Canada Geese in North America
by
Donald H. Rusch
National Biological Service
Richard E. Malecki
National Biological Service
Robert Trost
U.S. Fish and Wildlife Service
Canada Geese in North America | ||
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by Donald H. Rusch National Biological Service Richard E. Malecki National Biological Service Robert Trost U.S. Fish and Wildlife Service |
| Canada geese (Branta canadensis) are probably more abundant now than at any time in history. They rank first among wildlife watchers and second among harvests of waterfowl species in North America. Canada geese are also the most widely distributed and phenotypically (visible characteristics of the birds) variable species of bird in North America. Breeding populations now exist in every province and territory of Canada and in 49 of the 50 United States. The size of the 12 recognized subspecies ranges from the 1.4-kg (3-lb) cackling Canada goose (B.c. minima) to the 5.0-kg (11-lb) giant Canada goose (B.c. maxima; Delacour 1954; Bellrose 1976). | ||
| Market hunting and poor stewardship led to record low numbers of geese in the early 1900's, but regulated seasons including closures, refuges, and law enforcement led to restoration of most populations. Winter surveys were begun to study population trends and set responsible harvest regulations for these long-lived and diverse birds. Winter surveys begun in 1936-37 probably represent the oldest continuing index of migratory birds in North America. | ||
Surveys |
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| Sporadic counts of migrating and wintering Canada geese from the ground were supplemented by regular tallies from the air in the early 1950's. Winter surveys began because the subarctic and arctic nesting areas of many subspecies were still unknown and aerial surveys of these remote areas were impractical. | ||
| The well-designed spring surveys of Canada geese that began in the 1970's with the Eastern Prairie population have now expanded to include several others (Office of Migratory Bird Management 1993). Spring surveys estimate numbers of each population at the time of year when subspecies are reproductively isolated and geographically separated. The smaller subspecies of Canada geese nest farther north (arctic and subarctic regions of Alaska and Canada), and most winter farther south (gulf states and Mexico) than do the larger subspecies. | ||
Status and Trends |
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| Most aggregations of wintering geese were overharvested in the early 1900's. Those subspecies that nested in temperate regions closer to humans were most heavily hunted. By 1930 the giant Canada geese, which nested in the northern parts of the deciduous forest and tall-grass prairie, were believed extirpated. Numbers of the large geese that nested in the Great Plains and Great Basin (B.c. moffitti) were also severely reduced. Small Canada geese from the remote arctic and subarctic breeding ranges fared somewhat better, possibly because of less exposure to unregulated exploitation, but were also reduced in number. | ||
| Figure. Total numbers of Canada geese counted on winter surveys, 1936-93. | |
Although hunting depleted numbers of Canada geese, human activity also created new habitats for these birds. Agriculture led to the clearing of forests and the plowing of prairies, creating the open landscapes preferred by geese. Cereal grains and pastures provided new food sources for geese, and the development of mechanical combines and pickers created an increased supply of waste grain (Hine and Schoenfeld 1968). In addition, uniform hunting regulations and improved wildlife law enforcement curtailed goose harvests after the signing of the Migratory Bird Treaty in 1916, and most goose populations increased over the next several decades (Figure). National wildlife refuges provided key sanctuaries and further assisted recovery of Canada goose numbers. |
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| The giant Canada goose was "rediscovered" by Harold C. Hanson, a biologist of the Illinois Natural History Survey; the publication of his book The Giant Canada Goose in 1965 initiated a restoration effort that became one of the great success stories of wildlife management. These large geese were restored to their former range in the Mississippi and Central flyways and now breed in all states east of the Mississippi River. | ||
| Although small geese with long migrations have generally not fared as well as large geese with short migrations, some small geese have responded well to intensive management. Introduced Arctic foxes (Alopex lagopus) depleted populations of the Aleutian Canada goose (B.c. leucopareia), and the subspecies was nearly extinct by 1940. About 300 were rediscovered in the Aleutians on Buldir Island in 1962 (Jones 1963). Subsequent removal of foxes and translocation of wild geese have led to increases to about 750 geese in 1975 and more than 11,000 in 1993. | ||
| Heavy hunting caused numbers of cackling Canada geese to plummet to record lows in the early 1980's, but intensive research (Raveling and Zezulak 1992) and harvest control have brought about a sustained recovery (Table). | ||
| Recent genetic studies of Canada geese support the existence of two major groups that last shared a common ancestor about 1 million years ago. The large-bodied group (B.c. canadensis, interior, maxima, moffitti, fulva, occidentalis) is mainly continental in distribution, while the small-bodied group (hutchinsii, taverneri, minima, leucopareia) breeds in coastal Alaska and Arctic Canada (Rusch et al. in press). | ||
| The future of these diverse stocks of Canada geese depends upon information adequate to permit simultaneous protection of rare forms, responsible subsistence and recreational hunting of abundant populations, and control of nuisance Canada geese in urban and suburban environments. Delineation of breeding ranges and spring surveys that monitor numbers of pairs and their productivity offer the most realistic approach to population management and the conservation of this remarkable diversity of geese. | ||
| Ranges of most populations have been described, and spring surveys are in place for some. Development and continuation of spring surveys for each subspecies of Canada geese are prerequisites for their conservation and management. The species can no doubt be perpetuated without spring surveys, but without continued monitoring, management, and conservation, it is likely that rare forms will disappear, opportunities for subsistence and recreational hunting will diminish, and nuisance problems caused by large geese living near humans will increase. | ||
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National Biological Service Wisconsin Cooperative Wildlife Research Unit University of Wisconsin Madison, WI 53706 |
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| References | |
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Bellrose, F.C. 1976. Ducks, geese and swans of North America. Stackpole, Harrisburg, PA. 544 pp. Delacour, J.T. 1954. The waterfowl of the world. Vol. 1. Country Life, Ltd., London. 251 pp. Hanson, H.C. 1965. The giant Canada goose. Southern Illinois University Press, Carbondale. 226 pp. Hine, R.L., and C. Schoenfeld, eds. 1968. Canada goose management. Denbar Educational Research Services, Madison, WI. 194 pp. |
Jones, R.D., Jr. 1963. Buldir Island, site of a remnant population of Aleutian Canada geese. Wildfowl 14:80-84. Office of Migratory Bird Management. 1993. Status of waterfowl and fall flight forecast. U.S. Fish and Wildlife Service, Washington, DC. 37 pp. Raveling, D.G., and D.S. Zezulak. 1992. Changes in distribution of cackling Canada geese in autumn. California Fish and Game 78:65-77. Rusch, D.H., D.D. Humburg, M.D. Samuel, and B.D. Sullivan, eds. 1994. Biology and management of Canada geese. Proceedings of the 1991 International Canada Goose Symposium. In press. |