In August, a team of international scientists from the United Nations Food and Agriculture Organization (FAO) and the U. S. Geological Survey (USGS) joined the Wildlife Conservation Society (WCS) and Mongolian Academy of Sciences (MAS) in the surveillance project, which is part of the Wild Bird Global Avian Influenza Network for Surveillance (GAINS) program. The team attached the GPS transmitters to wild whooper swans in an effort to track the birds to their wintering grounds.
Such research is providing information on migration routes and informs governments about potential threats from diseases such as highly pathogenic avian influenza (HPAI). The HPAI strain known as H5N1 is highly lethal for a variety of species, especially poultry and some waterfowl species.
"We are working to understand the role wild birds may play in the spread of H5N1," said Dr. Scott Newman, International Wildlife Coordinator for Avian Influenza for FAO. "Although poultry and bird trade are probably the primary routes of movement, migratory birds are likely involved in some areas."
The whooper swans drew increased attention after large numbers perished in Mongolia in 2005 and in western China in 2005 and 2006 in areas where few poultry are present. Subsequent sampling of the dead swans by WCS scientists verified that some of the swans were infected with HPAI. This discovery suggested that HPAI may be moving through the region, prompting the study to identify where these migratory bird populations fly in the winter.
Each year whooper swans molt their feathers after the breeding season and during that flightless period the birds were captured by the international team on the grassland steppe of far eastern Mongolia, near the borders of Russian and China. Small, 2.3 ounce (or the weight of a dozen quarters) solar-powered transmitters were affixed on 10 of the 18-pound large swans with backpack harnesses. The harnesses are made of Teflon ribbon that deteriorates and falls off of the birds within a few years.
The GPS transmitters are made by a wildlife specialty company; it is only in the last 5 years that they were reduced to a size suitable for migratory birds. Their accurate locations, often better than 30 feet, provide a wealth of information on migrating birds and use of their habitats that was not available before. The locations are recorded every 2 hours and stored in the transmitter memory before being sent to the research team by email through weather satellites every 2 days.
The whooper swan locations are being updated twice weekly on a project Web page which includes access to the data in Google Earth format. WCS's director of the Field Veterinary Program in New York and coordinator of the GAINS system, Dr. William Karesh, explains that, "when we find infected birds, we need to know where they are going."
