Winter is the time of year when many people begin thinking about feeding birds. But before those cold months arrive and before you take your bird feeders out of storage and simply re-fill them with seed, make sure to give the feeders a thorough washing. Since neglected bird feeders and the areas around them are prime suspects for disease transmission, the importance of hosting clean feeding stations can not be overestimated.
Maintaining these areas doesn't have to take a lot of time. Here are some simple tips for preventing or minimizing disease problems at your feeders. Your feeders will not only look better, but you'll help your wild neighbors stay healthy, too.
Set up more than one feeder and allow ample space between feeders. Crowding is a key factor in spreading disease, since it creates stress which may make birds more vulnerable to illness. Spread feeders out and move feeders to different parts of your yard regularly to prevent buildup of waste and infectious organisms on the ground underneath.
Clean your feeders often. Studies have shown that tray feeders decrease the spread of disease when compared to tube feeders, because they allow the seed and surfaces to be exposed to air and light, which are deadly to many microorganisms. Ideally feeders should be scrubbed at least every week or so. To promote drainage and prevent standing water, drill small holes in tray feeders. Hot, soapy water with a little bit of bleach—about one part for every ten parts of water—is all that's necessary for cleaning. Let the feeders soak, then rinse them thoroughly. Feeders made of plastic and ceramic will be the easiest to maintain this way; wooden feeders should be disinfected with something other than bleach so the wood won't fade.
Make sure your feeders are safe. Choose feeders that have no sharp edges or points. To help keep food cleaner, use feeders that allow birds to perch away from the food.
Store your surplus food in a secure and dry place. Birdseed should always be kept dry and safe from rodents by storing it in a container with a tight-fitting lid, such as a clean garbage can. Discard any food that smells musty, is wet, looks moldy, or has fungus growing on it. It's best not to store bird seed over the summer; if you did, check it very carefully before you put it out this season.
Clean up wastes. Keep the feeder area clean of waste food and droppings. Rake up spilled seeds, hulls, and feces at least once a week. For ease of refilling and cleaning, hang your feeders where they'll be easily accessible to you.
Be alert for sick birds at your feeding stations. If you find dead birds or see obviously sick birds (they're less active and alert) at or near your feeding stations, stop feeding immediately. Discard all seed, then clean and disinfect all feeders and the ground below them. Wait a week or two before resuming feeding.
Several avian diseases are more prevalent among birds who visit bird feeders. Here are four diseases that frequently affect birds using feeders:
Salmonellosis: The most commonly spread disease at feeders is caused by the "Salmonella" group of bacteria. Birds don't often get sick from this disease, but they can become carriers. Infected birds spread the bacteria in their droppings. Other birds contract the disease when infected droppings land on food.
Trichomoniasis: This disease is caused by a one-celled protozoan parasite. Doves, pigeons, and birds of prey are particularly susceptible. Trichomoniasis causes sores in birds' mouths and throats, making it difficult for them to swallow or drink. The disease spreads when sick birds drop contaminated food or water at a feeder or watering area.
Avian pox: A virus that causes wartlike growths on featherless surfaces of a bird's face, feet legs or wings, or lesions in the mouth and throat. The virus spreads by direct contact, through feces, or by insects. Carriers of the organism may appear healthy but shed the organism periodically in their feces. Sick birds have been observed with ruffled feathers, perching for long periods of time at or around feeders.
Mycoplasmal Conjunctivitis: This bacterial disease causes respiratory infection and swollen, often crusty eyes in affected birds. It primarily strikes house finches, but it has also been documented in other members of the same family: goldfinches, purple finches, evening grosbeaks, and pine grosbeaks. This disease often kills birds indirectly when their vision becomes so compromised that they are unable to forage for food or evade predators.
What You Can Do
The Cornell Lab of Ornithology in Ithaca, New York, runs two "citizen science" research projects that depend on the observations of bird feeding enthusiasts nationwide. Project FeederWatch is the lab's winter-long survey of birds who visit feeders in backyards, schools, and other community areas in North America. The lab's House Finch Disease Survey specifically tracks the spread of mycoplasmal conjunctivitis among finches and other birds who visit feeders.
