Are Your Bird Feeders Spreading Deadly Diseases?

During the last five years, I have had personal experience with two wild bird infections, trichomoniasis and avian pox, that can be unintentionally spread by well-meaning people who have bird feeders in their yards. I hope the following will raise awareness of the importance of good hygiene practices in feeding wild birds.

Trichomoniasis

Trichomonas gallinae infection is common in some wild birds, especially pigeons and doves. Those of us who regularly raise and release orphaned doves often have the heartbreak of caring for little ones who are infected with this parasite. Left untreated, it is almost always fatal. These little birds begin with difficulty swallowing and difficulty breathing. The progression of the disease ultimately makes swallowing impossible and their airways become completely closed off, causing them to die.

Adult birds can be asymptomatic carriers and may pass this disease on when feeding their young.

Another way the disease is spread is from infected water and food. When an infected bird drinks from a water source, the parasite swims out of its mouth and is then present in the water for other birds to pick up when they drink. When an infected bird picks up a seed or other food and then drops it, another bird may become infected after picking it up and eating it.

This disease is not easy to spot. The only thing you can do is to try to be on the lookout for lethargic, fluffed up birds or birds who seem to keep their mouths open. This is your cue to take extra special care with the above precautions. If you see numerous sick birds, it would be best to discontinue feeding for the time being.

Avian Pox

I witnessed this one in my neighborhood a couple of years ago when diseased purple finches were coming to my patio to feed. I was seeing numerous birds with very large wart-like growths on their feet, legs, heads, and other parts of their bodies. I called South Plains Wildlife Rehab Center in Lubbock, TX. Their director helped me to determine that what I was seeing was an outbreak of avian pox.

Birds with this disease can become unable to perch when lesions affect their legs and feet, causing them to be more vulnerable to predators. They may also become unable to eat when lesions keep them from opening or closing their beaks to swallow food. They may be unable to find food if they become blinded by their lesions. It is so sad to witness and it is very contagious. Some birds survive, depending on the extent of the lesions and systemic involvement, but many of them die.

This disease is easy to spot. You can see photos of infected birds by following the link given at the end of this article. I'll warn you that the sight of this is not pretty and can be very upsetting. If you see even one diseased bird with these wart-like lesions anywhere on its body, immediately take your feeders and water sources away and disinfect them before putting them out again. If you see two or more diseased birds, it is recommended that you discontinue feeding for a week or longer to discourage the spread of the disease. Infected birds might have a better chance of surviving if you continue to feed, but because they will live longer they will be able to infect a greater number of healthy birds.

Other Diseases

Other fatal diseases can be spread from poor hygiene practices associated with feeding of birds. The recommendations below will go a long way toward limiting your unintentional participation in spreading disease.

By doing a web search or following some of the links I have given below, you can read more about the prevalence and devastating effects of trichomonas, avian pox, and other diseases that are unintentionally spread by human carelessness. Multiple localities in the U.S. (and worldwide) have been forced to issue public warnings to residents to discontinue feeding in an attempt to control particularly widespread outbreaks of these diseases. A little knowledge and prevention can go a long way.

What You Can Do to Prevent Spreading Disease to Birds at Your Feeders

Always offer clean water in clean containers. Water needs to be changed as often as possible. You can clean containers with bleach regularly and then rinse and dry them completely before refilling them. You also need to keep bird baths clean.

I use a plastic container meant for keeping individual sandwiches fresh. I change the water three times a day. I change the container once daily, putting the previously used one into the dishwasher to be disinfected.

Be sure you clean up the feeding area. Removing old seed and hulls and bird droppings (which may be infected) from under and around your bird feeders is essential.

I have found this to be easier when feeding over a concrete surface instead of somewhere over a grass-covered area.

Don't use bird feeders that birds must stick their heads into. When an infected bird sticks its head into the openings of this type bird feeder, it leaves body fluids behind. This is especially a risk if the feeders have sharp edges or protrusions that might nick or cut the bird. Subsequently, when a healthy bird comes to the same feeder, it becomes infected. All bird feeders need to be regularly disinfected.

I don't use any type of bird feeder. To feed seed at my house, I use an old door that rests on two sawhorses. With each feeding, I first sweep the door and the patio surface under the door and then I wash both with the water hose. I spread newspaper on top of the door and anchor it with bricks (also washed) and spread the portion of seed I plan to feed as widely as I can. Alternatively, you could buy old plates or saucers at a consignment store and use clean ones each time you feed, putting the used ones into the dishwasher. I have also used cookie sheets which I lined with newspaper. I used the newspaper partly because the cookie sheets, being metal, heated up in the sunlight to the point that I was concerned about burning the birds' feet.

Offer fresh food. Throw away food that has become wet and moldy or otherwise contaminated. Store food in mouse-proof containers. Mice love birdseed and they are carriers of diseases that can be dangerous for birds.

I am making food available to wild birds that I have hand-fed and released so I am now putting out seed three times daily. I never keep a bag of seed long enough for it to get old. If you find a bag of seed is lasting too long, buy smaller bags. It may cost a little bit more but you will not subject the birds to as much risk. I store seed in a plastic trash can with a tight-fitting lid that flips open.

Make others aware. Consider telling your neighbors what you are doing and why. If you know that diseased birds are coming to your feeders, let others know about it and let them know what to do.

When I saw so many birds coming to my yard that were obviously infected with avian pox, I discontinued feeding for about ten days. I made up a flier and put it out to all the houses in my neighborhood. I also wrote a letter to the editor of my local newspaper in case the disease was showing up in other neighborhoods.

If Following These Recommendations is Too Much Trouble

Feeding birds at bird feeders poses risks for the birds that do not occur in the same way in nature. If you are feeding birds in your backyard, you probably have regard for keeping them as safe as possible and that comes with some responsibility. Please consider discontinuing feeding if you are unable to take the time to institute good feeding practices.

Also please be aware that owning wild birds is illegal and babies can be easily killed by well-meaning people who think they are rescuing them. If you find a baby bird that you think needs help, don't pick it up unless you have first researched what to do. You may be taking it away from nearby parents at a critical time in its life. If you are sure it needs help, call the nearest trained wildlife rehabilitator. In other words, with regard to feeding and raising wild baby birds, follow the old caveat: "don't try this at home" unless you have thoroughly educated yourself on what to do and what not to do.

Sources for further information:

David Lucas, "Spic 'N' Span." Wild Bird Magazine.

No author listed, "Canker, Pigeon Canker, Trichomoniasis, Roup or Frounce." Beauty of Birds.

No author listed, "Avian Pox Virus." Beauty of Birds.

Kate Cleary, "Fact Sheet: Coping with Diseases at Bird Feeders." USGS National Wildlife Health Center.

No author listed, "Diseased Birds at Your Feeder." Project Feeder Watch

No author listed, "Recognizing Conjunctivitis." House Finch Disease Survey