The bird capture sites for this project included Terkhiin Tsagaan Lake in west-central Mongolia and Hyachin Tsagaan (Ikh Delger) Lake in eastern Mongolia, the latter is part of the famous Mongol Daguur Specially Protected Area. Both sites are on the Ramsar List of Wetlands of International Importance and on the East Asian-Australasian Flyway Site Network. Both areas are important breeding and moulting areas for Bar-headed geese (Anser indicus), Whooper Swans (Cygnus cygnus), Swan Geese (Anser cygnoides), Ruddy Shelduck (Tadorna ferruginea) and other migratory waterfowl as well as staging sites for waterbirds during migration. The largest outbreak of Highly Pathogenic Avian Influenza (HPAI) H5N1 in wild birds occurred at Qinghai Lake, China in 2005, followed by an outbreak at Erkhel Lake, Mongolia which suggests a possible virus spread via a migratory linkage between these regions.
In July 2008, an international team from the Food and Agriculture Organization (FAO), the US Geological Survey (Western Ecological Research Center and Patuxent Wildlife Research Center), and the Wildlife Science and Conservation Center of the Mongolian Academy of Sciences implemented a migration and disease ecology study on bar-headed geese in western Mongolia. These field activities in western Mongolia also facilitated a project with the University of Wales Bangor, University of Birmingham, University of Tasmania, and University of British Columbia examining the physiology and flight performance of bar-headed geese with the support of the Max Planck Institute for Migration and the Biotechnology and Biological Sciences Research Council. Bar-headed geese migrate along the Central Asian Flyway breeding in Qinghai Lake, China and parts of Mongolia and wintering from the Tibet Autonomous Region, China to India. Some of these bar-headed geese fly over the Himalayas to reach their wintering destinations, encountering spatial and altitudinal gradients that pose physiological challenges to their migration.
In eastern Mongolia, the study focused on the migration and disease ecology of swan geese. The endangered Swan Goose is a restricted range species, breeding in eastern Mongolia, China and south-eastern Russia with an estimated population of 60,000-100,000 individuals. They migrate within the Australasian Flyway south to the Yangtze Valley floodplains in China and the Korean peninsula. A pilot satellite marking project undertaken by the team in 2006 had confirmed the movement of birds from eastern Mongolia to the Poyang Lake Ramsar site, and demonstrated that birds may use slightly different routes on southward and northward migration. Two individuals that had been marked in 2006 (with red and black neck collars) were observed back at the Hyachin Tsagaan Lake during the 2008 expedition.
Birds were captured during the short post-breeding moult period when adults are flightless. Tracheal and cloacal swabs plus blood samples were collected from all the birds for avian influenza testing at the Central Veterinary Laboratory facilitated by the Department of Veterinary Service of the Ministry of Food and Agriculture in Mongolia. All collected samples tested negative for HPAI H5N1.
To study migratory routes, 24 bar-headed geese and 15 swan geese were marked with satellite transmitters. In addition, 113 bar-headed geese and 38 swan geese were ringed and colour marked with green and white neck collars or leg bands. One whooper swan was also marked with a green and white leg band. Reporting of resightings of these colour-marked birds will provide additional data on the migratory patterns on these species.
Any person observing a colour-marked bird is requested to contact Dr. Tseveenmyadag Natsagdorj or Dr. Taej Mundkur with information on the location and date of observations, colour and number of the band, as well as other bird species (and numbers) observed with the marked bird. Photographs of marked birds will also be appreciated.
In understanding the disease status and the movement of these birds and the relationship to avian influenza outbreaks that occur along the as they migrate along the Central Asian- Indian flyway we hope to better understand the ecology of AIV and the role wild birds play in the spread of the disease.
Current locations of these birds are available at the USGS website.