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Simple Summary: The migration strategies, movement patterns, and habitat associations of long-distance migratory raptors remain largely unknown. We deployed PTT-GSM satellite transmitters on five raptor species, four of which are threatened, with the objective of investigating their daily and seasonal movement patterns, migration flyways, home-range patterns, and habitat associations in their wintering areas. This study shows that raptors wintering in Western India undertake annual migration across the Western Circum–Himalayan Corridor of the Central Asian Flyway (CAF) to circumvent some of the highest mountain ranges in the world. Single individuals of the Greater Spotted Eagle (Clanga clanga), Indian Spotted Eagle (Clanga hastata), Tawny Eagle (Aquila rapax), Western Marsh Harrier (Circus aeruginosus), and two Pallid Harriers (Circus macrourus) were deployed with satellite transmitters in 2021 to study their home ranges, habitat associations, movement, and migration patterns. Data were collected for a combined number of 2291 days, providing 84,544 locations. Home ranges were calculated as kernel utilization distributions and expressed as 95% KDE and core areas as 50% KDE. Overall, eagles had larger home ranges (mean ± SD) of 942.70 ± 937.83 km2 compared to harriers, 43.84 ± 35.55 km2. Among eagles, the Greater Spotted Eagle had the largest home-range size of 2147.03 km2 calculated in Kazakhstan, while the female Pallid Harrier had the smallest home range of 5.74 km2 in Russia. Daily and monthly distances varied among eagles and harriers. The female Pallid Harrier covered the longest average monthly distance of 8585.43 ± 11,943.39 km, while the shortest monthly distance of 1338.22 ± 716.38 km was traveled by the Indian Spotted Eagle. All tagged birds migrated toward higher latitudes in the Northern hemisphere, except the Indian Spotted Eagle, which migrated to Pakistan. The male Western Marsh Harrier covered the longest migration distance in a shorter span of time, while the female Pallid Harrier took the longest to cover its migration distance. Overall, the daily distance covered during migration varied from 115.09 km traveled by the Indian Spotted Eagle to an overwhelming distance of 2035.85 km covered by the male Western Marsh Harrier. Scrubs, water bodies, croplands, and settlements were important habitat features associated with eagles, while croplands, open scrub, and built-up areas were associated with the female Pallid Harrier. The male Western Marsh Harrier was found to be primarily associated with saltpans and salt-affected areas having emergent vegetation. This study presents new insights into the movement and spatial ecology of long-distance migrant raptors that winter in Western India. We provide preliminary support for the use of the Western Circum–Himalayan Corridor as one of the important corridors of the Central Asian Flyway that warrants much appreciation among the current set of flyway corridors. [ABSTRACT FROM AUTHOR]

Single individuals of the Greater Spotted Eagle (Clanga clanga), Indian Spotted Eagle (Clanga hastata), Tawny Eagle (Aquila rapax), Western Marsh Harrier (Circus aeruginosus), and two Pallid Harriers (Circus macrourus) were deployed with satellite transmitters in 2021 to study their home ranges, habitat associations, movement, and migration patterns. Data were collected for a combined number of 2291 days, providing 84,544 locations. Home ranges were calculated as kernel utilization distributions and expressed as 95% KDE and core areas as 50% KDE. Overall, eagles had larger home ranges (mean ± SD) of 942.70 ± 937.83 km2 compared to harriers, 43.84 ± 35.55 km2. Among eagles, the Greater Spotted Eagle had the largest home-range size of 2147.03 km2 calculated in Kazakhstan, while the female Pallid Harrier had the smallest home range of 5.74 km2 in Russia. Daily and monthly distances varied among eagles and harriers. The female Pallid Harrier covered the longest average monthly distance of 8585.43 ± 11,943.39 km, while the shortest monthly distance of 1338.22 ± 716.38 km was traveled by the Indian Spotted Eagle. All tagged birds migrated toward higher latitudes in the Northern hemisphere, except the Indian Spotted Eagle, which migrated to Pakistan. The male Western Marsh Harrier covered the longest migration distance in a shorter span of time, while the female Pallid Harrier took the longest to cover its migration distance. Overall, the daily distance covered during migration varied from 115.09 km traveled by the Indian Spotted Eagle to an overwhelming distance of 2035.85 km covered by the male Western Marsh Harrier. Scrubs, water bodies, croplands, and settlements were important habitat features associated with eagles, while croplands, open scrub, and built-up areas were associated with the female Pallid Harrier. The male Western Marsh Harrier was found to be primarily associated with saltpans and salt-affected areas having emergent vegetation. This study presents new insights into the movement and spatial ecology of long-distance migrant raptors that winter in Western India. We provide preliminary support for the use of the Western Circum–Himalayan Corridor as one of the important corridors of the Central Asian Flyway that warrants much appreciation among the current set of flyway corridors.

The seasonal pattern of species diversity and abundance of waterbirds of the Chambal River in the extent of Mukundra Hills National Park, Rajasthan, India was evaluated. The pre-monsoon (March-April 2021) and post-monsoon surveys (August-September 2021) were carried out using the direct count method with the help of a motorboat to monitor the population status of waterbirds. A total of 44 species of waterbirds belonging to 15 families and nine orders were identified, including 11 winter migratory species. Forty species of birds were recorded during pre-monsoon and 27 species during post-monsoon seasons. The species richness and relative abundance varied significantly between observed seasons (x2 = 532.77, df = 43, p <0.05). Breeding activities of three species were recorded, namely, Grey Heron, Black-crowned Night Heron, and the 'Near Threatened' Woolly-necked Stork. The present study reveals the status of waterbirds in the protected area of Mukundra Hills National Park. [ABSTRACT FROM AUTHOR]

The article reports on the occurrence of the migratory species Marecastrepera, commonly known as Gadwall from a freshwater pitlake of Eastern Coal Fields in India. Topics discussed include characteristics of gadwall, the abundance of Marecastrepera on small prairie marshes than in temporary water areas, and a threat to the water bird habitat.

This preliminary assessment study focused on the shorebird population from Vellanathuruthu beach of Kollam district, Kerala. The study was carried out from August 2022 to July 2023 using point count method. A total of 20 species of migrant shorebirds, spanning four families within the order Charadriiformes (Scolopacidae, Charadriidae, Laridae and Haematopodidae) were documented. Among the observed species, 17 are categorized as least concerned according to IUCN Red List. However, two species Eurasian Curlew Numenius arquata and Curlew Sandpiper Calidris ferruginea are classified as near threatened, while Great Knot Calidris tenuirostris is endangered, according to IUCN Redlist category. The study identified sand mining as the major cause of erosion and alteration of Vellanathuruthu coastal line. The significant presence migrants and threatened species highlights the importance of the study area, emphasizing the need for future conservation efforts. [ABSTRACT FROM AUTHOR]

Simple Summary: We studied the home ranges, movement, migration patterns, and habitat use of Common Cranes and Demoiselle Cranes using satellite telemetry. The average home ranges calculated in India were slightly greater than in their breeding areas. Common Crane-1 covered 12,982 km in 17 days to reach Russia. On the return journey, it covered a total distance of 14,873 km in 72 days. Common Crane-2 covered a total distance of 4500 km in 30 days to reach Kazakhstan. While returning to India, it covered 4922 km in 25 days. On the other hand, Demoiselle Crane-1 covered a total distance of 4968 km in 18 days during its northbound migration to Kazakhstan and 7394 km in 105 days to reach India. Demoiselle Crane-2 traveled a distance of 4310 km in 18 days to reach Kazakhstan and then made the return journey to India, covering a distance of 7757 km over a period of 128 days. Croplands and water bodies were the most important habitat variables influencing crane presence positively. The changing crop patterns from cereal grains to cotton, coupled with the shrinkage of water bodies within the study area, may raise concerns about their presence during winter in the near future. Using satellite telemetry, it is possible to track long-distance migrant birds with high accuracy and greater spatial coverage. However, prior to 2014, less than 1% of bird species in India had been monitored using this technology. Between January and February 2022, we deployed leg-mounted solar GPS/GSM satellite transmitters to Common Cranes and Demoiselle Cranes (two each) to study home ranges, movement, migration patterns, and habitat use. We used 95% kernels to define the total home range size and 50% kernels to delimit the core areas. The winter habitat use was assessed using Generalized Linear Models (GLM). The average home range of Common Cranes and Demoiselle Cranes was estimated as 161.22 ± 172.08 km2 and 971.40 ± 1023.57 km2, respectively. During migration, Common Crane-1 and Common Crane-2 traveled an average of 471.19 ± 442.42 and 176.97 ± 24.82 km per day, and Demoiselle Crane-1 and Demoiselle Crane-2 covered an average daily distance of 168.10 ± 203.77 and 192.97 ± 250.72 km, respectively. Water bodies and croplands were the most important habitat variables influencing crane presence positively. In recent years, the share of food grain crops within the study area has declined from 43% in 1994–1995 to 36% in 2014–2015, while the share of cotton crops has doubled from 11% to 20%, indicating a probable cause of concern in the near future. [ABSTRACT FROM AUTHOR]

The Pokkali wetlands of Ernakulam District, Kerala, are incredibly nutrient-rich, biodiverse habitats that offer a wide range of benefits. There are important bird areas that lie under the Central Asian Flyway (CAF) and the Vembanad Ramsar site. An intensive study was carried out on the physico-chemical properties of water samples collected from the Pokkali wetlands of Ernakulam, Kerala, from 1 June 2016 to 31 May 2019. The water parameters, such as temperature (°C), pH, depth (cm), dissolved oxygen (DO) (mg/L), salinity (mg/L), turbidity (NTU), and electrical conductivity (μS cm−1) were analysed and recorded. The correlation between various parameters was analysed using the PAST software. The physico-chemical parameters of water have an influence on the biodiversity and ecology of the study area. Data collection about these aquatic parameters is essential to assess the status and biodiversity of the wetland ecosystem. HIGHLIGHTS This is the first study at Pokkali fields.; Wetlands under the Ramsar site were studied.; This study area comes under the Central Asian Flyway.; A large number of people live in these areas, so water analysis is essential.; Habitat analysis study is essential for understanding the biodiversity as well as for conservation;

Using satellite telemetry, it is possible to track long-distance migrant birds with high accuracy and greater spatial coverage. However, prior to 2014, less than 1% of bird species in India had been monitored using this technology. Between January and February 2022, we deployed leg-mounted solar GPS/GSM satellite transmitters to Common Cranes and Demoiselle Cranes (two each) to study home ranges, movement, migration patterns, and habitat use. We used 95% kernels to define the total home range size and 50% kernels to delimit the core areas. The winter habitat use was assessed using Generalized Linear Models (GLM). The average home range of Common Cranes and Demoiselle Cranes was estimated as 161.22 ± 172.08 km2 and 971.40 ± 1023.57 km2, respectively. During migration, Common Crane-1 and Common Crane-2 traveled an average of 471.19 ± 442.42 and 176.97 ± 24.82 km per day, and Demoiselle Crane-1 and Demoiselle Crane-2 covered an average daily distance of 168.10 ± 203.77 and 192.97 ± 250.72 km, respectively. Water bodies and croplands were the most important habitat variables influencing crane presence positively. In recent years, the share of food grain crops within the study area has declined from 43% in 1994–1995 to 36% in 2014–2015, while the share of cotton crops has doubled from 11% to 20%, indicating a probable cause of concern in the near future.

Any new economic activity in a virgin area brings landscape changes, making it essential to document baseline biodiversity areas to understand the impacts on habitats. Avifaunal inventories are critical for previously undocumented areas like the Valinokkam Lagoon in the Ramanathapuram District of Tamil Nadu, which is an undocumented wintering site for shorebirds in the Central Asain Flyway (CAF). To formulate site and species-specific conservation management tools, the first bird baseline recorded 154 species of 16 orders and 46 families from August 2016 to February 2023. Order-wise, Charadriiformes (47 species) dominated the study area, followed by Passeriformes (39 species) and Pelecaniformes (20 species). Furthermore, according to the IUCN Red List Category, 11 Near Threatened (NT) species, one Endangered (EN) species (Great Knot Calidris tenuirostris), and one unassessed Hanuman Plover (Charadrius seebohmi) were recorded. The relative abundance indicated that 61 % (94 species) were Common (C), 26.6% (41 species) were uncommon (UC), and 12.3 % (19 species) were rare (Ra). Based on the residential status, winter visitors constituted 37.6 % (58 species) and one Passage Migrant (Rosy Starling Pastor roseus). This baseline data emphazises the importance of Valinokkam Lagoon as a crucial wintering site in the CAF on the southeastern coast of India for migratory shorebirds and the need for more conservation priorities for regional endemic birds like Hanuman Plover. [ABSTRACT FROM AUTHOR]

Simple Summary: The Hengduan Mountain area in southwest China is an important migratory channel for migratory birds in the Central Asian flyway. The lakes along the way have different ecological functions for the life histories of waterbirds. In order to determine the ecological functions of high-altitude lakes, we selected Mangcuo Lake in Markam County to investigate the waterbird community in four seasons. The results show that Mangcuo Lake provides a breeding habitat for nine species of birds and also supports excellent numbers of birds migrating in the spring and autumn. In view of the role of Mangcuo Lake in the migration route, we propose upgrading the protection level of the Mangcuo Lake. The stopovers provide food and habitat for migratory birds and therefore play an important role in facilitating the birds' completion of their migration. The Hengduan Mountains, which have a complex topography, are located in a large corridor of the Central Asian migratory flyway, so the lakes along the Hengduan Mountains are important for waterbird migration. The existing research on lakes in the Hengduan Mountain area is mostly concentrated in the central and southern parts of the mountains, which proves that many lakes are wintering grounds for migrating birds. We wonder whether the ecological functions of lakes will change more with further elevation. With this question, we conducted four surveys for the seasonal bird survey in Mangcuo Lake, which is located in the northwest of the Hengduan Mountains, in Markam County of Qamdo City, between October 2019 and July 2020. We recorded a total of 6109 birds from 20 species of waterbirds, including 20 species of migratory waterbirds, accounting for 100% of all bird species. The diversity and richness of waterbirds in Mangtso Lake is shown as spring > autumn ≥, summer > winter, with no waterbirds in winter. The black-necked grebe (Podiceps nigricollis), great crested grebe (Podiceps cristatus), bar-headed goose (Anser indicus), and ruddy shelduck (Tadorna ferruginea) were the dominant species in the waterbird community. The highest number of waterbird species and total individuals were found in the transition zone between the marsh wetlands and lakes, and the number of waterbird species differed significantly among habitats (X2 = 14.405, p = 0.000), with habitat complexity being an important factor influencing waterfowl abundance and distribution. The IUCN Red-listed species recorded include the black-necked crane (Grus nigricollis), painted stork (Mycteria leucocephala), and common pochard (Aythya ferina). By comparing with other lakes in Hengduan Mountain, we found that the ecological functions of the plateau lakes in the Hengduan Mountains, to support the life histories of migrating waterbirds, are gradually transforming as the altitude rises, and can be divided into approximately three levels, with the first level of Qionghai, Chenghai, Erhai, and Jianhu at altitudes of 1500–2200 m being the most important ecological function in terms of providing wintering grounds for migrating birds. The second layer, at an altitude of 2400–3300 m, includes Lashihai, Lugu Lake, and Napahai, which are not only wintering wetlands for migratory birds but also important stopover sites. The third layer of Mangcuo Lake, which is above 4000 m above sea level, provides a breeding ground for some migratory waterbirds in summer and a migratory resting place for migratory waterbirds in spring and autumn. We advocate for the importance of Mangcuo Lake in the alpine region along the central Asian flyway, as well as emerging nature conservation action that was previously neglected. [ABSTRACT FROM AUTHOR]

Avifaunal inventories are crucial to the formulation of conservation and management strategies for habitats and species. An annotated checklist of the birds of the Karangadu eco-tourism area located in the Palk Bay in Ramanathapuram district of Tamil Nadu, was prepared. We listed a total of 107 species belonging to 18 orders and 40 families. Orders Charadriiformes, Suliformes, and Pelecaniformes dominated the habitat. Among the families, Scolopacidae (10 species) was dominant, followed by Ardeidae (9), and Laridae (8). In addition, the study also documented three globally 'Near Threatened' species: Painted Stork Mycteria leucocephala, Black-tailed Godwit Limosa limosa, and Black-headed Ibis Threskiornis melanocephalus. The observed frequency of the species was: 57% (61 spp.) common, 32.7% (35 spp.) uncommon, and 10.3% (11 spp.) rare. Categorization based on the residential status of birds revealed that 31% (33 spp.) were winter visitors, and one was a passage migrant (Rosy Starling Pastor roseus). These baseline data highlight the importance of Karangadu as an important site on the southeastern coast of India for migratory shorebird conservation priorities. [ABSTRACT FROM AUTHOR]

Every research endeavour must start with closing the information gap about species distribution and biodiversity systematically. Even though enough avifaunal research has been done on the Gulf of Mannar, southeastern India, there have been limited studies about the avifauna from all 21 islands except two. Increasing species occurrence data on distribution from all the islands is highlighted for the future conservation plans for this Important Bird Area. We provide an updated and detailed checklist and distribution of bird groups for all islands individually from a sampling period of 2015-2022. A total of 96 bird species belonging to 34 families from 13 orders were recorded from all the islands; of which 58 species were waterbirds and other terrestrial ones. Of the 29 shorebird species recorded, one is Endangered and seven are Near Threatened by IUCN Red List. Some of the earlier recorded species, not seen in our survey, are not annotated as no record exists for the last decade. [ABSTRACT FROM AUTHOR]

The stopovers provide food and habitat for migratory birds and therefore play an important role in facilitating the birds’ completion of their migration. The Hengduan Mountains, which have a complex topography, are located in a large corridor of the Central Asian migratory flyway, so the lakes along the Hengduan Mountains are important for waterbird migration. The existing research on lakes in the Hengduan Mountain area is mostly concentrated in the central and southern parts of the mountains, which proves that many lakes are wintering grounds for migrating birds. We wonder whether the ecological functions of lakes will change more with further elevation. With this question, we conducted four surveys for the seasonal bird survey in Mangcuo Lake, which is located in the northwest of the Hengduan Mountains, in Markam County of Qamdo City, between October 2019 and July 2020. We recorded a total of 6109 birds from 20 species of waterbirds, including 20 species of migratory waterbirds, accounting for 100% of all bird species. The diversity and richness of waterbirds in Mangtso Lake is shown as spring > autumn ≥, summer > winter, with no waterbirds in winter. The black-necked grebe (Podiceps nigricollis), great crested grebe (Podiceps cristatus), bar-headed goose (Anser indicus), and ruddy shelduck (Tadorna ferruginea) were the dominant species in the waterbird community. The highest number of waterbird species and total individuals were found in the transition zone between the marsh wetlands and lakes, and the number of waterbird species differed significantly among habitats (X2 = 14.405, p = 0.000), with habitat complexity being an important factor influencing waterfowl abundance and distribution. The IUCN Red-listed species recorded include the black-necked crane (Grus nigricollis), painted stork (Mycteria leucocephala), and common pochard (Aythya ferina). By comparing with other lakes in Hengduan Mountain, we found that the ecological functions of the plateau lakes in the Hengduan Mountains, to support the life histories of migrating waterbirds, are gradually transforming as the altitude rises, and can be divided into approximately three levels, with the first level of Qionghai, Chenghai, Erhai, and Jianhu at altitudes of 1500–2200 m being the most important ecological function in terms of providing wintering grounds for migrating birds. The second layer, at an altitude of 2400–3300 m, includes Lashihai, Lugu Lake, and Napahai, which are not only wintering wetlands for migratory birds but also important stopover sites. The third layer of Mangcuo Lake, which is above 4000 m above sea level, provides a breeding ground for some migratory waterbirds in summer and a migratory resting place for migratory waterbirds in spring and autumn. We advocate for the importance of Mangcuo Lake in the alpine region along the central Asian flyway, as well as emerging nature conservation action that was previously neglected.

Bangladesh hosts most of what is left of Indian Skimmer (Rhynchops albicollis) populations, a globally endangered species. Each October-March from 2015-2020, 21 surveys of nonbreeding birds were made in Nijhum Dweep National Park, Bangladesh. High tide or evening roosts were counted from vantage points whenever a buildup or breakdown of skimmer concentrations was noticed, and site use noted by marking all observations of presence and activity on maps. The largest single count was 3,108 skimmers on 18 February 2020, constituting 30-50% of the known global population. Indian Skimmers mostly occurred in Damar Char West and at the tip of the Majher Char. Throughout the day with incoming tide, skimmers moved between preferred roosting areas to forage in the shallows. We describe a unique group-foraging strategy in which skimmers chase fish from deep water to shallow water along the shoreline. Circling high over the tidal channel, the flock of skimmers dives down in unison to just above the water surface, then spreading like a net towards the shore. Raptors caused disturbances to roosting skimmers, and we observed one instance of predation of a skimmer by a White-bellied Sea Eagle (Haliaeetus leucogaster). Human fishing activities disturbed nearshore foraging and shoreline roosting skimmers. We suggest protecting Damar Char West by regulating human activities to minimize disturbance from December to March. [ABSTRACT FROM AUTHOR]

ABSTRACTThe spread of highly pathogenic avian influenza (HPAI) H5N1 virus is associated with wild fowl migration in East Asian-Australasian (EA) and Central Asian (CA) flyways. However, the spread of H5N1 virus between the two flyways is still unclear. Here, the movements of wild waterfowl were obtained from satellite tracking data covering seven bar-headed geese and three great black-headed gulls breeding in the Qinghai Lake area (along the EA flyway), and 20 whooper swans wintering in the Sanmenxia Reservoir area (at the CA flyway). From the 2688 samples that were screened from wild birds at Qinghai Lake after an outbreak of H5N1 in July 2015, four genomes of H5N1 virus were obtained from bar-headed geese. The results of phylogenetic analysis indicated that these H5N1 viruses belonged to clade 2.3.2.1c and their gene fragments were highly homologous with A/whooper swan/Henan/SMX1/2015 (H5N1) virus (ranging from 99.76% to 100.00%) isolated from a dead whooper swan from the Sanmenxia Reservoir area along the EA flyway in January 2015. Furthermore, the coincidental timing of the H5N1 outbreak with spring migration, together with phylogenetic evidence, provided new evidence of the east-to-west spread of HPAI H5N1 between the EA and CA migratory flyways of China.

Highly pathogenic avian influenza A(H5N8) clade 2.3.4.4 virus emerged in 2016 and spread to Russia, Europe, and Africa. Our analysis of viruses from domestic ducks at Tanguar haor, Bangladesh, showed genetic similarities with other viruses from wild birds in central Asia, suggesting their potential role in the genesis of A(H5N8).

Abstract To evaluate the potential contribution of captive breeding to the conservation of exploited migratory Asian houbara Chlamydotis macqueenii , we estimated release numbers required to stabilise a population in a hunting concession (14,300 km2), under scenarios of local licensed hunting and flyway-scale protection. We developed a population model, initially 2350 adult females, re-sampling parameters measured through fieldwork and satellite telemetry, over 1000 iterations. With current flyway-scale unregulated harvest, and without any licensed hunting in the concession, populations declined at 9.4% year−1 (95% CI: −18.9 to 0% year−1); in this scenario a precautionary approach (85% probability λ ≥ 1.0) to population stabilisation required releasing 3100 captive-bred females year−1 (131% of initial wild numbers). A precautionary approach to sustainable hunting of 100 females year−1 required releasing 3600 females year−1 (153% of initial wild numbers); but if interventions reduced flyway-scale hunting/trapping mortality by 60% or 80%, sustaining this quota required releasing 900 or 400 females year−1, 38% and 17% of initial wild numbers, respectively. Parameter uncertainty increased precautionary numbers for release, but even with reduced precaution (50% probability λ ≥ 1.0), sustainable hunting of 100 females year−1 required annual releases of 2200 females (94% wild) without other measures, but 300 (13%) or no (0%) females under scenarios of a 60% or 80% reduction in flyway-scale hunting/trapping. Captive breeding cannot alone sustain migrant populations of wild C. macqueenii because it risks replacement and domestication. Trade and exploitation must be restricted to avoid either extinction or domestication. For exploited populations, supplementation by captive breeding should be used with caution. Highlights • Informs international, transboundary management of IUCN Vulnerable species • Evaluates strategy of stabilising exploited population by captive-bred releases • Demographic model parameterised by extensive fieldwork and satellite telemetry • Management solely through captive breeding risks domestication and replacement • Shows stabilisation requires controlling of hunting on flyway [ABSTRACT FROM AUTHOR]

The present study documents the first sightings of the migratory Pallas’s Gull at two different locations (Cholamu Lake and Singtam Valley) in the eastern Himalayan state of Sikkim in India. We recommend that long term surveys are required to determine and establish the distribution and status of the species in the state.

The emergence of highly pathogenic avian influenza (HPAI) viruses has raised concerns about the role of wild birds in the spread and persistence of the disease. In 2005, an outbreak of the highly pathogenic subtype H5N1 killed more than 6,000 wild waterbirds at Qinghai Lake, China. Outbreaks have continued to periodically occur in wild birds at Qinghai Lake and elsewhere in Central China and Mongolia. This region has few poultry but is a major migration and breeding area for waterbirds in the Central Asian Flyway, although relatively little is known about migratory movements of different species and connectivity of their wetland habitats. The scientific debate has focused on the role of waterbirds in the epidemiology, maintenance and spread of HPAI H5N1: to what extent are they victims affected by the disease, or vectors that have a role in disease transmission? In this review, we summarise the current knowledge of wild bird involvement in the ecology of HPAI H5N1. Specifically, we present details on: (1) origin of HPAI H5N1; (2) waterbirds as LPAI reservoirs and evolution into HPAI; (3) the role of waterbirds in virus spread and persistence; (4) key biogeographic regions of outbreak; and (5) applying an ecological research perspective to studying AIVs in wild waterbirds and their ecosystems. [ABSTRACT FROM AUTHOR]

The spread of highly pathogenic avian influenza (HPAI) H5N1 virus is associated with wild fowl migration in East Asian-Australasian (EA) and Central Asian (CA) flyways. However, the spread of H5N1 virus between the two flyways is still unclear. Here, the movements of wild waterfowl were obtained from satellite tracking data covering seven bar-headed geese and three great black-headed gulls breeding in the Qinghai Lake area (along the EA flyway), and 20 whooper swans wintering in the Sanmenxia Reservoir area (at the CA flyway). From the 2688 samples that were screened from wild birds at Qinghai Lake after an outbreak of H5N1 in July 2015, four genomes of H5N1 virus were obtained from bar-headed geese. The results of phylogenetic analysis indicated that these H5N1 viruses belonged to clade 2.3.2.1c and their gene fragments were highly homologous with A/whooper swan/Henan/SMX1/2015 (H5N1) virus (ranging from 99.76% to 100.00%) isolated from a dead whooper swan from the Sanmenxia Reservoir area along the EA flyway in January 2015. Furthermore, the coincidental timing of the H5N1 outbreak with spring migration, together with phylogenetic evidence, provided new evidence of the east-to-west spread of HPAI H5N1 between the EA and CA migratory flyways of China.

Highly pathogenic avian influenza A(H5N8) clade 2.3.4.4 virus emerged in 2016 and spread to Russia, Europe, and Africa. Our analysis of viruses from domestic ducks at Tanguar haor, Bangladesh, showed genetic similarities with other viruses from wild birds in central Asia, suggesting their potential role in the genesis of A(H5N8).