A Sick Bird at Your Feeder: How to Tell, and What to Do

The legal line you should not cross

This is the part most guides bury. Project FeederWatch states it plainly: only veterinarians or federally licensed wildlife rehabilitators can legally treat wild birds. If you see a bird that appears compromised by sickness or injury, do not try to care for it yourself. It is illegal for you to possess most wild birds unless you are under the direction of someone licensed for their care.

That rules out the advice you will find on forums — dosing a bird with antibiotics, keeping it in a box, "nursing it back." The correct move is always the same: reduce transmission at the feeder, and get the bird to someone licensed.

What a sick bird looks like

A healthy feeder bird is alert, moves quickly, and leaves when you approach. The signs below are the ones the sources actually describe — not a diagnostic key, but a reason to act.

Two nuances matter. First, some infected birds show no outward symptoms but are carriers and can spread infection — so a feeder that looks fine is not proof it is clean. Second, salmonellosis symptoms are "not always obvious," which is exactly why the routine cleaning schedule exists rather than a clean-only-when-you-see-a-problem approach.

The four diseases worth knowing

House finch eye disease

Caused by the bacterium Mycoplasma gallisepticum. The bacterium was long known as a pathogen of domestic turkeys and chickens but has been observed in House Finches since 1994. It has also affected American Goldfinch, Evening Grosbeak and Purple Finch.

Why it matters for feeder design: conjunctivitis spreads through eye discharge. FeederWatch notes that tube feeders with ports are especially risky for this route, because birds rub their eyes against the openings. If you see it, disinfect tube feeders with particular care.

Avian pox

Caused by several strains of pox virus and reported in at least 60 species. In the common form, wart-like growths appear on featherless areas — around the eye, at the base of the bill, on the legs and feet. In the second form, plaques develop on mucous membranes of the mouth, throat, trachea and lungs, causing impaired breathing and difficulty feeding.

It spreads by direct contact with infected birds or contaminated surfaces such as feeders, or by ingesting contaminated food or water.

Salmonellosis

Caused by Salmonella bacteria and described by FeederWatch as a common cause of mortality in feeder birds. It is transmitted primarily by faecal contamination of food and water by sick birds, though bird-to-bird contact also spreads it. Outbreaks can cause significant mortality in certain species, including Pine Siskin, Redpoll and American Goldfinch.

Why it matters for feeder design: because the route is oral-faecal, tray feeders — where birds stand in what others have left — are the higher-risk type. FeederWatch suggests considering retiring tray feeders if you observe a disease spread this way.

Avian influenza

An influenza virus that occurs naturally in wild aquatic birds including ducks, geese and gulls. Mild forms (low pathogenic) are routinely found in wild birds and do not cause serious illness, but a mild strain can mutate into highly pathogenic avian influenza, which can cause severe disease. Symptoms vary by strain and species.

Because the situation changes, check current guidance rather than relying on a fixed rule. Cornell Lab publishes outbreak updates.

What to do, in order

1. Take down the feeders the sick bird was using for a couple of weeks. FeederWatch's stated reason is to ensure disease is not being spread at your feeders and to give birds a chance to disperse.
2. Clean the feeders and the feeder area thoroughly while they are down. Not just the feeder — the ground beneath it too.
3. Contact a wildlife rehabilitator if you believe the bird needs intervention to survive. The Humane Society lists rehabilitators by U.S. state, and Nature Canada lists them by province.
4. Consider whether taking feeders down helps in your area. FeederWatch notes this action is likely to help only if you live in an area with few feeders. Where feeding is popular, removing your feeders can concentrate birds at the remaining ones and increase transmission.
5. Add other resources. Native plant gardens encourage birds to disperse from feeders and use more of the yard, which reduces crowding.
6. Report unusual mortality. In the U.S., contact the National Wildlife Health Center; in Canada, the Canadian Wildlife Health Cooperative.

The cleaning sequence

FeederWatch's routine: take the feeder apart, scrub off debris, wash thoroughly with warm water and dish soap, and rinse thoroughly. A dishwasher works well for feeders that are dishwasher safe; otherwise use a scrub brush or bottle brush. Allow to dry completely before refilling. Do not use feeders that cannot be thoroughly washed, such as wooden ones.

For disinfection, soak the cleaned parts for about 10 minutes in one part bleach to nine parts water, then rinse carefully and dry completely before reassembly. Alternatively, wipe down the cleaned and reassembled feeder with a bleach wipe and dry completely. Boiling water or diluted vinegar are alternatives if you prefer not to use bleach, though FeederWatch notes not all alternatives meet disinfectant standards.

Disinfect during periods of heavy use, or if you observe sick birds in your area — not only in a crisis.

Hygiene and food choice are the same problem from two sides. If you are rethinking what you put out, see the food-by-food guide.

Prevention that actually works

• Clean seed and suet feeders every week or two, and more often during heavy use or wet weather.
• Clean hummingbird feeders every couple of days in warm weather, ideally each refill. Discard cloudy solution or black mould immediately.
• Keep the ground clean. Rake or sweep below feeders to prevent accumulation of droppings, mouldy food and spoiled seed.
• Rotate feeder positions periodically to limit waste building up in one spot.
• Do not use wooden feeders you cannot wash.
• Wear gloves when handling feeders, and a mask when raking underneath. Wash your hands after.
• If you cannot keep up with cleaning, FeederWatch suggests limiting feeding to the times of year you can do it safely.

Frequently asked questions