This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the blue grosbeak.
The male blue grosbeak (passerina caerulea) is a large, vibrantly blue bunting with an enormous silver-colored thick bill and chestnut wing bars. Similar to, but larger than, an indigo bunting, the blue grosbeak measures 5.5 to 7.5 inches in length with a wingspan ranging from 10 to 11 inches.
They are uncommon, but widespread, across most of the southern United States and northern Mexico, where they nest after migrating, primarily from Central America. The blue grosbeak may arrive to nest as late as July. The male mates with the cinnamon-colored female to often raise two broods in a season.
They build nests low in small trees, shrubs, and tangles of vines and briars, but like to be close to open areas or roads. Their compact nest is cup-shaped, woven with whatever is available: twigs, bark, rootlets, cotton rags, newspaper, string, snakeskin, leaves and grass. Their nests are heavily parasitized by cowbirds, who lay eggs in their nests.
The male sings a rich, warbling song which often alerts you to his presence before he is seen. These birds forage on the ground, in shrubs and in trees for seeds, insects, snails, spiders, grains and wild fruits.
Blue grosbeaks thrive in abandoned agricultural land and avoid suburban habitat. Here, they are most commonly seen in June and July in the Navajo Lake area. Their overall population is stable.
For information on future events, visit www.weminucheaudubon.org and www.facebook.com/weminucheaudubon/.