Northern Oriole PATCHED

The Baltimore oriole (Icterus galbula) 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 17th century 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.[2]

northern oriole

The Baltimore oriole was one of the many bird species originally described by Carl Linnaeus in the 1758 10th edition of his Systema Naturae, where it was given the binomial name of Coracias galbula.[3]

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".[4] 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.[5]

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.[10]

Baltimore orioles are basically solitary outside their mating season. The species is generally considered monogamous, although evidence suggests that extra-pair copulation is relatively 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.[citation needed]

The Baltimore oriole's nest is built by the female. It is a tightly woven, bindle-like pouch located on the end of a branch, consisting of any fine plant or animal materials available, hanging down on the underside.[13] Trees such as elm, cottonwood, maple, willow, or apple are regularly selected, with the nest usually located around 7 to 9 m (23 to 30 ft) above the ground. The female lays three to seven eggs, with the norm being around four. The eggs are pale gray to bluish white, measuring 2.3 cm 1.6 cm (0.91 in 0.63 in) on average. The incubation period is 12 to 14 days. Once the nestlings hatch, they are fed by regurgitation by both parents and brooded by the female for two weeks. After this the young start to fledge, becoming largely independent shortly thereafter. If the eggs, young, or nest are destroyed, the oriole is unable to lay a replacement clutch.[10]

Predation of adults is a common source of mortality, typically also occurring with eggs, nestlings and fledglings. Common predators at Baltimore oriole nests can include common grackles, American crows, blue jays, black-billed magpies, tree squirrels and domestic cats, which most commonly capture newly fledged orioles or adults engaged in brooding behavior. Rapacious birds commonly prey on both young and fully-grown orioles, the most prolific being the eastern screech owl and Cooper's and sharp-shinned hawks. Somewhat larger rapacious birds also sometimes opportunistically prey on the oriole, including peregrine falcons, great horned owls, and barn owls, while merlins may do so while orioles are migrating.[14][15]

Baltimore orioles forage in trees and shrubs, also making short flights to catch insects. They acrobatically clamber, hover and hang among foliage as they comb high branches. They mainly eat insects, berries and nectar, and are often seen sipping at hummingbird feeders. Their favored prey is perhaps the forest tent caterpillar moth, which they typically eat in their larval stage, and can be a nuisance species if not naturally regulated by predation. The larvae caterpillar are beaten against a branch until their protective hairs are skinned off before being eaten. They will also consume beetles, grasshoppers, wasps, bugs, and spiders.[12] Unlike American robins and many other fruit-eating birds, Baltimore orioles seem to prefer only ripe, dark-colored fruit. Orioles seek out the darkest mulberries, the reddest cherries, and the deepest-purple grapes, and will ignore green grapes and yellow cherries even if they are ripe. Baltimore orioles sometimes use their bills to "gape", stabbing their closed bill into soft fruits, then opening it to lap the juice with their tongues. During spring and fall, nectar, fruit and other sugary foods are readily converted into fat, which supplies energy for migration. Many people now attract Baltimore orioles to their backyards with oriole feeders. Many contain essentially the same food as hummingbird feeders, but are designed for orioles, and are orange instead of red and have larger perches. Baltimore orioles are also fond of halved oranges, grape jelly and, in their winter quarters, the red arils of gumbo-limbo (Bursera simaruba).[16] If they discover a well-kept feeder, orioles lead their young there.[citation needed]

Baltimore Orioles seek out ripe fruit. Cut oranges in half and hang them from trees to invite orioles into your yard. Special oriole feeders filled with sugar water supplement the flower nectar that Baltimore Orioles gather. You can even put out small amounts of jelly to attract these nectar-eaters (just don't put out so much that it risks soiling their feathers). Planting bright fruits and nectar-bearing flowers, such as raspberries, crab apples, and trumpet vines, can attract Baltimore Orioles year after year. Find out more about what this bird likes to eat and what feeder is best by using the Project FeederWatch Common Feeder Birds bird list.

Dr. James D. Rising is a professor in the Department of Zoology at the University of Toronto. He is an authority on Baltimore and Bullock's Orioles, and co-author of the accounts for both species for the mostimportant current work on American species, TheBirds of North America. Dr. Rising has conducted careful studies of how severalrelated species pairs of eastern and western birds hybridize on the Great Plains, and specifically studied oriolesthere during a 30-year research project. He currently serves on the American Ornithologists' Union Committee onClassification and Nomenclature. Because he is the recognized authority on the subject, we asked him to explainto us at Journey North exact ly why ornithologists used to think Bullock's and Baltimore Orioles were the same species,called the "Northern Oriole," and why they changed their mind. Dr. Rising explains:First things first: What Is a Species?"To answer your question we first must ask, "What is a species?" The simple answer is "Twokinds of plants or animals that are different." But, of course, it really isn't as easy as that. You mightask, "What do you mean by different?" and that would be a good question. Usually it means that they lookdifferent. Eastern Bluebirds and American Robins look different, and they are different species. However, maleand female Cardinals also look different, but they are not different species. They are simply different sexes ofthe same species. So there must be more to it than that. Biologists, therefore, often define a species as a groupof individuals who cannot mate with individuals of another group (species) and produce healthy young that willbe able to reproduce when they are adults. For example, the Hooded Merganser and Common Goldeneye (two kinds ofducks) sometimes hybridize, but the young that they produce almost certainly cannot breed and produce young. Alsomatings between these two ducks are very rare. Thus, they are not considered to be the same species." Back to the Oriole QuestionAudubon's Oriole Paintings When John James Audubon painted these birds in 1836 and 1825, he consideredthem to be two different species. For about three decades starting in the late 1960s, many ornithologists thoughtthey were the same species and "lumped them" into the Northern Oriole. Now they've "split"them back the way Audubon thought they were all along.Bullock's Oriole maleBaltimore Oriole maleDr. Rising continues, "Why have scientists' ideas on whether orioles are one or two species changed over time?About 50 years ago people found that in the western prairies there was a zone where both Baltimore and Bullock'sOrioles are found. Many individuals had one parent that was a Baltimore Oriole and one that was a Bullock's Oriole,that is to say, they were hybrids. These hybrids appeared to be perfectly healthy and they themselves matedwith other orioles and produced healthy young. The scientists reasoned that because of this hybridization in timethe two kinds of orioles would blend into one single kind of oriole. Therefore, they combined them into a singlespecies, and named it the Northern Oriole. 041b061a72