Each spring and fall, hundreds of thousands of Canada geese (not "Canadian" geese) pass through Wisconsin in their famous V-formations, honking up a storm. At the same time, people flock to Wisconsin wetlands to see this amazing wildlife event. What do we know about geese? Where do they come from and where are they going?
When you look at a large flock of Canada geese, they all look pretty much alike; grayish-brown body feathers, white underside from the neck to the tail, long black neck and head with a white chin/cheek patch. In North America, there are at least 12 different groups of this species, each having a different breeding and wintering area and they travel different migration routes. In Wisconsin, you may see four different sub-species of the Canada goose. The "interior" Canada geese are more commonly seen during peak migration times 'just passing through.' The "giants" are commonly seen year-round. The largest of the sub-species, they weigh up to 18 lbs. Giants can be seen in city settings hanging out at park-like ponds and open areas with mown grass. The city goose population is growing fast. And, they can be a nuisance in some places. The other two sub-species, the "lesser" and "Richardson's" Canada geese are uncommon. They are very small geese, about the size of a small duck. They nest in Alaska.
Many of Wisconsin's Canada geese belong to the "Mississippi Valley Population," called MVP. These are geese that exclusively fly from Canada through Wisconsin along the "Mississippi River" flyway which includes Horicon Marsh and other south-eastern Wisconsin refuges. Wildlife biologists know this because they track the birds by placing bands on their necks and legs.
There are more than 1 million Canada geese in the MVP, with about 100,000 - 200,000 stopping at Horicon Marsh each fall. Flocks select a wetland area and stay near there for 6-10 weeks to refuel and rest during their long journey. While there, they eat grass and grain. Each goose eats about ½ lb. of food per day. That's a lot of food!
Beginning in late spring, geese in the MVP find a nesting territory and selects a nesting site in north-central Canada along the western shore of James Bay and the southern edge of Hudson Bay. After a large nest is built of grasses and downy feathers, a clutch of 4-6 eggs is laid. The goose (female) incubates them with her warm body for about 26 days while the gander (male) guards the nest. Soon after the goslings (young) hatch, the family searches for tender stems of marsh grass. Within 70 days, the goslings test their new wings and learn to fly. The family will stay together and migrate as fall approaches.
Some families of geese arrive in Wisconsin's wetlands as early as mid-September and others wait until October or November. Peak migrations happen in our state between October and November. Flocks of geese fly in a v-shaped group and some will travel non-stop for up to 16 hours to cover the 850 miles from Hudson Bay to central Wisconsin. Flocks will also make shorter flights depending on wind patterns and where food is available. During migration, geese can travel as fast as 70 miles per hour with a good tail wind at an altitude of up to 9,000 feet. Geese, like most of our migratory birds, often migrate during the night. Scientists are not positive how geese know their way along the migration route.
Once the flocks arrive at Wisconsin's wetlands, they quickly get into a routine of feeding mostly in area crop fields in the morning and late afternoon. During the daytime, geese mainly loaf around. Just before sunset you can see the geese fly back in several groups to rest for the night at nearby wetlands. Watch for spectacular flights of thousands of geese landing at marshes, especially Horicon and Theresa Marshes. This schedule is kept by the geese for about 4 to 8 weeks and then they are ready to head south.
Family groups of geese mostly stay together for the first year of life. If separated, geese will always rejoin others of their own kind. Many geese stay at Wisconsin marshes until the cold freezes their roost sites on open water and snow covers their food. Geese continue their migration to wildlife refuges in southern Illinois, western Kentucky and Tennessee, about 450 miles south of Wisconsin. Around late February/early March, geese return north along the same routes, stopping at Wisconsin wetlands as the snow and ice melt, before continuing to Hudson Bay in April. Horicon Marsh and all of east-central Wisconsin is an important "staging ground" for geese - a place that provides water, shelter, and the food which gives geese the energy to travel the many miles of their annual journey.