The Baltimore Oriole is Back
And vultures will soon be storks as experts release a new official list of American bird names later this year.
When european settlers first came to North America's mid-Atlantic shore, they found winging through leafy forest shadows a bright spark of feathered flame, a small bird that suspended basketlike nests high in the tallest trees. The flashy male of the species-decked out in the black and orange heraldic colors of Lord Baltimore, the English nobleman who founded Maryland-earned the species its name, Baltimore oriole.
That name stuck for more than two centuries, until scientists observed that the Baltimore oriole in the western portions of its range hybridized with another bird, the Bullock's oriole. Biologists regard such cross-breeding, if it produces fertile young, as a sign that two seemingly different animals are in fact members of the same species.
And so in 1973, ornithologists officially lumped the two birds into a single species, the northern oriole. Angry objections followed. Baltimore's city fathers felt bereft and betrayed, an American League baseball team found itself named after a bird that did not exist, and birders were forced to scratch two popular species off their life lists. Too bad. Science had decreed that the birds were a single species. The Baltimore and Bullock's orioles would be no more, and that was that.
The perpetrator of the deed was the American Ornithologists' Union's (AOU) Committee of Classification and Nomenclature, the nation's official regulator of avian names. Its publication, the Checklist of North American Birds, usually announces the scientific and common names by which bird species will be known. However, publication of a 1975 AOU interim report, prior to the 1983 Check-list, introduced the northern oriole to the world.
The committee has been playing musical chairs with bird names almost since AOU created it in 1886, only three years after AOU itself was born. Over the decades, the nomenclature committee has produced six editions of the Checklist of North American Birds, and all but the first edition have announced extensive changes both in common and scientific bird names. An estimated 80 percent of the 700 or so birds that are listed inthe first edition have since undergone name changes.
AOU will release the seventh edition of the Check-list late this year, bringing several dozen changes to bird names. This will be the first new edition since 1983. Although new editions have been released at irregular intervals in the past, AOU staff hope now to release them every 10 years. The nomenclature committee is already studying changes for the next revision. Grounds for future changes are fertile, since the check-list has grown to include about 1,950 species thanks to the addition of Central American, Hawaiian and West Indies birds.
The 5,000-member AOU is headquartered at the Smithsonian Institution's National Museum of Natural History in Washington, D.C., but the heart of the nomenclature committee lies in Kentucky on the University of Louisville campus, specifically in the office of Burt L. Monroe Jr., chairman of the Department of Biology. He began studying birds as a small boy, joining his father on birding trips. In time, the study of birds and their names became his life's work.
Monroe's office is awash with papers, books and correspondence. Lying open on a stand beside his desk is a thoroughly marked copy of The Distribution and Taxonomy of the Birds of the World, the weighty volume that he co-authored with Charles G. Sibley, an ornithologist who is now retired from Yale University. Monroe has seen some 2,600 of those bird species.
The 25- to 30-member governing body known as the AOU Council made Monroe chairman of the nomenclature committee more than a dozen years ago. His taxonomic activities are not limited to the United States, however. Every four years countries around the globe send delegates to the International Ornithological Congress, which has its own group for standardizing the names of the world's approximately 9,700 bird species. Monroe is chairman of that group, too.
The eight U.S. scientists now serving on the AOU nomenclature committee are among the nation's top-ranking avian taxonomists. The committee itself chooses each new member. A seat on the committee-like one on the Supreme Court-has no termination date.
Although anyone-ornithologist or otherwise-can suggest name changes, most recommendations follow publication of data indicating that a bird has been misclassified. "With each change," says Monroe, "we are trying to get closer to the truth." As in all fields, the truth is elusive. Locating it requires a mustering of new field and laboratory findings.
In recent years, the study of DNA has brought a new level of sophistication to this effort. DNA-deoxyribonucleic acid-is the material in a cell that carries the genetic code across generations. Because the arrangement of the chemical components of DNA is unique within any taxonomic group, analysis of an organism's DNA can reveal its biological relationships, bringing greater accuracy to sorting out its classification.
Some names are changed simply to bring them in line with related European species. For example, in 1983, AOU changed the marsh hawk-a name evocative of a white-rumped grayish hawk hovering over grassy wetlands-to "northern harrier," which sounds vaguely like a New York commuter on a bad-traffic day. However, harrier is an old English word for hunter and is the name by which a similar European hawk is known. Changing the common name of the marsh hawk underscored the taxonomic relationship. Similarly, the nomenclature committee changed the baldpate duck to the American wigeon in 1957 to indicate its relationship to the European wigeon.
Recommendations for name changes go through a scientific gauntlet as they circulate among committee members before the annual mid-winter meeting. The committee makes its decisions at the meeting during three days set aside exclusively for nomenclature. Democracy rules: Members vote on the names, with Monroe casting his lot only to break a tie.
After any given change, says Monroe, "Somebody will say, 'Why in hell did you do that? It's stupid.'" Name changes, it seems, rarely please everyone. Birders, whose avocation sometimes takes on the intensity of religion or politics or both, can grow irate when their life lists-meticulous compendia of every bird seen in a lifetime-are shortened by the combining of species. The birders' frustration is compounded when species that may look only remotely alike are combined, as when the committee merged the slate-colored and Oregon juncos in 1957.
Scientists also may dispute among themselves the taxonomy of a given species. Much of the scientific controversy over reclassifications doubtless springs from the ancient conflict between "lumpers," who believe in combining similar or cross-breeding birds into a single species, and "splitters," who search for differences that might justify dividing recognized species. The bird list shrinks or grows depending upon which camp is in ascendance. Presently, splitters seem to be on top, so the Check-list, and birder life lists, are likely to grow.
Concern over bird-name changes can come from unexpected quarters. One such case occurred in 1983 when the birding world learned that America's most abundant swan, the whistling, was going to be combined with the Old World Bewick's swan because the two interbreed. The duo became the tundra swan, a name chosen in recognition of the three or four months each year that the birds nest in the Far North.
The logic of this change was lost on two history-conscious members of the Lewis and Clark Heritage Trail Associalion who flew from Portland, Oregon, to New York City so they could corner Monroe at an AOU meeting and try to persuade him to leave the swan's name unchanged. The whistling swan, they argued, appears in the writings of Lewis and Clark, those stalwart explorers who have won a special place in the hearts of Old West afficionados. For history's sake, the Oregonians asked, couldn't the swan's name remain the same?
Alas, the two met more resistance from AOU than Lewis and Clark did from Native Americans. In brief, the answer was no, and the two men flew back to the West Coast bewildered by the dominance of scientific opinion over historic tradition.
Other changes are more welcome, coming as they do after years, even decades, of analysis and contemplation. For example, although bird books put vultures in the hawk family, doubt about this classification dates at least to 1873, when some scientists argued that the New World vultures are more closely related to storks. This is an idea whose time has come, according to Monroe. "Vultures are nothing but short-legged storks," he says.
Evidence for this has been building for decades. In 1967, J. David Ligon, now chairman of the Department of Biology at the University of New Mexico, completed anatomical comparisons that revealed a number of features shared by storks and vultures, including bone structure and nestling plumage. These suggested the two groups are related.
Solid evidence that storks and vultures arose from a common ancestor has been mounting. In 1983, Amadeo Rea, an ornithologist at the San Diego Museum of Natural History-after reviewing the anatomy, physiology, behavior and cellular biology of hawks, vultures and storks -- concluded that storks and vultures belong in the same family. Recent DNA analysis supports such findings. Consequently, the new check-list will group New World vultures with storks.
The search for additional birds whose names merit change could turn up numerous candidates deserving the taxonomists' attention. What about that noisy, pointy-tailed duck, the oldsquaw, whose common name combines age discrimination, sexual bias and racial slurring in a single package? Monroe himself has suggested changing the duck's name, but the committee has failed to act. This idea will surface again someday, partly because of the oldsquaw's close relationship to the Old World's long-tailed duck, and perhaps because of added social pressure.
Even with this ongoing search for more appropriate names, some birds escape the AOU Nomenclature Committee's critical review. The committee ridded lists of the baldpate duck, whose head is feathered, not bald, but what about America's world-famous national bird? Should we change the bald eagle's name because it isn't really bald?
Monroe smiles. "I wouldn't touch that one with a 10-foot pole."
One that he will touch, however, is the northern oriole. After 20 years of contention over loss of the Baltimore oriole, scientists have discovered that, even though the bird has been spreading westward and increasingly overlapping the range of Bullock's oriole, very little breeding occurs between the two. This changes the whole picture, because the small amount of interbreeding is not significant enough to justify separating the birds into two species. Consequently, the new check-list probably will revive the Bullock's and Baltimore orioles.
"You can tell everyone," says Monroe, "that they are likely to get their Baltimore oriole back."--The Editors