By Dr. Becker
State wildlife officials in California have asked residents with birdbaths and feeders in their yards to take them down in response to an outbreak of salmonella among songbirds in the Bay Area and Sierra Nevada counties.
The problem seems to have started in late December, when people began reporting sightings of sick or dead songbirds. The pine siskin, a small brown migratory finch with bright yellow markings, is especially vulnerable to salmonella infections.
When the little birds gather in high numbers at feeders and baths, they spread the bacteria in their feces, making other finch species susceptible to infection as well.
Birds with salmonella appear lethargic with closed or squinty eyes, ruffled or puffy feathers and sometimes, labored breathing. The infection spreads throughout the body, causing it to shut down.
Salmonella outbreaks also occurred in 2008 and 2012. The disease usually occurs during the winter when there are large populations of pine siskin.
Salmonella Infections in Birds Are Caused by Bird Feeders
In California, salmonellosis in birds is seen almost exclusively at bird feeders, which create unnatural conditions.
"Really, prevention is key, by not feeding wild birds or maintaining exceptionally clean bird feeders and birdbaths," says Krysta Rogers of the state Department of Fish and Wildlife. "At a minimum, those things need to be cleaned at least three times a week."
For the time being, however, Rogers recommends that people in the Bay Area put away their feeders and birdbaths to stop further spread of the disease.
The salmonella strain most often found in birds can also cause illness in people, so it's important to take precautionary measures when cleaning feeders and baths, and after contact with birds.
Another disease affecting Bay Area songbirds is mycoplasmosis, which is a bacterial infection that causes eye inflammation and respiratory problems. Telltale signs in birds include runny, crusty and swollen eyes; abnormal breathing (including open-beak breathing); and lethargy.
Tips for Keeping Bird Feeders and Birdbaths Clean
WildCare, an animal rehab center in San Rafael, California, offers the following tips and guidelines.1
For people who find sick or dead birds in their yard:
✓ Remove bird feeders and birdbaths immediately
✓ Disinfect feeders and baths with a bleach solution of 9 parts water and 1 part bleach (unless you have a hummingbird feeder — more about that below)
✓ Scrub well and allow to soak for 10 to 20 minutes
✓ Rinse very thoroughly and allow to dry
✓ Don't reinstall feeders or baths for at least one month after the last sick or dead bird is seen in your yard
✓ Re-sterilize and allow to dry before re-installing
If you haven't yet seen sick or dead birds, take the following preventive measures and perform them on a routine basis to help the birds in your yard stay healthy.
• Avoid wooden feeders.
• Disinfect bird feeders every two weeks, and empty and clean birdbaths daily. Make up a 9:1 bleach solution in a container you can bring outside.
Scrub the feeder and birdbath with a hard brush and let them soak in the solution for 10 to 20 minutes, covered with a board so no birds can bathe in the bleach. Rinse thoroughly and allow to dry before refilling (a dry feeder deters mold growth).
• For hummingbird feeders, do not use bleach. Use vinegar and water in a 9:1 solution (9 parts water to 1 part vinegar) and special bottle brushes to get into small holes. Rinse thoroughly. Change food often.
Clean every one to two days or more often if the feeder gets cloudy or moldy. Fill with only enough food to last one to two days.
Always wear water-resistant gloves to keep your hands free of bleach, and a facemask to avoid inhaling or accidently ingesting feces, bleach, etc.
Keep a large tray under the feeder to catch hulls/seed that falls to the ground. Empty the tray each day to avoid rodent infestations, and to prevent mold and disease from infecting ground feeding birds.
If you have nighttime wildlife visits from rats, raccoons, skunks, etc., it's a good idea to bring the feeder inside at night.