Canada geese are monogamous, one female and one male mate. Pairs form during the winter, during migration or on their wintering grounds, for the next breeding season. Mated pairs may stay together for more than one year, sometimes staying together for life.
Males fight over females with their wings and bills. The winner approaches the female with his head down and neck undulating. He makes hissing and honking noises. The pairs mate either before or after they have found a nesting location.
Mating System: monogamous
The average clutch sizes are 5 eggs although this size ranges from 2 to 9 eggs. The incubation period lasts 23 to 30 days. Incubation must occur immediately after the last eggs are laid.
Females choose the location for nesting and even build the nest without the males. The males defend the territory, nest, and eggs from intruders, such as other geese. Female Canada geese pick nesting sites that have good visibility but are isolated. This allows them to readily see danger approaching and to be difficult to get at. The nesting area also must have open water with low banks so they can have access to water plants and places to get into or out of the water. Swamps, marshes, meadows, lakes, and other such areas are among some of their favorite nesting spots. The Canadian and Alaskan shorelines have expanses of tundra habitat that provide good nesting sites. Canada Geese are are often seen nesting on small islands that don't have very tall grasses or on muskrat houses (which are similar to small islands).
Nests are very simple and are made quickly. Materials that are used are weeds, twigs, grass, moss, needles, and other such materials. After some collection and building, female geese round out a curve or depression with their bodies. They drop the materials around themselves and move the items to get the best fit. From time to time they round out the center with their chests or feet. If there are no items of vegetation the nest may only be a depression in the ground shaped by their chests and feet. Once the eggs are laid, the nest is lined with feathers and down. Down insulates against extreme warmth as well as cold, stabilizing egg temperature.
Females have to leave the nest to eat, rest, swim, and preen. Young geese hatch with the use of an egg tooth on top of its beak to crack open the shell. Goslings keep cracking open the shells until they are completely free between 24 and 48 hours later. All of the eggs in the clutch are fully hatched with in 24 hours. The goslings with in a clutch usually have a gender ratio that is equally males and females.
Breeding interval: Canada geese breed once yearly.
Breeding season: Females start laying eggs during the first weeks of March and continue as late as June in parts of the Arctic.
Range eggs per season: 2 to 9.
Average eggs per season: 5.
Range time to hatching: 23 to 30 days.
Range fledging age: 68 to 78 days.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate)
Average eggs per season: 5.
After the eggs hatch, the family group (the offspring and parents) leave the nest and begin to travel together to feed and seek shelter. Both males and females feed and guard their young. Upon hatching, young Canada geese are able to follow their parents around and leave the nest.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)