At least 2000 birds have died from an outbreak of avian botulism in Portland, Oregon. This outbreak could reduce the area’s migratory bird population significantly. Officials are currently working to contain the outbreak.
Avian botulism is caused by the bacterium Clostridium botulinum, which is found in the soil and activated by warm temperatures. Experts believe that the warm weather combined with decomposing plant materials have led to elevated bacteria levels in the area.
Birds can be infected with avian botulism through consuming the bacteria directly or by consuming other invertebrates that are infected with the bacteria. In this outbreak, maggots have been feeding on dead birds, and other birds become infected by eating these maggots.
For this reason, experts are focusing on clean up of sick and dead birds as the primary means of prevention. Dan Moeller, Metro’s Natural Areas Land Manager, explained to Portland’s local news station, KGW, “If groups of scientists and workers aren’t out here collecting the dead materials then it can spread very quickly. And that’s what we’ve been doing ever since we found it was occurring, was to get out here as quickly as possible.”
Wetlands areas with high rates of deaths have been closed to visitors until further notice. Experts believe that cool rains will also help reduce the water temperature and stop the outbreak.
The disease affects birds’ nervous systems, causing paralysis in legs, necks, and wings, and eventual death. There are two strains that occur most commonly: type C affects waterfowl, shorebirds, and colonial wetbirds, and type E affects gulls and loons.
While human botulism does exist, avian botulism cannot be transmitted to humans.