The Light Geese

The term “light geese” includes Ross's geese, lesser snow geese, and greater snow geese. All three species nest in the Arctic. Ross's geese and lesser snow geese winter together in mixed flocks in both the Mississippi and Central flyways. As a result, biologists have combined light geese into two populations: the midcontinent population, wintering in Texas, Louisiana, and Arkansas, and the western Central Flyway population wintering in Colorado, New Mexico, and the Texas Panhandle.

Things are a little less confusing in other flyways. The only light geese in the Atlantic Flyway are greater snow geese, most of which winter along the coast from New Jersey to North Carolina. Most snow geese in the Pacific Flyway nest in the western Arctic or on Russia's Wrangel Island. Western Arctic birds winter in California and Mexico, while Wrangel Island geese use winter habitats in Washington's Puget Sound, Oregon, and California.

Light geese have been front and center these past few years. Much of this attention has focused on the midcontinent population where winter counts increased from less than a million birds in 1970 to almost 3 million birds by the late 1990s. While increases in midcontinent light geese have been a boon to U.S. hunters, the consequences for Arctic landscapes have been far less favorable. Light geese and their young feed in large groups. As bird numbers grew, the geese began to overgraze much of their Arctic breeding grounds. This led to changes in soil salinity and soil moisture that fundamentally altered Arctic plant communities, and not for the better. Some of the worst overgrazing occurred along the coast of Hudson Bay. The damage has been so extensive that biologists have concluded it will take hundreds of years for these Arctic areas to recover, if ever.

Waterfowl managers recognized that the continued destruction of these habitats would have dire consequences both for geese and other Arctic wildlife. The best way to reduce midcontinent light geese was to reduce the survival of adult geese, and the best way to do that was through increased hunting. In 1998, special conservation seasons were put in place to give hunters additional opportunities to harvest light geese. The goal of these extended seasons was to reduce the annual survival rate of adult geese below 80 percent. If that could be accomplished, goose numbers would come down, and the destruction of Arctic breeding grounds would be slowed.

So how have we been doing in our efforts to control light geese? According to Dr. Ray Alisauskas, a research scientist with the Canadian Wildlife Service who is analyzing survival rates of midcontinent light geese, preliminary results indicate that survival rates of adult geese have remained above the 80 percent target, despite recent increases in the total harvest of midcontinent geese. The struggle to control light geese continues.

Overpopulation of light geese isn't confined to the midcontinent. Greater snow geese in the Atlantic Flyway increased from less than 50,000 birds in the 1960s to nearly a million birds by 2003. Although these geese have yet to impact their Arctic breeding grounds, continued growth will eventually threaten the Arctic ecosystem. Lowering adult survival rates through increased harvest remains the best option.

Light goose populations elsewhere are also on the march. The western Central Flyway population has increased from 12,000 to 150,000 birds. Controlling light goose numbers may be the most significant challenge faced by waterfowl managers and hunters in the coming years. While harvests of some goose populations may have to be increased to prevent overabundant birds from damaging fragile tundra habitats, other goose populations may require harvest restrictions to help them bounce back during years when breeding success is poor. As waterfowl managers continue to learn more about the birds and refine their management strategies for different populations, the future for geese looks brighter than ever.

Dr. Mark Petrie, manager of conservation planning at DU's Pacific Northwest office, wishes to thank the many state, federal, and university biologists who provided information for this report.