By Mary Anne Bishop
For The Cordova Times
A new study from researchers at the Prince William Sound Science Center, in collaboration with colleagues at Tufts University and other institutions, identified which bird species contribute most to the spread of avian influenza. The study, which was published May 19 in the journal PLOS Pathogens, examined influenza viruses circulating among different groups of birds and characterized which types of birds are involved in spreading the virus.
The study found that global spread of avian influenza was driven by contributions from many ecologically diverse species, such as gulls, ducks, geese, and domestic birds. Wild dabbling ducks have historically been considered the “super-spreaders” of avian flu. However, in this study, wild geese played a major role in transmitting the virus to domestic geese, ducks, chickens, and turkeys. They also found that gulls were responsible for moving avian influenza more rapidly than any other bird host. This is likely due to the long-distance oceanic movements of gulls compared to the shorter land-based movements undertaken by wild ducks.
For over a decade at the Prince William Sound Science Center I have been studying avian flu in local gulls and shorebirds, with assistance from biologists like Anne Schaefer. We collect samples from live birds that we capture with nets and we also monitor for flu in fecal droppings collected from the local docks and beaches.
Various strains of influenza are always circulating among avian populations, however the timing of the paper is coincidental with a highly contagious strain of bird flu known as H5N1 that has been spreading across North America and recently into Alaska. Science center researchers have detected strains of H5 influenza in shorebirds and gulls during the decade of monitoring, but it is usually only present in very low levels if at all.
Though avian influenza is a zoonotic disease, meaning it can be transmitted between animal species and humans, the risk to humans is very low. If you do see a bird that seems to be sick, please do not touch it but contact the local Alaska Department of Fish and Game or Cordova Ranger District.
Mary Ann Bishop us a senior research scientist at PWSSC. Her research focuses primarily on migration strategies of birds and fishes and on estuarine ecology, including the shorebirds, estuarine fishes and benthic invertebrates that inhabit the estuarine environment.