Read an Excerpt
On Audubon and Those Confusing Warblers
Several of my friends have taken me to task for giving two of the color plates in my eastern field guide the title “Confusing Fall Warblers.” They are not confusing, they insist. Perhaps not to them, but the little greeny-brown jobs remain confusing to 95 percent of the bird watching crowdor at least to those who do not consider themselves “hard-core.” Even Audubon was confused. Of the thirty-eight species of wood warblers found normally in eastern North America he eventually knew all but one. In attempting to sort them out, he was relatively late on the scene. Early on, Linnaeus, the creator of the Systema Naturae, and his successor, Johann Georg Gmelin, as well as a number of other workers, had already named and described twenty-five species of North American warblers. That was before Alexander Wilson published his American Ornithology, wherein he described another ten. By the time Audubon came on the scene, twenty years later, he was able to add only two new ones: Swainson’s warbler and the now nearly extinct Bachman’s warbler, both furtive southerners first discovered by his friend the Reverend Bachman of Charleston. After Audubon, only one species, Kirtland’s warbler, a rarity restricted to the pine barrens of Michigan, remained to be described.
But Audubon tried hard; he named and illustrated ten or eleven species that did not existvariants or obscure plumages of already well- known species.
Many birders have found that the sumptuous showcase of Audubon’s prints published by Abbeville PressThe Baby Elephant Foliowas beyond their pocketbooks. But if they did purchase the book, they may have looked only at the pictures, ignoring the text prepared after considerable research by my wife, Ginny, and me. Inasmuch as the tome weighs eighteen pounds, it is not exactly a field guide or bedtime reading. For the benefit of a wider audience, I have pulled things together and adapted from the book the following capsule accounts of the eleven “species” of warblers that led Audubon astray:
“Children’s Warbler” (Yellow Warbler) When Audubon painted two little yellowish birds at Oakley Plantation in Louisiana, he tentatively inscribed his drawing “Louisiana Warbler,” Sylvia ludoviciana. Later, feeling quite certain that they represented something new, he crossed out the scientific name and inked in Sylvia childreni, naming it “children’s warbler” in honor of the secretary of the Royal Society, John George Children, who managed his affairs in London. He had drawn not a new species but a female and immature yellow warbler. Obviously he became aware of this at a later date, because it was omitted in his octavo Birds of America.
It is understandable that Audubon, having virtually no books, should be confused by obscure plumages of certain warblers. Any modern field guide would have informed him that with the exception of the unmistakable female redstart, the yellow warbler is the only warbler with yellow (not white) spots in its tail. Had he known this simple fact, he would have been spared two major errors in the original Elephant Folio.
“Rathbone’s Warbler” (Yellow Warbler) This is another instance in which Audubon mistook two juvenile yellow warblers for something new. He wrote:
Kind reader, you are now presented with a new and beautiful little species of Warbler, which I have honored with the name of a family that must ever be dear to me. . . . I trust that future naturalists, regardful of the feelings which have guided me in naming this species, will continue to [give] it the name of Rathbone’s Wood-Warbler. I met with the species . . . only once. They were actively engaged in searching for food amongst the blossoms and leaves of the bignonia.
Audubon’s good intentions toward the Rathbones went for naught. He did not state where he collected these young yellow warblers, but his original pastel was inscribed July 1, 1808, at the “Falls of the Ohio.” Later, in 1825, it was used as a basis for the color plate that was inscribed with the same date as the pastel. Curiously, he defines the bird’s range in his Birds of America as “Mississippionly one pair seen.” “Pine Swamp Warbler” (Black-throated Blue Warbler) When Audubon painted these birds in the Great Pine Swamp of Pennsylvania on August 11, 1829, he took Alexander Wilson as his authority, as did his contemporary, [Thomas] Nuttall, in his own manual. Audubon wrote that this bird “delights in the dark humid parts of thick underwood, by the sides of small streams.” Several years later, in his octavo edition, he corrected this error, putting the blame on Wilson:
The birds represented in Plate 48 of my large edition as Sylvia ssphagnosa, are the young of the Black-throated Blue Warbler, the female of which resembles them so much that I looked upon it as a species distinct frooooom the male. I have no doubt that this error originated with Wilson who has been followed by all our writers. Now, however, the Sylvia or Sylvicola sphagnosa of Bonaparte which he altered from Wilson’s S. pusilla, must be erased from our fauna.
We must remember that Wilson, Audubon, and their contemporaries were at the very frontiers of ornithology and that such misconceptions were inevitable. In presenting the new plate in the miniaturized version, Audubon combined the figure of the upper bird, a female, with that of the male, which in the original plate was shown alone on a spray of columbine.
“Blue-Green Warbler” (Cerulean Warbler) When Audubon painted this bird in Louisiana, in August 1821, he again believed he had found something new. He named it the “bluegreen warbler,” Sylvia rara. Later he realized that it was simply a female or possibly a young male cerulean warbler. In his octavo Birds of America, published several years later, he combined his original color plate of the cerulean warbler with this one. He dropped out the lower bird of the earlier version; it apparently had been copied by Havell the engraver from a drawing by Wilson.
Knowledge of birds was growing rapidly at that time, and Audubon’s own revisions were extensive. His critics pointed out certain errors and discrepancies in the text of his Ornithological Biography, and thus he was able to make corrections when he published the smaller octavo version.
“Hemlock Warbler”(Blackburnian Warbler) Here again Audubon was misled by Wilson into cataloging a female warbler as a distinct species. He wrote:
It is to the persevering industry of Wilson that we are indebted for the discovery of this bird. He has briefly described the male [actually the female] of which he had obtained but a single specimen. Never having met with it until I visited the Great Pine Forest where that ornithologist found it, I followed his track in my rambles there, and had not spent a week among the gigantic hemlocks which ornament that interesting part of our country before I procured upwards of twenty specimens.
Audubon never did correct this mistake in his octavo edition, which was prepared several years later, even though he correctly added a female to his original plate of the male Blackburnian. Of this supposed “species” he wrote:
The tallest of the hemlock pines are the favorite haunts of this species. It appears first among the highest branches early in May, breeds there, and departs in the beginning of September. Like the blue yellow-back warbler [parula warbler] its station is ever amidst the thickest foliage of the trees, and with as much agility as its diminutive relative it seeks its food by ascending from one branch to another, examining most carefully the underparts of each leaf as it proceeds.
“Autumnal Warbler” (Bay-breasted Warbler) In 1829, while investigating the Great Pine Swamp near Mauch Chunk, Pennsylvania, where he collected so many Blackburnians, Audubon painted two plain-looking warblers that were unfamiliar to him. They were obviously young bay-breasted warblers, and inasmuch as it was late August, we might assume they were early fall migrants because bay-breasteds have never been known to nest that far south. Audubon bestowed the new name Sylvia autumnalis, but later, when he reworked his text in the octavo edition, he must have had second thoughts. There was no mention of this “species,” nor was the plate included. It became simply one of those “confusing fall warblers,” which to this day are the bane of the average birder.
“Vigor’s Warbler” (Pine Warbler) One day in May 1812, Audubon discovered a small yellow-breasted bird fluttering in the tall grass on a little island in Perkiomen Creek on his farm, Mill Grove, near Valley Forge, Pennsylvania. It perched on the bladelike leaves of the spiderwort on which he drew its portrait. Believing it was something new, he called the diminutive bird “Vigor’s Warbler” after Nicholas Vigor, an English naturalist. Actually it was an immature pine warbler, a species that had already been described by Wilson and that Audubon came to know well, particularly during his years in Louisiana. But this individual, away from its usual haunts in the pines, threw him off. It seemed different, and this is quite understandable; pine warblers can vary a lot, with few marks that are distinctive other than the strong wing bars. In his octavo Birds of America, rewritten later, Audubon made no mention of this “species.” He was pioneering, and although birds new to science were still being described, most Americans were so busy pushing other frontiers that they had little time for ornithology. Today birders are legion. The binocular has replaced the gun, and field guides have made identification quick and accurate.
“Roscoe’s Yellowthroat” (Common Yellowthroat) When Audubon made the drawing of this bird in 1821, his inscription at the bottom of the plate identified it as “Louisiana Yellow-throat.” Under the impression that it was new, he changed the name to “Roscoe’s Yellow- throat,” in honor of William Roscoe, an English historian. But later, when he published his octavo Birds of America, he vetoed the idea. Recomposing the plate of the “Maryland Yellowthroat,” he added this figure, which he then presumed to be an immature male of the common species.
Audubon described still another yellowthroat from a California specimen obtained from Mr. Townsend, naming it “Delafield’s Ground Warbler,” in honor of Colonel Delafield, president of the Lyceum of Natural History in New York. He said that it so much resembled the “Maryland Yellow-throat,” that one might easily confuse the two species. Years later it was designated as a mere subspecies by the checklist committee of the American Ornithologists’ Union.
“Selby’s Flycatcher” (Hooded Warbler) When Audubon was at the plantation of James Pirrie in Louisiana during the summer of 1821, he painted still another rather nondescript warbler, which he thought was new. The notes on his original drawing indicate that he first called it “Louisiana Flycatcher,” Muscicapa ludoviciana. Later he renamed it “Selby’s Flycatcher” in honor of a British ornithologist, Prideaux John Selby. Actually it was an immature hooded warbler. Scarcely a month later he drew the hooded warblers that appear on plate 190 in his Elephant Folio. Somehow he did not make the connection between this young bird and the adults he drew subsequently. Hooded warblers are common in the wooded countryside of the southern states, and Audubon undoubtedly knew them well, but females and especially immature birds are variable.
Determining the exact identity of some of Audubon’s birds, especially immatures, has demanded a degree of detective work and intuition on the part of later scholars. In fact, several of his birds have never been satisfactorily identified to this day.
Wilson, often called the “Father of American ornithology,” had the jump on Audubon by about twenty years; therefore he was the first to describe and name ten species of warblers that were new to science. But there was equivocation at that time as to whether some of these little birds were warblers or flycatchers. And there were certain other warblers, such as the ovenbird and Louisiana waterthrush, that were regarded as thrushes. Audubon lumped them with the robin and the wood thrush in the genus Turdus. As for the two waterthrushes, Louisiana and northern, he knew them both and figured them correctly in his Elephant Folio, then had a change of mind and lumped them as one in his revised octavo edition, inventing a new name“Aquatic Wood Wagtail.” This, of course, muddied the waters for a while, but eventually other scholars changed things back. However, the inappropriate name “waterthrush” remains.
“Bonaparte’s Flycatcher” (Canada Warbler) When Audubon first drew this little bird, poised on the fruiting branch of a magnolia, he inscribed it as a “Cypress Swamp Flycatcher,” then changed it to “Bonaparte’s Flycatcher,” in honor of Prince Charles-Lucien Bonaparte. Later, when he published his octavo Birds of America, he again changed the name to “Bonaparte’s Flycatching Warbler.” In due time it was confirmed that it was a warbler, not a flycatcher, and not a new species as he had thought, but actually a young female Canada warbler, a species that he was to paint again eight years later under the name “Canada Flycatcher.” There is an evolution in names, and although some stick, no matter how inappropriate, others change. Many birds portrayed by Audubon are known by names that are quite different today. Usage has dictated some; others have been modified as their relationships were clarified.
If the author of every new bird book decided to change names to suit himself, chaos would result. Hence the scientific organization known as the American Ornithologists’ Union (AOU) has set up a checklist committee to pass on questions of nomenclature. The scientific names they decide on become official. As for English names, the checklist committee of the American Birding Association (ABA) has helped to standardize those we use today.
In his great folio, Audubon painted forty species of North American warblers, including three western varieties sent to him by Mr. Townsend. This does not include the dozen invalid forms he so optimistically described and named. Of the forty, only oneSwainson’s warblerstill carries the same scientific name he gave itLimnothlypis swainsonii. But even that species carried a different common name“Brown-headed Worm-eating Warbler.” As for the vernacular or English names of the forty warblers, twenty-five go by approximately the same names today, whereas fifteen do not. So it would seem evident that common names have been more stable than scientific nomenclature.
“Carbonated Warbler” (A mystery) This is one of Audubon’s mystery birds, a very convincing drawing of a bird that had never been seen and described before, nor has it been since. He wrote:
I shot the two little birds here represented, near the village of Henderson, in the State of Kentucky, in May 1811. They were both busily engaged in searching for insects along the branches and amongst the leaves of a Dogwood Tree. . . . On examination they were found to be both males. I am of the opinion that they were each young birds of the preceding year, and not in full plumage, as they had no part of their dress seemingly complete, excepting the head. Not having met with any other individuals of this species I am at this moment unable to say anything more about them. They were drawn like almost all the other birds which I have represented, immediately after being killed.
Audubon’s portrayal of this puzzler does not seem contrived. His “Carbonated Warbler,” deep yellow with a black cap, streaked breast, and strong wing bars looks quite logical, but quite unlike any known species. One could easily dismiss such a bird as being a mutant or an aberrant individual; but the anomaly is that there were two. We would not expect to find two identical mutants at the same time. There is a remote possibility that it was a species already close to extinction. Inasmuch as the Kirtland’s warbler, unknown in Audubon’s day, numbers scarcely more than four hundred individuals in its restricted range in the Michigan pine barrens, and the Bachman’s warbler of the southern swamps is sometimes not recorded for several years in succession, it is possible that this bird, the “Carbonated Warbler,” actually did exist, and that it was a species at the end of the line.
Copyright © 2006 by the Estate of Roger Tory Peterson. Reprinted by permission of Houghton Mifflin Company.