by Linda de Kort
One of the small birds we enjoy observing throughout the year has an unusually “cute” scientific name: Spinus pinus; its common name is Pine siskin. Pine siskins are especially interesting because their populations change so dramatically from winter to winter. Sometimes we see them, sometimes we don’t.
When the winter population count is unusually high, it is called an “irruption”. We are assuming that these birds are irrupting from their northern and higher elevation homes in search of more abundant food. We seldom regard our Flathead Valley as a banana belt but these little birds, like a few other bird species that breed in Canada, come here (sometimes) to spend the winter. The bitter cold of winter does not seem to bother them. They have some uncanny way of increasing their metabolism to withstand subzero temperatures all winter long. One study showed that Pine siskins could increase their metabolic rate up to 40 percent more than a typical songbird to survive temperatures as low as -94 degrees Fahrenheit.
Pine Siskins are not territorial and we usually see them in large flocks to feed and even nest. The flocks fill the air with their raspy chatter, which is punctuated with a loud ascending zipper like sound. They have delicate beaks well suited to “tweezering” out conifer seeds from pinecones (as their name implies) as well as small seeds from flower heads. Backyard feeders with thistle seed are one of their favorites. The delicate beak of the siskin distinguishes it from other brownish, streaked birds. It is also smaller than most finches and sparrows, only about 41/2 inches from tip of beak to tip of tail. Both male and female have bright yellow markings at the base of the tail and on the wings that are most conspicuous when they are in flight, flittering at the feeder or during courtship. The male and female have very similar markings so it is very difficult to distinguish them from each other.
Pine Siskins generally nest in open coniferous or mixed forests; their breeding range often changes. The exact time for courtship also seems erratic, based mostly on the availability of food. The male feeds the female during courtship, nest building and incubation. The nest is an open cup, well hidden on a horizontal branch of a conifer. There are up to 5 greenish-blue speckled eggs, which hatch in about 13 days. The young leave the nest when they are only about 15 days old.
Every December, on specific days, members of local Audubon Chapters gather in small groups to observe and record the numbers of birds seen and heard within a defined 15-mile radius circle. This information has been gathered and recorded for over a hundred years nationwide and gives us a good picture of changes that might not be obvious on a small scale but patterns can be observed over the decades. In December 2018, 742 Pine Siskins were counted on that one winter day; a year later we recorded only 15. Pine Siskins have been seen on the Kalispell Count for 20 of 21 years. The low count was 0. If you are interested in joining friends on a specific day in December to observe winter birds in our area, please contact firstname.lastname@example.org or email@example.com. You can also find out more about how to add to this valuable data base (Christmas Bird Count), by visiting the Flathead Audubon website https://www.flatheadaudubon.org/