1) Biology & ecology
- Yao, S., X. Li, C. Liu, J. Zhang, Y. Li, T. Gan, B. Liu and W. Kuang (2020). “New assessment indicator of habitat suitability for migratory bird in wetland based on hydrodynamic model and vegetation growth threshold.” Ecological Indicators 117: 106556.
- Zhang, F., S. Cui, S. Gao, R. Hough, P. Hu, Z. Zhang, Q. Fu, T. Yu and K. Li (2020). “Heavy metals exposure risk to Eurasian Spoonbill (Platalea leucorodia) in wetland ecosystem, Northeast China.” Ecological Engineering 157: 105993.
- Lisovski, S., K. Gosbell, C. Minton and M. Klaassen. (2020). “Migration strategy as an indicator of resilience to change in two shorebird species with contrasting population trajectories.” Journal of Animal Ecology.
- Zhu, B.‐, Verkuil, Y.I., Conklin, J.R., Yang, A., Lei, W., Alves, J.A., Hassell, C.J., Dorofeev, D., Zhang, Z. and Piersma, T. (2020). Discovery of a morphologically and genetically distinct population of Black‐tailed Godwits in the East Asian‐Australasian Flyway. Ibis. https://doi.org/10.1111/ibi.12890
- Fanjuan Meng, Xin Wang, Nyambayar Batbayar, Tseveenmyadag Natsagdorj, Batmunkh Davaasuren, Iderbat Damba, Lei Cao, Anthony D Fox, Consistent habitat preference underpins the geographically divergent autumn migration of individual Mongolian common shelducks, Current Zoology, Volume 66, Issue 4, August 2020, Pages 355–362.
- Liu, H., L. Zheng, L. Jiang and M. Liao (2020). “Forty-year water body changes in Poyang Lake and the ecological impacts based on Landsat and HJ-1 A/B observations.” Journal of Hydrology 589: 125161.
- Li, D., Davison, G., Lisovski, S. et al. Shorebirds wintering in Southeast Asia demonstrate trans-Himalayan flights. Sci Rep 10, 21232 (2020).
2) Conservation & management
- Si, Y., Wei, J., Wu, W. et al. Reducing human pressure on farmland could rescue China’s declining wintering geese. Mov Ecol 8, 35 (2020). https://doi.org/10.1186/s40462-020-00220-y
- Wikramanayake, E., C. Or, F. Costa, X. Wen, F. Cheung and A. Shapiro (2020). “A climate adaptation strategy for Mai Po Inner Deep Bay Ramsar site: Steppingstone to climate proofing the East Asian-Australasian Flyway.” PLOS ONE 15(10): e0239945.
- Hu, R., Y. Gu, M. Luo, Z. Lu, M. Wei and J. Zhong (2020). “Shifts in bird ranges and conservation priorities in China under climate change.” PLOS ONE 15(10): e0240225.
- Wu, H.-b. and B.-h. Zheng (2020). “Wetland area identification and waterbird protection management in consideration of lake topography and water level change.” Global Ecology and Conservation 23: e01056.
- Jackson, M. V., R. A. Fuller, X. Gan, J. Li, D. Mao, D. S. Melville, N. J. Murray, Z. Wang and C.-Y. Choi (2021). “Dual threat of tidal flat loss and invasive Spartina alterniflora endanger important shorebird habitat in coastal mainland China.” Journal of Environmental Management 278: 111549.
- Zhao, S., H. Xu, N. Song, Z. Wang, B. Li and T. Wang (2020). “Effect of wind farms on wintering ducks at an important wintering ground in China along the East Asian–Australasian Flyway.” Ecology and Evolution 10(17): 9567-9580.
- Doyle, S., A. Gray and B. J. McMahon (2020). “Anthropogenic impacts on the demographics of Arctic-breeding birds.” Polar Biology 43(12): 1903-1945.
3) Avian Influenza /Others
- Tang, L., W. Tang, L. Ming, J. Gu, K. Qian, X. Li, T. Wang and G. He (2020). “Characterization of Avian Influenza Virus H10–H12 Subtypes Isolated from Wild Birds in Shanghai, China from 2016 to 2019.” Viruses 12(10): 1085.
1) Biology & ecology
Siyang Yao, Xinyu Li, Chenglin Liu, Jing Zhang, Yuekang Li, TingT Gan, Bo Liu, Weiming Kuang
Abstract: Migratory birds are indicator organisms for the health of wetland ecosystems. Choosing the key environmental indicators is vital to the assessment of habitat suitability for migratory birds. In the study, hydroperiod was used to predict wetland suitability for migratory birds. It control growth of vegetation used for migratory birds’ food and could predicted by hydrodynamic model. This study presents a new indicator for assessing migratory bird habitat suitability in wetland, continuous flooding time (CFT), based on two-dimensional (2D) hydrodynamic model and vegetation growth threshold. In Poyang Lake wetland (the largest migratory bird wintering based in Asia), variation in CFT amongst different hydrological years (wet, dry and normal flow years) was calculated by using the 2D hydrodynamic model based on incompressible Reynolds Average Navier-Stokes (N-S) equation. The habitat suitability for migratory birds were calculated based on the vegetation growth threshold (CFT) of Carex spp., Phalaris arundinacea and Polygonum criopolitanum in the typical (hydrological) years. Results show that migratory birds have the largest suitable area (with High and Very High suitability) in 2009 (normal flow year). The suitable area in severe drought (flood) year is significantly less than the area in normal dry (wet)year. The average of the suitable CFTs (with High and Very High suitability) are almost equal in 2007 (dry year) and 2002 (wet year). The suitable CFT is between 120 and 240 days, and the average of the suitable CFT is 170.39, 190.26 and 173.49 days in 2007 (dry year), 2009 (normal flow year) and 2002 (wet year), respectively. Overall, the study provides a valuable evaluation indicator of habitat suitability for migratory bird, however the use of the indicator must depend on a certain study of the vegetation growth threshold and the feeding habit of migratory birds for the study area. The proposed indicator can further improve the comprehensive evaluation system for wetland migratory birds and provide a scientific reference of the water environment planning and ecological management for the scheduled Poyang lake dam.
Fuxiang Zhang, Song Cui, Shang Gao, Rupert Hough, Peng Hu， Zulin Zhang, Qiang Fu, Ting Yu, Kunyang Li
Abstract: Qixing River wetland is very representative of the marsh environment of Sanjiang Plain, northeast China. The wetland plays an important role in maintaining ecological service functions especially for protecting migratory birds. Despite Qixing River wetland being impacted by a number of diffuse and point sources of pollution (primarily from agricultural activities), a comprehensive survey of heavy metal exposure risk to migratory birds has never been undertaken. Identifying heavy metals exposure risk is significant for further improving the protection scheme of migratory birds. In the present study, the comprehensive water pollution index (WPI) and geo-accumulation index (Igeo) were calculated to assess the degree of contamination of water and sediments, respectively. Single-pollutant exposure metrics (HQ) were applied to measured concentrations in order to estimate the heavy metal exposure risk to migratory birds. In addition, an integrated hazard index (HI) was derived to assess the comprehensive risk of exposure to multiple heavy metals and associated risk threshold values calculated. The decreasing trends of average concentration of heavy metals were Zn > Cr > Ni > Cu > Pb > Cd in sediments and Zn > Cr > Pb > Ni > Cu > Cd in water. Concentrations of Cr were significantly elevated compared to the threshold of Aquatic Life Water Permissible Limits (AWPL) and Sediment Quality Guidelines (SGQ) (p < 0.01), thus may pose negative impacts to the aquatic ecological system. Values of WPI indicated ‘Clean’ status for more than 85% sampling sites with Zn accounting for 58% of the value of the WPI. Most of the sediment sampling locations were deemed to be ‘Clean’ or ‘Low’ status as defined by Igeo with Zn and Cd (mainly derived from agricultural sources) identified as the dominant indicators of pollution. Comprehensive exposure risk assessment indicated ‘Moderate’ risk (HI > 1) status for local populations of Eurasian Spoonbill. Despite the majority of heavy metals (except for Zn) being assigned ‘Clean’ or ‘Low’ pollution status, the elevated hazard quotient (HQ > 3) associated with Cr enhanced overall values of HI, especially for nestlings, indicating that current pollution control measures are insufficient for the protection of migratory birds. This study has supplemented current knowledge of the impacts of agriculture on wetland ecosystems and provides evidence that exposures of migratory birds to some heavy metals may exceed ‘safe’ levels. This study thus provides a scientific rationale for determining the safe feeding water depth for migratory birds.
Simeon Lisovski, Ken Gosbell, Clive Minton, Marcel Klaassen
Abstract: Many migratory birds are declining worldwide. In line with the general causes for the global biodiversity crisis, habitat loss, pollution, hunting, over‐exploitation and climate change are thought to be at the basis of these population declines. Long‐distance migrants seem especially vulnerable to rapid anthropogenic change, yet, the rate of decline across populations and species varies greatly within flyways. We hypothesize that differences in migration strategy, and notably stopover‐site use, may be at the basis of these variations in resilience to global change. By identifying and comparing the migration strategies of two very closely related shorebird species, the Curlew sandpiper Calidris ferruginea and the Red‐necked stint Calidris ruficollis, migrating from the same non‐breeding site in Australia to similar breeding sites in the high Russian Arctic, we aimed to explain why these two species express differential resilience to rapid changes within their flyway resulting in different population trajectories in recent times. Based on 13 Curlew sandpiper and 16 Red‐necked stint tracks from light‐level geolocator tags, we found that individual Curlew sandpipers make use of fewer stopover areas along the flyway compared to Red‐necked stints. Furthermore, and notably during northward migration, Curlew sandpipers have a higher dependency on fewer sites, both in terms of the percentage of individuals visiting key stopover sites and the relative time spent at those sites. While Curlew sandpipers rely mainly on the Yellow Sea region, which has recently experienced a sharp decline in suitable habitat, Red‐necked stints make use of additional sites and spread their relative time en‐route across sites more evenly. Our results indicate that differential migration strategies may explain why Curlew sandpipers within the East Asian‐Australasian Flyway are declining rapidly (9.5%–5.5% per year) while Red‐necked stints remain relatively stable (−3.1%–0%). We consider that more generally, the number of sites per individual and among a population, the spatial distribution across the flyway, as well as the relationship between the time spent over sites may prove to be key variables explaining populations and species’ differential resilience to environmental change.
Bing‐Run Zhu, Yvonne I. Verkuil, Jesse R. Conklin, Ailin Yang, Weipan Lei, José A. Alves, Chris J. Hassell, Dmitry Dorofeev, Zhengwang Zhang, Theunis Piersma
Abstract: Occurring across Eurasia, the Black‐tailed Godwit Limosa limosa has three recognized subspecies, melanuroides, limosa and islandica from east to west, respectively. With the smallest body size, melanuroides has been considered the only subspecies in the East Asian‐Australasian Flyway. Yet, observations along the Chinese coast indicated the presence of distinctively large individuals. Here we compared the morphometrics of these larger birds captured in northern Bohai Bay, China, with those of the three known subspecies and explore the genetic population structuring of Black‐tailed Godwits based on the control region of the mitochondrial genome (mtDNA). We found that the Bohai Godwits were indeed significantly larger than melanuroides, resembling limosa more than islandica, but with relatively longer bills than islandica. The level of genetic differentiation between Bohai Godwits and the three recognized subspecies was of similar magnitude to the differentiation among previously recognized subspecies. Based on these segregating morphological and genetic characteristics, we propose that these birds belong to a distinct population, which may be treated and described as a new subspecies.
Fanjuan Meng, Xin Wang, Nyambayar Batbayar, Tseveenmyadag Natsagdorj, Batmunkh Davaasuren, Iderbat Damba, Lei Cao, Anthony D Fox
Abstract: While many avian populations follow narrow, well-defined “migratory corridors,” individuals from other populations undertake highly divergent individual migration routes, using widely dispersed stopover sites en route between breeding and wintering areas, although the reasons for these differences are rarely investigated. We combined individual GPS-tracked migration data from Mongolian-breeding common shelduck Tadorna tadorna and remote sensing datasets, to investigate habitat selection at inland stopover sites used by these birds during dispersed autumn migration, to explain their divergent migration patterns. We used generalized linear mixed models to investigate population-level resource selection, and generalized linear models to investigate stopover-site-level resource selection. The population-level model showed that water recurrence had the strongest positive effect on determining birds’ occupancy at staging sites, while cultivated land and grassland land cover type had strongest negative effects; effects of other land cover types were negative but weaker, particularly effects of water seasonality and presence of a human footprint, which were positive but weak or non-significant, respectively. Although stopover-site-level models showed variable resource selection patterns, the variance partitioning and cross-prediction AUC scores corroborated high inter-individual consistency in habitat selection at inland stopover sites during the dispersed autumn migration. These results suggest that the geographically widespread distribution (and generally rarity) of suitable habitats explained the spatially divergent autumn migrations of Mongolian breeding common shelduck, rather than the species showing flexible autumn staging habitat occupancy.
Hai Liu, Liang Zheng, Liang Jiang, Mingwei Liao
Abstract: With global warming and aggravation due to human activities, many lakes on Earth are facing a series of worsening environmental problems, such as shrinking areas and declining water quality. Poyang Lake is the largest freshwater lake in China, an important wetland in the world and the largest migratory bird habitat in Asia. The ecological environment of the lake has a widespread influence and has attracted international attention. It is necessary to use long-term frequent satellite observations to investigate the Poyang Lake due to its high-frequency fluctuations characteristics. However, most remote sensing data cover only a short period of time, which cannot reflect the long-term change to the Poyang Lake water, no satellite mission currently fits such requirements. Based on HJ-1A/B and Landsat data from 1989 to 2018, the dynamic changes in water quantity in Poyang Lake are monitored in this paper, and the influencing factors and ecological impacts of the changes are analyzed. The results show that in terms of the water area change trend, on the annual scale, the annual mean values of water area and water volume exhibit overall decreasing trends. The water area was the largest in 1998 at 4068.33 km2 and smallest in 2014 at 899.68 km2; the water volume was largest in 1992 at 25,810 million m3 and smallest in 2014 at 5880 million m3. On the monthly scale, the water area was the smallest in January, largest in July, and showed an increasing trend from January to July; subsequently, a decreasing trend was observed from August to January. The water volume was smallest in February, largest in July, and showed an increasing trend from February to July; then, a decreasing trend was observed from August to February. The water volume of Poyang Lake is affected by seasonal changes in precipitation, and the correlation coefficient between monthly precipitation and monthly water volume is 0.603 (P < 0.05). In summer, the water volume is affected by the water level in the Yangtze River; the construction of the Three Gorges Dam in the Yangtze River caused a prolonged duration of the low water period and an advanced low water period, which are also important factors affecting the water volume change. In terms of the impact of water volume on ecology, the relationship between water volume and NH3-N concentration is obvious, with a correlation coefficient of −0.679 (P < 0.01). A large water volume will increase the lake water level, reduce the habitats for migratory birds, and provide food to fewer migratory birds.
Benjamin J Lagassé, Richard B Lanctot, Mark Barter, Stephen Brown, Chung-Yu Chiang, Chi-Yeung Choi, Yuri N Gerasimov, Steve Kendall, Joseph R Liebezeit, Konstantin S Maslovsky, Alexander I Matsyna, Ekaterina L Matsyna, David C Payer, Sarah T Saalfeld, Yoshimitsu Shigeta, Ivan M Tiunov, Pavel S Tomkovich, Olga P Valchuk, Michael B Wunder
Abstract: The degree to which individuals migrate among particular breeding, migration, and wintering sites can have important implications for prioritizing conservation efforts. Four subspecies of Dunlin (Calidris alpina) migrate along the East Asian−Australasian Flyway. Each subspecies has a distinct and well-defined breeding range, but their migration and winter ranges are poorly defined or unknown. We assessed the migratory connectivity of 3 of these subspecies by evaluating a dataset that encompasses 57 yr (1960–2017), and comprises more than 28,000 Dunlin banding records and 818 observations (71 recaptures and 747 band resightings). We present some of the first evidence that subspecific segregation likely occurs, with arcticola Dunlin wintering in areas of Japan, and other arcticola, actites, and sakhalina Dunlin wintering in areas of the Yellow and China seas. Observations indicate that whether an arcticola Dunlin winters in Japan or the Yellow and China seas is independent of their breeding location, sex, or age. Furthermore, observations indicate that ≥83% of arcticola Dunlin exhibit interannual site fidelity to specific wintering sites. This suggests that the degradation of specific wetland areas may negatively affect particular individuals of a particular subspecies (or combination of subspecies), and, if widespread, could result in population declines. Given the possible biases inherent in analyzing band recovery data, we recommend additional flyway-wide collaboration and the use of lightweight tracking devices and morphological and genetic assignment techniques to better quantify subspecies’ migratory movements and nonbreeding distributions. This information, when combined, will enable effective conservation efforts for this species across the East Asian−Australasian Flyway.
Shorebirds wintering in Southeast Asia demonstrate trans-Himalayan flights
David Li, Geoffrey Davison, Simeon Lisovski, Phil F. Battley, Zhijun Ma, Shufen Yang, Choon Beng How, Doug Watkins, Philip Round, Alex Yee, Vupasana Srinivasan, Clarice Teo, Robert Teo, Adrian Loo, Chee Chiew Leong & Kenneth Er
Abstract: Many birds wintering in the Indian subcontinent fly across the Himalayas during migration, including Bar-headed Geese (Anser indicus), Demoiselle Cranes (Anthropoides virgo) and Ruddy Shelducks (Tadorna ferruginea). However, little is known about whether shorebirds migrate across the Himalayas from wintering grounds beyond the Indian subcontinent. Using geolocators and satellite tracking devices, we demonstrate for the first time that Common Redshanks (Tringa totanus) and Whimbrels (Numenius phaeopus) wintering in Singapore can directly fly over the Himalayas to reach breeding grounds in the Qinghai-Tibet Plateau and north-central Russia respectively. The results also show that migratory shorebirds wintering in Southeast Asia can use both the Central Asian Flyway and the East Asian-Australasian Flyway. For Redshanks, westerly-breeding birds crossed the Himalayas while more easterly breeders on the Plateau migrated east of the Himalayas. For Whimbrels, an individual that crossed the Himalayas was probably from a breeding population that was different from the others that migrated along the coast up the East Asian-Australasian Flyway. The minimum required altitude of routes of trans-Himalayan Redshanks were no higher on average than those of eastern migrants, but geolocator temperature data indicate that birds departing Singapore flew at high elevations even when not required to by topography, suggesting that the Himalayan mountain range may be less of a barrier than assumed.
2) Conservation & management
Reducing human pressure on farmland could rescue China’s declining wintering geese
Yali Si, Jie Wei, Wenzhao Wu, Wenyuan Zhang, Lin Hou, Le Yu & Ben Wielstra
Abstract：While goose populations worldwide benefit from food provided by farmland, China’s threatened wintering goose populations have failed to capitalize on farmland. It has been proposed that, due to an exceptionally intense human pressure on Chinese farmland, geese cannot exploit farmland in their wintering sites and hence are confined to their deteriorating natural habitat. If this were true, locally decreasing this human pressure on farmland ‘refuges’ would represent a promising conservation measure. We investigate habitat use of two declining migratory goose species in their core wintering (Yangtze River Floodplain) and stopover (Northeast China Plain) regions, compare the human pressure level at both regions, and adopt a mixed-effect resource selection function model to test how human pressure, food resource type (farmland or wetland/grass), distance to roosts, and their interaction terms influence the utilization of food resources for each species and region. To this aim we use satellite tracking of 28 tundra bean geese Anser serrirostris and 55 greater white-fronted geese A. albifrons, a newly produced 30 m land cover map, and the terrestrial human footprint map. Geese use farmland intensively at their stopover site, but hardly at their wintering site, though both regions have farmland available at a similar proportion. The human pressure on both farmland and wetland/grass is significantly lower at the stopover region compared to the wintering region. At both sites, the two goose species actively select for farmland and/or wetland/grass with a relatively low human pressure, positioned relatively close to their roosting sites. Our findings suggest that if human pressure were to decrease in the farmlands close to the roost, China’s wintering geese could benefit from farmland. We recommend setting aside farmland near roosting sites that already experiences a relatively low human pressure as goose refuges, and adopt measures to further reduce human pressure and increase food quality and quantity, to help counter the decline of China’s wintering goose populations. Our study has important conservation implications and offers a practical measure for migratory waterfowl conservation in areas of high human-wildlife conflict.
Eric Wikramanayake, Carmen Or, Felipe Costa, Xianji Wen, Fion Cheung, Aurélie Shapiro
Abstract：The ecological functionality of the East Asian-Australasian Flyway is threatened by the loss of wetlands which provide staging and wintering sites for migrating waterbirds. The disappearance of wetland ecosystems due to coastal development prevents birds from completing their migrations, resulting in population declines, and even an eventual collapse of the migration phenomenon. Coastal wetlands are also under threat from global climate change and its consequences, notably sea level rise (SLR), extreme storm events, and accompanying wave and tidal surges. The impacts of SLR are compounded by coastal subsidence and decreasing sedimentation, which can result from coastal development. Thus, important wetlands along the flyway should be assessed for the impacts of climate change and coastal subsidence to plan and implement proactive climate adaptation strategies that include habitat migration and possibility of coastal squeeze. We modelled the impacts of climate change and decreasing sedimentation rates on important bird habitats in the Mai Po Inner Deep Bay Ramsar site to support a climate adaptation strategy that will continue to host migratory birds. Located in the Inner Deep Bay of the Pearl River estuary, Mai Po’s tidal flats, coastal mangroves, marshes, and fishponds provide habitat for over 80,000 wintering and passage waterbirds. We applied the Sea Level Affecting Marshes Model (SLAMM) to simulate habitat conversion under two SLR scenarios (1.5m and 2.0m) for 2050, 2075, and 2100 for four accretion rates (2mm/yr, 4 mm/yr, 8 mm/yr, 15 mm/yr). The results showed no discernible impact to habitats until after 2075, but projections for 2100 show that the mangroves, marshes and tidal flats could be impacted in almost all scenarios of SLR and accretion. Under a 1.5m SLR scenario, even at low tide, if accretion levels decrease to 4 mm/yr, the tidal flats will be inundated and with a 2 mm/yr accretion the mangroves will also be inundated. Thus, important shorebird habitats will be lost. During high tide the ponds inside the nature reserve, which are intensively managed to provide high tide roosting sites and other habitats for waterbirds, will also be inundated. Thus, with a 1.5m SLR and declining sedimentation the migratory shorebirds will lose habitat, including the high tide roosting habitats inside the nature reserve. The model also indicates that the fishponds further inland in the Ramsar site will be less impacted. Most fishponds are privately owned and could be developed in the future, including into high rise apartments; thus, securing them for conservation should be an important climate change adaptation strategy for Mai Po, since they provide essential habitats for birds under future climate change scenarios. But Mai Po is only one steppingstone along the EAAF, and hundreds of other wetlands are also threatened by encroaching infrastructure and climate change. Thus, similar analyses for the other wetlands are recommended to develop a flyway-wide climate-adaptation conservation strategy before available options become lost to wetland conversion.
Shifts in bird ranges and conservation priorities in China under climate change
Ruocheng Hu , Yiyun Gu , Mei Luo , Zhi Lu , Ming Wei, Jia Zhong
Abstract：Climate change is one of the most significant causes of species range shift and extinction. Based on a citizen science dataset of birds in China, the Bird Report, we developed a high-resolution map of bird species richness in China, and simulated the range shifts and area changes of the 1,042 birds through the year 2070 using three different General Circulation Models and two different Representative Concentration Pathways (RCPs, including RCP 2.6 and RCP 8.5). It was found that 241–244 (under different scenarios) bird species would lose a portion of their distribution ranges; and that most species in China would move to either higher elevations or northward. The other 798–801 species would experience range expansion. Compared to resident species (n = 516), migratory birds (n = 526) may undergo more limited range expansion but a longer range shift distance on average. The species diversity of birds will considerably increase in areas higher than 1,500 m in elevation under both RCPs. Conservation priorities with higher species richness were also identified using the Zonation model. The existing national nature reserves are not sufficient for protecting important bird habitats, especially after range shifts. Significant gaps in protected areas were observed in the northern Xinjiang, southern Tibet, Greater Khingan, Sanjiang Plain, Songnen Plain, northern Bohai Rim, and southeastern coastline areas. Many of these areas are characterized by high human populations and intensive development, and establishing sizable protected areas has become difficult. Inclusive conservation mechanisms that include restoring habitats in urban parks and sharing habitats in farmland areas, may be a feasible solution.
Hai-bing Wu, Bing-hui Zheng
Abstract：Dongting Lake Wetlands are a key waterbird habitat. Wetland area and biomass growth are the two primary factors that influence the lives of waterbirds. Lake topography and water level changes significantly influence wetland area and biomass growth processes. However, to date, no study has quantified the associations of spatial-temporal patterns of wetland area changes and wetland plant biomass growth processes with lake topography and water level changes. Therefore, the land use-water level change simulation model is established to provide a simulation platform for spatial-temporal simulation of wetlands and plants biomass to provide support for the protection and management of wetlands and waterbirds. Dongting Lake, which is the second largest freshwater lake in China and an important habitat for migratory birds, is adopted as the study region. The influence of the Three Gorges Project on Dongting Lake water levels and wetlands is revealed through model simulation. After construction of the three Gorges Project, the highest water level value decreased 0.18 m, and the lowest water level value increased from 20.56 m to 21.11 m. The spatial-temporal patterns of wetland area and plant biomass growth were accurately calculated. The results suggest that the water level of the three Gorges Project can be maintained at a relatively high level from 167 m to 175 m, confirming the low and safe water level in Dongting Lake. The temporal water level adjustment frequency of the three Gorges Project should be further assessed in future research. The simulation model and the research results could provide a significant tool for wetland conservation and waterbird protection.
Micha V. Jackson, Richard A. Fuller, Xiaojing Gan, Jing Li, Dehua Mao, David S. Melville, Nicholas J. Murray, Zongming Wang, Chi-Yeung Choi
Abstract：China’s coastal wetlands are critically important to shorebirds. Substantial loss of tidal flats, shorebirds’ primary foraging grounds, has occurred from land claim and other processes, and is driving population declines in multiple species. Smooth cordgrass Spartina alterniflora was intentionally introduced to the coast of China in 1979 to promote conversion of tidal flats into dry land and has since spread rapidly. The occurrence of S. alterniflora reduces the availability of foraging and roosting habitat for shorebirds, and may be particularly detrimental in places that have experienced other tidal flat loss. However, the extent to which S. alterniflora is encroaching upon important shorebird habitat throughout coastal mainland China, and its intersection with tidal flat loss, has not been quantified. Here, we i) estimate change in the spatial extent of tidal flats between 2000 and 2015 in coastal mainland China where internationally important numbers of shorebirds have been recorded; ii) map the extent of S. alterniflora coverage in 2015 at the same set of sites; and, iii) investigate where these two threats to important shorebird habitat intersect. Our analysis of remote sensing data indicated a 15% net loss in tidal flat area between 2000 and 2015 across all sites, including a net loss in tidal flat area in 39 of 53 individual sites (74%). Spartina alterniflora occurred at 28 of 53 sites (53%) in 2015, of which 22 sites (79%) also had a net loss in tidal flat area between 2000 and 2015. Combined pressures from tidal flat loss and S. alterniflora invasion were most severe in eastern coastal China. Species highly dependent on migrating through this region, which include the Critically Endangered Spoon-billed Sandpiper and Endangered Nordmann’s Greenshank and Far Eastern Curlew, may be particularly impacted. Our results underscore the urgent need to arrest tidal flat declines and develop a comprehensive control program for S. alterniflora in coastal areas of mainland China that are important for shorebirds.
Shanshan Zhao, Huan Xu, Ningning Song, Zhenghuan Wang, Ben Li, Tianhou Wang
Abstract：Wind farms offer a cleaner alternative to fossil fuels and can mitigate their negative effects on climate change. However, wind farms may have negative impacts on birds. The East China Coast forms a key part of the East Asian–Australasian Flyway, and it is a crucial region for wind energy development in China. However, despite ducks being the dominant animal taxon along the East China Coast in winter and considered as particularly vulnerable to the effects of wind farms, the potential negative impacts of wind farms on duck populations remain unclear. We therefore assessed the effects of wind farms on duck abundance, distribution, and habitat use at Chongming Dongtan, which is a major wintering site for ducks along the East Asian–Australasian Flyway, using field surveys and satellite tracking. We conducted seven paired field surveys of ducks inside wind farm (IWF) and outside wind farm (OWF) sites in artificial brackish marsh, paddy fields, and aquaculture ponds. Duck abundance was significantly higher in OWF compared with IWF sites and significantly higher in artificial brackish marsh than in aquaculture ponds and paddy fields. Based on 1,918 high‐resolution satellite tracking records, the main habitat types of ducks during the day and at night were artificial brackish marsh and paddy fields, respectively. Furthermore, grid‐based analysis showed overlaps between ducks and wind farms, with greater overlap at night than during the day. According to resource selection functions, habitat use by wintering ducks was impacted by distance to water, land cover, human activity, and wind farm effects, and the variables predicted to have significant impacts on duck habitat use differed between day and night. Our study suggests that wintering ducks tend to avoid wind turbines at Chongming Dongtan, and landscape of paddy fields and artificial wetlands adjoining natural wetlands is crucial for wintering ducks.
Anthropogenic impacts on the demographics of Arctic-breeding birds
Susan Doyle, Aimée Gray & Barry J. McMahon
Abstract：The Arctic supports a diversity of breeding birds. Since the mid-twentieth century, anthropogenic-source climate change, industrial activity and harvest have impacted this ecosystem and the demographics of its breeding birds, highlighting the need to synthesise current knowledge. A scoping review was conducted to quantify recent population trends and identify impacts of anthropogenic activity on species’ demography. The literature revealed that many seabird trends were mixed or uncertain. Trends among waterfowl, divers and cranes were largely upward or stable. Trends among waders, passerines and raptors, however, were more evenly distributed upward and downward. Wader trends tended to be more positive in the East Atlantic flyway compared to other flyways, while many raptor populations are recovering following historic losses. In contrast, grouse experienced uncertain or negative trends. Weather regime and vegetation shifts, phenological mismatches and diminishing sea ice associated with climate change are important drivers of demography. The strength and direction of these impacts, however, varies among guilds and between the low and high-Arctic. The extraction, chemical, agriculture and fisheries industries also impact demography. Research on heavy metal and organochlorine contamination was prevalent in the literature, despite having relatively weaker impacts than other drivers. Although bird harvest has had profound impacts on Arctic populations, recently updated regulations and improvements in policy have ameliorated its impact somewhat. Nonetheless, many anthropogenic impacts are predicted to become more severe in the future, with consequences for breeding bird trends, therefore continued pan-Arctic monitoring and addressing knowledge gaps will be necessary to preserve this unique biome.
3) Avian Influenza /Others
Ling Tang, Wangjun Tang, Le Ming, Jianming Gu, Kai Qian, Xiaofang Li, Tianhou Wang, Guimei He
Abstract：H10, H11 and H12 (H10–H12) subtypes of the avian influenza virus (AIV) are associated with waterfowl. Although these subtypes of AIV are infrequently detected in nature, they can undergo reassortment with other AIV subtypes. Few H10–H12 subtypes of AIV have been isolated from wild birds in China. In this study, 12 AIV isolates of H10–H12 subtypes were identified via routine surveillance of wild birds in Shanghai, China from 2016 to 2019, including two H10, three H11 and seven H12 isolates. Sequence and phylogenetic analyses revealed that the genomic segments of the 12 isolates are highly diverse. These 12 isolates are closely related to those in the Eurasian lineage and share a high degree of sequence identity with those from wild birds and domestic ducks in countries in the East Asian–Australasian Flyway, including Japan, Korea, Bangladesh, Vietnam and China. However, parts of the genomic segments of two H12N2 isolates (NH112319-H12N2 and NH101807-H12N2) belong to the North American lineage, suggesting intercontinental reassortment among H12 AIVs in Eurasia and North American. To better understand the ecological and phylodynamic features of H10–H12 subtypes in wild birds, a large-scale surveillance of AIVs in wild birds is warranted.
Key words for searching in web of Science：
East Asian-Australasian flyway, flyway, migratory, water bird, wetland, Asia, Australia, shorebird, wader, Anatidae, seabird.
