While watching a flock of goldfinches feed I noticed several pine siskins (Spinus pinus). A member of the same family as the lesser and American goldfinches, pine siskins often associate with their “cousins”.
A very small bird, the pine siskin is entirely brown and heavily streaked. The yellow edge on the flight feathers and tail are visible when the wings are folded. The long, sharp, pointed bill is dark and more slender than the bills of other finches.
Pine siskins are gregarious birds and forage in flocks, constantly twittering. They prefer conifer or mixed forests but are most adaptable and can often be found in more urban settings, particularly near feeders.
Although pine siskins breed in the boreal area of Canada, northern United States and western mountains, in the winter pine siskins move and migrate in response to the availability of feed. Although extremely variable, in some years they can be found throughout most of the contiguous states during the winter.
The metabolic rate of a pine siskin is about 40% higher than most birds. During cold nights it can accelerate its metabolism to about five times normal. Pine siskins also put on more winter fat than their goldfinch relatives, which helps them survive cold nights. In addition, pine siskins can store seeds in their crop. That little extra bit of food can make a difference when nighttime temperatures plunge. The female never leaves the nest once the eggs are laid, depending on the male to bring all her food thus protecting the brood from the cold.
Pine siskins eat the seeds of pines and other conifers, deciduous seeds and young tree buds as well as grass and weed seeds. Insects, spiders and grubs picked from tree leaves and branches round out their diet. Pine siskins will also frequent mineral deposits and the edges of roads where they can eat the salt. I love to watch these little birds cling to dandelions, thistles and grasses to harvest the seeds. They are little acrobats.
This pine siskin was photographed amid a goldfinch flock near Cassel CA. The pine siskin is also often classified in the genus Carduelis.