![]() CANADA GOOSEINTRODUCTION
DESCRIPTIONThe Canada goose is easily distinguished from other North American waterfowl by their size and coloration. The Canada geese in Michigan are primarily from two subspecies, Branta canadensis interior (interior Canada goose) and Branta canadensis maxima (giant Canada Goose). The interior Canada goose may weigh from 7 10 pounds and is shorter and more slender than the giant Canada goose which may weigh up to 15 pounds. Their size difference makes them relatively easy to distinguish in a mixed group of geese. The Canada goose's head, bill and neck are black except for its white cheek patches. The body feathers vary from gray brown to dark brown with the belly feathers being white. Its tail feathers are black. A white bar separates the tail from the rump feathers. Young of the year geese are identified by the notch on the tip of their tail feathers. Both the goose (female) and the gander (male) are colored the same. Their feet are colored solid black. POPULATION/DISTRIBUTIONCanada geese seen in Michigan may represent several groups. During the spring and fall migrations, geese which breed in Canada pass through Michigan on their way to breeding grounds or wintering grounds in Mississippi or Tennessee. These geese may stop at rest points along the way for periods of rest and feeding. Michigan also has a population that breeds here but usually migrates to Mississippi or Tennessee wintering grounds. A third population, generally the giant Canada goose, both breeds and winters in Michigan unless they are forced south by extremely cold temperatures that freeze all the open water they need. Michigan's breeding population consists of 30,000 35,000 birds on about May 1. By fall, the population increases to 80,000 birds. Hunters harvest 15,000 20,000 birds each year. Waterfowl biologists speak of the various flyways when describing populations of geese and other waterfowl. Flyways are artificially established boundaries which follow the natural migration routes as much as possible. Natural migration routes sometime overlap, but the geese separate at some point to fly to the different wintering grounds. Because of waterfowl management practices, the Canada goose population remains stable. The United States Fish and Wildlife Service, a division of the United States Department of the Interior, sets annual hunting quotas for each flyway in cooperation with state governments. The individual states then establish each year's hunting season. HABITATCanada geese live in wetland habitats which provide the necessary food, water, shelter and breeding areas. Farmland with large, open fields with waste grain and nearby water provide excellent habitat during migration and staging (gathering of many family groups before leaving on the migration). Marshes containing cattails, bulrushes, sedges, willow, and alder are good breeding areas. Giant Canada geese have learned to make use of the limited wetland habitat that often occurs around heavily developed urban and suburban lakes and rivers. FOOD AND FEEDINGCanada geese eat a wide variety of food items. Plants such as grasses, sedges, seeds, berries are important for grazing. Canada geese eat yellow and white water lilies, pond weed, milfoil, and coontail. They also eat cultivated grains such as millet, corn, oats, soybeans, and sorghum. These grains are especially important on the winter feeding grounds and along migration routes. They may also eat green barley, wheat, rye, alfalfa and clover. During the fall, acorns become an important food item for the Canada goose and many other wildlife species. Canada geese eat some animal matter such as insects and small crustaceans. Like all waterfowl, Canada geese need a source of gravel. They ingest the gravel which remains in their gizzard. The gravel helps break down the food into digestible sized particles. MORTALITYThe Canada goose reaches an average age of 7 9 years in the wild. Records show that a wild bird reached 23 years and one in captivity reached 33 years of age. Wild populations experience a 30 50% annual mortality rate. The main cause of mortality for juvenile and adult Canada geese is hunting. Some natural predators such as coyotes, wolves, bobcats, lynx, bears, cougars and eagles will attack an adult goose. However, in Michigan, these predators have been eliminated or exist in low numbers. Occasionally viral or bacterial diseases spread through wintering populations when geese are extremely crowded. Mortality is high for the unhatched eggs and young goslings. Raccoons, striped skunks, red fox, coyotes, crows, ravens and gulls prey on the eggs of the Canada goose and other waterfowl eggs. Some nests may be deserted because of predator or human activity or because of extremely poor weather conditions. At the Seney National Wildlife Refuge in the Upper Peninsula, black flies have killed goslings by spreading disease through biting. BEHAVIORCourtship and Breeding. The Canada goose breeds throughout Michigan. They establish a pair bond (attachment between male and female goose) either on the wintering grounds or on the nesting grounds. The female indicates her choice of a male by beginning to follow him on land or water. The male indicates his choice by beginning to defend the immediate area around the female. Once paired, the geese stay bonded until one member of the pair dies. Mated pairs who have been separated for even a short time greet each other with an elaborate greeting display. This display includes loud honking between the pair and head rolling by the male. During head rolling, the neck is extended and the head is rolled back and forth. The geese also raise their head and bodies and flap their wings. Nesting begins when the geese arrive back at their nesting grounds in April or early May. The female picks the nest site of her choice. The male will try to chase another pair away from the nest if it is already claimed. Most pairs try to use their nesting ground from the previous years if possible. The nest site is usually located on an elevated area on an island, at the top of small hills, or on the raised perimeter of a lake. Old muskrat houses, beaver lodges, gravel bars, dikes or artificial structures such as wooden platforms may be used. The number of nests within a given area depends on the aggressiveness of the geese and how close they allow another pair to nest. This varies widely from bird to bird. The female builds the nest by making a depression in the ground and lining it with mosses, lichens, twigs, and leaves. She uses down (soft fuzzy feathers) from her breast to create a soft lining. The total process takes about 4 hours with the first egg being laid shortly afterwards. Canada geese lay 1 egg every 1 to 2 days. The average clutch consists of 5 6 dull white, oval eggs. Incubation takes 28 days, with the female sitting on the eggs and the male guarding the area around the hen. The female leaves the nest in the early morning and late afternoon to feed, drink, bathe, and preen. Territory. Canada geese have well defined and defended territories. The purpose of the territory is to prevent disturbance of the female during egg laying and incubation from other geese and predators including wild animals, humans and their pets. Territories also seem to create more social stimulation between the pair members. Canada geese are very aggressive in defending territories. They will even charge humans who approach too near to the nest site or to the goslings. Their beaks and wings can cause serious bruises. The male defends the area surrounding the nest and feeding sites while the female defends only the nest site itself. The male warns intruders by giving a loud "ahonk ahonk" call. If that doesn't scare the intruder off, he gives the rolling neck display (neck is extended outward, head and neck wave back and forth in arc). The attack follows quickly if the intruder still doesn't leave. Nest site defense ends after the goslings have hatched. However, defense of the family unit continues until late summer. Hatching/Early life. The eggs hatch at about the same time. The young goslings are brooded (kept warm and protected from predators) by the female for several hours following birth and at night for several days. On the day after they hatch, the goslings are taken by both the goose and gander to the brood rearing area. Several family groups rear broods in the same locality. The brood flocks consisting of several families are called creches. The flocks stay together for 2 months until the young can fly. Family importance. The family groups stay together at least until fall. Large families have dominance over small families. Any size family is dominant over paired or unpaired birds who do not have families. The ranking of the gander within the larger flock is dependent on the size of his immediate family group. Molting. Adults molt (loss of feathers) old, worn feathers during the brood rearing stage. The molting process takes from 3 4 weeks. During this time both adults and young stay secluded since neither are able to escape predators by flying. Both adults and young birds acquire their flight feathers about the same time. They join large flocks of geese when they are able to fly. Migration. Migration flights go north to breeding grounds in March. The flocks make many stops along the way to feed. These flocks consist of paired adults, young from the previous breeding year and subadults (birds not old enough to nest). The Canada goose passing through Michigan in late March to early May are those which breed in Canada. During the late summer, family groups begin gathering at staging areas for the fall migration to southern wintering grounds. This migration seems to be triggered by the onset of cold weather. The flocks usually arrive at the southern feeding grounds during mid November. ECONOMIC IMPORTANCEThe Canada goose is a mixed blessing for local economies. They sometimes consume large amounts of crops on agricultural land which may upset the farmer. However, many farmers lease their cropland for hunting purposes. Hunters spend millions on food, lodging and fuel and hunting equipment. Wildlife refuges attract thousands of wildlife enthusiasts each year. These people also spend millions in local economies for food, lodging and fuel. They may have invested in binoculars and cameras before even leaving home. Urban flocks entertain residents who enjoy watching and feeding them, but large concentrations of geese pollute water and soil beaches and lawns. This entire website is copyrighted by Diana Pederson, 1997-2008. Use of any page |