A small (4 ½ -5 inches) finch, the male Pine Siskin is most easily identified by its streaked brown body, dark wings, and conspicuous yellow wing bar. Female Pine Siskins are similar to males, but are somewhat duller and lack the yellow on the wing. This species may be separated from dull winter American Goldfinches (Spinus tristis) by that species’ plain, not streaked, body. The Pine Siskin breeds across southern Alaska, southern Canada, and the northern United States. This species’ range extends southward at higher elevations through the western U.S., continuing as far south as Mexico and Guatemala. Northerly-breeding populations may withdraw from their breeding range during the winter, and small numbers may move far south of this species’ main range during winters when food is scarce, but much of the time this species within its breeding range. Pine Siskins inhabit northern and high-mountain evergreen forests. Likewise, individuals wandering further south in winter typically associate themselves with evergreen habitats, although they also visit bird feeders as well. Pine Siskins eat seeds, particularly those of cone-bearing evergreen trees, a fact which explains this species’ habitat preferences as well as its name. In appropriate habitat, Pine Siskins may be observed perching on or hanging from seed cones while plucking out the seeds contained within. Birdwatchers may also listen for this species’ song, a series of squeaky “clee-ip” notes. Pine Siskins are primarily active during the day, although individuals may forage for food by moonlight when food is scarce.
occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Nesting range extends from central and south-coastal Alaska east across Canada to Labrador, and south to northern Baja California, southern Mexico and Guatemala, western Texas, Great Lakes region, and northern New England, and sporatically southward to the central Great Plains region and southern Appalachian Mountains region (Dawson 1997, AOU 1998).
Winter range extends from the breeding range (except far northern noncoastal part) south to southern Mexico and Guatemala, Gulf coast of the United States, and northern Florida (Dawson 1997, AOU 1998).
Length: 13 cm
Weight: 15 grams
See McLaren et al. (1989, Am. Birds 43:1268-1274) for detailed information on distinguishing between pine and Eurasian siskins.
Habitat and Ecology
Comments: Habitats include various forests and woodlands, parks, and gardens and yards in suburban areas. In migration and winter, this species occurs in a variety of woodland and forest habitats, partly open situations with scattered trees, open fields, pastures, and savanna (AOU 1983). It has been positively affected by forest fragmentation in southern Wyoming (Keller and Anderson 1992). Nests often are placed about half way up a conifer or deciduous tree and are hidden among outer branches.
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Pine siskins may wander irregularly during winter.
Comments: This species forages in trees and on the ground for seeds (e.g., of alder, birches, pines, maples, thistles) and insects. It also eats flower buds of elms, and drinks nectar from eucalyptus blossoms and sap from sapsucker holes (Terres 1980).
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: > 300
Comments: This species is represented by a very large number of occurrenes (subpopulations).
Comments: Total adult population size is unknown but certainly exceeds 1,000,000. Despite apparent declines, this species remains common in many areas. Rich et al. (2004) estimated population size at 22,000,000.
Pine siskins are gregarious in fall and winter and often travel in flocks of typically 50-200. Occasionally a few siskins travel in flocks with goldfinches and redpolls during winter (Terres 1980).
Life History and Behavior
Lifespan, longevity, and ageing
Clutch size is 3-4, sometimes 5. Incubation, by female, lasts 13 days (Terres 1980). Both parents tend young, which leave nest 15 days after hatching. Sometimes individual females produce 2 broods/year. Pine siskins frequently nest in loose colonies.
Molecular Biology and Genetics
Barcode data: Carduelis pinus
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Carduelis pinus
Public Records: 9
Specimens with Barcodes: 9
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Large range almost confined to North America; large number of subpopulations; large population size; BBS data indicate substantial population declines since the 1960s; causes of the apparent decline are uncertain. Further review of global rank is needed; NatureServe rank calculator version 6.2 yielded a rank of G4.
Global Short Term Trend: Decline of 30-50%
Comments: Breeding Bird Survey (BBS) data indicate a statistically significant range-wide decline of 5% per year for 1980-2007 (5% annual decline equals a 40% decline over 10 years).
Global Long Term Trend: Decline of 50-70%
Comments: Long-term trend (last 200 years is unknown). Breeding Bird Survey (BBS) data for 1966-2003 indicate substantial declines in most of western North America and parts of eastern North America. A smaller area, mostly in eastern North America, exhibited substantial increases in abundance. BBS data indicate a statistically significant range-wide decline of 3% per year for 1966-2007 (= 71% over this period).
Degree of Threat: Very high - high
Comments: Cause(s) of the range-wide population decline indicated by Breeding Bird Survey (BBS) data are uncertain. Deforestation has eliminated or reduced habitat in some areas, but this species is adaptable and frequently uses and nests in altered and anthropogenic habitats (Dawson 1997), so it seems unlikely that this is responsible for the decline. Salmonellosis, apparently associated with siskin use of bird feeders, has caused die-offs in some areas in some years (Dawson 1997); further study is needed on the effects of this disease on siskin populations.
Biological Research Needs: Beter information is needed on demographics and causes of population trends and movements (Dawson 1997).
Global Protection: Very many (>40) occurrences appropriately protected and managed
Comments: Many occurrences are in protected areas.
These birds are fairly small, being around the same size as the widespread American goldfinch. In both sexes, total length can range from 11–14 cm (4.3–5.5 in), with a wingspan of 18–22 cm (7.1–8.7 in) and weight of 12–18 g (0.42–0.63 oz).
Adults are brown on the upperparts and pale on the underparts, with heavy streaking throughout. They have short forked tails. Their bills are conical like most finches but are more elongated and slender than those of other co-occurring finches. Variably, pine siskins have yellow patches on their wings and tails, which may also consist of white streaks on the wings. Although they can be confused by the more inexperienced for other finches or even American sparrows, pine siskins are distinguished by their heavy streaking, relatively slender bills, notched tail, yellow or whitish patches on the wings and smallish size.
Separation from European siskin
Pine siskin in its typical morph is a drab bird, whereas European siskin (a bird the species does not naturally co-exist with), in many plumages, is much brighter. Adult male European siskins are bright green and yellow with a black cap, and an unstreaked throat and breast; pine siskin does not have a corresponding bright plumage. Adult female European siskins also usually have green and yellow plumage tones: for example, yellow in the supercilium and on the sides of the breast, green tones in the mantle and yellow in the rump. Adult pine siskins of the typical morph do not have green and yellow tones, although juveniles can have a yellowish-buff wash on their underparts and buff-toned wingbars, for a short period prior to their autumn migration. The ground colour of the underparts of European siskin is normally pure white, whereas on pine siskin it is usually a dirtier colour. In female and juvenile European siskin, the centre of the belly and lower breast are often largely or entirely unstreaked, whereas in most pine siskins the streaking extends across the whole of the underparts. The wingbars of European siskin are broad and yellow (with the tips white) whereas they are normally narrower and buffish-white in pine siskin, contrasting with the bright yellow flash at the base of the primaries. Pine siskins have a longer bill, usually with a straight culmen, compare with a short bill in European siskin, with a decurved culmen. There is a green morph of pine siskin, closer in appearance to European siskin; these birds make up only 1% of the population. These are closer in appearance to female European siskin, but differ in that they have a yellow-wash on the undertail-coverts (white on European siskin), no yellow in the supercilium, reduced underparts streaking, and much yellow at the base of the tail and remiges; there may also be a difference in the extent of yellow in the underparts but this needs further study.
Distribution and habitat
Their breeding range spreads across almost the entirety of Canada, Alaska and, to a more variable degree, across the western mountains and northern parts of the United States. As their name indicates, the species occurs mostly as a breeder in open conifer forests. Northern pine forests supports the majority of the species breeding population. However, stands of ornamental conifers or deciduous trees may support nesting birds in partially developed parks, cemeteries, and suburban woodlands. While they favor feeding in open forest canopies where cone seeds are abundant, they'll forage in habitats as diverse as deciduous forests and thickets, meadows, grasslands, weedy fields, roadsides, chaparral, and backyard gardens and lawns. They flock to backyard feeders offering small seeds. Mineral deposits can lure them to otherwise unattractive habitats like winter road beds that are salted to melt snow and ice. The nest is well-hidden on a horizontal branch of a tree, often a conifer.
Migration by this bird is highly variable, probably related to food supply. Large numbers may move south in some years; hardly any in others. This species is one of a few species that are considered "irruptive winter finches" because of the high variability of their movements based on the success of crops from year to year.
These birds forage in trees, shrubs and weeds. They mainly eat seeds, plant parts and some insects. In winter, they often feed in mixed flocks including American goldfinches and redpolls. Small seeds, especially thistle, red alder, birch, and spruce seeds, make up the majority of the pine siskin's diet. In a part of their esophagus called the crop, the species can store up to 10% of their body weight in seeds overnight, providing extra food on cold days. They will alternately eat the young buds of willows, elms and maples, and the soft stems and leaves of weeds and even young garden vegetables. They'll glean the seeds of grass, dandelions, chickweed, sunflowers and ragweed. Bird feeders often attract pine siskins, where they may eat fragments of heavy-shelled seeds, such as black oil sunflowers, left behind by heavier-billed bird species. In summer, they will eat many insects, especially aphids, as well as a few spiders and grubs, which they then feed to the young as a protein-rich food that contributes to their growth. By the time of winter, even first year siskins predominately eat seeds.
Pine siskins can survive in very cold temperatures. The metabolic rates of this species are 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. They also can protect their young from cold as well. Nests are often heavily insulated with thick plant materials and females may literally never cease incubating their eggs and hatchlings, while being fed by their male mate.
Although considered Washington's most common finch, the pine siskin has suffered a significant annual decline in population since 1966, according to the Breeding Bird Survey. Due to the irruptive nature of this species, populations vary widely from year to year, and trends can be difficult to interpret. 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 will help keep this bird common.
Taxonomy and evolution
• The Eurasian siskin, S. spinus is the ancestor of pine siskin, Antillean siskin, S. dominicensis, and black-capped siskin, S. atriceps. The sub-species S. pinus perplexus may be closer to S. atriceps; they both thrive in the Guatemalan-Mexican altiplano.
• This siskin seems to belong to the North American Spinus/Carduelis evolutive radiation, whose parental species is the Eurasian siskin. This finch may have displaced from America to the parental species Eurasian siskin.
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Names and Taxonomy
Comments: Formerly (AOU 1983, 1998) listed in Carduelis. Acanthis and Spinus were considered separate genera prior to their merger into Carduelis (AOU 1983), in part following Mayr and Short (1970), although they continued to be listed as subgenera. Recent mitochondrial genetic data (Arnaiz-Villena et al. 2008) indicate that Carduelis is polyphyletic and that Acanthis spp., Spinus spp., Carduelis carduelis, and Chloris sinica belong to different clades.