The Dark Side of Bird Feeders

Story by Emma Bjornsrud

April 13, 2021

Streaks of dull brown and flashes of yellow whirled around the sky, flitting to trees and taking shape with folding wings and ruffling feathers. Last December in a long, narrow Puyallup backyard, dozens of small pine siskins hopped around, pecking at birdseed in a hanging feeder and on the ground below.

Nearby in a large lilac bush, one small siskin sat still, in glaring contrast of the hyper birds foraging for food. Its feathers were fluffed out, making the bird appear round and plushy.

Close enough to touch it, backyard birder Liz Steenbeeke watched this solitary siskin. From its behavior and appearance, she guessed it would die.

“I got really close to it and that’s not normal,” Steenbeeke said. “It just looked bleak and miserable.”

In conifer forests, pine siskins forage for seeds. In urban areas though, pine siskins frequently clump together at bird feeders, clinging to each available post, almost cartoonishly at max capacity.

It’s the dense gathering of siskins at feeders that threatens their health.

A salmonella outbreak in northern pine siskins is raging across the Northwest, spreading with ease because it is transmitted from fecal material at bird feeders. Especially if feeders go uncleaned, pecking for food means birds are also pecking at poo.

The Washington Department of Fish and Wildlife (WDFW) has asked everyone to take down their bird feeders through April to stop the spread of salmonella.

“Initially we thought it was in a limited number of counties,” said Staci Lehman, the WDFW communications manager for eastern Washington. Then reports of outbreaks started coming from all around the state, as well as from groups in British Columbia, Montana and Idaho.

The pine siskin is a type of finch, a songbird that’s often found across North America. Small and marbled brown, it resembles a sparrow, except for its forked tail and yellow-lined wings.

Siskins breed in the summer in northern Canada and Alaska. They fly between food sources in large groups and thousands of them can flock together. The migration patterns can lead to a huge winter-time population across the United States and further south into parts of Mexico.

Such is the case this season. In October 2020, an irruption, or mass migration, of pine siskins was big news in the bird community. It is common for a large migration to occur every few years when food runs short in their northern habitat.

“One of the reasons for this irruption is because there’s so many pine siskins up in the northern boreal forest, but the cone crop was really poor,” said Steven Harper, president of the North Cascades Audubon Society. “So, they had to come south.”

The siskin population is about 100 times bigger this year than in a normal year, Harper said.

This influx of birds to the United States has resulted in an unusually high number of cases of salmonella in siskins. The PAWS Wildlife Center based in Lynwood, Washington, took in 135 sick siskins in January and February, almost triple the previous record of 46 siskins in the winter of 2011–2012.

The Whatcom County Humane Society took in over 100 birds from January to the beginning of March, compared to just 10 or 20 cases a year in past years, said Alysha Evans, manager of the Whatcom Humane Society’s wildlife rehabilitation services.

“It’s a very fatal disease and has a very high mortality rate,” she said. “Unfortunately, by the time that people are actually able to catch [sick birds] and bring them to us, they’re quite often emaciated and severely dehydrated, and sometimes treatments will work but sometimes they do not.”

Although salmonella bacteria are naturally present in birds, pine siskins are more likely to get sick because of it, according to Kim Thorburn, a member of the Washington Ornithological Society.

“The reason we feed birds is to attract birds to our yard so we can enjoy them,” Thorburn said. “And, you know, why not make a little sacrifice, like wearing a mask or taking your feeders down, to try to prevent the spread of the disease?”

The salmonella outbreak is just one of the dark sides of bird feeders.

Bird feeding increased the number of birds in urban areas, especially non-native species, a 2015 study found. As a result, native species must compete for available food and habitat.

Since feeders provide an easy and reliable source of food, native and non-native birds can become dependent upon them. Birds may be put in danger by close proximity to cars or house cats when they begin to trust humans, or they might even become aggressive when they expect birdseed.

Wrong placement of feeders can even be dangerous — birds can slam into windows when feeders are placed too near houses because they cannot see the glass. The Cornell Lab recommends hanging feeders either within one meter of windows and houses or more than nine meters away.

Bird seed mixes can also include foods that birds don’t normally eat, such as peanuts, which can cause digestion problems and illnesses, according to Evans.

With the exception of hummingbirds, who rely on additional food sources in the winter, Evans said there is no reason for humans to feed birds.

However, bird feeding is unlikely to stop, even in the case of a salmonella outbreak. A centuries-old tradition, feeding birds can even have emotional and behavioral benefits for humans, according to a 2019 research article.

WDFW tries to discourage the feeding of wildlife in general, Lehman said.

“We understand that people really, really enjoy watching their birds, ” she said.

Steenbeeke will replace the feeders in her maple tree in April when the WDFW says it is safe to do so. In the meantime, for her juncos, sparrows and chickadees, she is spreading seeds on the ground to prevent birds from congregating.

“It’s an epidemic, it’s like what we’re going through personally with COVID,” she said. “You have to stop doing the things that are going to spread it and you just have to do what you have to do. But I miss them all!”

Emma Bjornsrud is an environmental journalism major at Western Washington University and is currently a story editor for The Planet Magazine. She is pursuing journalism to communicate with the public the importance of environmental and social justice.