Abstract
Of all of the world's geese perhaps the least known has been the rule goose. This bird, a large representative of the white-fronted goose family, was first described in 1852 by Hartlaub from specimens taken in Texas. At that time Hartlaub recognized that two distinct forms of white-fronted geese existed in Texas - a pale colored race, abundant in number, and a larger and darker form substantially less common. Hartlaub referred to the more abundant form as the Pacific white-fronted goose, Anser albifrons frontatis, and the larger birds as rule geese, Anser albifrons gambeli.
About the turn of the century it was discovered that big, dark, white-fronted geese existed in the interior valley areas of California. Although differences seemed to exist between the Texas and California birds, both forms were grouped together as tule geese, Anser albifrons gambeli.
Early in this century numerous observations of the California birds were made by James Moffitt. Most of Moffitt's observations were from birds collected in the Butte Sink area of the Sacramento Valley. Moffitt's untimely death ended his efforts and, unfortunately, no one continued his work. Subsequent to Moffitt's studies little additional information was recorded. Ultimately tule geese became something of a mystery, and many wildlife specialists doubted their existence. The aura of mystery continued, and only recently have discoveries been made which have resolved much of that mystery.
For many years Bob Elgas, an aviculturist from Montana, has been involved in the keeping and rearing of wild geese. About 1960, and quite by accident, he came into possession of an adult male tule goose. The bird had been acquired by personnel of the Oregon Game Department after presumably having been injured during a storm. The bird ultimately made its way into the Elgas flock, initiating in Elgas an interest that has endured to this day, an interest that has resolved much of the mystery that has enshrouded the tule goose.
The differences between the Pacific white-fronted goose and the tule whitefronted goose are substantial. The Pacific white-front, which enjoys wide distribution throughout the western United States, is a medium sized goose in which the general color pattern is brownish grey. In adult plumage all white-fronted geese are characterized by irregular black splotching on the underside, and are frequently known by the vernacular name of "speckle-belly" It is noteworthy that juveniles in their first year lack the black breast markings of the adults. The correct name, whitefronted goose, originates with the ring of white feathers surrounding the base of the bill. Tule white-fronted geese are similar in plumage to their smaller cousins, but the greyish color is replaced by a rich tone of brown. The head and neck in particular are much darker. The tule goose is also a larger bird, and the physical structure is much more elongate. The wings are proportionately large, a characteristic which is especially noticable when the birds are in flight. As an overwintering species Pacific white-fronts are relatively abundant and are widely distributed throughout the western United States. The tule goose, however, is restricted to areas of the central valley of California, with a population only a fraction that of the common form.
The arrival of the tule goose from Oregon initiated a desire for further information which resulted in a flow of correspondence between Elgas and other wildlife specialists. It soon became obvious that little information was available, and, indeed, many within professional circles questioned the birds' very existence. On rare occasions when one of the big geese came to the attention of wildlife specialists they frequently expressed the opinion that despite the very different appearance, the bird in question was not representative of a valid race, but was an atypical individual taken from a flock of otherwise normal Pacific white-fronted geese.
In establishing the validity of a race it is important that the breeding ground be known. Elgas was familiar with big, dark white-fronted geese seen occasionally during migration in the western portion of the province of Saskatchewan. He reasoned that birds migrating through that area could be expected to have originated somewhere eastward of the mountainous barrier of Alaska. The MacKenzie River Delta area of the Northwest Territories seemed the most logical place to expect to find the big birds. Regarding their breeding areas, wild geese are categorized into two general groups - those that are known as tundra nesting species, which utilize the open coastal tundras of the arctic, and those that are known as forest dwelling species, usually the larger varieties, which choose more inland breeding areas that are more heavily vegetated. Available information indicated that tule geese could be expected to fall within the latter category.
After having evaluated considerable material Elgas decided that a search of the MacKenzie Delta area was worthwhile. In 1964, Bob Elgas and Jack Kiracofe, an experienced waterfowl aviculturist from Pennsylvania, with their respective wives, formed the Elgas-Kiracofe expedition. The expedition was partially funded by the International Council for Bird Preservation, and World Wildlife Fund, and was made possible by the effort of Dr. S. Dillon Ripley, Secretary of the Smithsonian Institution. Elgas and Kiracofe searched the area extensively. In the southwest portion of Old Crow Flats in the Yukon Territory a breeding population of large, dark white-fronted geese was found. A number of birds, both adult and downy young, were captured and returned to the United States for evaluation. Additionally, some fifty adult birds were captured, banded with U.S. Fish & Wildlife Service bands, and released. The banded birds would be of utmost importance in determining exact wintering areas.
The live birds which were returned to the United States were evaluated by personnel of the U.S. Fish & Wildlife Service. As a result of that evaluation it was determined that indeed the birds from Old Crow Flats did answer Hartlaub's description, and they were identified as tule geese, Anser albifrons gambeli. Initial evaluations were made before band recoveries were returned. Ultimate band recoveries came as a great surprise in that the recoveries came not from California, as was anticipated, but from Texas and Northern Mexico. This was altogether unexpected and resulted in re-evaluation of criteria. It was then determined that the birds discovered by Elgas and Kiracofe were actually the Texas race, as described by Hartlaub in 1852, leaving the California birds as an essentially undescribed form.