Spring brings migrating birds back north, and many of us enjoy their visits to our feeders. As well, year round birds are more active, and may be spending more time visibly feeding. Unfortunately, this may bring diseases to a central site: the feeder. Just as children all seem to get colds in the first few weeks of the school year, bringing animals together under slightly stressful conditions may spread disease. In wild birds, bacteria such as salmonella are normally present in very small amounts. However, once they congregate -- and especially if the feeder allows their droppings to fall into the food source -- it’s easy for the bacteria to start spreading, and making birds sick.

Increased deaths of songbirds have occurred in the North East in the past, including during 1988, 1992-3 and 1997-8 in the Canadian maritime provinces. The species that were the most susceptible were Common Redpoll and Pine Siskins. In these outbreaks, most birds seemed to have died due to Salmonella typhimurium infection.

So far this year, some wild bird deaths in Maine have been documented to be due to salmonella infection. It’s more important than ever for the backyard birders to help avoid the spread of this disease.

What to do to help prevent the spread of bird diseases

1. Clean your bird feeders. Take down all your feeders, empty and scrub them well, using a dilute (10%) bleach solution. Dry them using a hair dryer or direct sunlight. Discard old or broken feeders.
2. Remove old seed from the ground. If birds have been dying, clean up all the old seed around the feeder. If you still have lots of snow on the ground, cover up the old feed with tarps so birds and squirrels won’t eat old or contaminated seed. Remove old seed; incinerating is best.
3. If possible, relocate your feeders to a “clean” site.
4. Use fresh seed. Be sure the feed you are using is in date, has been properly stored, and doesn’t smell “musty.” Get rid of old or spoiled feed; incinerating is best.
5. Limit the number of feeders you put out; as you attract more birds, you may spread more disease.
6. Keep pets away from the feeder; this will protect both your pets- and you!

Other diseases -- particularly avian influenza -- may cause large die-offs of birds. If you find a group of birds that have died, and do not see a reason for this, then you may wish to call your local extension office or the state Department of Agriculture to have the birds tested for avian influenza. More information about avian flu can be found at www.cdc.gov/flu/avian/gen-info/facts.htm and at What Maine People Need to Know About Avian Influenza ("Bird Flu").

Remember: with any dead animals, try not to handle them directly. Be sure to wash your hands well after handling them, or cleaning the feeders.

Additional resources:

• Keeping Your Yard Safe for Birds: in-depth information about avoiding disease and feeder cleaning and maintenance.

• Understanding Ruby-Throated Hummingbirds and Enhancing Their Habitat in Maine: includes information on cleaning hummingbird feeders.