Pine Siskin, Spinus pinus

Pine Siskin, Spinus pinus pinus. Photograph taken within a residential community in Hereford, Arizona, January 2008. Photograph and identification courtesy of Bob Behrstock, Sierra Vista, Arizona (naturewideimages.com).

The Pine Siskin, Spinus pinus pinus, is one of three subspecies of Pine Siskin, all three of which are found in Mexico. They are a member of the Fringillidae Family of Finches, Euphonias and Allies, which has two hundred forty-nine members placed in forty-nine genera, and one of twenty global species of the Spinus Genus. They are known in Mexico as dominico pinero.

The Pine Siskin are very small in stature. The sexes are similar in appearance. They have heavily streaked contoured feathers with dusky brown to blackish on drab to brown background upperparts and on pale neutral gray to white underparts. Their wings are dusky brown or black with two buff wing-bars and the tail is dusky brown or blackish. The basal portions of the remiges are yellow. There is a small percentage of male Pine Siskins that are darker and more greenish upperparts and are known as a “green morph.” Their bill is slender with a dusky upper mandible, and dusky to black lower mandible with a whitish or bluish base with a dark brown tip, their iris is brown, and their legs and feet vary from dark brown to reddish to dusky and their tail is notched and tinged in yellow.

The Pine Siskin is typically found within coniferous or mixed coniferous-deciduous forests. They are an irruptive species that follow food sources and are abundant in a given location one year and absent the next. Northern birds are known to make southern migrations during the coldest months. They are considered to be partial migrators with some birds breeding and summering in southern Canada from British Columbia to Labrador and Newfoundland and Alaska that make annual southerly migrations for wintering. Others are year-round residents of Mexico. Their abundance at particular localities varies widely from year to year. They are a gregarious species that forage in open flocks in deciduous trees and thickets, meadows, grasslands, weedy fields, roadsides, and chaparral. They often associate with American Goldfinches, Crossbills and Redpolls during the winter. They primarily consume the seeds of a variety of annual plants including grasses and small trees and the buds of deciduous trees. The supplement their diets with smaller quantities of insects and spiders. They are known to frequent bird feeders where they become aggressive. They form monogamous pairs for breeding and have an elaborate courtship with females building the nests with the males providing mate guarding services. Their nests are built in loose colonies and defended by both parents. Their nests are prone to predation by domestic cats, red squirrels and a wide variety of raptors, jays, and crows. To help avoid predation that that participate in communal roosting. They have life spans of ten years.

The Pine Siskin breeds as far north as Alaska and northern Canada but also ranges south into northern Baja California, eastern Sonora and western Chihuahua through the Mexican highlands south to Michoacán and east through the central volcanic belt to Hidalgo and west-central Veracruz where breeding populations exist. They are a cold-hardy species that can breed at low temperatures. They winter at lower elevations. The pinus subspecies found from Baja California to Nuevo León.

The Pine Siskin differ from goldfinches by their steaked appearance. They differ from the Common Redpoll, Acanthis flammea (red spot on the crown and black area on the throat).

From a conservation perspective the Pine Siskin is currently considered to be of Least Concern, however their populations are currently in decline. They are prone to habit loss due to the removal of coniferous and mixed coniferous-deciduous forests via human development. They date to the late Pleistocene Period, 25,000 years ago.