Avian cholera claims waterfowl near Parma

Idaho Department of Fish and Game personnel have confirmed avian cholera killed more than 500 ducks and geese near Parma, west of Boise in Canyon County.

The dead waterfowl were found dead and reported by a concerned citizen on private land on Thursday, Feb. 9.

Fish and Game was notified and staff collected the carcasses of approximately 500-600 birds. Two Canada geese, six mallards and one red-tailed hawk were sent to the Fish and Game’s Wildlife Health Laboratory for further testing, and avian cholera has been confirmed as the culprit. The rest of the carcasses were buried to prevent ingestion by scavengers.

Avian cholera is the result of infection with the bacterium Pasteurella multocida. The bacterium kills swiftly — sometimes within 6 to 12 hours — and is released into the environment by dead or dying birds, or by birds carrying the disease. Consequently, dense concentrations of waterfowl can enhance disease transmission among healthy birds.

Fish and Game continues to monitor for any additional mortality events, and encourages the public to report any observations involving numerous dead waterfowl.

“Outbreaks of avian cholera have occurred annually in the area over the past decade,” said Tyler Archibald, Fish and Game Habitat Biologist at Fort Boise Wildlife Management Area. “We’re actively looking for dead birds and will dispose of any we find.”

Fort Boise is a popular migratory stopover for thousands of waterfowl each spring — holding up to 60,000 lesser snow geese and up to 45,000 white-fronted geese.

Lesser snow geese are known carriers of avian cholera and often associated with outbreaks. No snow geese were found dead at this site and had not been observed in the area until after the outbreak occurred. Avian cholera was responsible for killing over 2,000 waterfowl in Washington along the Snake River near the Tri-Cities in late January.

According to the National Wildlife Health Center, avian cholera is not considered a high risk disease for humans.

If the public observes numerous dead birds, they are asked to call and report the location to one of Fish and Game’s regional offices. Contact Fish and Game’s Coeur d’Alene office: (208) 769-1414.

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Mike Demick is the conservation information supervisor for the Idaho Department of Fish and Game.