1) Biology & ecology
- Conklin, J. R., S. Lisovski, and P. F. Battley. 2021. Advancement in long-distance bird migration through individual plasticity in departure. Nature Communications 12:4780.
- Wang, Y., I. Damba, Q. Zhao, Y. Xie, X. Deng, R. Ga, G. Liu, Z. Xu, Y. Li, D. Gao, W. Xu, G. Chen, and L. Cao. 2021. Organising a juvenile ratio monitoring programme for 10 key waterbird species in the Yangtze River floodplain: analysis and proposals. Avian Research 12:72.
- Li, X. Z., C. J. Anderson, Y. Y. Wang, and G. C. Lei. 2021. Waterbird diversity and abundance in response to variations in climate in the Liaohe Estuary, China. Ecological Indicators 132.
- Huang, Z., X. Zhou, W. Fang, H. Zhang, and X. Chen. 2021. Autumn migration routes and wintering areas of juvenile Chinese Egrets (Egretta eulophotes) revealed by GPS tracking. Avian Research 12:65.
- Batbayar, N., K. P. Yi, J. J. Zhang, T. Natsagdorj, I. Damba, L. Cao, and A. D. Fox. 2021. Combining Tracking and Remote Sensing to Identify Critical Year-Round Site, Habitat Use and Migratory Connectivity of a Threatened Waterbird Species. Remote Sensing 13.
- Huang, P. Y., E. S. K. Poon, A. T. C. Wong, I. W. Y. So, Y. H. Sung, and S. Y. W. Sin. 2021. DNA metabarcoding reveals the dietary composition in the endangered black-faced spoonbill. Scientific Reports 11.
- Morrick, Z. N., A. Lilleyman, R. A. Fuller, R. Bush, J. T. Coleman, S. T. Garnett, Y. N. Gerasimov, R. Jessop, Z. Ma, G. Maglio, C. D. T. Minton, E. Syroechkovskiy, and B. K. Woodworth. 2021. Differential population trends align with migratory connectivity in an endangered shorebird. Conservation Science and Practice, e594.
- Zhu, Y. W., H. X. Wang, and W. X. Guo. 2021. The impacts of water level fluctuations of East Dongting Lake on habitat suitability of migratory birds. Ecological Indicators 132.
- Zhu, B. R., M. A. Verhoeven, A. H. J. Loonstra, L. Sanchez-Aguilar, C. J. Hassell, K. K. S. Leung, W. P. Lei, Z. W. Zhang, and T. Piersma. Identification of breeding grounds and annual routines of the newly discovered bohaii subspecies of Black-tailed Godwits. Emu – Austral Ornithology: 292-302.
- Sasin, A., A. Serdyuk, B. Zhu, and Q. Zhao. 2021. Individual tracking reveals first breeding of Oriental Storks at age 2 years in the wild. Avian Research 12:64.
- Zhang, J., Y. Zhang, H. Lloyd, Z. Zhang, and D. Li. 2021. Rapid Reclamation and Degradation of Suaeda salsa Saltmarsh along Coastal China’s Northern Yellow Sea. Land 10:835.
- Pandiyan, J., S. Mahboob, K. A. Al-Ghanim, F. Al-Misned, Z. Ahmed, G. Karthikeyan, K. Gopinath, and M. Govindarajan. 2021. Factors determine the population characteristics of migratory shorebirds and their prey species in the coastal saltpans. Estuarine, Coastal and Shelf Science 260:107490.
2) Conservation & management
- Yuan, L., D. Y. Liu, B. Tian, X. Yuan, S. Q. Bo, Q. Ma, W. Wu, Z. Y. Zhao, L. Q. Zhang, and J. K. Keesing. 2022. A solution for restoration of critical wetlands and waterbird habitats in coastal deltaic systems. Journal of Environmental Management 302.
- Zhang, Y., L. Zhou, L. Cheng, and Y. Song. 2021. Water level management plan based on the ecological demands of wintering waterbirds at Shengjin Lake. Global Ecology and Conservation 27:e01567.
- Zhang, S. D., Q. Q. Bai, D. S. Melville, C. C. Feng, T. Piersma, and Z. J. Ma. 2021. Food supplementation as a conservation intervention: A framework and a case of helping threatened shorebirds at a refuelling site. Biological Conservation 264.
- Jia, Y., Y. Liu, S. Jiao, J. Guo, C. Lu, Y. Zhou, Y. Wang, G. Lei, L. Wen, and X. Mo. 2021. Shifting of the Migration Route of White-Naped Crane (Antigone vipio) Due to Wetland Loss in China. Remote Sensing 13:2984.
- Yang, Z. Y., J. Li, Y. X. Han, C. J. Hassell, K. S. K. Leung, D. S. Melville, Y. T. Yu, L. Zhang, and C. Y. Choi. 2021. Coastal wetlands in Lianyungang, Jiangsu Province, China: probably the most important site globally for the Asian Dowitcher (Limnodromus semipalmatus). Avian Research 12.
- Clemens, R. S., D. I. Rogers, C. D. T. Minton, K. G. Rogers, B. D. Hansen, C. Y. Choi, and R. A. Fuller. 2021. Favourable inland wetland conditions increase apparent survival of migratory shorebirds in Australia. Emu-Austral Ornithology 121:211-222.
- Damba, I., J. Zhang, K. Yi, H. Dou, N. Batbayar, T. Natsagdorj, B. Davaasuren, L. Cao, and A. D. Fox. 2021. Seasonal and regional differences in migration patterns and conservation status of Swan Geese (Anser cygnoides) in the East Asian Flyway. Avian Research 12:73.
- Xi, J., X. Deng, G. Zhao, N. Batbayar, I. Damba, Q. Zhao, S. Cui, C. Jiang, Y. Chen, Y.-t. Yu, L. Cao, and A. D. Fox. 2021. Migration routes, behavior and protection status of Eurasian Spoonbills (Platalea leucorodia) wintering in China. Avian Research 12:70.
- Ren, J., J. Chen, C. Xu, J. van de Koppel, M. S. Thomsen, S. Qiu, F. Cheng, W. Song, Q.-X. Liu, and C. Xu. 2021. An invasive species erodes the performance of coastal wetland protected areas. Science Advances 7:eabi8943.
- Xu, W., D. Solovyeva, S. Vartanyan, H. Zheng, V. Pronkevich, Y. Gong, and H. Wang. 2021. Modelling suitable breeding habitat and GAP analysis for the endangered Scaly-sided Merganser Mergus squamatus: implications for conservation. Bird Conservation International:1-12.
- Yang, X. T., Z. Z. Duan, Y. H. Hu, J. C. Liu, Y. C. Xu, H. J. Hu, G. D. Hua, X. K. Liu, J. J. Gan, X. W. Zeng, and S. M. Lin. 2021. Mangrove planting strategies should consider the optimal ratio between the area of tidal flats and the area of mangroves. Ocean & Coastal Management 213.
- Jackson, M. V., B. K. Woodworth, R. Bush, R. S. Clemens, R. A. Fuller, S. T. Garnett, A. Lilleyman, M. Maron, C. Purnell, D. I. Rogers, and T. Amano. 2021. Widespread use of artificial habitats by shorebirds in Australia. Emu-Austral Ornithology 121:187-197.
- Choi, G., M. S. Do, S.-J. Son, and H.-K. Nam. 2021. Effect of different management techniques on bird taxonomic groups on rice fields in the Republic of Korea. Scientific Reports 11:22347.
- Cheng, Y., Y. Zha, W. Zhang, G. Wei, C. Tong, and D. Du. 2021. The bird community in a coastal wetland in East China and its spatial responses to a wind farm. Community Ecology 22:413-426.
3)Avian Influenza /Others
- Chai, H., X. Li, M. Li, X. Lv, W. Yu, Y. Li, J. Sun, Y. Li, H. Sun, J. Tian, Y. Xu, X. Bai, P. Peng, L. Xie, S. Qin, Q. An, F. Zhang, H. Zhang, J. Du, S. Yang, Z. Hou, X. Zeng, Y. Wang, J. A. Richt, Y. Wang, Y. Li, and J. Ma. 2021. Emergence, Evolution, and Pathogenicity of Influenza A(H7N4) Virus in Shorebirds, China. Journal of Virology.
- Inumaru, M., Y. Odaya, Y. Sato, and A. Marzal. 2021. First records of prevalence and diversity of avian haemosporidia in snipe species (genus Gallinago) of Japan. International Journal for Parasitology-Parasites and Wildlife 16:5-17.
1) Biology & ecology
Advancement in long-distance bird migration through individual plasticity in departure
Jesse R. Conklin, Simeon Lisovski & Phil F. Battley
Abstract: Globally, bird migration is occurring earlier in the year, consistent with climate-related changes in breeding resources. Although often attributed to phenotypic plasticity, there is no clear demonstration of long-term population advancement in avian migration through individual plasticity. Using direct observations of bar-tailed godwits (Limosa lapponica) departing New Zealand on a 16,000-km journey to Alaska, we show that migration advanced by six days during 2008–2020, and that within-individual advancement was sufficient to explain this population-level change. However, in individuals tracked for the entire migration (50 total tracks of 36 individuals), earlier departure did not lead to earlier arrival or breeding in Alaska, due to prolonged stopovers in Asia. Moreover, changes in breeding-site phenology varied across Alaska, but were not reflected in within-population differences in advancement of migratory departure. We demonstrate that plastic responses can drive population-level changes in timing of long-distance migration, but also that behavioral and environmental constraints en route may yet limit adaptive responses to global change.
Yuxi Wang, Iderbat Damba, Qingshan Zhao, Yanbo Xie, Xueqing Deng, Rdi Ga, Guanhua Liu, Zhiwen Xu, Yue Li, Dali Gao, Wenbin Xu, Guoxun Chen & Lei Cao
Abstract: Background In the face of continued degradation and loss of wetlands in the Yangtze River floodplain (YRF), there is an urgent need to monitor the abundance and distribution of wintering waterbirds. To understand fully observed annual changes, we need to monitor demographic rates to understand factors affecting global population size. Annual reproduction success contributes to dynamic changes in population size and age structure, so an assessment of the juvenile ratio (i.e. first winter birds as a proportion of total number aged) of overwintering waterbirds can be an important indicator of the reproductive success in the preceding breeding season. Methods During 2016-2019, we sampled juvenile ratios among 10 key waterbird species from the wetlands in the YRF. Based on these data, we here attempt to establish a simple, efficient, focused and reliable juvenile ratio monitoring scheme, to assess consistently and accurately relative annual breeding success and its contribution to the age structure among these waterbird species. Results We compared juvenile ratio data collected throughout the winter and found that the optimal time for undertaking these samples was in the early stages of arrival for migratory waterbirds reaching their wintering area (early to mid-December). We recommend counting consistently at key points (i.e. those where > 1% biogeographical flyway population were counted) at sites of major flyway importance (Poyang Lake, East Dongting Lake, Shengjin Lake, Caizi Lake, Longgan Lake and Chen Lake). Based on this, the error rate of the programme (155 planned points, the count of 10 waterbird species is 826-8955) is less than 5%. Conclusions We established a juvenile ratio monitoring programme for 10 key waterbird species in the wetlands of the YRF, and discuss the feasibility and necessity of implementing such a future programme, and how to use these data in our monitoring and understanding of the population dynamics of these waterbird populations.
Waterbird diversity and abundance in response to variations in climate in the Liaohe Estuary, China
Xiuzhong Li, Christopher J. Anderson, Yuyu Wang, Guangchun Lei
Abstract: Birds are sensitive to environmental change and thus good indicators of biodiversity and ecosystem health. Because birds fill a variety of functional roles, understanding their diversity patterns is important to inform and support conservation management. This study focused on the diversity and abundance of waterbirds occupying the Liaohe Estuary, an internationally important habitat, and migratory stopover in northeast China. Analyzing data from 42 monitoring stations/transects collected over ten years, we determined the seasonal abundance and distribution of waterbirds throughout the estuary and surrounding lands and looked for associations with climatic data shown to influence bird populations. Results showed that although global populations of waterbirds are decreasing, bird abundance, richness, and alpha diversity increased in the Liaohe Estuary during our 10- year study. Distinct annual patterns of species distribution were detected during spring and autumn with population lower in spring than autumn. Analyses with non-metric multidimensional scaling (NMS) showed that spring populations had a strong and positive relationship to temperature variables including spring mean temperature and cumulative temperature days. There was a clear distribution of waterbird species along the axis of the spring temperature range and precipitation. Whereas in autumn, waterbird populations had a strong and negative relationship to precipitation variables including annual precipitation, autumn precipitation, and autumn maximum precipitation. These findings indicate that waterbird diversity in this region and others may be responsive to climate change, especially in spring season. We discuss the ramifications of these shifts in terms of future utilization of the estuary by waterbirds in the region. We project that as temperatures continue to warm and precipitation decreases, there may be increasing migratory stopover and breeding in the Liaohe Estuary and thus populations may continue to increase in the future.
Zhijun Huang, Xiaoping Zhou, Wenzhen Fang, Hailong Zhang & Xiaolin Chen
Abstract: Background The vulnerable Chinese Egret (Egretta eulophotes) is a long-distance migratory waterbird whose migration and wintering information is poorly understood. This study aims to identify the autumn migration routes and wintering areas of juvenile Chinese Egrets and determine the migration movement traits of this species. Methods Thirty-nine juvenile Chinese Egrets from the Fantuozi Island, an uninhabited offshore island with a large breeding colony of Chinese Egrets in Dalian, China, were tracked using GPS/GSM transmitters. Some feathers from each tracked juvenile were collected for molecular identification of sex in the laboratory. The GPS locations, recorded at 2-h intervals from August 2018 to May 2020, were used for the analyses. Results Of the 39 tracked juveniles, 30 individuals began their migration between September and November, and 13 successfully completed their autumn migration between October and November. The juveniles migrated southward via three migration routes, coastal, oceanic and inland, mainly during the night. The migration duration, migration distance, flight speed, and stopover duration of the 13 juvenile egrets that completed migration averaged 5.08 +/- 1.04 days, 3928.18 +/- 414.27 km, 57.27 +/- 5.73 km/h, and 23.08 +/- 19.28 h, respectively. These juveniles wintered in the coastal wetlands of Southeast Asia including those in the Philippines, Vietnam, and Malaysia, and only one successfully began its spring migration in June 2020. Conclusions This study newly finds that the oceanic route taken by juvenile Chinese Egrets, suggesting that the juveniles are able to fly over the Pacific Ocean without a stopover. Moreover, our novel data indicate that coastal wetlands along the East Asian-Australasian Flyway are important areas for both autumn migration stopover and the wintering of these juveniles, suggesting that international cooperation is important to conserve the vulnerable Chinese Egret and the wetland habitats on which it depends.
Nyambayar Batbayar, Kunpeng Yi, Junjian Zhang, Tseveenmyadag Natsagdorj, Iderbat Damba, Lei Cao and Anthony David Fox
Abstract: We tracked 39 western flyway white-naped cranes (Antigone vipio) throughout multiple annual cycles from June 2017 to July 2020, using GSM-GPS loggers providing positions every 10-min to describe migration routes and key staging areas used between their Mongolian breeding and wintering areas in China’s Yangtze River Basin. The results demonstrated that white-naped cranes migrated an average of 2556 km (±187.9 SD) in autumn and 2673 km (±342.3) in spring. We identified 86 critical stopover sites that supported individuals for more than 14 days, within a 100–800 km wide migratory corridor. This study also confirmed that Luan River catchment is the most important staging region, where white-naped cranes spent 18% of the annual cycle (in both spring and autumn) each year. Throughout the annual cycle, 69% of the tracking locations were from outside of the currently protected areas, while none of the critical staging areas enjoyed any form of site protection. We see further future potential to combine avian tracking data and remote-sensing information throughout the annual range of the white-naped crane to restore it and other such species to a more favourable conservation status
DNA metabarcoding reveals the dietary composition in the endangered black-faced spoonbill
Pei-Yu Huang, Emily Shui Kei Poon, Anson Tsz Chun Wong, Ivy Wai Yan So, Yik-Hei Sung & Simon Yung Wa Sin
Abstract: Extensive loss of natural wetlands caused by changes in land use largely diminishes the food resources essential for the survival of migratory waterbirds. Globally, the decline in waterbird populations in East Asia is the most serious, with 64% of these populations showing a decreasing trend. In this study, we applied DNA metabarcoding to examine the spatiotemporal variations and diversities in the dietary compositions of migratory waterbirds in a natural/artificial wetland complex in Asia. By investigating 110 fecal samples from the endangered black-faced spoonbill (Platalea minor) wintering in the wetland, our results show that P. minor had a broad dietary spectrum. The birds fed on at least 26 species in the classes Actinopterygii and Malacostraca, with Mugiliformes, Cichliformes, and Gobiiformes being the main taxa in their diets. Our results also demonstrated clear patterns of the spatiotemporal variations between the roosting groups and intraspecific variations between the individuals, which potentially reflect some of their feeding habits, and the probable usage of different habitat types in the wetland complex. Using high-throughput sequencing, we were able to elucidate the food resources that are critical to P. minor non-invasively, this method can also be used to provide invaluable information for the conservation of many other waterbird species.
Houlang Duan, Xiubo Yu, Shaoxia Xia, Guangshuai Zhang
Abstract: Natural wetlands along the coasts of the Yellow and Bohai Seas provide key stopover sites for migratory waterbirds. However, these wetlands are facing land loss. Understanding how natural wetland loss influences habitat is important for habitat management. We used species distribution models to report changes in area of suitable habitat and analysed the effects of natural wetland loss on habitat for 80 waterbird species of four functional categories (shorebirds, ducks, herons, gulls) between 2000 and 2015 beside the Yellow and Bohai Seas. Between 2000 and 2015, 1794.8 km2 (29.27%) of coastal wetland was lost to development, most of which were tidal flats that were lost by conversion into aquaculture and salt pan habitat or land for construction. Consequently, habitat for 73 of these 80 species has decreased in area over this time period. Generally, the proportional decline in habitat suitable for duck species was less than that for shorebirds, and the proportional decline in suitable habitat was not significantly different between National Protected Species and Non-National Protected Species. The proportional loss of tidal flats that formerly represented suitable habitat was also significantly higher for shorebirds, herons and gulls than for ducks. Because more duck species exploit aquaculture and salt pan habitat that was converted from tidal flats habitats, such conversion of tidal flats poses a greater threat to shorebirds, herons and gulls than to ducks. Preventing further reclamation of tidal flats and managing artificial wetlands are priorities for waterbird conservation.
Differential population trends align with migratory connectivity in an endangered shorebird
Zaine N. Morrick, Amanda Lilleyman, Richard A. Fuller, Robert Bush, Jonathan T. Coleman, Stephen T. Garnett, Yuri N. Gerasimov, Roz Jessop, Zhijun Ma, Grace Maglio, Clive D. T. Minton, Evgeny Syroechkovskiy, Bradley K. Woodworth
Abstract: Migratory connectivity describes the extent to which migratory species’ populations are connected throughout the annual cycle. While recognized as critical for understanding the population dynamics of migratory species and conserving them, empirical evidence of links between migratory connectivity and population dynamics are uncommon. We analyzed associations between spatiotemporal connectivity and differential population trends in a declining and endangered migratory shorebird, the far eastern curlew (Numenius madagascariensis), with multiyear tracking data from across the Australian nonbreeding grounds. We found evidence of temporal and spatial segregation during migration and breeding: curlew from southeast Australia initiated northward migration earlier, arrived at breeding sites earlier, and bred at lower latitudes than curlew from northwest Australia. Analysis of land modification intensity revealed that populations from southeast Australia face greater human impacts compared to those from northwest Australia at both the breeding and nonbreeding grounds, a pattern that aligns with steeper population declines in southeast Australia. This alignment between migratory connectivity, human impacts, and differential population change highlights the importance of a full annual cycle approach to conservation that includes mitigating threats on the breeding grounds and better protecting nonbreeding habitats in Australia where far eastern curlew spend over half of each year.
Yongwei Zhu, Hongxiang Wang, Wenxian Guo
Abstract: Understanding responses of habitat suitability of migratory birds to the water level is significant for providing countermeasures of wetland protection. East Dongting Lake serves critical wintering habitat for migratory birds along the East Asian-Australasian Flyway. However, the response relationships between the water level and the weighted usable area (WUA) for migratory birds remain largely unknown. Therefore, we established a habitat suitability model of migratory birds based on the Digital Elevation Model (DEM) and Normalized Difference Vegetation Index (NDVI) and recognized the change of WUA by comparing the transition of land-cover of similar hydrologic years before and after the operation of Three Gorge Dam (TGD). The results demonstrated that (1) the ecological water level of migratory birds in East Dongting Lake is 20.47–21.55 m. (2) Compared with the pre-TGD period, the start date of the ecological water level advanced by 25 days, the duration of the ecological water level increased by 16 days, and the fluctuation range of water level was more concentrated near the ecological water level, indicating that the TGD provides benefits for the migratory birds. (3) The most prominent transition among changes of land-cover was that the Reed beach (RB) (155.07 km2) and Marsh land (ML) (150.66 km2) changed to Tender Marsh land (TML) during dry hydrologic years, and the RB (171.90 km2) and ML (174.30 km2) changed to TML during normal hydrologic years. The findings show that water level changes habitat suitability of migratory birds by changing vegetation distribution at different elevations.
Bing-Run Zhu, Mo A. Verhoeven, A. H. Jelle Loonstra, Lisa Sanchez-Aguilar, Chris J. Hassell, Katherine K-S. Leung, Weipan Lei, Zhengwang Zhang & Theunis Piersma
Abstract: The Bohai Black-tailed Godwit (Limosa limosa bohaii) is a newly discovered subspecies in the East Asian-Australasian Flyway. Based on satellite tracking of 21 individuals that were tagged in northern Bohai Bay, China, from 2016 to 2018, we here describe the annual cycle of this subspecies. All the birds had Thailand as their southernmost ‘winter’ destination. The spring departure was in late March during northward migration, Bohai Bay was the first stopping site where they spent on average 39 days (± SD = 6 d), followed by Inner Mongolia and Jilin province (stopping for 8 d ± 1 d). The arrival of the breeding grounds in the Russian Far East was centred in late May. Two breeding sites were detected, with average locations 1100 km apart; the eastern site was beyond the known Asian breeding distribution of the Black-tailed Godwit. Southward migration started in late June, with the godwits tending to make longer stops at the same two main stopping sites used in the spring, i.e. Inner Mongolia and Jilin province (32 ± 5 d) and Bohai Bay (44 ± 8 d), with some individuals making a third stop in the middle-lower reaches of the Yangtze River in southern China (12 ± 4 d). By the end of September, most tracked individuals had arrived in Thailand. Compared with the previously known subspecies, bohaii godwits have strikingly different schedules of migration and moult, this study thus adding to the knowledge about intraspecific diversity of black-tailed godwits in the East Asian-Australian Flyway.
Individual tracking reveals first breeding of Oriental Storks at age 2 years in the wild
Anton Sasin, Anna Serdyuk, Baoguang Zhu & Qingshan Zhao
Abstract: In this study, we report the first ever documented instances of attempted and successful reproduction (rearing two offspring) of Oriental Storks (Ciconia boyciana) at age 2 years in a wild population in the middle Heilongjiang-Amur River Basin in Russia, using a combination of GPS-GSM tracking, DNA sex identification and field verification.
Jing Zhang, Yan Zhang, Huw Lloyd, Zhengwang Zhang and Donglai Li
Abstract: Suaeda salsa saltmarshes are an important coastal wetland habitat of China’s northern Yellow Sea, which plays a critical role in sequestering carbon (blue carbon), protecting shorelines, maintaining biodiversity, and has substantial economic value (e.g., ecotourism). However, the area of S. salsa has been rapidly declining due to several different threats from reclamation and invasive species that impact its natural succession. Here, we map the changes in the distribution of the S. salsa saltmarshes along the northern Yellow Sea of China (NYSC) at 5-year intervals by applying the supervised maximum likelihood method to analyze Landsat images from 1988 to 2018 and investigate the potential impact of three important factors on habitat change by analyzing the temporal changes in S. salsa saltmarshes with other land covers. S. salsa saltmarsh areas have decreased by 63% (264 km2 ha to 99 km2), and the average loss of S. salsa saltmarshes was 5.5 km2/year along the NYSC over the past three decades. There have been many dramatic declines in the two main distribution areas of S. salsa saltmarshes with a 77% loss of habitat area in Liaodong Bay (from 112 km2 to 26 km2) and a 52% loss in the Yellow River Delta wetland-Guangli-Zhima estuarine wetland (from 137 km2 to 65 km2). Land reclamation is the most important impact factor in the loss of S. salsa saltmarshes, while there have been limited effects of natural succession and smooth cordgrass (Spartina alterniflora) invasion. In light of the important ecological services and economic value of the S. salsa habitat, emergency conservation actions (e.g., habitat restoration, strictly supervision) are needed to limit the rapid habitat loss, which should include the immediate cessation of extensive land reclamation along the NYSC.
Jeganathan Pandiyan, Shahid Mahboob, Khalid A.Al-Ghanim, Fahad Al-Misned, Zubair Ahmed, Ganesan Karthikeyan, Kasi Gopinath, Marimuthu Govindarajan
Abstract: Naturally-occurring seasonal saltpans serve as a major foraging ground for migratory shorebirds. Nevertheless, little is known about the role of various environmental factors in determining the density, diversity and species richness of shorebirds and their prey in India. This study was designed to collect quantitative data for the first time on the role of season, salinity, water depth, and prey availability in influencing the density, diversity, and species richness of migratory shorebirds in the eastern coastal saltpans of Tamilnadu, India. Selected sites were classified as seasonal saltpans and hypersaline saltpans based on the concentration of salinity in water. Shorebirds were counted systematically from (August) 2012 to (May) 2015 using the total count method. The measurement of salinity level and water depths of each sighting was also collected. The density, diversity and species richness of shorebirds showed highest in the seasonal saltpans than the hypersaline saltpans. The monsoon season attracted more shorebird density, diversity species richness when compared to other seasons. Calidris alpine was only the migratory shorebird species recorded in both types of saltpans and across seasons. The micro and macro-invertebrate prey species showed the highest in the seasonal saltpans. The Chironomid larva showed the highest turnover than other species recorded in the studied saltpans. The multiple regression models showed that the year, season, salinity, and water depth influence the shorebird density, diversity, species richness, and prey species’ density with a more significant percentage. The study results found that saltpans are also an ideal habitat for migratory shorebirds and their diverse prey species seasonally.
2) Conservation & management
A solution for restoration of critical wetlands and waterbird habitats in coastal deltaic systems
LinYuan, Dongyan Liu, Bo Tian, Xiao Yuan, Shunqi Bo, Qiang Ma, Wei Wu, Zhiyuan Zhao, Liquan Zhang, John K. Keesing
Abstract: Loss of coastal wetland habitats has been directly linked to a decline in waterbird populations including migratory species, leading to calls to reverse this trend in part by restoring these habitats. However, distinct “sediment scarcity” has hindered coastal habitat restoration. Here, taking the Yangtze River Delta, China as an example, we put forward a feasible solution to solve the sediment shortage in habitat restoration so necessary to restore migratory waterbird numbers. Four biological indices including total wetland area, wetland vegetation area and waterbird species richness and abundance, were used to compare and assess the restorative efforts. Three solutions were adopted for the rehabilitation sites, including promoting sediment deposition and settlement through engineering intervention in Chongming Dongtan (CD) and Eastern Nanhui (EN), and using dredged sediments to nourish and create new habitats in Hengsha Eastern Shoal (HES). The mean wetland area increased 19.66 km2/yr in EN, 8.78 km2/yr in HES and 3.83 km2/yr in CD after rehabilitation. Along with the increase of wetlands and habitats, the abundance of waterbirds increased 1.3 times, 121 times and 1.5 times in EN, HES and CD, respectively. In contrast, in the site of Fengxian and Jinshan (FJ) where no any rehabilitation measure was taken after reclamation, the habitats were lost almost completely and the waterbird abundance dropped drastically. The comparison and assessment results demonstrate that proper coastal silting structures and ecological utilization of nearby dredged sediments are the feasible and effective solutions to retain sediments, restore coastal habitats and increase waterbird diversity and abundance.
Water level management plan based on the ecological demands of wintering waterbirds at Shengjin Lake
Yiqun Zhang, Lizhi Zhou, Lei Cheng, Yunwei Song
Abstract: 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
Minghao Gong, Shiliang Pang, Zhongyan Gao, Wanyu Wen, Ling Zhang, Gang Liu, Huixin Li, Fawen Qian and Wenfeng Wang
Abstract: Supplemental feeding to mitigate the effects of food shortages may in some cases provide critical help to species conservation. However, supplemental feeding may have both positive and negative effects on wildlife and the environment. A scientifically designed feeding project helps to achieve conservation targets and reduces adverse effects. Here, we summarize a three-step framework for food supplementation that we used in practice: (1) determining whether supplemental feeding is required; (2) designing and implementing a practical feeding scheme; and (3) evaluating the effectiveness of food supplementation. We supplemented food for great knots (Calidris tenuirostris), an endangered migratory shorebird, at a recently impoverished refuelling site (Yalu Jiang estuary) in the Yellow Sea in spring 2018. The abundance of the staple food of great knots (Potamocorbula laevis, which had become very rare after 2012), was insufficient for the birds to refuel before the migratory flight to the breeding grounds. In our practical test, living P. laevis were collected in subtidal areas and transported to the intertidal area where great knots had been foraging in earlier years. The supplemented areas attracted 48% of all the great knots present in the 200 km(2) study area. Nearly 90% of the supplemented food was consumed. Most great knots (>80%) foraged in the high-density supplementation zone where the densities of P. laevis were restored to the naturally occurring levels in 2011-2012. Here, food intake rates (mg AFDM/s) were 4.2 times those in the adjacent control zones. The framework and the feeding practice should help guide future supplemental feeding in a wide range of species.
Shifting of the Migration Route of White-Naped Crane (Antigone vipio) Due to Wetland Loss in China
Yifei Jia, Yunzhu Liu, Shengwu Jiao, Jia Guo, Cai Lu, Yan Zhou, Yuyu Wang, Guangchun Lei, Li Wen and Xunqiang Mo
Abstract: In the last 15 years, the west population of white-naped crane (Antigone vipio) decreased dramatically despite the enhanced conservation actions in both breeding and wintering areas. Recent studies highlighted the importance of protecting the integrity of movement connectivity for migratory birds. Widespread and rapid landcover changes may exceed the adaptive capacity of migrants, leading to the collapse of migratory networks. In this study, using satellite tracking data, we modeled and characterized the migration routes of the white-naped crane at three spatial levels (core area, migratory corridor, and migratory path) based on the utilization distribution for two eras (1990s and 2010s) spanning 20 years. Our analysis demonstrated that the white-naped crane shifted its migratory route, which is supported by other lines of evidences. The widespread loss of wetlands, especially within the stopover sites, might have caused this behavioral adaptation. Moreover, our analysis indicated that the long-term sustainability of the new route is untested and likely to be questionable. Therefore, directing conservation effects to the new route might be insufficient for the long-term wellbeing of this threatened crane and large-scale wetland restorations in Bohai Bay, a critical stopover site in the East Asian-Australasian flyway, are of the utmost importance to the conservation of this species.
Ziyou Yang, Jing Li, Yongxiang Han, Chris J. Hassell, Kar-Sin Katherine Leung, David S. Melville, Yat-tung Yu, Lin Zhang & Chi-Yeung Choi
Abstract: Background Despite an increasing number of surveys and a growing interest in birdwatching, the population and distribution of Asian Dowitcher (Limnodromus semipalmatus), a species endemic to the East Asian-Australasian and Central Asian Flyways, remains poorly understood, and published information about the species is largely outdated. In boreal spring 2019, over 22,432 Asian Dowitchers were recorded in a coastal wetland at Lianyungang, Jiangsu Province, China, constituting 97.5% of its estimated global population. Methods In 2019 and 2020, we conducted field surveys at Lianyungang to determine the numbers of Asian Dowitchers using the area during both southward and northward migrations. We also assessed the distribution and abundance of Asian Dowitchers elsewhere along the China coast by searching literature and consulting expert opinion. Results The coastal wetlands of Lianyungang are the most important stopover site for Asian Dowitchers during both northward and southward migrations; they supported over 90% of the estimated global population during northward migration in two consecutive years (May 2019 and 2020). This area also supported at least 15.83% and 28.42% (or 30.74% and 53.51% using modelled estimates) of the global population during southward migration in 2019 and 2020 respectively. Coastal wetlands in the west and north of Bohai Bay also have been important stopover sites for the species since the 1990s. Although comprehensive, long-term monitoring data are lacking, available evidence suggests that the population of the species may have declined. Conclusions The high concentration of Asian Dowitchers at Lianyungang during migration means the species is highly susceptible to human disturbances and natural stochastic events. The coastal wetlands of Lianyungang should be protected and potentially qualify for inclusion in China’s forthcoming nomination for World Heritage listing of Migratory Bird Sanctuaries along the Coast of Yellow Sea-Bohai Gulf of China (Phase II) in 2023. Additional research is needed to understand Asian Dowitchers’ distribution and ecology, as well as why such a high proportion of their population rely on the Lianyungang coast.
Favourable inland wetland conditions increase apparent survival of migratory shorebirds in Australia
Robert S. Clemens, Danny I. Rogers, Clive D. T. Minton, Ken G. Rogers, Birgita D. Hansen, Chi-Yeung Choi & Richard A. Fuller
Abstract: Many migratory shorebird species using the East Asian–Australasian Flyway are declining rapidly. While the loss of staging habitats in East Asia is considered the primary cause, stressors to fitness often occur throughout the geographic range of declining species, and threats in the non-breeding grounds have been comparatively poorly studied. Three species of migratory shorebird, Curlew Sandpiper (Calidris ferruginea), Sharp-tailed Sandpiper (C. acuminata) and Red-necked Stint (C. ruficollis), use Australia’s dynamic temporary wetland systems opportunistically, yet these large wetland systems have become increasingly degraded, with reduced frequency and extent of flooding. Here, we test whether variables related to wetland availability in Australia’s interior can explain annual variation in apparent survival, abundance or immature to adult ratios at three well-monitored coastal shorebird areas in southern Australia (total area > 1315 km2). We show that coastal annual bird abundance and ratios of immatures at the coast were higher when inland Australia was relatively hot and dry. Also, a small but significant amount of variation in annual apparent survival can be explained by annual variation in inland conditions, with higher survival rates in years when inland conditions were relatively wet and cool. For the endangered Curlew Sandpiper, the impacts of Australian environmental conditions may be exacerbating the impacts of conditions experienced in other parts of its range on fitness and survival. While the effects we document here are relatively weak, they do suggest that management of inland wetlands for these shorebirds may positively affect survival rates of these sharply declining species.
Iderbat Damba, Junjian Zhang, Kunpeng Yi, Huashan Dou, Nyambayar Batbayar, Tseveenmyadag Natsagdorj, Batmunkh Davaasuren, Lei Cao & Anthony David Fox
Abstract: The Swan Goose (Anser cygnoides) breeds across Mongolia and adjacent China and Russia and winters exclusively in China. It is globally threatened, showing long-term major range contractions and declining abundance, linked to habitat loss and degradation. We remain ignorant about the biogeographical subpopulation structure of the species and potential differences in their migration timing, stopovers and schedules, information that could be vital to effective conservation of different elements of the species population, which we address here with results from a telemetry study. In 2017–2018, we attached GPS/GSM telemetry devices to 238 Swan Geese on moulting sites in three discrete parts of their summering area (Dauria International Protected Area, Central Mongolia and Western Mongolia), generating 104 complete spring and autumn migration episodes to compare migration speed and nature between birds of different summer provenances. Birds from all three breeding areas used almost completely separate migration routes to winter sympatrically in the Yangtze River floodplain. Although many features of the spring and autumn migrations of the three groups were similar, despite the significantly longer migration routes taken by Western Mongolian tagged birds, birds from Dauria Region arrived significantly later in winter due to prolonged staging in coastal areas and took longer to reach their breeding areas in spring. Among birds of all breeding provenances, spring migration was approximately twice as fast as autumn migration. Areas used by staging Swan Geese (mainly wetlands) in autumn and spring almost never fell within national level protected areas, suggesting major site safeguard is necessary to protect these critical areas. This study showed the discreteness of migration routes taken by birds of different summer provenances and differences in their migratory patterns, highlighting key staging areas (Yalu River Estuary in China/North Korea for Dauria Region breeding birds, Daihai Lake for Central Mongolian and Ordos Basin for Western Mongolian birds). Based on this new knowledge of the biogeographical subpopulation structure of the Swan Goose, we need to combine data on subpopulation size, their distribution throughout the annual life cycle and conservation status, to develop more effective conservation strategies and measures to reverse population decline throughout the range.
Jire Xi, Xueqin Deng, Gerelt Zhao, Nyambayar Batbayar, Iderbat Damba, Qingshan Zhao, Shoubin Cui, Chao Jiang, Yiwen Chen, Yat-tung Yu, Lei Cao & Anthony David Fox
Abstract: The Eurasian Spoonbill (Platalea leucorodia) occurs throughout Eurasia and North and sub-Saharan Africa, with three recognized subspecies and six geographically distributed populations. However, in China, we knew almost nothing about migration routes, habitat use and effectiveness of current site protection measures for this species. We deployed Global Positioning System/Global System for Mobile Communications (GPS/GSM) satellite trackers on 29 Eurasian Spoonbills captured in summer in Mongolia and northeastern China, to obtain complete migration routes data from 10 individuals from 19 complete migration episodes. Tracking data showed no geographical overlap during the annual cycle in Eurasian Spoonbills marked in the two main summering areas. Birds marked in the Naoli River Basin in Heilongjiang Province, China, wintered along the Jiangsu coastline in China, while Eurasian Spoonbills from two discrete summering areas (in Inner and western Mongolia) overwintered inland in the Yangtze River floodplain of China. Excluding the single Inner Mongolian bird, spring migration was significantly faster than autumn migration in the other two groups of birds. Eurasian Spoonbills mainly used water, wetland and grassland habitats in summer, but almost exclusively water in winter. Lack of protection of staging sites used by all the birds in spring and poor levels of protection throughout the annual cycle for western Mongolian birds (5–22%) gives considerable cause for concern, although sites used in other time by East Mongolian and Naoli River birds in the rest of their annual life cycle enjoyed good levels of protection (49–95%). These results revealed previously unknown relationships between summering and wintering areas, migration routes and stopover sites for Eurasian Spoonbills wintering in China, suggesting the existence of discrete biogeographical population units. They also identified winter habitat use of Eurasian Spoonbills in China, confirming open water habitats as being critical throughout the annual cycle, although based on small sample size, gaps in current site safeguard networks for these populations.
An invasive species erodes the performance of coastal wetland protected areas
Junlin Ren, Jianshe Chen, Changlin Xu, Johan van de Koppel, Mads S. Thomsen, Shiyun Qiu, Fangyan Cheng, Wanjuan Song, Quan-Xing Liu, Chi Xu, Junhong Bai, Yihui Zhang, Baoshan Cui, Mark D. Bertness, Brian R. Silliman, Bo Li, Qiang He
Abstract: The world has increasingly relied on protected areas (PAs) to rescue highly valued ecosystems from human activities, but whether PAs will fare well with bioinvasions remains unknown. By analyzing three decades of seven of the largest coastal PAs in China, including World Natural Heritage and/or Wetlands of International Importance sites, we show that, although PAs are achieving success in rescuing iconic wetlands and critical shorebird habitats from once widespread reclamation, this success is counteracted by escalating plant invasions. Plant invasions were not only more extensive in PAs than non-PA controls but also undermined PA performance by, without human intervention, irreversibly replacing expansive native wetlands (primarily mudflats) and precluding successional formation of new native marshes. Exotic species are invading PAs globally. This study across large spatiotemporal scales highlights that the consequences of bioinvasions for humanity’s major conservation tool may be more profound, far reaching, and critical for management than currently recognized.
Xu, Wenyu, Solovyeva, Diana, Vartanyan, Sergey, Zheng, Haifeng, Pronkevich, Vladimir, Gong, Ye, Wang, Haitao
Abstract: The Scaly-sided Merganser Mergus squamatus is a globally ‘Endangered’ species breeding in north-east Asia. Limited by information on the geographic distribution of suitable habitat, the conservation management programme has not been comprehensive or spatially explicit for the breeding population. This study combines potentially important environmental variables with extensive data on species occurrence to create the first species distribution model for the breeding Scaly-sided Merganser, followed by a GAP analysis to highlight the unprotected areas containing suitable habitat. The predictive map showing the most suitable breeding habitat for the Scaly-sided Merganser covered broad-leaved deciduous forest distributed in six provincial regions in south-east Russia, north-east China, and North Korea. The conservation GAP, i.e. 90% (38,813 km2) of highly suitable habitat, is mainly concentrated in the Sikhote-Alin and Changbai mountain ranges. This study suggests that prioritizing conservation of unprotected broad-leaved deciduous riverine forests within the above two mountainous regions should be included in international conservation planning, and the remaining suitable patches need to be preserved to allow range expansion in future. This predictive map improves the expert global assessment of breeding Scaly-sided Merganser distribution and provides a basic reference for establishing conservation areas or implementing conservation actions for the breeding Scaly-sided Merganser in north-east Asia.
Xitao Yang, Zhizhao Duan, Yuhua Hu, Jincheng Liu, Yanchun Xu, Huijian Hu, Guodong Hua, Xinke Liu, Jiajun Gan, Xiangwu Zeng, Shouming Lin
Abstract: Many countries, including China, have increased new areas of mangrove plantations to reverse the decline in mangrove ecosystem functions. However, this has led to the intrusion of mangroves into many tidal flat areas, which are important habitats for shorebirds. A reduction in the available tidal flat areas will reduce the diversity of shorebirds, therefore bringing mangrove conservation into conflict with shorebird conservation. In fact, a certain area of mangroves is an indispensable element of shorebird habitat. Therefore, this study proposes the maintenance of a ratio between the area of tidal flats and the area of mangroves within a mangrove ecosystem which is optimal for both mangrove conservation and shorebird conservation. This study recorded data for shorebird distribution, areas of mangrove and tidal flats, and other relevant data for Guangdong Province, China. The ratios of tidal flat areas to mangrove areas within mangrove ecosystems were established and a mathematical model was applied to establish the relationship between shorebird diversity and abundance and the ratios of tidal flat areas to mangrove areas. The results showed that: (1) there was no significant correlation between mangrove area and shorebird richness (r = 0.176, p = 0.230)and abundance(r = 0.104,p = 0.481), whereas there was no significant correlation between tidal flat area and shorebird richness(r = 0.153, p = 0.299)and abundance(r = −0.063,p = 0.670); (2) the relationship between the ratios of tidal flats area to mangrove area [x] and shorebird richness [f(x)] and abundance [g(x)] satisfied the cubic function equation f(x) = (0.0265≤x ≤ 13.8100) (R2 = 0.714, P = 0.000), (0.0265≤ x ≤ 13.8100) (R2 = 0.713, P = 0.000); (3) the appropriate value of x is 3.5662or 3.9785, and maintaining this ratio can reduce the conflict between mangrove conservation and shorebird conservation and promote the sustainable development of the mangrove ecosystem. This information can contribute to the sustainable development of mangrove planting management strategies at various scales and will be invaluable in assessing the effectiveness of existing mangrove management approaches.
Widespread use of artificial habitats by shorebirds in Australia
Micha V. Jackson, Bradley K. Woodworth, Robert Bush, Robert S. Clemens, Richard A. Fuller, Stephen T. Garnett, Amanda Lilleyman, Martine Maron, Chris Purnell, Danny I. Rogers & Tatsuya Amano
Abstract: Shorebirds in the East Asian-Australasian Flyway have experienced population declines linked to loss of coastal wetlands. Despite this vulnerability to habitat loss, shorebirds regularly use artificial habitats, especially for high-tide roosting. Understanding the distribution of shorebirds in artificial versus natural roosts could inform habitat management strategies aimed at population recovery. We analysed time-series of high-tide shorebird monitoring data from five developed regions of Australia where artificial habitat use has previously been documented and made three key discoveries. First, artificial habitat use was generally high across the regions, with >50% of the average proportion of the regional population of 39 of 75 species-region combinations (52%) using artificial habitats at high tide. Second, in 84% of species-region combinations the average proportion of birds that used artificial habitats from the time of their establishment onward did not show a significant temporal trend. Third, migratory and coastal specialist species showed lower proportional artificial habitat use than non-migratory and generalist/inland specialist species. These findings showing consistent, widespread use of artificial habitats by large shorebird aggregations at high tide suggest that a framework for high-tide habitat management that includes artificial habitats alongside preservation of remaining natural habitats could make a significant contribution to shorebird conservation in Australia
Green Choi, Min Seock Do, Seok-Jun Son & Hyung-Kyu Nam
Abstract: Many bird species rely on the ecological functions of rice field habitats (e.g., paddy, levee, road, and ditch). However, recent intensive practices are causing rice fields to provide fewer suitable habitats. This study examined bird habitat usage and how it is affected by cultivation methods (e.g., eco-friendly vs conventional fields). Eco-friendly and conventional rice fields in the midwestern region of the Republic of Korea were surveyed from January 2014 to December 2016, and the species presence, number of birds, and locations of observed habitats were recorded. It was found that shorebirds and herons used more eco-friendly rice paddies with lower or no pesticide and/or herbicide use, while waterfowl used paddy habitats more than the other habitats, regardless of the amounts of pesticides and/or herbicides used. Land birds used ditches or roads in conventional rice fields more than those in fields that used pesticides and/or herbicides. Pesticide and/or herbicide use affected bird taxonomic groups differently. Consequently, the use of habitats by different bird taxonomic groups varied depending on the crop cultivation as well as the cultivation methods. These results provided valuable information for managing rice fields, which serve as habitats for birds.
The bird community in a coastal wetland in East China and its spatial responses to a wind farm
Yinrui Cheng, Yong Zha, Wenmin Zhang, Geng Wei, Chuan Tong & Dandan Du
Abstract: Coastal wetlands in East China are essential stopover places for birds along the East Asian-Australian Flyway. However, numerous wind turbines have been built in or near these wetlands in recent years, which might disturb the bird community in the area. Therefore, investigating the bird community and its responses to wind farms in coastal wetlands of East China is of great significance for bird conservation. In the spring and autumn of 2019 and 2020, we investigated the bird community in the Rudong coastal wetland in East China using point counts and analysed the relationship between bird number and distance to the wind farm boundary through partial correlation analysis. A total of 11 orders and 103 species of birds, including four endangered species, were observed during our survey. Charadriiformes was the dominant taxon in the wetland. Passeriformes exhibited high species richness but low numbers. The results of partial correlation analysis indicated that birds’ responses to the wind farm varied depending on their dominance and category: dominant and subdominant birds tended to avoid the wind farm, whereas rare birds tended to approach them; aquatic birds were alert to the wind farm, whereas terrestrial birds better adapted to them. We concluded that the dominant aquatic birds, including the endangered species Calidris tenuirostris, were most negatively impacted by the wind farm; the occasional birds and rare aquatic birds might be disturbed by wind farms but not significantly so; and the rare terrestrial birds were least disturbed by or even benefited from the wind farm.
3) Avian Influenza /Others
Emergence, Evolution, and Pathogenicity of Influenza A(H7N4) Virus in Shorebirds, China.
Hongliang Chai, Xiang Li, Minghui Li, Xinru Lv, Wentao Yu, Yi Li, Jing Sun, , Yulei Li, Heting Sun, Jingman Tian, Yu Xu, Xiaoli Bai, Peng Peng, Linhong Xie, Siyuan Qin, Qing An, Fengjiang Zhang, Hailong Zhang, Jiang Du, Siyuan Yang, Zhijun Hou, Xiangwei Zeng, Yulong Wang, Juergen A. Richt, Yajun Wang, Yanbing Li, Jianzhang Ma
Abstract: A 2-year surveillance study of influenza A viruses in migratory birds was conducted to understand the subsequent risk during the migratory seasons in Dandong Yalu River Estuary Coastal Wetland National Nature Reserve, Liaoning Province, China, a major stopover site on the East Asian-Australasian flyway. Overall, we isolated 27 influenza A viruses with multiple subtypes, including H3N8 (n=2), H4N6 (n=2), H4N7 (n=2), H7N4 (n=9), H7N7 (n=1), H10N7 (n=7), and H13N6 (n=4). Particularly, a novel reassortant influenza A(H7N4) virus was first identified in a woman and her backyard poultry flock in Jiangsu Province, China, posing a serious threat to public health. Here, we describe the genetic characterization and pathogenicity of the nine influenza A(H7N4) isolates. Phylogenetic analysis indicated that complex viral gene flow occurred among Asian countries. We also demonstrated a similar evolutionary trajectory of the surface genes of the A(H7N4) isolates and Jiangsu human-related A(H7N4) viruses. Our A(H7N4) isolates exhibited differing degrees of virulence in mice, suggesting a potential risk to other mammalian species, including humans. We revealed multiple mutations that might affect viral virulence in mice. Our report highlights the importance and needs for the long-term surveillance of avian influenza virus in migratory birds, combined with domestic poultry surveillance along migratory routes and flyways, and thereby develop measures to manage potential health threats. Importance The H7 subtype avian influenza viruses, such as H7N2, H7N3, H7N4, H7N7, and H7N9, were documented being capable of infecting humans, and the H7 subtype low pathogenic avian influenza viruses are capable of mutating into highly pathogenic avian influenza; therefore, they pose a serious threat to public health. Here, we investigated the evolutionary history, molecular characteristics, and pathogenicity of shorebird-origin influenza A(H7N4) viruses, showing a similar evolutionary trajectory with Jiangsu human A(H7N4) viruses in HA and NA genes. Moreover, our isolates exhibited variable virulence (including moderate virulence) in mice, suggesting a potential risk to other mammalian species, including humans.
Mizue Inumarua, Yoshiya Odaya, Yukita Sato, Alfonso Marzal
Abstract: Migratory birds are important carriers of pathogens such as viruses, bacteria and protozoa. Avian haemosporidia have been detected from many wild birds of Japan, but the infection status of migratory birds and transmission area are still largely unknown. Gallinago snipes are long-distance migratory shorebirds, and five species migrate to or through Japan, including Latham’s snipe which is near threatened. Haemosporidian parasites in four snipe species were investigated to understand the role of migratory birds in the transmission of avian haemosporidia. Namely, this study aimed: i) to investigate differences in parasite prevalence and related factors explaining infection likelihood among these migratory species, ii) to explore the diversity in haemosporidian lineages and possible transmission areas, and iii) to assess the possibility of morphological effects of infection. Blood samples were collected from snipes caught in central and southwest Japan during migration. Parasites cytb gene DNA were detected via PCR-based testing, and detected lineages were phylogenetically analyzed. Additionally, factors related to prevalence and morphological effects of infection were statistically tested. 383 birds from four Gallinago snipe species were caught, showing higher overall prevalence of avian haemosporidia (17.8 %) than reported in other wader species in previous studies. This high infection rate is presumably due to increased contact with vector insects, resultant of environmental preferences. The prevalence of Plasmodium spp. Was higher in Swinhoe’s snipes, while Haemoproteus spp. Was higher in Latham’s snipes. These differences are thought to be related to ecological factors including habitat use, distribution and migratory route. Six lineages detected from juveniles indicate transmission between the breeding and sampling area. Contrary to expectations, a direct link between morphological features and haemosporidian parasite infection were not detected. These findings provide valuable information for conservation of this endangered migratory bird group. Further studies linking biological and parasitological research are anticipated to contribute to conservational actions.
