Pine Siskin

Spinus pinus

Compiled by Lisa S. Graham. 

The Pine Siskin is a small, lively finch with a streaky appearance and restless nature. Often more heard than seen, this thin-billed bird is a common visitor to backyard feeders in some years and a near-ghost in others – all dependent on the seed crop in their home forest. When present, their energetic behavior, distinctive flight call, and tendency to move in flocks make it a fun species to observe.

Pine Siskins are small—about 4.5 to 5.5 inches long—with thin, pointed bills adapted to extracting seeds. Their plumage is a pattern of brown and buff streaks across the body, with subtle yellow edging on the wings and tail that flashes in flight. Males and females are similar; the yellow highlights and wing pattern are helpful ID marks – they are more vivid on males. In flight their quick, undulating wingbeats and a sharp, buzzing flight call often reveal them before they appear.

True to their name, Pine Siskins favor coniferous forests and edge habitats where seeds are plentiful, but they are flexible and will use mixed woodlands, backyards, and parks—especially in winter. They are highly social birds that travel in flocks, sometimes mixed with other finches and chickadees. Expect rapid movements, acrobatic clinging to twigs and cones, and frequent visits to feeders, where they favor tube and nyjer feeders.

Seeds dominate the Pine Siskin’s diet—conifer seeds, weed seeds, and seeds from plants like alder and birch. Their thin bills and agile feet let them extract seeds from cones and tease seeds out of small flower heads. In winter, they readily turn to backyard feeders, sunflower seed, and nyjer. They may also consume some buds and small insects during the breeding season to supply extra protein.

Breeding typically takes place in coniferous or mixed forests. Pine Siskins build compact cup nests of twigs, grasses, and plant down, usually tucked in the fork of a conifer branch. Clutches usually contain 3 to 6 eggs, incubated by the female. Both parents feed the young, and broods can be variable depending on food abundance. Because they are so responsive to seed crops, some years see greater local breeding success than others.

Some fun facts about the Pine Siskin:

• Their migrations are “irruptive,” meaning they move south in large numbers only during certain years when the seed crops in their usual boreal forest homes have failed.
• They can store up to 10% of their body mass in seeds in their crop for energy.
• They have a fondness for salt, which they may lick from roadsides in winter.

Sources include All About Birds (Cornell) and Audubon Field Guide.   Photo credit:  Jonathan Irons, Macaulay Library.