Blue Streak
Listen for the sound of the blue grosbeak’s loud “chip” call this time of year
By Susan Campbell
‘Tis the season for the annual appearance of blue grosbeaks! Begin spotting this handsome, medium-sized songbird any day now along fencerows and on electric wires in rural areas throughout the Piedmont. Returning to the United States in April after long winter stays in Central America and the Caribbean, blue grosbeaks breed across much of America, from central California throughout the Plains states and up into Virginia. And now, ahead of migration southward to tropical wintering grounds, these chunky songbirds seek out easy seed sources in order to bulk up before the long journey south.
Although this bird is common throughout the Piedmont during the breeding season, it is often missed by casual observers. It is a bird of both pine and mixed forest, often encountered along edges associated with farming. Blue grosbeaks’ large silvery bill is what really makes this bird distinctive. The sexes are quite different, with males a dark blue. Also look for a small black mask around the bill and eyes, as well as chestnut wing bars. Females are more of a cinnamon hue than blue, with rusty wing bars and a bit of blue on the rump extending into the tail. Immature females have plumage very much like their mothers’.
Plumage counts. Some males in their first spring will not breed successfully because they do not have the extensive blue of fully mature males and are not able to attract mates in order to start a family. However, after a full year of singing, fighting and extensive experience foraging, they will become excellent prospects come their second spring as long as they survive the winter.
The blue grosbeak’s song is a rich warble, and their call a loud, metallic “chip.” Hearing these vocalizations is the best way to find them, given their propensity for spending a lot of time in thick vegetation. They prefer shrubbery for breeding, look for nests low in thick vegetation and viny tangles. The nest is a compact cup-shaped affair comprised of twigs, grasses, leaves and rootlets, often studded with paper, string or other litter. Blue grosbeaks are one of only a few migrant species that raise not just one, but two broods of between three and five young in a season.
Unfortunately blue grosbeaks all too often end up unwittingly raising the young of parasitic brown-headed cowbirds. Cowbird females are experts at laying eggs in the nests of other species found in open or semi-open habitat. The eggs, which are larger, generally hatch ahead of the hosts’ brood. They produce young that then grow larger and faster, oftentimes outcompeting the nestling grosbeaks.
Like most of our songbirds, this species feeds heavily on insects in the summer months. Caterpillars make up a significant portion of the diet. But blue grosbeaks also will hunt for food at or near ground level, collecting adult grasshoppers and crickets as well as other large insects. Their outsized bills are effective at breaking up prey items as well as large seed, such as sunflower kernels. Expect individual blue grosbeaks to show up at feeding stations soon — but they do not congregate the way other finches do. So keep an eye out if you live on the edge of town or in a more rural location. Spotting one of these distinctive birds is quite a treat! OH
Susan would love to receive your wildlife sightings and photos. She can be contacted by email at susan@ncaves.com or by phone at (910-695-0651).
