the blue grosbeak (passerina caerulea , formerly guiraca caerulea), is a medium-sized seed-eating bird in the same family as the northern cardinal , "tropical" or new world buntings , and "cardinal-grosbeaks" or new world grosbeaks .
the male blue grosbeak is a beautiful bird , being almost entirely deep blue .
the female is mostly brown .
both sexes are distinguished by their large , deep bill and double wing bars .
these features , as well as the grosbeak's relatively larger size , distinguish this species from the indigo bunting .
length can range from 14 to 19 cm (5.5 to 7.5 in) and wingspan is from 26 to 29 cm (10 to 11 in) .
body mass is typically from 26 to 31.5 g (0.92 to 1.11 oz) .
this is a migratory bird , with nesting grounds across most of the southern half of the united states and much of northern mexico , migrating south to central america and in very small numbers to northern south america; the southernmost record comes from eastern ecuador .
it eats mostly insects , but it will also eat snails , spiders , seeds , grains , and wild fruits .
the blue grosbeak forages on the ground and in shrubs and trees .
this species is found in partly open habitat with scattered trees , riparian woodland , scrub , thickets , cultivated lands , woodland edges , overgrown fields , or hedgerows .
it nests in a low tree or bush or a tangle of vegetation , usually about 13 m (3.39.8 ft) above ground , often at the edge of an open area .
