Wild Side: Canada geese elude hunters, loaf on Lake George
Canada geese are known for their aggressively protective attitude, fidelity to their mates and families, and their ability to rapidly process food through their digestive systems. They have become prominent citizens in River Falls, lazing their days away on Lake George and flying off to feed in surrounding fields.
On a recent walk along the White Pathway, I counted about 1,000 of the big birds on the water. When the sun was low in late afternoon they flew up off the river in loudly honking family groups, making a scene over downtown reminiscent of Alfred Hitchcock's movie, "The Birds."
Of the seven currently-recognized subspecies, the most abundant in our area are the giant Canada geese, Branta canadensis maxima. These are the largest wild geese in the world, weighing up to 20 pounds. Most adults weigh about 12 pounds and have five- to six-foot wingspans. This subspecies of geese was almost hunted to extinction by the 1930s. In 1948, a power plant built in Rochester, Minn., kept Silver Lake on the Zumbro River ice free during the winter and Canada geese flocked there.
In 1962, Harold Hanson of the Illinois Natural History Survey identified a remnant flock of giant Canada geese on Silver Lake in Rochester. The Minnesota DNR, the U.S. Fish and Wildlife Service and the Canadian Wildlife Service entered into a cooperative agreement to protect the nesting grounds of the birds in the Interlake region north of Winnipeg in Manitoba and to protect their winter habitat on Silver Lake.
Since then, the giant Canada goose population has increased from about 6,000 individuals to about 1.6 million in the Mississippi flyway today. Giant Canada geese have re-established populations throughout their former range.
Unlike their more migratory cousins, giant Canada geese are comfortable living in developed areas and have established many non-migratory populations. Their increased abundance and preference for grassy open areas near water have made them nuisance animals around golf courses, airports and urban areas.
Non-migratory flocks of giant Canada geese occur in this area where they have open water during winter, including Lake George in River Falls, on the St. Croix River at Kinnickinnic Narrows, and on the St. Croix and Lake Mallalieu in Hudson.
Giant Canada geese are long-lived and become "educated" by hunters. The River Falls flock has modified its feeding habits to loaf around on Lake George during the day, flying off at about the end of shooting hours and feeding on waste grain in fields after dark.
Brian Thompson of River Falls is an avid goose hunter. He told me it has become difficult to shoot Canada geese around here because the geese have become very wary of hunters and have changed their feeding habits to be more nocturnal.
The River Falls flock of geese returns to Lake George after feeding; digest their food and excrete feces, making them a source of nutrient loading to the St. Croix River. Various studies of the effects of waterfowl on water quality have shown that on average, a goose excretes about half a gram of phosphorus each day. The River Falls flock of Canada geese probably doesn't contribute a large fraction of the 9,520 kilograms of phosphorus annual load of the Kinnickinnic River to the St. Croix River estimated by the U.S. Geological Survey.
The River Falls flock of giant Canada geese on Lake George provides plenty of entertainment for wildlife viewers in town and challenging game for hunters.