Last week my friend Brian called. He had found a grounded bird outside and wasn’t sure if it was stunned or injured. He asked me what he should do—I always worry about grounded birds because of domestic or feral cats that can be lurking in the shadows. I told him to watch the bird for awhile and if it didn’t fly away, to put it in a small box or basket with a small perch and give it a few drops of water. I asked what kind of bird it was, but when he went back to check, the bird had left. I am guessing that the bird flew into something and was only stunned a bit. Brian looked the bird up in his bird book and said it was a Pine Siskin.
A delightful, sweet bird, the Pine Siskin (Spinus pinus) is a North American bird in the finch family. All of the Carpodacus finches are considerably larger with thicker bills and lack the yellow flash in the wing characteristic of siskins. Pine Siskins are tiny songbirds with sharp, pointed bills and short, notched tails. They are closely related to the Redpoll and the Goldfinches.
These little birds are opportunistic and adaptable, foraging in weedy fields, scrubby thickets, or backyards and gardens. They appear in flocks and have a distinctive call like a piece of paper slowly being teared into pieces; bird books described it as a buzzy, rising zreeeeee.
As their name suggests, Pine Siskins have an appetite for the seeds of pines, cedars, larch, hemlock, and spruce. They will eat the young buds of willows, elms, and maples. They’ll glean the seeds of grasses, dandelions, chickweed, sunflowers, and ragweed and forage for insects. They also like mineral deposits, including ashes, road salt, and fresh cement. Pine Siskins are a frequent visitor at my feeder in the winter here in the SF Bay area and I see them occasionally eat suet, too. They also have been seen drinking from sapwells drilled by sapsuckers, something I’d really like to see.
Males Pine Siskins sing from high perches and during circular courtship flights. The female begins building a nest in the shape of a shallow saucer with twigs, grasses, weed stems, rootlets, bark strips, and lichens, 2.5–6 inches across. She insulates the inner cup with fur, feathers, grass, moss, or thistle down, up to 2 inches deep. Sometimes the male may contribute nest material as well. Nests can be vulnerable to gusty winds because they are loosely attached to branches. The female remains on the nest continuously, fed by the male. They will have 1 to 2 broods a season laying 3 to 5 eggs that are pale greenish-blue with brown or reddish-brown spots. Incubation period is about 13 days.
Pine Siskins numbers can be difficult to estimate due to the large and hard-to-predict movements they make each year. The 2014 State of the Birds Report listed them as a Common Bird in Steep Decline, and they rate a 10 out of 20 on the Partners in Flight Continental Concern Score. Domestic cats, red squirrels, hawks, jays, and crows can prey on adult birds and on their eggs or young. They are particularly vulnerable to outbreaks of salmonella transmitted at feeders. Loss of habitat from forest-clearing may be balanced by new commercially planted coniferous forests, and by the Pine Siskin’s willingness to nest in shrubs and ornamental trees. Parasitism by brown-headed cowbirds can have a significant impact on Pine Siskin productivity, and forest fragmentation has increased their contact with cowbirds. Maintaining large tracts of coniferous forest is important to keep this bird a common visitor.