Care and Safety

Why Are Mourning Doves Dying Under My Feeder?

Doves sitting fluffed up with wet faces, failing to swallow, then turning up dead: that is the pattern of canker. The feeders and the bird bath come down today and stay down until the sick birds are gone.

Several mourning doves dead or dying under a feeder, especially between late spring and fall, most likely means trichomonosis, the dove disease known as canker. It is caused by Trichomonas gallinae, a single-celled parasite that lives in the mouth and throat, and the Cornell Wildlife Health Lab names pigeons and doves, mourning doves especially, as the main species it affects.

The response does not wait for a diagnosis. Take down every feeder and the bird bath, disinfect them with 1 part household bleach to 9 parts water, and leave them down until no more sick birds are coming in. That is the instruction from both the Texas Parks and Wildlife Department and the Wisconsin DNR, and neither puts a number of days on it.

Canker does not infect people, cats or dogs. Wear gloves anyway, for a reason the table below makes plain.

Why doves, and why now#

Most adult doves carry the parasite without showing it. Cornell explains that adults pass it to their young in regurgitated food and to each other during beak-to-beak courtship, which is why clinical disease turns up most often in young birds, and why the disease is most frequent in late spring, summer and fall. A summer die-off of young mourning doves fits that pattern exactly.

The feeder is the second route. A bird that cannot swallow drops saliva-soaked seed and drools into water. Texas and Wisconsin use the same words for it: feeders and birdbaths "can become contaminated from the mouths of infected birds." Doves feed shoulder to shoulder on trays and spilled seed, the setup described in how to attract mourning doves, and every one of them drinks from the same bath.

Not every infected bird gets sick. Cornell notes that strains vary: virulent ones build masses of dead tissue in the mouth and throat until the bird dies of starvation or suffocation, in days to weeks, while milder strains, or recovery from a mild infection, may leave a bird immune.

Doves are not the only casualties. In Wisconsin it has killed purple finches, house finches and one peregrine falcon, and Cornell lists house sparrows and raptors among the birds commonly infected. Hawks catch it by eating sick doves; in raptors it is called frounce.

Canker or something else: four feeder diseases side by side#

Fluffed up, lethargic and slow to fly describes nearly every sick bird at a feeder. What separates the diseases is where the signs sit, which birds carry them, and when. The rows come from the Cornell Wildlife Health Lab and Wisconsin DNR sheets for each disease.

The column that matters is the mouth. Three of these diseases can leave lesions in a bird's mouth: canker, salmonellosis and the wet form of avian pox, which Cornell reports in mourning doves too. So cheesy matter in a dead dove's throat is strong evidence, not proof. What tips it toward canker is the combination: doves rather than finches, warm months rather than winter, drooling and failed swallowing, and no warts on the bare skin of the face and feet.

Cleaning differs too. The canker parasite cannot survive for long outside a bird in dry conditions. Avian pox virus is highly resistant to drying and can last outside a host for months to years. Drying finishes canker off; for pox, the bleach soak does the work.

What to do today#

1. Take down every feeder and the bird bath. One feeder left up just concentrates the flock onto it.
2. Clear the ground. Rake up and bag the spilled seed and hulls under each feeder. Doves feed there, and Texas warns that wet seed gives the parasite a better place to survive. The ground half of the job is in seed mess, hulls and dead grass.
3. Scrub, then disinfect. Hot soapy water first, then 1 part household bleach to 9 parts water, the dilution Texas spells out and Cornell and Wisconsin call a 10% bleach solution. Rinse well and dry before reuse. The full method is in how to clean a bird feeder.
4. Bag the dead birds. Gloves or an inverted bag, double-bag the carcass, household trash, wash your hands.
5. Report it. Texas asks anyone who finds birds with signs of the disease to contact their local TPWD wildlife biologist. Elsewhere, your state wildlife agency is the place to report a die-off.
6. Do not treat. Cornell notes that treatment means giving oral drugs, which is impractical in wild birds. Nothing goes in the seed or the water. For a live, struggling bird, the steps are in there is a sick bird at my feeder.

The bird bath is the weak point#

Every advisory on canker names the bath alongside the feeder, and it deserves more attention than the feeder. The parasite travels in saliva, it does not last long once it dries, and the bath is the one shared surface at a feeding station that never dries. Doves drink with the bill submerged, sucking continuously, so a bird with an infected mouth leaves the parasite in the water the next dove drinks.

Wet seed is the second risk. Texas advises feeders that keep seed dry, because seed exposed to rain "provides a more suitable environment for parasite survival." An open tray left out through a summer storm, or a mat of soaked millet under the feeder, is exactly that. If you feed doves on a platform feeder, pick one with a mesh floor and put out only what goes by dusk.

When the bath goes back up, empty and refill it every day or two rather than topping it up. The cleaning routine is in bird baths.

How long to keep the feeders down#

No source gives a number of days for canker. Texas says to stop using feeders and baths "until affected birds are gone from the area." Wisconsin says they "should not be put back up until the affected birds are gone from the area." Cornell's sheet gives no shutdown period at all. The fixed figures you will see elsewhere belong to other diseases: at least a week for finch eye disease in Wisconsin's advice, at least two weeks for avian pox in Cornell's, and about two weeks in our own guide to taking feeders down.

So the test is what you see, not the calendar. While doves are still sitting fluffed up with wet faces, or fresh carcasses are still turning up, the yard stays closed, even if that runs past two weeks. Once they stop, rehang one feeder, not all of them, and watch it. If a sick dove appears, take it down again. Feeders are a supplement rather than a lifeline, as do birds depend on feeders explains, so a long pause costs the doves nothing.

When this page does not apply#

• Finches dying in winter. That season and that species point to salmonellosis, and the shutdown routine for it is on its own page.
• Several species at once, or dead waterfowl or raptors. Report it and do not handle the carcasses, as set out in avian flu and feeders.
• You keep chickens. Cornell notes that domestic poultry can be infected by drinking water or eating feed contaminated by infected pigeons, and Texas advises keeping wildlife away from backyard flocks. Keep wild doves out of the coop's feed and water.