Understanding waterfowl movement and bird flu

Scores of waterfowl are currently on the move, and experts are worried they could further spread highly pathogenic avian influenza, commonly known as bird flu. But these flocks, which can number in the thousands and include Canada geese and snow geese, are of most concern around poultry houses, said University of Delaware’s Christopher Williams. The risk to humans and dogs getting bird flu from geese who inhabit their neighborhoods remains low, Williams said.

Williams, a professor wildlife ecology in UD’s College of Agriculture and Natural Resources, explained why this is happening:

• Smaller ducks such as blue-winged teal, larger ducks such as mallards, and larger geese like Canada geese and snow geese are heading north to their breeding grounds.

• Waterfowl are a primary reservoir for avian influenza viruses, meaning they can harbor bird flu strains viruses, spread them, and in some cases show no signs of disease. They can shed the virus through their saliva, naval secretions, and feces.

• Waterfowl serve as the primary vector of avian influenza to the U.S. poultry industry which has affected more than 8 million commercial and backyard chickens and turkeys that have been culled to keep the virus from spreading.

“While we are worried about these flocks congregating near poultry houses, the risk of humans getting bird flu from waterfowl remains low,” Williams said. “Further, walking dogs around areas with geese flocks should pose little threat to dogs’ health as avian influenza is very rare in dogs.”

Nevertheless, Williams cautions people and dogs to avoid touching sick birds or dead birds.

A large segment of the Canada geese population are not migratory, Williams said. They will stick around the Mid-Atlantic year-round and tend to congregate and breed near grocery store parking lots, golf courses and neighborhoods.

“Those birds are being drawn to needing two things. No. 1 is they need water including any natural pond or water containment area,” Williams said. “And all the geese species are herbivores, so No. 2 they eat grass. There are places that have both water and grass that will provide ideal nesting habitat for the geese and their chicks.”

Reporters can connect with Williams by visiting his profile and clicking on the “contact” button.