Salmonellosis is caused by bacteria belonging to the genus Salmonella. It is a common cause of mortality in feeder birds, but the symptoms are not always obvious. Sick birds may appear thin, fluffed up, and depressed and may have pasted vents and swollen eyelids. They are often lethargic and easy to approach. Some infected birds may show no outward signs, but are carriers of the disease and can spread the infection to other birds.
Salmonellosis is primarily transmitted by fecal contamination of food and water by birds, though it can also be transmitted by bird-to-bird contact. Infected birds shed the bacteria in their feces, and if they are frequenting a bird feeder, the surface of the feeder or the food itself is likely to become contaminated with their feces. In this way, the feeder becomes a vector for the disease, spreading it to other birds.
All species of birds are susceptible to salmonella infection. Occasionally, outbreaks of the disease can cause significant mortality in certain species including Pine Siskin, Common Redpoll and American Goldfinch. Most commonly, the first appearance of this disease is seen in Pine Siskins.
Feeder cleanliness is key to healthy bird environments. Seattle Audubon recommends routinely cleaning your feeders even when there is no sign of disease. Feeders should be disinfected at least once or twice a month, but weekly is even better. Prevent overcrowding by adding more feeders or setting up different types of feeders that allow only a few birds to visit at one time. Click to view or download The Nature Shop's Backyard Bird Feeding brochure which includes feeder cleaning instructions.
NOTE: At the first sign or notification of salmonellosis, Seattle Audubon recommends taking down all seed feeders to prevent the spread of the disease.
To treat an infected area
To mitigate the spread of salmonellosis, feeders should be cleaned regularly and the ground under feeders should be cleaned more diligently as droppings will contain the bacteria.
- Clean your feeders with warm, soapy water. Disinfect with a 10 percent bleach solution to kill the bacteria. Rinse the feeder and allow it to dry completely before using it again. Disinfect your birdbaths as well.
- Clean your bird feeding area by washing all structures holding your feeders and raking the ground surrounding the feeders.
- Do not reinstall your feeders for a few weeks. As siskins begin to migrate and cease traveling in flocks, it will be okay to put feeders back up.
If you do continue to feed birds
- Discourage large concentrations of birds from gathering in one location by varying your feeder locations
- Remove feeders that allow contact between fecal material and food, such as platform feeders.
- Clean your feeders with a bleach solution several times a week. Be sure that feeders are dry before filling them with seed
What do I do if I see a sick bird?
Only veterinarians or federally licensed wildlife rehabilitators can legally treat wild birds. No medical treatment is known to completely cure birds infected with Salmonella bacteria. If you find a dead bird, place it in a double plastic bag and into the garbage (wear gloves).
Alternatives to bird feeders
Feeding birds is one of America’s favorite pastimes. By providing feeders, we’re encouraging birds to feeders so that we may enjoy their beauty and songs up-close. It’s fascinating to watch them interact and bathe in your yard. But, providing food isn’t limited to feeders. Creating a bird-friendly environment can provide a dependable food supply year-round. With a little effort, you can turn your yard into an oasis for birds. Click here for the inspirational workbook Gardening for Life.