Extension Service Garden Hints

Clean bird feeders to prevent disease

CORVALLIS, Ore. - Imagine a fast food joint where nobody ever cleaned the kitchen, the tables or the bathrooms. Now think about your bird feeder. When is the last time you cleaned it?

As birds crowd to feeders, they are bound to catch diseases from each other. Salmonellosis and other diseases can be spread from bird to bird at feeders. Wildlife and poultry specialists at Oregon State University and other institutions around the country are recommending that people clean up their bird feeders as soon as possible to avoid spreading diseases.

“You can spot sick birds in a crowd,” said Dan Edge, wildlife biologist with the OSU College of Agricultural Sciences. “They are less alert and less active. They feed less and often cower on a feeder, reluctant to fly. Sick birds are more vulnerable to starvation, dehydration, predation and severe weather.

“Sick birds show up at feeders and the other birds may get sick as a consequence,” Edge added. “But this does not mean that bird feeding is bad or should be stopped. There’s an ethical obligation not to jeopardize wild birds. What is called for is intelligent bird feeding.”

Salmonellosis is the most commonly spread disease at feeders. This bacterial disease can kill birds quickly. Symptoms include abscesses in the lining of the upper digestive tract of the birds. Infected birds spread the bacteria in their droppings. Other birds get sick when infected droppings land on food.

Other diseases that affect birds typically using feeders also include:

- Trichomoniasis - caused by a one-celled protozoan parasite. Mourning doves are particularly susceptible. Trichomoniasis causes sores in birds’ mouths and throats, making it difficult for birds to swallow or drink. The disease spreads when sick birds drop contaminated food or water at a feeder or watering area.

- Aspergillosis - a mold that grows on damp feed and in the debris beneath feeders. Birds inhale the mold spores and infection spreads in the lungs, causing bronchitis and pneumonia.

- Avian Pox - a virus that causes wartlike growths on featherless surfaces of a bird’s face, feet, legs or wings. Virus spreads by direct contact, by insects or by viruses shed on food by infected birds.

- Avian influenza (H5N1) virus - much in the news, this disease has infected poultry throughout Asia, Russia, and Europe, but has not yet been identified in any birds in North America, or the Western Hemisphere, explained Jim Hermes, OSU Extension poultry specialist. Although one strain is known to infect humans, most strains do not.

“The press has been talking about an avian influenza ‘pandemic’ and equating the current avian influenza problem with the great influenza epidemic in the early part of the 20th century,” said Hermes. “Please realize that the designation of a pandemic is a ‘worst case scenario.’ We are not currently in an avian influenza pandemic. That designation will not occur until the current problematic virus strain mutates from a bird to human infective virus to a human to human infective virus, an event that may or may not occur.”

With the recent frequent media coverage raising concerns about avian influenza, the Cornell Lab of Ornithology is stressing that it is safe to continue to watch, feed and attract birds, said Bruce Dugger, the Mace Professor of Watchable Wildlife in OSU’s Department of Fisheries and Wildlife.

To minimize the spread of disease at your feeder, Dugger and Edge both recommend following these seven easy steps to foster sanitation:

• Give the birds enough space. Do you have only one feeder? Get another if your feeder is crowded.

• Clean your feeder and the droppings on the perching area each time you fill your feeder.

• Disinfect the feeder once or twice a month with one part of liquid chlorine household bleach in nine parts of warm water. If possible, immerse the feeder for two to three minutes and allow to air dry.

• Feed birds only high quality food. Moldy seed or bread or spoiled leftovers doesn’t do them any more good than it would do you.

• Keep rodents out of food. Mice can carry some bird diseases.

• Act early and spread the word. Don’t wait until you see sick birds huddled at the feeder. And tell your friends who feed birds to take the above precautions.

• Check your feeder for sharp edges where birds might cut themselves. Small scratches or cuts allow bacteria and viruses to infect a bird more easily.

Keep in mind that even if you practice all the above procedures, you may still see a sick bird at your feeder, said Dugger.

“Remember, a sick bird is not necessarily your fault,” explained Dugger. “Birds die of natural causes all the time. We just tend to see them more when we feed birds.”

By: Carol Savonen
Source: Dan Edge, Jim Hermes, Bruce Dugger

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