For the Birds: Pine Siskin—the irruptive songbird

Male Pine Siskin
Photo by Christine Southwick

By Christine Southwick

In the trees you hear a rising zhreeeee voiced by a number of birds. Your feeder has several smallish heavily-striped brownish birds with varying amounts of yellow on their wings and a needle-like bill. What are they? If you said Pine Siskins, give yourself a pat on the back. These small songbirds stump lots of people

Their gregarious flocks are highly nomadic as they follow the cone seed crop. One year you may see them much of the time, other years you may not see them at all. They are often seen clinging upside to branches of conifers, but they will also eat the seeds of garden flowers not dead-headed until spring, and they think dandelion seeds are a treat.

Because of their small bills, they won’t eat large unshelled sunflower seeds. They will eat black-oiled sunflowers, and shelled seeds, as will American Goldfinches.

Photo by Christine Southwick

Pine Siskins are susceptible to salmonella, so keep your seed feeders clean. I have stopped using Niger seed because it molds quickly, and it is expensive. During winter I buy inexpensive feeders, and replace, rather than wash, a feeder when it gets dirty.

Pine Siskins are serially monogamous and pick their mates during winter flocks. That’s why you will often see dominance fighting that isn’t seen in other species until spring. Nests are placed far out on a horizontal conifer branch, and hold three to four eggs. Well hidden, the nest may be part of a loose colony, or by itself.

Since the majority of the Pine Siskins breed in colder northern Canada, they have evolved to the female not leaving the insulated nest once the eggs are laid—the male feeds her until the babies are several days old, then both parents feed the nestlings for about twelve days after they have fledged. Pine Siskins can also increase their metabolic rate during sub-zero temperatures.

Pine Siskin on backyard bird bath
Photo by Christine Southwick

Once considered the most common finch in Washington, their numbers have gone down since 1966. Their nests are easily parasitized by Brown-headed Cowbirds which inhabit forest edges. Shrinking forest lands create more forest edges and more cowbirds are around looking for nests like Pine Siskins’.

Pine Siskins constantly chatter to each other, and even twitter while in flight. Their loud upward Zhreeee is an easy identifier. Once you hear that, look for heavily-striped birds at your feeders and watch for those flashes of yellow as they take wing.

Christine Southwick is on the Board of the Puget Sound Bird Observatory and is their Winter Urban Color-banding Project Manager. She is a National Wildlife Federation Certified Wildlife Habitat Steward, having completed their forty hour class. We're happy that she is sharing her expertise with us about the birds in our backyards.