IAB News Release
Chena River ducks provide scientists an unusual flu lab
FOR IMMEDIATE RELEASE
14 December 2012
FAIRBANKS, Alaska —
The 300 or so mallards that appear to forgo fall migration and overwinter on an ice-free patch of the Chena River in Fairbanks are providing scientists with an unusual opportunity to study how avian influenza viruses move through a bird population.
Waterfowl are the major reservoir of avian influenza virus in North America and more viruses have been isolated from ducks than any other species. While these viruses can make waterfowl sick they rarely infect humans.
“The unusual part of this study is that we can sample the same birds repeatedly in the same setting over the winter,” said Mark Lindberg, wildlife ecologist and project leader from the University of Alaska Fairbanks Institute of Arctic Biology.
Scientists typically use tissue swabs or blood tests to identify flu in birds. Swabbing detects flu only during the few days a bird sheds virus particles. Lindberg and collaborators are collecting blood samples because antibodies to avian influenza in the blood give a more accurate history of infection rates at the population level. This is because antibodies can remain detectable within birds for several months.
It is usually difficult for scientists to determine how long ducks stay infected or have an immune response, since migratory birds rarely stay in a specific location for enough time to study the same individual or population repeatedly.
“The Chena mallards provide an ideal situation to assess relationships between timing of infection and duration of an immune response,” said Lindberg. “This study will also help us understand why some ducks choose to winter this far north and how that influences their survival and body condition.”
Lindberg and Brandt Meixell, a wildlife biologist and co-investigator with the U.S. Geological Survey Alaska Science Center in Anchorage, have taken samples from about 200 mallards since August and plan to continue sampling about 50 ducks per month through April or May 2013.
For each duck captured, Lindberg’s team will take a fecal or oral swab and a blood sample, and then weigh, measure and mark each bird with a leg band prior to release. They expect to have results from their work in fall 2013.
“Determining how long antibodies remain detectable in birds following influenza infection will help biologists understand how many ducks contract influenza each year and how infection varies relative to species, age or influenza strain,” said Meixell. “Our results should provide information on how ducks are able to keep influenza virus circulating year in and year out.”
The ducks may hold other surprises. Of the 200 banded so far, only six have been recaptured.
“It seems that most of the birds we banded in August and September have boogied,” said Lindberg. “One mallard banded in August was shot by a hunter in Washington in November and we know from previous banding at Minto Flats that birds commonly fly over the Alaska Range and use year-round open water in coastal areas.”
About the UAF Institute of Arctic Biology
The Institute of Arctic Biology at the University of Alaska Fairbanks is Alaska’s principle research and educational unit for investigating high-latitude biological systems and providing the public and state of Alaska policy makers the necessary knowledge to interpret, predict and manage biological systems in the face of uncertainty.
ADDITIONAL CONTACTS: Mark Lindberg, professor of biology, 907-474-6598,firstname.lastname@example.org. Brandt Meixell, USGS wildlife biologist, 907-786-7157,email@example.com.
ON THE WEB:
Institute of Arctic Biology: www.iab.uaf.edu
USGS Alaska Science Center: http://alaska.usgs.gov/