian white crane population

The work is devoted to the study of the dynamics of the wetlands area in the Keoladeo National Park (Bharatpur province, Rajasthan, India) over the past decades in connection with changes in climatic parameters to assess the wintering conditions of the endangered West Siberian White Crane population (Leucogeranus (=Grus) leucogeranus Pallas, 1773). The article presents the results of a statistical analysis of the main meteorological parameters (average maximum and minimum temperatures of the surface layer of the atmosphere in 1971–2022, average precipitation per year and from October to March (the wintering period of West Siberian White Crane) in 1958–2021); the results of an analysis of the ratio of areas of different types of habitats according to remote sensing data in 1972–2022; the results of statistical analysis of the volume of water entering the park from the Ajahn Bund reservoir in 1980–2010. During the study period, a significant increase in the average maximum and minimum temperatures of the winter period was revealed, which, along with the absence of a significant trend towards an increase in the average amount of precipitation and an increase in the number of dry years, indicates a warming climate with an increase in its aridity. A statistically significant reduction in the area of habitats suitable for West Siberian White Crane has been established. This indicates a significant decrease in the water level in the Keoladeo wetlands, both due to increased evaporation and a significant reduction in the volume of water entering the park from the reservoir. The results of the study show that in the conditions of observed climate changes, the main regulators of the water level and the state of the ecosystem of the Keoladeo wetlands are agricultural users, whose water consumption increases with increasing aridity of the climate.

Multi-scale habitat selection throughout the annual cycle of a long-distance avian migrant

Long-distance migrants are constrained by widely separated hospitable habitats in geographically isolated locations, making them vulnerable to environmental change, both through natural and anthropogenic causes. Knowledge about their resource selection decisions is imperative to understand the drivers of their declines. The distinct periods within an annual cycle, when individuals experience different environmental circumstances, are inextricably linked through carry-over effects which can have important consequences for the individual, and consequently the population. In this study, we employ precise archival GPS-tracking data of European Nightjars (Caprimulgus europaeus) and high-resolution global land cover data to examine habitat selection during the sedentary wintering and breeding periods, as well as during autumn and spring migration, using a correlational approach. We demonstrate how nightjars use general habitat characteristics, such as landscape diversity, for high-order habitat selection, while resource selection at a finer spatial scale is reliant on fine-scale variables related to a habitat’s suitability, such as surface area of grassland and shrubland. We show that nightjars favour spatially diverse landscapes, which allows them to minimize time spent searching for optimal habitats. The considerable variation in the drivers of habitat selection between and within seasons shows how anthropogenic land-use change can have an array of different impacts on migrants by influencing large- and fine-scale habitat selection. This study shows the advantages of an individual based GPS-tracking approach, combined with high spatial resolution remote sensing data, and highlights the need for full annual-cycle research on scale dependent habitat selection of long-distance avian migrants.

Estimation of Fishery Losses from Great Cormorants during the Wintering Period in Greek Lagoons (Ionian Sea, W. Greece)

The present study aims through a modeling approach to quantify fishing losses from the impact of great cormorants (Phalacrocorax carbo sinensis) during their wintering period in Greek lagoons. A number of assumptions were incorporated into the model regarding fish population growth, species distribution, age (or size) of fish caught, and the different fishing strategies that could be applied in the studied lagoons. The results indicated that the mean value of daily economic losses ranged from 0.614 to 1.075 €·bird−1·day−1, whereas the ratios of biomass losses to landings biomass and of economic losses to economic profit ranged from 0.18:1 to 3.80:1 and from 0.14:1 to 4.18:1, respectively, depending on the lagoon. The results supported a strong competitive relationship between great cormorants and fisheries in lagoons of the Amvrakikos Gulf.

Evaluation of the Effect of Pb Pollution on Avian Influenza Virus-Specific Antibody Production in Black-Headed Gulls (Chroicocephalus ridibundus).

Lead (Pb), an environmental pollutant, has been widely reported to have contaminated mammals, including humans and birds. This study focuses on the effects of Pb pollution on avian influenza virus (AIV) antibody production. A total of 170 black-headed gulls (Chroicocephalus ridibundus) were captured in Tokyo Bay (TBP) from January 2019 to April 2020 and in Mikawa Bay (MBP) from November 2019 to April 2021. The gulls were weighed, subjected to blood sampling, and released with a ring band on their tarsus. The samples were used to measure blood Pb levels (BLL) and AIV-specific antibodies. The BLL were compared using the Wilcoxon two-sample test between the period when black-headed gulls arrived and the wintering period, defined by the number of gulls counted in each area. A significant increase was found in the TBP. A decrease in BLL significantly increased antibody titer during wintering in TBP and MBP. Pb pollution had a negative effect on the production of AIV antibodies. These findings suggest that wild birds that were contaminated by Pb in the environment may facilitate the spread of zoonotic diseases, further increasing the possibility that environmental pollutants may threaten human health.

Spatio-Temporal Distribution Patterns and Determinant Factors of Wintering Hooded Cranes (Grus monacha) Population

Hooded Cranes (Grus monacha) rely on wetlands for the majority of their life cycle and respond to the environmental conditions during the wintering period. Future conservation planning should be driven by an understanding of how cranes respond to environmental factors at degraded wetland sites and the changes in their spatio-temporal distribution. In recent years, the spatial and temporal distribution of waterbirds and determinant factors have become a research focus. However, research on the specific factors influencing the relative abundance of Hooded Cranes from multiple perspectives in the different habitat patches at Shengjin and Caizi Lakes is lacking. Therefore, from 2021 to 2022, we investigated the quantity and distribution of Hooded Cranes in the upper part of Shengjin and Baitu Lake part of Caizi Lakes. We considered multiple habitat variables, including patch size, food biomass, food availability, and human disturbance, and analyzed the dynamic changes in the distribution of the population in different wintering periods. We used model selection and averaging to select the best model and identify key variables. During different wintering periods, the spatio-temporal distribution of the crane population differed in the upper part of Shengjin Lake, but the crane was mainly distributed in the northern part of the Baitu Lake part of Caizi Lake. The model that included food biomass and patch size was the best for predicting the relative abundance of Hooded Cranes. Cranes foraged in areas with large patches and abundant food resources. Therefore, we suggest reserving patch integrity and availability in the current habitats and protecting and restoring the main food resources to provide high-quality habitat patches and plentiful food resources for wintering populations of Hooded Cranes.

Role of weather and other factors in the dynamics of a low-density insect population.

Insect population dynamics are the result of an interplay between intrinsic factors such as density dependence, trophic web interactions, and external forces such as weather conditions. We investigate potential mechanisms of population dynamics in a natural, low‐density insect population. Eggs and larvae of the noctuid moth, Abrostola asclepiadis, develop on its host plant during summer. The population density, and mortality, was closely monitored throughout this period during 15 years. Densities fluctuated between one and two orders of magnitude. Egg–larval developmental time varied substantially among years, with lower survival in cool summers with slower development. This was presumably due to the prolonged exposure to a large guild of polyphagous arthropod enemies. We also found a density‐dependent component during this period that could be a result of intraspecific competition for food among the last larval instars. Dynamics during the long period from pupation in late summer through winter survival in the ground to adult emergence and oviposition the next year displayed few clear patterns and more unexplained variability, thus giving a more random appearance. The population hence shows more unexplained or unpredictable variation during the long wintering period, but seems more predictable over the summer egg–larval period. Our study illustrates how weather—via a window of exposure to enemies and in combination with density‐dependent processes—can determine the course of population change through the insect life cycle.

Features of the growth and formation of the physique of nenets reindeer from birth to puberty

In the Yamalo-Nenets Autonomous District were studied 169 heads of Nenets deer from birth to 18 months of age The maximum rate of weight gain of live weight of calves is observed in the first 6 months of postnatal development and has sexual differentiation: in males it was 52.5, in females – 46.5 kg. From 6 to 12 months of age, which falls during the wintering period, in the studied groups of deer there was a drop in absolute indicators of live weight gain to minus values: males -5.3 kg, females -1.7 kg. In the period from 12 to 18 months of age, the absolute growth rates of males and females turned out to be equal. The rate of linear growth and the formation of the physique of young deer in the period from birth to 6 months of age, no significant difference between males and females was found either visually or instrumentally.. During the first wintering period, an increase in absolute value was observed by measurements associated with the growth of the skeleton: height at the withers, height at the elbow, head length, chest depth, oblique length of the butt. The age period from 12 to 18 months is characterized by a significant increase in linear body sizes in the studied deer, but the difference in almost all measurements did not exceed 4%. A comparison of 10 indices of physique in animals showed that at 6 and 18 months of age, the main proportions of the physique are close, which indicates a high rate of formation of the physique in young domestic reindeer. A comparison of the physique indices revealed no signs of sexual dimorphism for any of them, except for the pelvic index, which was higher in females at all age periods and the broadbodied index at 18 months of age.

Determination of Marine Biotoxins Contamination Level of Mussel (Perna Perna) (Linne, 1758) from the Mamelles Bay, Dakar

This study evaluating marine biotoxins contamination level of mussel ( Perna Perna ) in the Mamelles Bay (Ouakam) of Dakar is the first report in Senegal. It took place over one year (from March 2018 to February 2019). Liquid chromatography with mass spectrometry (LC-MS-MS) reference method (Regulation (EC) 15/2011 of 10 January 2011) was used to quantify marine biotoxins. Okadaic acid (OA) and its esters are the most problematic of all the researched biotoxins. They are present throughout most of the year, except September and November, with an average monthly concentration of 163 µg/kg, slightly above the regulatory limit (160 µg/kg). The sanitary status of the mussel shows two peaks of contamination, the first of which occurs in the rainy season (August) and the second in the cold season (December), with values equal to 654 and 802 µg/kg respectively 4 to 5 times higher than the regulatory threshold set by Regulation (EC) No 853/2004 of 29 April 2004 supplemented by Regulation (EU) No 786/2013 amending its Annex III and Senegalese Order No 07951 of 12 May 2017. These two peaks coincide with (i) the wintering period, marked by continental land-based inputs due to rainwater runoff, but also with the temperature rise, or (ii) the cold period with the appearance of upwelling (upwelling of cold water, rich in nutrient salts). In addition to the chemical analyses carried out on the mussel, the research work on phytoplankton and the surveys of physicochemical parameters carried out on the water at the collection site show (i) the existence of toxic algae of the Dinophysis genus and Gambierdiscus , in June, i.e., one to two months before the first peak of contamination of the Perna perna by AO; (ii) also a coincidence between the appearance of these phenomena and variations in surface water temperature and salinity, which are determining factors in the appearance and development of harmful algal blooms. Concerning the other biotoxins investigated, in particular AZA and yessotoxins, it was noted that AZA was absent throughout the year, unlike yessotoxins, which were found in the flesh of Perna perna at concentrations below the regulatory limit set at 3750 µg/kg. The maximum being 51 µg/kg obtained in June, i.e., 73 times lower than the regulatory threshold. In the light of the results obtained, it appears that the periods of high contamination are the winter period and the upwelling period, which could lead to closure measures to guarantee the safety of the mussels. It would be interesting to extend the study to all other bivalve mollusks and gastropods, to carry out an inventory and quantify the toxic microalgae present in the water. To this end, the effectiveness of purification techniques would be tested. Keywords: Mussel ( Perna perna ), Marine biotoxins, Toxic microalgae, Mamelles, Dakar. DOI: 10.7176/FSQM/117-04 Publication date: July 31 st 2022

Variation Among Species and Populations, and Carry-Over Effects of Winter Exposure on Mercury Accumulation in Small Petrels

Even in areas as remote as the Southern Ocean, marine organisms are exposed to contaminants that arrive through long-range atmospheric transport, such as mercury (Hg), a highly toxic metal. In previous studies in the Southern Ocean, inter-specific differences in Hg contamination in seabirds was generally related to their distribution and trophic position. However, the Blue Petrel (Halobaena caerulea) was a notable exception among small seabirds, with higher Hg levels than expected. In this study, we compared the Hg contamination of Blue Petrels and Thin-billed Prions (Pachyptila belcheri), which both spend the non-breeding season in polar waters, with that of Antarctic Prions (Pachyptila desolata), which spend the winter in subtropical waters. We collected body feathers and blood samples, representing exposure during different time-frames. Hg concentrations in feathers, which reflect contamination throughout the annual cycle, were related to δ13C values, and varied with ocean basin and species. Blue Petrels from breeding colonies in the southeast Pacific Ocean had much higher feather Hg concentrations than expected after accounting for latitude and their low trophic positions. Both Hg concentrations and δ15N in blood samples of Blue Petrels were much lower at the end than at the start of the breeding period, indicating a marked decline in Hg contamination and trophic positions, and the carry-over of Hg burdens between the wintering and breeding periods. Elevated Hg levels may reflect greater reliance on myctophids or foraging in sea-ice environments. Our study underlines that carry-over of Hg concentrations in prey consumed in winter may determine body Hg burdens well into the breeding season.

High Variability and Dual Strategy in the Wintering Red Kites (Milvus milvus)

To develop effective conservation strategies for migratory birds, it is essential to understand the ecology of a species at each biological phase, including its wintering (or non-breeding) season. For the red kite (Milvus milvus), an endangered raptor from the Western Palearctic, its wintering ecology is little known. We tagged 44 red kites using GPS/satellite transmitters to study their non-breeding seasons in Spain. Two spatial strategies were recorded: 34 individuals (77%) spent all their wintering periods in only one area, whilst the remaining individuals (23%) moved between two main areas at least once. This strategy, however, was not consistent over the years. In the latter case, the distance between wintering areas was 311.6 ± 134.7 km, and individuals usually spent equally long periods in each area (96 ± 35 days). No effects of age or sex were found on these area shifts, so they may have been driven by food or habitat resource availability. We also found high interindividual variability in home range sizes. The home ranges of adults were two- to three-times smaller than those of immatures, probably due to a better knowledge of the territory.

Increasing temperature during early spring increases winter wheat grain yield by advancing phenology and mitigating leaf senescence

High temperature usually reduces wheat yield, especially at critical growth stages, such as anthesis and grain filling. However, effects of increasing temperature during wintering period on winter wheat growth and development are rarely reported. Hence, this three-year field experiment evaluated how artificial warming during early spring (wintering period) affects winter wheat. The warming treatment (WT) advanced the wheat reviving, jointing, anthesis, and maturity stages, but the average temperature in each growing stage reduced, thus extending the duration of tillering, spike differentiation, and grain filling. Concurrently, the leaf area index and biomass accumulation were obviously increased. Additionally, WT showed a lower leaf senescence rate compared with that of control (CK). Also, the photosynthesis rate and SPAD of WT were increased relative to CK. WT increased superoxide dismutase and peroxidase activities, and reduced malondialdehyde content in flag leaf during the grain filling stage, suggesting WT during early spring could delay leaf senescence after anthesis, which contributed to a high filling rate and long filling duration. Correspondingly, the final spike number, kernel number, and kernel weight of WT were significantly increased compared with CK. In the three seasons, grain yield was increased by 18.2%–37.5% in WT compared with CK. Results of this study provided a new viewpoint that increasing temperature could shorten the wintering period but extend the effective growth phase, and increase grain yield in winter wheat.

Conservation value of the Kruglaya Bay and the rationale to establish a new protected object in Sevastopol (Crimea, Black Sea)

The bays of the northern coast of the Heraclean Peninsula including the Kruglaya Bay are characterized by the abundance and diversity of the winter hydrophilic ornithocomplex, which is one of the largest in Crimea. To date, the bird list of the Kruglaya Bay includes 75 species. Its coast and water areas are suitable for the wintering of hydrophilic birds, of which 8 species winter annually and 20 - periodically. The total number of birds was 0.99-1.38 thousand individuals during the main wintering period (December-January) in different years, with a significant dominance (55-72%) of the coot and black-headed gull. The protected species include 13 bird species listed in the Red Data Books (RDB) of various ranks, of which 10 species are represented in the RDB of the Russian Federation, 4 in the RDB of Sevastopol and 4 in the IUCN List of Threatened Species. In addition to the diverse and numerous hydrophilic ornithocomplex, a significant species richness of aquatic organisms and a variety of benthic biotopes were observed in the Bay. The ichthyofauna is represented by 60 species (2 of them are protected), the macrophyte flora includes 41 species (4 protected), the macrozoobenthos - 124 species (7 protected), and 43 species of the epiphyton are registered. 90 vascular plant species have been identified in the coastal zone, of which 12 species are protected. Large regular and seasonal accumulations of hydrophilic birds, a high degree of biota diversity, the presence of many protected species and diverse biotopes testify to the nature conservation value of the Bay. They are the basis to establish an ornithological reserve in its water area with a protection regime in winter, as one of the largest avifauna reserves in Southern Crimea.

Risk evaluation of onshore wind farms in relation to wild duck (Anatidae) movements in the Yangtze River Mouth, China

Although wind power is a promising source of renewable energy, previous studies have focused on uncovering species and abundance decreases caused by wind farms. However, very few studies focus on collision risk of onshore wind farms in relation to birds’ movements which are the important indicators for balancing wind energy development and biodiversity conservation. Here, birds’ movement were recorded by combining 15 ducks’ satellite tracking and six field surveys to assess collision risks in Yangtze River Mouth, the wintering site for migratory waterbirds along the East Asian–Australasian Flyway. It is found that distances between ducks’ locations and nearest wind turbines in middle and later wintering periods were significantly higher than during early period. Besides, ducks inside wind farm tended to fly outside turbine rotor height range (45–135 m: between lowest and highest points the rotor tips) within 300 m from the dyke where the turbines were located, thus decreasing their collision risk. Ducks also tended to fly below the minimum rotor tip height (< 45 m) when the turbines were rotating. These results suggest that ducks adopt behavioural avoidance strategies in response to wind farms, and turning off turbines to reduce collision risks may be unnecessary.

Scale and Landscape Features Matter for Understanding Waterbird Habitat Selection

Clarifying species-environment relationships is crucial for the development of efficient conservation and restoration strategies. However, this work is often complicated by a lack of detailed information on species distribution and habitat features and tends to ignore the impact of scale and landscape features. Here, we tracked 11 Oriental White Storks (Ciconia boyciana) with GPS loggers during their wintering period at Poyang Lake and divided the tracking data into two parts (foraging and roosting states) according to the distribution of activity over the course of a day. Then, a three-step multiscale and multistate approach was employed to model habitat selection characteristics: (1) first, we minimized the search range of the scale for these two states based on daily movement characteristics; (2) second, we identified the optimized scale of each candidate variable; and (3) third, we fit a multiscale, multivariable habitat selection model in relation to natural features, human disturbance and especially landscape composition and configuration. Our findings reveal that habitat selection of the storks varied with spatial scale and that these scaling relationships were not consistent across different habitat requirements (foraging or roosting) and environmental features. Landscape configuration was a more powerful predictor for storks’ foraging habitat selection, while roosting was more sensitive to landscape composition. Incorporating high-precision spatiotemporal satellite tracking data and landscape features derived from satellite images from the same periods into a multiscale habitat selection model can greatly improve the understanding of species-environmental relationships and guide efficient recovery planning and legislation.

Water level management plan based on the ecological demands of wintering waterbirds at Shengjin Lake

A reasonable hydrological regime is of great significance for ecosystem services and wildlife habitat management in river-connected lakes. Shengjin Lake is a Ramsar site with international importance for wintering migratory waterbirds. Since the Huangpen River sluice began operations, the lake’s hydrological rhythm was changed. We investigated the effect of different hydrological conditions under water level control on the abundance of waterbird foraging guilds using habitat as an intermediary. First, linear models of 12 years dataset (2008–2019) based on waterbird surveys and satellite remote sensing images were constructed to analyse the relationship between habitat area and water level. Then, generalized linear mixed models were used to explore the effects of habitat area on abundance in different waterbird foraging guilds. Finally, the abundance of each type of waterbird guild was predicted at intervals of 0.10 m at the water level. Overall, 60% of the abundance of waterbird foraging guilds could be explained by water level with habitat as an intermediary, and this was affected by the rate of change of their preferred habitat area with water level increase. When the water level was less than 10.2 m, the meadow area was negatively correlated with the D80 water level (average water level of 71–80 days before waterbirds wintering), which was the main factor that affected tuber foragers and seed foragers/dabbling waterbirds. The abundance of food for these herbivorous waterbirds during the middle wintering was affected by the exposed tidal flat area in October, which provided suitable conditions for the secondary growth of grass. Starting from 10.20 m, waterbird abundance rapidly reduced with a sharply increasing water area, which was influenced by artificial sluice control and reduced rainfall. Therefore, management should be focused on appropriately lowering the water level in the early wintering period. Considering the suitable habitat area, hysteresis of meadow growth, and residential water demand, a water level control scheme was recommended to be 8.65–9.50 m in the early wintering period, 8.11–8.80 m in the middle wintering period, and 8.09–9.40 m in the late wintering period. The results of this study will help to promote the reasonable water level control for the lakes as the wintering grounds of migratory waterbirds.