Bird Feeder Diseases and Challenges

By Kimberly Mason
For The Chronicle 

In early spring wild bird feeders have an interesting — and sometimes heartbreaking — challenge. As feeders become overrun with new birds migrating through our area and our ever active population of local year-round birds continue to dine, bird feeding stations are overrun with challenges.

One of the issues that I have found most challenging is the recent influx of owls, hawks and other meat-eating birds to my backyard.

There are no less than five different species of hawks and four different owls hunting and haunting my backyard on any given day. I have seen many injured birds at my feeders and spotted several piles of feathers as I have been out walking.
When my bird feeders become a self-serve dinette station for birds of prey, I am saddened by the sight.

But, I have to remind myself, it is just nature taking its course. Birds of prey need to eat too.

Ill health and disease is part of Nature’s way also, but there are ways that we contribute to Nature’s despicable way of getting rid of the weak and the helpless — through our dirty bird feeders, bird baths and nesting boxes.

The photographs included with this story may be hard to look at, but the sight a diseased bird at your own feeder at home is heartbreaking.

You can help your wild birds by knowing the signs and learning how to prevent the spread of disease.

How to Clean Bird Feeders

Clean your feeders about once every two weeks, more often during times of heavy use.

For best results wash your feeder thoroughly in soapy water, then soak or rinse it in a solution of one part bleach to nine parts water. Dry the feeder thoro

ughly before refilling.

There are products available at local feed stores that are specifically made to dissolve bird droppings and old feed crust. These products can be used on wood, plastic, glass or metal. After cleaning feeders with these products, you must still disinfect with a bleach solution.

Hummingbird feeders should be cleaned every time you refill the nectar (every three to five days).

Mold: Aspergillosis

Bird seed left to mold in feeders or on the ground is a killer.

Ground feeders such as juncos, sparrows, Mourning Doves and pigeons contract aspergillosis by inhaling mold spores. It can also be a serious problem for waterfowl.

Aspergillosis attacks the lungs, air sacs, and occasionally the windpipe. Look for birds at your feeders that gasp and wheeze or sit quietly for long periods of time.

Avian Pox

Two forms of avian pox exist. In one form, wart-like growths appear on the featherless areas of the body — around the eye, at the base of the bill, and on the legs and feet.

In the second form, plaques develop on the mucous membrane of the mouth, throat, trachea, and lungs, resulting in impaired breathing and difficulty feeding. These birds eventually starve to death.

Avian pox can be caused by several strains of the pox virus and has been reported in at least 60 species of birds, including turkeys, hawks, owls, and sparrows. The virus can b

e spread by direct contact with infected birds or contaminated surfaces or by ingestion of contaminated food or water.

House Finch Eye Disease

Avian conjunctivitis (commonly referred to as House Finch disease) can also affect the American Goldfinch, Purple Finch, Evening Grosbeak and Pine Grosbeak.

Symptoms include swollen eyes, oozing and crusty eyes, but this is primarily a respiratory infection.

You may see an infected bird sitting quietly in your yard, clumsily scratching an eye against its foot or on a perch. Some infected birds recover, but many die from starvation, exposure, or predation.


Salmonellosis has been seen in many avian species throughout the world including the following local birds: American Goldfinch, Bald Eagle, Black-capped Chickadee, Brown Creeper, Cooper’s hawk, Dark-eyed Junco, Double-crested Cormorant, Evening Grosbeak, Great Blue Heron, House Finch, House Sparrow, Mallard duck and, what seems to be the most common of all the suffers in our area, the Pine Siskin.

Salmonellosis is transmitted directly through fecal contaminated food products or from bird to bird.

Signs range from sudden death to a gradual onset of depression over 1 to 3 days, accompanied by huddling of the birds, fluffed-up feathers, unsteadiness, shivering, loss of appetite, markedly increased or absence of thirst, rapid loss of weight, accelerated respiration and watery yellow, green or blood-tinged droppings.


To do your part to help control outbreaks, disinfect all feeders and bird baths with soap and water and then a 10% bleach solution, clean up all spilled seed.

If you see sick birds, take down the bird feeders and put them away for at least 1 week and up to 4 weeks. With the food supply removed, birds will be dispersed, and the carrier and susceptible birds will be separated.

Kimberly Mason is a freelance writer based in Cinebar. She can be contacted at