We were glad to have a small flock of pine siskins feeding at Goose Pond feeders this winter.
Pine siskins are brown and very streaky birds with subtle yellow edgings on wings and tails. They are about the same size as American goldfinches, and frequently feed with them. Sometimes you hear them before you see them since they are gregarious, foraging in tight flocks and twittering incessantly to each other, even during their undulating flight!
Pine Siskins have a fondness for the seeds of pines and other conifers like cedars, larch, hemlock, and spruce. At our bird feeders, they prefer sunflower fines or hulled sunflowers. Pine Siskins get through cold nights by ramping up their metabolic rates—typically 40% higher than a “normal” songbird of their size. When temperatures plunge as low as –70°C (–94°F), they can accelerate that rate up to five times normal for several hours. They also put on half again as much winter fat as their Common Redpoll and American Goldfinch relatives.
Pine Siskins can also temporarily store seeds totaling as much as 10% of their body mass in a part of their esophagus called the crop. The energy in that amount of food could get them through 5–6 nighttime hours of sub-zero temperatures.
Sam Robbins wrote in Wisconsin Birdlife that pine siskins in southern Wisconsin are uncommon to fairly common winter residents, and rare in summer. Every couple of years, pine siskins make unpredictable movements called irruptions into southern and eastern North America. Though they’re erratic, these movements may not be entirely random. Banding data suggest that some birds may fly west-east across the continent while others move north-south. One of the largest pine siskin observations was on October 21, 1969 at Cedar Grove Hawk Research Station (Sheboygan County) when Dan Berger reported 50,000 pine siskins moving south!
Following a large irruptive winter flight, some individuals may stay near a dependable food source and breed far south of the normal breeding range. In the first Breeding Bird Atlas of Wisconsin there was a record of a nesting in Dane and Columbia County. In the first year of the Atlas II project Charles Henrikson photographed a nest being built at the UW Arboretum in a red pine, and Andrea Szymczak located a nest, also in a red pine, in southeast Jefferson County. The only other confirmation in south central Wisconsin was a siskin family feeding at a feeder in Montello. Siskins can begin nesting in April and they protect their eggs from cold by building a highly insulated nest. The female remains on the nest continuously, fed by the male throughout brooding.
At our cabin near Rio we are feeding a flock about 50 pine siskins. We are looking forward to counting birds including pine siskins on the Great Backyard Bird Countbeing held on February 12-15th. Check out the bird count link and see how you can help on this citizen science project!
If you find a siskin nest or family this spring please contact the atlas coordinator for your county! http://wsobirds.org/atlas-county-coordinators
By Mark and Sue Foote-Martin, Resident Managers, Goose Pond Sanctuary - email Mark and Sue at firstname.lastname@example.org