Pine Siskin (Carduelis pinus), an irruptive visitor

Pine Siskins at a thistle feeder. March, 2012.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

Living in the northeast United States and having thistle feeders out during the winter months, I expect to see large numbers of American goldfinches, which I do, and I also expect to see pine siskins on occasion. Until this year, however, I had not seen a single pine siskin on our property, despite living here during the 2008-2009 pine siskin irruption documented by the Cornell lab of Ornithology's Project Feeder Watch. This year, beginning in early March, we finally have pine siskins at the thistle feeder on our back deck.

Irruptive Migrants

Pine siskins fall into the group of birds known as irruptive migrants. That means that they may or may not migrate for the winter depending upon local conditions. These types of birds often form small flocks during the winter and move from food source to food source. When there is plenty of food in their usual summer territories during the winter, they may not move far at all. When this happens relatively few pine siskins will be seen in the southern reaches of their winter range although there are usually still some that make the trip. In other years, if food is scarce in their summer range during the winter months, pine siskins or other irruptive migrants may come south in great numbers and be widely seen over a much broader range.

While I haven't seen great numbers of reports that would suggest that this winter (2011-2012) has seen a large irruptive influx of pine siskins, there is an ordinary number of reports of pine siskin sightings throughout New Hampshire and we are lucky enough to have spotted them for the first time in our yard.

Similar to American Goldfinch

Pine Siskin (Carduelis pinus) in profile.
Photo by Brad Sylvester. Copyright 2012.

Pine siskins enjoy thistle seed as do American goldfinches. They are often seen together, with one or more pine siskins mixed in with a larger group of goldfinches. When this happens, they can be easy to miss unless one looks closely. Pine siskins look a bit like goldfinches when the latter is in its winter drab colors. Indeed, they are from the same taxonomic genus as the goldfinch: Carduelis. They are a similar size and shape, behave similarly at the feeder, may show a bit of yellow coloring when the wings are folded, and even have wing bars that can resemble those of goldfinches when they are mixed together and swarming a bird feeder.

Upon closer examination though, they are easy to differentiate. Most notably, the pine siskin has prominent streaking on its underside. The American goldfinch's underside is a nearly uniform pale olive-yellow during the winter months. Likewise, the pine siskin's head shows streaking as opposed to the solid yellow-drab of the winter goldfinch (although males may also show the beginnings of the black forehead and crown they'll wear in the summer). The pine siskin will have a relatively bright yellow patch visible on the lower part of its folded wing.

When the wings are extended, the yellow patch of the wings and another on each side of the base of the tail become more visible. The pine siskin is also decidedly more brown in color than the American goldfinch and can sometimes be mistaken for  female house finches or female purple finches until the yellow markings on the tail and wings are spotted.

Attracting Pine Siskins to your Yard

Pine siskin (Carduelis pinus) looking at the camera.
Photo by Brad Sylvester. Copyright 2012. Do not copy.

Your best bet for attracting pine siskins in the winter in the United States is to put up thistle feeders like one of these. If you are getting American Goldfinches in the winter, then you've done all you can to also attract irruptive pine siskins. To encourage them to breed, well, either you've got an established coniferous forest, or you don't.

Quick facts about the Pine Siskin (Carduelis pinus):

What do Pine Siskins Eat? Pine siskins eat small seeds such as thistle seeds,dandelion, and pine seeds, and many others. They also eat small insects and the small buds of trees such as birch and maple.The Cornell Lab of Ornithology says they also may be attracted to mineral deposits like road salt, ashes, or fresh cement.

Range: In the summer, the pine siskin lives mainly in Canada and the extreme northern United States, but can also be found throughout the Rocky Mountains and in parts of California. Sometimes, after a particularly irruptive winter, a few pine siskins will stay in the southern winter range to nest. I'm hopeful that some of those visiting us this month will remain to breed here as we have many large, established evergreen trees in our backyard forest.

Where does it go in winter? As irruptive migrants, pine siskins generally do move south for the winter, but the distance and degree to which they migrate depends upon local food conditions. Movement is generally done is short flights over a period of time. In some winters, they may be found all over the continental United States in good numbers, in others, they may be much more sparse throughout the United States and absent in many regions.

Lifespan: Unavailable

Nesting: According to the Cornell Lab of Ornithology's All About Birds site, nests are built toward the end of the branch of an evergreen tree, well-hidden by the needles. 3-5 greenish-blue eggs with brown or reddish-brown spots are laid in a shallow nest made of twigs, grasses and other fibrous plant material, lined with feathers, thistle-down or other softer material to cushion and insulate the eggs against cold temperatures in the northern nesting range. The eggs take 13 days to hatch.

IUCN Red List Status: Species of least concern. Large population over a wide range.

Pine Siskin Taxonomy:

Kingdom: Animalia

Phylum: Chordata

Class: Aves

Order: Passeriformes

Family: Fringillidae

Genus: Carduelis

Species: Carduelis pinus