Baltimore Oriole (c1833). Etching, watercolor. 65 x 100. The Baltimore oriole is a small icterid blackbird common in eastern North America as a migratory breeding bird. It received its name from the resemblance of the male's colors to those on the coat-of-arms of Lord Baltimore. Observations of interbreeding between the Baltimore oriole and the western Bullock's oriole, Icterus bullockii, led to both being classified as a single species, called the northern oriole, from 1973 to 1995. Research by James Rising, a professor of zoology at the University of Toronto, and others showed that the two birds actually did not interbreed significantly. The Baltimore oriole is the state bird of Maryland. It is also the inspiration for the Baltimore Orioles baseball team. Like all New World orioles, this species is named after an unrelated, physically similar family found in the Old World: the Oriolidae. Oriole ultimately derives from Latin aureolus, golden. The genus name Icterus is from Ancient Greek ikteros, a yellow bird, usually taken to be the Eurasian golden oriole, the sight of which was thought to cure jaundice. The specific galbula is the Latin name for a yellow bird, again usually assumed to be the golden oriole. This medium-sized passerine measures 17-22 cm in length and spans 23-32 cm across the wings. Their build is typical of icterids, as they have a sturdy body, a longish tail, fairly long legs and a thick, pointed bill. The body weight averages 33.8 g, with a range of weights from 22.3 to 42 g. The male oriole is slightly larger than the female, although the size dimorphism is minimal by icterid standards. Adults always have white bars on the wings. The adult male is orange on the underparts shoulder patch and rump, with some birds appearing a very deep flaming orange and others appearing yellowish-orange. All of the rest of the male's plumage is black. The adult female is yellow-brown on the upper parts with darker wings, and dull orange-yellow on the breast and belly. The juvenile oriole is similar-looking to the female, with males taking until the fall of their second year to reach adult plumage. Baltimore orioles are found in the Nearctic in summer, including the Canadian Prairies and eastern Montana in the northwest eastward through southern Ontario, southern Quebec and New Brunswick and south through the eastern United States to central Mississippi and Alabama and northern Georgia. They migrate to winter in the Neotropics as far north as Mexico and sometimes the southern coast of the United States, but predominantly in Central America and northern South America. Some areas of the southern United States may retain orioles all winter if they have feeders that appeal to them. The range of this bird overlaps with that of the similar Bullock's oriole in the Midwest, and the two species were once considered to be conspecific under the name northern oriole because they form fertile hybrids. The Baltimore oriole is a rare vagrant to Western Europe. Baltimore orioles are often found high up in large, leafy deciduous trees, but do not generally reside in deep forests. The species has been found in summer and migration in open woodland, forest edge, and partially wooded wetlands or stands of trees along rivers. They are very adaptable and can breed in a variety of secondary habitats. In recent times, they are often found in orchards, farmland, urban parks and suburban landscapes as long as they retain woodlots. In Mexico, they winter in flowering canopy trees, often over shade coffee plantations. The male sings a loud flutey whistle, with a buzzy, bold quality, a familiar sound in much of the eastern United States. The male typically sings from the tree canopy, often giving away its location before being sighted. Problems playing this file? See media help. Baltimore orioles are basically solitary outside their mating season. The species is generally considered monogamous, although evidence suggests that extra-pair copulation is reasonably common. In the spring, males establish a territory then display to females by singing and chattering while hopping from perch to perch in front of them. Males also give a bow display, bowing with wings lowered and tail fanned. Depending on their receptiveness, the females may ignore these displays or sing and give calls or a wing-quiver display in response. The wing-quiver display involves leaning forward, often with tail partly fanned, and fluttering or quivering slightly lowered wings. The Baltimore oriole's nest is built by the female. It is a tightly woven pouch located on the end of a branch, consisting of any plant or animal materials available, hanging down on the underside.