Salmonella outbreaks come with the season

Along with warmer temperatures, spring brings conditions that are conducive to the growth of bacteria around your bird feeders. Some species, particularly the finches, can be highly susceptible to salmonellosis, caused by bacteria belonging to the genus Salmonella. This disease is a common cause of mortality in feeder birds, but the symptoms are not always obvious. Sick birds may appear thin and fluffed up. They are often lethargic and easy to approach. Some infected birds may show no outward symptoms but are carriers of the disease and can spread the infection to other birds.

Salmonella has received considerable attention lately due to the contamination of human food supplies, particularly peanut butter products. Some pet and bird foods have also been recalled due to potential contamination. Recalled products should be returned to the store or disposed of properly. Contaminated foods, however, are likely not the cause of most salmonellosis in birds. Salmonella bacteria normally circulate in populations of wild birds. The bacteria are primarily transmitted among birds through fecal contamination of food and water.

Outbreaks of the disease can occasionally cause significant mortality in some species like Pine Siskin and American Goldfinch. Given the large numbers of Pine Siskins that moved into the southeastern United States this past winter, we can expect to see the widespread outbreaks of salmonellosis that typically accompany siskin movements.

Create a safe bird-feeding environment

If you notice a sick bird at your feeders or bird bath, minimize the risk of infecting other birds by cleaning your feeder area thoroughly. If you see several diseased birds, take down all of your feeders for at least a week to give the birds a chance to disperse. Salmonella strains found in birds can be dangerous to humans, so do not handle any sick or dead birds, and be sure to wash your hands thoroughly after handling feeders. With proper care and attention, you can maintain a safe bird-feeding environment in your yard.

More information about salmonellosis can be found at the National Wildlife Health Center.

For more information on other diseases affecting wild birds, visit the National Wildlife Health Center or the Canadian Cooperative Wildlife Health Centre.