Giant Canada goose makes recovery
This giant Canada goose at Silver Lake sports a neck band placed by wildlife managers as part of a study to learn more about the birds. n a bitterly cold day in January 1962, it took a five-pound bag of sugar and 10 pounds of flour to convince skeptical biologists what others had suspected for years: The giant Canada goose wasn't extinct after all. The largest of the North American geese, which once nested from southern Iowa well into Canada, were thought to be extinct because they hadn't been seen on their traditional breeding grounds in the United States.
But some people kept insisting that a flock of Canada geese that came to Rochester every fall was too large to be the interior goose, the next-largest subspecies. So experts came to the lake that cold day, captured some geese and weighed them.
Scales were out of whack, experts said. They were registering weights much too high for the interior Canada goose. So one man went to a local grocery store, bought the sugar and flour, which were in bags of known weight, and checked the scales.
The scales were right and the experts were wrong.
Branta canadensis maxima, the giant Canada goose, was alive and well.
Today, there are about 250,000 of them in several distinct populations in North America. Some spend all year in and around large cities, but one of them, known as the Interlake population, comes to Rochester every fall. It is named for the area where it breeds between huge lakes north of Winnipeg.
How they got here, and how they survived extinction, is a story of chance and serendipity, of some captive geese and a power plant.
Jack Heather, area Department of Natural Resources wildlife manager, said the geese probably came to this area in winter for many centuries because of food and open water in local streams. But the geese were shot by market hunters or for subsistence when settlers came to the Upper Midwest, he said. Because of the heavy hunting, and because they weren't being seen by some bird experts, they were thought to be extinct.
While they were on the list of extinct species, however, the Mayo brothers got some tame geese from Michigan about 1924 and put them in Mayowood Lake. In 1936, the Rochester Park and Recreation Department put six geese at Silver Lake and was later given a flock of 12 large Canada geese by a Mayo Clinic patient who enjoyed seeing the other flock.
In 1948, a pivotal event happened. The Silver Lake Power Plant was built. It discharged warmed water into the lake, keeping it open most of the winter. More geese, many of them very large, were attracted to the captive birds and the open water. More continued to come here, and the population reached 4,000 about 1960.
Wildlife experts wondered about their large size. And in 1962, the geese were ``rediscovered,'' much to Rochester's delight.
Giant Canada geese look much like other Canada geese, with their dark necks, white cheek patch and grayish-brown bodies. They are just larger. They can weigh up to 24 pounds and have wingspans of 84 inches, though most are smaller. But they are generally several pounds heavier than the interior species of geese.
They are also strong traditionalists, going back to the same breeding areas and returning to Rochester, even to the same spot on Silver Lake, year after year.
Breeding grounds are in wilderness land between Lake Manitoba to the east and lakes Winnipeg and Winnipegosis to the west.
In late summer and early fall, geese stage on the bigger lakes for fall migrations. When cold hits, they fly south about 500 miles to Rochester. Some stop en route, and others make the 10hour flight non-stop, Heather said. A few Interlake geese head directly to Kansas, but most come here. Around Thanksgiving, there are 30,000 or more geese in the Rochester area.
When they first arrive, they are more skittish and won't come near people. ``They will eventually tame down a bit to the point where they will take corn that is thrown to them,'' he said.
Within a few weeks, as winter hammers this area, some of the geese will fly further south into Missouri or southern Illinois.p