This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the pine grosbeak.
Take a look at the range map for a pine grosbeak and one will quickly realize just how fortunate we are to find an occurrence in the San Juans of such a showy denizen of northern climes. This large member of the finch family typically resides in the boreal forests of Canada ranging from British Columbia to Newfoundland. Lucky for us, the spruce-fir forests of the high elevation Rocky Mountain spine provide adequate forage to coax this stunning avian species further south than it would otherwise be.
Despite a stubbier bill than their fellow conical beak-bearing grosbeaks, this stocky finch has a round head and long, notched tail. Males are a scarlet reddish-pink from the breast throughout the head and onto their mantle between the wings. Females and immature males are golden yellow-orange from breast to back. Both sexes have gray flanks and wings, donning two notable white wing bars.
Spring and summer breeding songs have the sing-song whistling quality and character one may hear from black-headed grosbeaks, only flutier. Flight calls (used to locate one another) are reported to vary from region to region and mate selection appears to correlate with vocal familiarity. Considering that this species occurs additionally throughout Eurasia, one can imagine that there is a lot of variation.
Pine grosbeaks are altitudinal migrants here. They spend three seasons of the year higher up in Englemann spruce and sub-alpine fir, foraging for new evergreen leaf and bud growth, insects, and berries. Only in winter do they drop down into lower elevation pine stands to seek out seed crops and visit feeders. On years of poor spruce-fir seed crops, irruptions (large forays outside of their typical range) occur, resulting in uncommon sightings.
They’ve received a Continental Concern Score of 10 out of 20, as their primary habitat (boreal forest) is indelibly threatened by climate change.
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