Even though there are lots of advantages to feeding birds, your feeders could possibly be to blame for a vast die-off of birds. Wildlife rehabilitation centers throughout the area have been reporting huge increases in Pine Siskins suffering from salmonellosis, an often-fatal bacterial disease. This disease is easily transmitted through the saliva and feces of sick birds, and because Pine Siskins flock together in large numbers at feeders, this makes them especially susceptible to infection. Adding to this issue, is that this winter marks an irruption year for boreal finches in which large populations migrate south due to a poor food crop in their usual wintering grounds in Canada.

Sick Pine Siskins are typically easy to spot: they are often isolated and look lethargic and fluffed. While some wildlife veterinarians recommend taking sick Pine Siskins to wildlife rehabilitation centers, Washington Department of Fish and Wildlife (WDFW) veterinarian, Kristin Mansfield, believes that the best course of action is to leave these birds alone and report your sightings, including dead birds, using their online form: https://survey123.arcgis.com/share/a384e90f69744f2e846135a9ce80027f.

WDFW also recommends temporarily discontinuing to feed birds for at least two weeks to hopefully encourage birds to feed on natural food sources elsewhere. Some wildlife rehabilitators have suggested feeding more intermittently, such as every other day, in order to stop spreading the disease. Either way, if you are going to continue to feed birds, it is strongly recommended that you clean your feeders on a regular basis (ideally daily) by washing them with warm soapy water and disinfecting them with a 9 parts water to 1 parts bleach solution before rinsing and drying them thoroughly. You will also want to rake up any feces and seed casings found below your feeders as well as clean your bird baths on a regular basis.

~Kim Nelson, Skagit Audubon Society

For more information, see this WDFW FAQ on Salmonellosis in Wild Birds