For years, it’s been widely recognized that waterfowl such as ducks and geese are carriers of avian influenza virus and pose a transmission risk to humans as well as livestock. Now researchers are suggesting that some songbirds also carry AIV.

A team of researchers, including Trevon Fuller, University of California, examined samples from 225 bird species in 41 states. They found the average prevalence of AIV in passerines — or perching birds — is greater than the prevalence in eight other bird groups. Perching birds include sparrows, robins, blackbirds, starlings, jays and finches.

The researchers found that 22 species of songbirds and perching birds are reservoirs for AIV in the contiguous United States. Also, the greatest risk was in the Great Plains and the Pacific Northwest.

So what should you do on your farm? “Maintain bird netting, keep feed spills cleaned up, prevent birds from nesting in feed mill or manufacturing locations, and keep doors and windows closed or at least covered with screens,” says Lisa Becton, DVM, swine health information and research director, National Pork Board.

Ventilation inlets and doors are important areas to check. “If the bird netting at ventilation inlets (soffits, gable ends, side walls) and outlets (chimneys) is maintained, then doors are the biggest bird entry source,” says Mike Brumm, Brumm Swine Consultancy.  “It seems like birds can tell when a door is left open.”

Unsecured lids and doors can cause a biosecurity breach. “If lids are left open or if wind blows them open, bird feces can end up in bulk bins,” Brumm adds.

“Birds and other wildlife can carry many diseases other than influenza, so it’s part of good production practices to keep wildlife from coming into your farm,” Becton says. “If producers focus on maintaining their external and internal biosecurity, this can help prevent many diseases from entering their premises.”