The blue grosbeak (Passerina caerulea ), is a medium-sized North American passerine bird in the cardinal family Cardinalidae. It is mainly migratory, wintering in Central America and breeding in northern Mexico and the southern United States. The male is blue with two brown wing bars. The female is mainly brown with scattered blue feathers on the upperparts and two brown wing bars.
Blue grosbeaks are medium-sized colorful songbirds found in North and Central America. Males are almost entirely deep blue in color while females are mostly brown. Both sexes are distinguished by their large, deep bill and double wing bars.
Blue grosbeaks breed 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. These birds live in partly open habitats with scattered trees, riparian woodland, scrub, thickets, cultivated lands, woodland edges, overgrown fields, or hedgerows.
Blue grosbeaks are social birds and often gather in flocks to feed before migrations. Mating pairs spend most of their time together. Blue grosbeaks are active during the day spending most of their time foraging. They forage on the ground by hopping awkwardly or flying above the ground; they also forage in shrubs and in trees. Blue grosbeaks are shy birds and if alarmed usually dive into dense cover. These birds communicate with each other vocally but only males are known to sing. They sing to attract a female and to proclaim territory to other males.
Blue grosbeaks are carnivores (insectivores); they eat mostly insects, but will also take snails, spiders, seeds, grains, and even wild fruits.
Blue grosbeaks are serially monogamous and pairs remain together during the breeding season. The breeding season usually lasts from early April to late August. These birds nest in a low tree or bush or a tangle of vegetation, usually about 1-3 m (3.3-9.8 ft) above ground and often at the edge of an open area or near roads. The female builds the nest which is made with grass, twigs, and leaves and lined with fine grass or animal hair. After the nest is ready the female lays 3 to 5 eggs and incubates them within 11-12 days. The chicks are altricial; they are hatched with reddish bodies, with brownish-gray down, and closed eyes. They are fed mostly by the female until they fledge and leave the nest; this occurs 9 to 10 days after hatching. When the female begins building her second nest, the male may continue to feed the young for some time more.
There are no major threats to the Blue grosbeak at present.
According to the All About Birds resource, the total breeding population size of the species is 24 million individuals. Overall, currently, Blue grosbeaks are classified as Least Concern (LC) on the IUCN Red List and their numbers today are increasing.