Birdwatching, Observation-based Field Ornithology, and the Conservation Movement

William E. Davis, Jr.

September 22, 2015 17 MIN READ Feature Articles

The Amateur and the Professional, an Historical Perspective

In no other science, with the possible exception of astronomy, is the concept of “amateur” and “professional” more blurred than it is in ornithology. In the latter half of the 19th century, few people earned their living from studying birds. Although there were a few museum ornithologists, most of the influential ornithologists of the day, such as William Brewster and Eliot Coues, were men of independent means, were physicians, or were connected to the army. There was little difference between the museum professional and, for example, the group of young men who founded the Nuttall Ornithological Club—all were serious students of bird life, and all published their scientific studies. The museum professionals developed extensive networks among the amateur ornithologists, many of whom supplied the museums with their growing collections of bird skins, which was the currency of ornithological study of the time.

In the 20th century and into the 21st, the influx of ornithologists into the academic sphere, conservation organizations, and state and local government agencies has increased the number of ornithologists who earn their living working with birds. Many of these professional ornithologists started out as birdwatchers and many remain active birdwatchers throughout their lives. Also, professionals often recruit and train amateurs to help with their bird research, which further improves the amateur’s skill level. These are a couple of examples why the distinction between the professional and the serious amateur remains blurred.

From Shotgun to Field Glasses

The latter half of the 19th century produced an explosive development of interest in natural history in general and birds in particular. By 1850, the U.S. National Museum, under the leadership of Spencer Fullerton Baird, began to stir interest in natural history, and a widespread movement began in earnest after the Civil War. The roots of this cultural trend can be traced to upper-class emulation of a similar earlier trend in Europe, and in a middle class with leisure time. Museums proliferated: the Museum of Comparative Zoology (MCZ) at Harvard University was established in the late 1850s under the leadership of Louis Agassiz, followed by the American Museum of Natural History (AMNH) in 1869, Chicago’s Field Museum in 1893, and the Carnegie Museum of Pittsburgh in 1895. The hobby of collecting bird skins, nests, and eggs became widespread. Bird clubs and journals that dealt with birds and other natural history subjects proliferated remarkably (for an excellent discussion of these trends, see Barrow 1998).

The first organization that dealt solely with birds was the Nuttall Ornithological Club (NOC), established in 1873 by William Brewster and seven of his friends. From 1876 to 1883, the NOC published the Bulletin of the Nuttall Ornithological Club, the first journal in North America dedicated exclusively to birds. The Bulletin became The Auk in 1884 when it was transferred, editor and all, to the fledgling American Ornithologists’ Union (AOU). The NOC is still alive and well, its members influential in a wide spectrum of local and national organizations (Davis 1987). The NOC is of particular interest because both Ludlow Griscom and Roger Tory Peterson were influential in this organization.

Another organization that had a profound effect on the development of ornithology and recreational birding was the Linnaean Society of New York, founded in 1878 by C. Hart Merriam, John Burrows, Eugene P. Bicknell (of Bicknell’s Thrush fame), and seven other prominent naturalists. The Linnaean Society was a progressive organization that admitted women as members as early as 1890, including Florence Merriam, Olive Thorne Miller, and Mabel Osgood Wright, all of whom became influential writers and popularizers of birds.

The “shotgun school” of ornithology prevailed through the early 20th century, when birds were shot rather than studied alive in the field. But by 1900, several things occurred that substantially changed this approach. One was the development of the protectionist movement, and another was the availability of high-quality German prism binoculars. These optics facilitated the development of modern birding, complete with its year lists, life lists, and “Big Day” competitions, and helped transform ornithology from a hobby to, in some aspects, a competitive sport.

Fig. 2. Excerpt from a letter to Griscom by Louis Agassiz Fuertes, showing the finer points of Ring-necked Duck (Aythya collaris) identification in the field. Cornell University Olin Library Archives, Ludlow Griscom papers.

The conservation movement began as a protectionist trend. After a false start in the mid-1880s with the formation of an Audubon Society for the Protection of Birds by George Bird Grinnell, it began in earnest in 1896 with the founding of the Massachusetts Audubon Society with William Brewster as the organization’s first president (Walton and Davis 2010). By 1901, there were three dozen local or state Audubon organizations, and by 1905 William Dutcher organized the National Association of Audubon Societies for the Protection of Birds and Mammals, which later became the National Audubon Society. This flurry of activity resulted from alarm and consternation over the slaughter of egrets, gulls, terns, and other species for the millinery trade and the slaughter of ducks, shorebirds, and doves for commercial markets. The protectionist movement, which gradually morphed into the conservation movement, slowly promoted a national interest in birds that influenced the development of birding, the demise of the shotgun school of ornithology, and the development of observation-based field ornithology.

Enter Ludlow Griscom and Roger Tory Peterson

Two of the most influential people in the development of birding, sight-based field ornithology, and the conservation movement were Ludlow Griscom and Roger Tory Peterson. Ludlow Griscom, whom Roger Tory Peterson described as “A genius at field identification” (Peterson 1980), was born in 1890. He recorded his first bird—an American Robin (Turdus migratorius)—at age four in Flushing, Long Island, New York, where he was raised (Davis 1994). At the age of 17 (1907), he formally became part of the birding community when he joined the Linnaean Society of New York. Here he became an ornithological force and a sight records guru (Figure 1).

In 1914, Ludlow Griscom entered Cornell University to obtain a Master’s degree under Arthur Allen, the first professor of ornithology in North America. His master’s thesis (1915) was titled The Identification of the Commoner Anatidae of the Eastern United States in the Field—demonstrating his commitment to and skill in rapid identification of live birds in the field (Figure 2). The following year he joined the staff of the American Museum of Natural History in New York City, a position he held until 1927, when he took up a curatorship in the Museum of Comparative Zoology in Cambridge, Massachusetts. The Linnaean Society of New York met twice monthly at the AMNH and Griscom was a major influence on, among others, a group of young men who called themselves the Bronx County Bird Club, many of whom went on to professional careers in ornithology. The group included Roger Tory Peterson, for whom Griscom was an inspiration and a mentor, and who wrote on numerous occasions about Griscom’s influence:

Ludlow Griscom was the first ornithologist I ever met, when, as a lad of 17 I came to New York in 1925 to attend my first meeting of the A.O.U… . I was to see him in action the following Saturday when he led the field trip to Long Beach on Long Island. On that day 13 new birds went down on my life list…Returning to New York a year later to take up my art education, I often saw Ludlow Griscom at the bimonthly meetings of the Linnaean Society which he dominated… . Griscom was our God and his “Birds of the New York City Region” [1923] our Bible. Every one of us could quote chapter and verse. We used his terminology and even his inflection when we pronounced something as “unprecedented” or “a common summer resident.” The leader of our little group, Jack Kuerzi, even parted his hair in the middle in the approved Griscom style. (Peterson 1960)

Clearly Griscom was a charismatic leader who exerted substantial influence over these young men. There is a frequently told story of Griscom facing down one of the old shotgun boys by identifying difficult birds, for example, a female Cape May Warbler high in a canopy. The old boy shot the bird and sure enough, it was a female Cape May. The story goes that Griscom repeated this procedure until he established credibility. Scott Weidensaul summed up the importance of this story:

True? The story was told by one of Griscom’s own students, so it might well be, but the factuality of it almost doesn’t matter; the story has been told so often because it boiled down the emergence of modern birding, with its reliance on the binocular instead of the gun, into a simple parable—the dawn of a new age in a single morning in Central Park…. (Weidensaul 2007: 184).

Griscom encouraged the keeping of careful records of the birds seen on every outing. He developed the habit of recording each species and the number of individuals seen, thus encouraging a quantitative aspect to record keeping, and a more scientific dimension to birding. By example, he encouraged his disciples to do the same.

Griscom also exerted influence on his professional colleagues. As a member of the ornithological staff at the prestigious AMNH for a decade, a fellow of the AOU, and a prolific publisher, he was respected throughout the professional ornithological community. His book Birds of the New York City Region drew good reviews and demonstrated his leadership in field ornithology. One review, by Witmer Stone, for decades the editor of The Auk, particularly demonstrated this:

As is well known Mr. Griscom has for some years been studying the possibilities of sight identification with the idea of eliminating so far as possible errors in field identification. He is not alone in this work as its importance is at once recognized by all students of living birds, but he has taken a leading part in it, and the results are beginning to show in the mention in our books of field marks by which a bird at some distance may be recognized….In cutting away from many of the traditional requirements of the last generation and considering the needs of the host of present day field students it sets a standard and example for what, as we have said elsewhere, might be termed the “new ornithology.” (Stone 1924)

Hence Griscom provided a strong influence on both the professional and amateur ornithological communities. He was a professional who espoused sight-recognition- based ornithology and an avid participant in birding-for-pleasure adventures, keeping year and life lists of species seen, and leading Big Day bird tours and pelagic trips. Dealing with both the professional and amateur communities was not an easy task; he faced resistance from more traditional shotgun ornithologists and he chided the birdwatchers for their burgeoning sight records that were often of dubious value. In a sense, with the birders, he thought he had created a monster that he felt obligated to corral. It is also true that Griscom might have been “riding the wave”—the development of ecology as a science and the rise of ornithologists in academia. But maybe Griscom, like a famous physicist who was accused of riding the wave, could respond: “Well, I made the wave didn’t I?”

Soon after Griscom arrived in Cambridge, he was welcomed into the Nuttall Ornithological Club, at the time a “Victorian men’s club” dominated by old-school ornithologists. Ironically it was Charles Foster Batchelder, one of the club’s founders in 1873, and decidedly of the old school, who nominated Griscom for resident membership. I wrote in the History of the Nuttall Ornithological Club 1873-1986:

Griscom was destined to have an enormous effect on the Club over the next 30 years. He was one of the prominent promoters of sight identification in the field and of the “sport of birding,” neither of which were particularly appealing to many of the older members, who were of the shotgun school. He would promote the active participation of amateurs in the Club, and, as we shall see, in many ways directed the Club along lines which, depending with whom you discuss the matter, either threatened the demise of the Nuttall Ornithological Club or led to its entering a new, modern, and productive era. (Davis 1987: 35)

Membership in the NOC was restrictive; women were not allowed to be members, speakers, or guests. Even Roger Tory Peterson, when he came to Boston in 1933, was not elected to membership the first time his name was proposed. This led the progressive Griscom, who had several female protégés, to float the idea of electing women as members. The backlash was significant, as the bylaws were swiftly changed in 1936 from “Resident members shall be persons interested in ornithology….” to “Resident Members shall be men interested in ornithology….” Sadly, it was not until 1974 that women were admitted to the NOC. Of the five women admitted that year, three were Griscom protégées.

Fig. 3. Roger Tory Peterson (left) and Ludlow Griscom. Smithsonian Institution Archives, Record Unit 7150, AOU Collection 1883–1977.

Griscom did more than anyone else to cause the shift from shotgun to observation- based ornithology in the NOC. He influenced a cadre of new, younger members by giving dozens of evening presentations on the state of the local seasonal bird migration and on sight identification of gulls, alcids, and other groups of birds. He shifted the focus of the meetings to include increased use of field notes based primarily on sight identifications instead of bird skins. During the 1930s and 1940s, as older members of the Club passed away, the tension over sight records diminished.

The Evolution of the Field Guide

In 1934, Roger Tory Peterson was ready to find a publisher for his new concept of a field guide for bird identification (Figure 3). There had been a number of previous attempts to produce a book or a system to facilitate the identification of birds in the field, but none had been entirely successful (Dunlop 2011). Most were better for identifying birds in the hand, were too large to be carried into the field, were poorly illustrated, or dealt with too limited a compliment of species. Some were a tad sentimental, and most importantly none was really satisfactory—perhaps the time for a comprehensive field guide simply had not arrived.

For example, Alexander Wilson’s nine volumes of Birds of America (1808-1813) had hand-colored plates that were designed to facilitate the identification of birds in the field or in the hand (Burtt and Davis 2013). But nine large volumes was hardly a “field guide.” Thomas Nuttall’s Handbook (1832, 1834; 1905) came closer, but was mostly restricted to northeastern birds. Elliott Coues’s Key (1872) was an improvement but was difficult to use. Chapman’s Handbook (1895) and particularly his Color Key (1903), which was a true visual guide and in many ways bridged the gap between shotgun and binocular bird identification, were steps in the right direction but still used keys. Florence Merriam Bailey’s Birds of Village and Field (1898) and Birds Through an Opera-Glass (Merriam 1896) dealt with sight identification but were not comprehensive in terms of species. Perhaps the best of the lot was Ralph Hoffmann’s A Guide to the Birds of New England and Eastern New York (1904). But it, too, was restricted in the species covered and was also a bit daunting to use.

Chester Reed produced a series of small oblong books that were aimed for beginning birders (e.g., 1906a,b). The guides were small enough for any pocket, had a color illustration of each species, and were inexpensive. They became the most successful of the early guides for the novice. Ernest Thompson Seton hit upon the idea of making comparative plates of ducks (Seton-Thompson 1903) and flying raptors as viewed from below at considerable distance (Thompson 1897), an idea that strongly influenced Roger Tory Peterson when he gathered together his first field guide. Hence by the early 1930s, many of the ideas that Peterson brought together in his 1934 field guide had been touched upon by previous authors except, perhaps, the drawing of lines (headless arrows) to show significant field marks. The stage was set.

Peterson consulted Griscom about his field guide plans, and Griscom read the manuscript but, because it was difficult to do much in the publication world during the Great Depression, Peterson’s manuscript was initially turned down. Peterson explains how the manuscript was finally accepted:

Through Ludlow and his young disciples, I learned the tricks of field recognition and, being trained as an artist, was able to pull things together and give them form. In 1934 my first field guide was published. William Vogt had taken it in unfinished form to four publishers who had turned it down…. However, Francis Allen, the top editor at Houghton Mifflin, was himself a member of the Nuttall Club. He saw the validity of my unorthodox approach—patternistic drawings with arrows pointing to the key field marks. He brought in Ludlow Griscom, then at the Museum of Comparative Zoology at Harvard, and seated him at the far end of the long table in the Houghton Mifflin board room in Boston. He then held up one plate after another. Without hesitation, Ludlow identified every bird. Having passed the test, Houghton Mifflin decided to gamble …. (Peterson 1994).

The rest, as they say, is history. Peterson revised his guide periodically and it became the jewel in the crown of the burgeoning Peterson Field Guide series that eventually included more than 50 titles on a broad spectrum of natural history subjects. It also spawned competition from Richard Pough and the National Audubon Society- sponsored series of three bird guides (e.g., 1946), the Golden Guide (Robbins et al.1966), the National Geographic Society (1983) guide and more recently the Sibley guides (e.g., Sibley 2000). Scott Weidensaul described the impact of the Peterson guides on the development of birding:

It is hard to overestimate the impact that Peterson’s guides have had on the world—not just on birding, but the way we as a culture think and feel about nature itself. Millions of people whose eyes were opened to the natural world in the pages of a Peterson guide provided the impetus for the modern environmental movement…. “In this century,” ecologist Paul Ehrlich said in the 1980s, “no one has done more to promote an interest in living creatures than Roger Tory Peterson.” (Weidensaul 2007: 181-182).

The National Audubon Society

Both Griscom and Peterson played significant roles in the National Audubon Society (Audubon), promoting birding and conservation. Frank Chapman, who ran the bird department at the American Museum of Natural History, founded what became the most popular bird magazine in America, Bird-Lore, in 1899. He remained its owner and editor until the mid-1930s when he sold it to the National Audubon Society; it morphed into Audubon Magazine in 1941 (Gibbons and Strom 1988). Peterson, who was employed by the society beginning in 1934, became the art editor of Bird-Lore, and education director of the society. He made the education section of the magazine prominent, revamped its cover, and graced the magazine with his bird art. Further, he wrote Junior Audubon leaflets, wrote articles for Bird-Lore, conducted radio shows, and gave lectures around the country, all with a strong conservation message. In his first four years at Audubon, he gave 100 lectures, 75 radio broadcasts, wrote 62 leaflets (3,800,000 printed), nine guides for teachers (87,500 printed), wrote 33 articles, and produced 480 paintings and illustrations for Bird-Lore—a prodigious effort (Carlson 2007). After he left Audubon, Peterson continued to influence birding and the conservation movement through his writings and through his long-term participation in the Audubon Screen Tours series (Rosenthal 2008).

Griscom became the “Seasons” editor for the Boston area for Audubon Magazine and by 1941 was the national editor. Griscom was great friends with Guy Emerson, president of the National Audubon Society, who leaned heavily on Griscom for advice, and in 1941, Griscom became a member of the board of directors. In 1944, when Emerson stepped down, Griscom refused the presidency and arranged a shake-up whereby John Baker, the executive director, would become president and Griscom chairman of the board. As chairman of the board, Griscom was in charge of Audubon policy and guided the society’s conservation initiatives for two decades. He also had access to high-ranking government officials. When Monomoy on Cape Cod and the Parker River and Plum Island areas north of Boston were under consideration as National Wildlife Refuges, Griscom threw his support behind the federal initiatives. When a storm of local opposition and lobbying arose, Griscom contacted Ira Gabrielson, Chief of the Biological Survey (now US Fish and Wildlife service), and Harold Ickes, Secretary of the Interior. With Griscom’s considerable influence, both places became National Wildlife Refuges. When he retired from the board in 1956 he received the society’s Conservation Medal.

Fig. 4. Photograph of the members of the Old Colony Bird Club, originally called the Outer Circle Bird Club. Ludlow Griscom seated on left; Margaret (second from left) and Arthur (fourth from left) Argue, leaders on Massachusetts Audubon Society birding bus tours; Ruth Emery (back row left), was the first “Voice of Audubon,” perhaps the first birding hotline in the United States; C. Russell Mason (back row, second from left) executive director of Massachusetts Audubon Society and founder of an early ecotourism company: Russ Mason’s Flying Carpet Tours. Ruth Emery and Margaret Argue were two of the five women admitted to membership in the Nuttall Ornithological Club in 1974, the first women so honored. Photograph courtesy of Ruth Emery.

Griscom, the Boston scene, and the Massachusetts Audubon Society

Perhaps Griscom’s greatest influence in promoting birding was in the greater Boston area through the Massachusetts Audubon Society (Mass Audubon). As I reported (Davis 1994: 160-161):

In the decade after his arrival [1927], Ludlow Griscom had a growing influence on the development of the Massachusetts Society. His championing of sight recognition in birds and the burgeoning sport of birdwatching and listing affected all levels at the society, from the backyard birdwatching member to the president. Many of the most active members and staff were, in effect, Griscom protégés. He reached them through personal contact in the field, either by inviting people to join his entourage for a day of birding or through accidental contact as the Griscom party crossed paths with other groups. (Figure 4).

Griscom also aided the rise of birding in New England through his dozens of articles in the Bulletin of the Massachusetts Audubon Society and the annual publication of his year list, which served as the bar to which local birders aspired. By the mid-1930s Griscom began publishing his sight records in the Bulletin rather than in The Auk. C. Russell Mason, executive director of Mass Audubon from 1939 through the mid-1950s, frequently recruited Griscom to give major talks at annual meetings, which were typically grandiose affairs held in Boston. Griscom was the guiding light for Records of New England Birds, a publication initially produced by the Boston Society of Natural History beginning in 1936, and later by Mass Audubon—the records therein were all sight records. Griscom served on three major Mass Audubon committees and was chairman of the Publications Committee. Griscom also pushed hard for conservation within Mass Audubon, as recalled by Henry Parker after Griscom’s death:

With the death of Ludlow Griscom…the Society lost a staunch supporter and friend…. Many of us may not have fully realized his grave concern and tireless drive, for a wider knowledge and acceptance of sound conservation methods throughout the country. This he saw as the backbone and “raison d’etre” of the Massachusetts Audubon Society. (Parker quoted in Davis 1994:164).

Perhaps in Mass Audubon, more than in other organizations where he served, his personality was a critical factor. He was the consummate showman who led the charge for increased public awareness and appreciation of birds and the natural world—and a love and thrill of birding.

The Legacy of Griscom and Peterson

Both Griscom and Peterson were influential in three areas: the development of birding, the scientific study of the living bird, and conservation. In addition, their efforts produced legions of birdwatchers. Since World War II, the contributions of birders to the science of ornithology has increased considerably, especially since the beginning of the age of the computer in the 1980s. Computers have made possible the collection, storage, compilation, and analysis of vast data sets that are a goldmine of information for professional ornithologists.

Perhaps the oldest data collection project is the Christmas Bird Count (CBC), established in 1900 by Frank Chapman of the AMNH. From a modest beginning, the number of birders participating in the CBC each year has burgeoned to the tens of thousands. Similarly, the various bird observatories scattered around the United States and Canada often rely on birders to aid with bird banding projects. Project FeederWatch of the Cornell Lab of Ornithology and Bird Studies Canada has enlisted the participation of thousands of birders, as has the eBird project at the Lab. The compiling of data for breeding bird atlases, some now in their second or third generation of data collection, have relied heavily on the participation of birders. Today there are shorebird monitoring projects, hawk migration counts, and the list goes on and on. These citizen science projects are providing crucial data for scientific study and also are the backbone of science-based conservation initiatives. The legacy of Ludlow Griscom and Roger Tory Peterson is, indeed, profound.

Literature Cited

• Bailey, F. M. 1898. Birds of Village and Field: A Bird Book for Beginners. Boston: Houghton Mifflin.
• Barrow, M. V. Jr. 1998. A Passion for Birds, American Ornithology after Audubon. Princeton, New Jersey: Princeton University Press.
• Burtt, E. H., Jr., and W. E. Davis Jr. 2013. Alexander Wilson, the Scott Who Founded American Ornithology. Cambridge: Harvard University Press.
• Carlson, D. 2007. Roger Tory Peterson: A Biography. Austin: University of Texas Press.
• Chapman, F. A. 1895. Handbook of Birds of Eastern North America. New York: Appleton.
• Chapman, F. A. 1903. Color Key to North American Birds. New York: Doubleday, Page.
• Coues, E. 1872. Key to North American Birds. Boston: Estes and Lauriat.
• Davis, W. E. Jr. 1987. History of the Nuttall Ornithological Club 1873-1986. Memoirs of the Nuttall Ornithological Club, No. 11, Cambridge, MA: NOC.
• Davis, W. E. Jr. 1994. Dean of the Birdwatchers, a Biography of Ludlow Griscom. Washington, D.C.: Smithsonian Institution Press.
• Dunlop, T. R. 2011. In the Field, Among the Feathered: A History of Birders & Their Guides. Oxford, UK: Oxford University Press.
• Gibbons, F., and D. Strom. 1988. Neighbors to the Birds: A History of Birdwatching in America. New York: W. W. Norton.
• Hoffmann, R. 1904. A Guide to the Birds of New England and Eastern New York. Boston: Houghton Mifflin.
• Merriam, F. A. 1891. Birds Through an Opera-Glass. Boston: Houghton Mifflin.
• National Geographic Society. 1983. A Field Guide to the Birds of North America. Washington, D.C.: National Geographic Society.
• Nuttall, T. 1905. A Popular Handbook of the Ornithology of the United States and Canada, New Revised and Annotated Edition (Montague Chamberlain, ed). Boston: Little, Brown, and Co.
• Peterson, R. T. 1934. A Field Guide to the Birds. Boston: Houghton Mifflin.
• Peterson, R. T. 1960. The Era of Ludlow Griscom. Audubon Magazine 62:102-103; 131; 146.
• Peterson, R. T. 1980. Evolution of a Field Guide. Defenders 55:282-288.
• Peterson, R. T. 1994. Forward. Pp ix-x in Davis, W. E., Jr. Dean of the Birdwatchers, a Biography of Ludlow Griscom. Washington D.C.: Smithsonian Institution Press.
• Pough, R. H. 1946. Audubon Bird Guide: Eastern Land Birds. New York: Doubleday.
• Reed, C. A. 1906a. Bird Guide: Water Birds, Game Birds, and Birds of Prey East of the Rockies. Worchester, MA: Charles K. Reed.
• Reed, C. A. 1906b. Bird Guide: Land Birds East of the Rockies. Worchester, MA: Charles K. Reed.
• Robbins, C. A., B. Bruun, and H. S. Zim. 1966. Golden Guide to Field Identification of the Birds of North America. New York: Golden Press.
• Rosenthal, E. J. 2008. Birdwatcher: The Life of Roger Tory Peterson. Guilford, CT: Lyons Press.
• Seton-Thompson, E. [Seton, E. T.] 1903. Two Little Savages. New York: Doubleday.
• Sibley, D. A. 2000. The Sibley Guide to Birds. New York: Alfred A. Knopf.
• Stone, W. 1924. Griscom’s “Birds of the New York City Region.” Auk 41:172-174.
• Thompson, E. S. [Seton, E. T.] 1897. Directive Coloration in Birds. Auk 14:395-396.
• Wiedensaul, S. 2007. Of a Feather: A Brief History of American Birding. Orlando:Harcourt.
• Walton, R. K., and W. E. Davis Jr. 2010. Massachusetts Audubon Society: The First Sixty Years. Pp. 1-63 in Contributions to the History of North American Ornithology, Volume III (W. E. Davis Jr. and J. A. Jackson, eds.). Memoirs of the Nuttall Ornithological Club, No. 17, Cambridge, MA: NOC.
• Wilson, A. 1808-1813. American Ornithology. Philadelphia: Bradford and Inskeep.

Ted Davis thanks John Kricher for helpful comments on the manuscript.