The Canada goose (Branta canadensis) is one of the most well known and popular game birds in the upper Midwest. It is instantly recognizable in a field or on a lake, and its distinctive V-shaped formations flying overhead are used as a sign of changing seasons. Canada geese figure strongly in tales and folklore: their heroic migration jaunts and devotion to their mate (they bond for life) make them good animal models for humans.

Canada geese also are a success story in wildlife management. By the early 1940s, heavy hunting had reduced Canada goose populations close to extinction. A concerted effort by federal agencies, particularly the U.S. Fish and Wildlife Service, has brought the Canada goose back to levels where hunting is again allowed—and has been for over 20 years. All in all, the Canada goose is a proud, respectable bird.

Until now. People tell tales about the Canada goose that drove them over the edge, until they ran screaming out of the house to chase away any goose that strayed into their yard. Suddenly the headlines are full of proposals to kill Canada geese and donate them as food for the homeless. Companies have sprung up that specialize in keeping Canada geese off of ponds and property. Why all the fuss? Quite simply, the problems started when some of the geese stopped migrating.

In the last ten years, the population of Canada geese permanently residing in suburban America has skyrocketed. These are full-time residents who don't fly away with the first ice. They are big and intimidating, hissing and charging in defense of their territory. There are so many of them that their ordinary honking can even become irritating. They eat turfgrasses down to a nub and then leave uncountable piles of slimy green droppings to be stepped in. And, they can spread disease. Almost overnight, these once-endangered birds have become pests at some Illinois lakes.

Canada geese have 11 subspecies. These subspecies range in size from 29 to 38 inches in length and 6 to 12 pounds in weight, with the smaller populations generally living further north. In 1965, a biologist found a population of the subspecies Branta canadensis maxima, the giant Canada goose, which had been thought to be extinct. This subspecies averages 12 pounds and is the subspecies that originally inhabited much of the upper Midwest, including Illinois. Since its rediscovery, the giant Canada goose has recovered more quickly than any other subspecies and now makes up the bulk of our resident goose populations. There are estimated to be as many as 1 million giant Canada geese in the Mississippi flyway, as many as all other Canada geese subspecies in the flyway combined.

Canada goose "paradise" would include acres of short tender grass, a freshwater pond for drinking water and security, and no predators. It would look much like a public park, corporate office campus, golf course, cemetery, or waterfront yard. However, while other Canada goose subspecies are wary of humans, giant Canada geese are predisposed to ignore people. The biologist who rediscovered the giant Canadians noted that the "placid disposition of the giant Canada goose sets it apart from all others."

Disposition or not, the giant Canada goose has adapted well to living among us. They have a weak migratory instinct and will stay in place as long as there is ice-free water and available food. Since people are willing to feed them and often keep their ponds ice-free in the winter, the geese have begun sticking around in suburbia. They have become accustomed to cars, planes, and other noises of modern life. In fact, they are so used to cars that they are willing to walk out in front of oncoming traffic, secure in the knowledge that the cars will stop for them.

The suburban landscape contains food and space to support a few geese without causing too much difficulty for people. Giant Canada geese, however, like to stay around where they are hatched, in the same way that migrating geese tend to return to the same spots year after year. The lack of predators and abundance of food allows giant Canada geese to lay more eggs and have more goslings survive to adulthood than would be normal in the wild, so a small population can quickly grow into a large population. In addition, the presence of geese and goslings (as well as ducks) is an attractant to other giant Canada geese who might have been displaced from another area.

In addition to the trouble they cause for people living around lakes, excessive, unnatural populations of giant Canada geese are as much or more of a problem for the lakes themselves. Geese eat plant material on land, but are frequently out on the water or ice when they defecate. This material is high in nutrients derived from the plants they eat. These nutrients are the same ones used for growth by algae and plants in the lake. When the geese become year-round residents, the nutrient loading can become very significant, contributing to algal blooms and excessive plant growth. In fact, one Canada goose can contribute about a half pound of phosphorus to the lake each year. If you have 20 resident geese on your lake, that is the same as dumping a 100-pound bag of fertilizer with a "10" phosphorus number into the lake each year!

The problems of year-round resident Canada geese exist on a national scale. Any real control effort will need to be approached regionally or nationally to be effective. However, that does not mean that there is no recourse to your local goose problems. But, it does mean that anything you accomplish is likely to be only temporary. If you move a flock of geese off your pond or lake, there are always more geese out there looking for a new home.

It is important to know that all Canada geese are protected by the federal Migratory Bird Treaty Act, whether they migrate or not. This means there are limits to what you can do to control Canada geese. You cannot physically harm the geese or their eggs without a permit. Killing geese outside of hunting season, or outside of designated areas during hunting season, is a federal crime and may violate state and local laws as well. With these restrictions in mind, there are still several approaches you can take to control your local Canada goose population.

Habitat changes caused by people have encouraged the geese to remain year-round. The most effective way of reducing these permanent populations is to change the habitat, at least to the extent possible. There are three changes that can be easily accomplished on most lakes: 1) Don't feed the geese!, 2) modify the shoreline vegetation, and 3) allow the lake to freeze over in winter, if possible.

	Canadian Geese (PDF printable version, 151KB)
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