The Washington state Department of Fish and Wildlife is urging people to stop using, or to deeply clean, their bird feeders in order to prevent the spread of a deadly disease that is killing birds.

The WDFW has been receiving reports of sick or dead birds at feeders in several counties, including King, Kitsap, Skagit, Snohomish, and Thurston. Locally, the song bird rehabilitation nonprofit Featherhaven has received so many calls and emails that Director Kelley Ward has lost count.

“The sad part is, you can’t save them,” Ward said in a recent interview. “You just can’t. I’ve tried.”

The culprit is salmonellosis, a common and usually fatal bird disease caused by the salmonella bacteria, WDFW veterinarian Kristin Mansfield said in a press release; “When birds flock together in large numbers at feeders, they can transmit the disease through droppings and saliva.”

According to the WDFW, the spread of the disease may have been exacerbated this year by what’s called an “irruption” (a sudden migration of unusually large numbers) of winter birds coming down from Canada and the far north.

Back in October, the Audubon Magazine reported that the current irruption of the Pine Siskin is “one of the biggest irruption years in recorded history for the finches… This year’s irruption is so strong, in fact, that Pine Siskins have also been recorded migrating at night — something highly unusual for the species and that has only been observed once before, during the last major irruption a decade ago.”

Signs that a bird may be sick include timidity and allowing a human to get close to the bird.

“The birds become very lethargic, fluff out their feathers, and are easy to approach. This kind of behavior is generally uncommon to birds,” Mansfield said. “Unfortunately, at this point there is very little people can do to treat them. The best course [is] to leave the birds alone.”

The WFDW recommends discontinuing the use of feeders until at least February, to encourage birds to not congregate in one area — much like the social distancing recommendations to keep from spreading COVID-19 in people.

“Birds use natural food sources year-round, even while also using backyard bird feeders, so they should be fine without the feeders,” Mansfield said.

People who wish to keep using their feeders can do so by cleaning the feeders daily with soap and water, then sanitizing the feeder by dunking it in a solution that is nine parts water, one part bleach, and then letting it dry before hanging it back up. It’s also recommended people keep the ground below the feeder clean of bird droppings.

“It is possible, although uncommon, for salmonella bacteria to transfer from birds to humans through direct contact with infected birds, droppings, or through domestic cats that catch sick birds,” the WFDW stated in a press release. “When handling birds, bird feeders or bird baths, it is best to wear gloves and wash hands thoroughly afterward.”

If you’ve seen a dead bird near your feeder, the WDFW is asking you to report the death online at https://survey123.arcgis.com/share/a384e90f69744f2e846135a9ce80027f and avoid handling it.