Geese are a species of waterfowl that spend most of their lives around water in wetlands, lakes, and rivers. They also live in open areas such as fields, parks, lawns, and golf courses. They are related to ducks and swans and are classified in the same order (Anseriformes).
These birds gather in large flocks throughout the year, except during breeding season. In the spring, geese leave their winter flocks with their mate and establish a territory they can defend to raise their young.
While some geese start breeding at age two or three, most wait until age 4. Once they choose a mate, geese usually stay with that bird for life until one of them dies or they divorce.
Divorce does occur between geese, but it does not happen often. The main reason mated pairs of geese divorce is because one of the geese decides to skip a year of breeding. When that occurs, the other may search for a new partner.
Do All Species of Geese Mate for Life?
Wild geese live for 10 to 25 years or more. The oldest recorded wild goose lived to be over 30 years old, and the oldest in captivity lived more than 40 years. That’s a long time for birds to stay together. Once geese survive to adulthood, their survival rate is 90%.
Deaths occur from hunting, predation, disease, and accidents, but most geese survive once they become adults, so mated pairs can stay together for many years.
Mated geese typically live longer than unmated geese. The cooperation exhibited by the male and female allows them to increase their odds of survival and the odds that they will successfully raise offspring. The longer a pair is mated, the more offspring they produce overall.
Geese may mate for life, but they are not always monogamous. Sometimes, male geese may fertilize the eggs of a different female outside of the mated pair bond. However, they continue to support their mate and defend their territory.
When Do Geese Mate?
The breeding season for geese starts in the early spring. Mated pairs break off from their flock in February and find a place to nest. Once they do, they aggressively defend that nesting area from any animals that get close, including humans.
In places where the population of geese is high, available nesting areas are limited. The mated geese will fight for their tiny territory and, ultimately, may nest close to others.
Once nesting begins in March, or later at higher latitudes, they finish most of the territorial disputes and settle into the business of raising their young.
In places with high densities of geese, several broods of goslings and their parents flock together in a gang once the babies are ten to twelve weeks old, and the parents are not quite as protective of their offspring.
How Do Geese Mate?
When a male goose is looking for a mate, it may chase around a female it wants. Once he corners her, he will try to entice her by dipping his head and bobbing it around on his neck in a dance-like way. Females select their mate based on the male’s apparent level of fitness.
When mate selection is completed, geese build nests with grasses, leaves, and moss, usually within 150 feet (46 meters) of water. Their nests are hidden from view in thick vegetation, among the roots of trees, in artificial nesting boxes, and planters.
After the nest is finished, the male copulates with the female either in the water or on land to fertilize the eggs. Females then lay an average of five eggs, although the number of eggs ranges between two and twelve. They incubate the eggs for up to four weeks before they hatch.
How Often Do Geese Mate?
The frequency of mating during the breeding season depends on several factors. Geese may mate several times with their partner during the breeding season to make sure all of the eggs laid in the nest are fertilized. The more eggs the female lays, the more frequently they mate.
If there are many territorial disputes, the geese may spend more time defending their territory and less time mating and laying eggs. If they nest in an isolated area, they may have more energy to spend on mating instead of defending their territory.
If the nest is destroyed before the eggs hatch, the mated pair will rebuild their nest and immediately begin mating again and laying eggs. Their goal is to produce offspring that survive their first year.
What Happens if a Goose Loses Its Mate?
When one of the geese in a mating pair does not return to the breeding site after the winter migration, the other goose may find a new mate before the breeding season begins.
If one of the geese dies during the breeding season, the remaining goose may try to find a new mate immediately and raise offspring if enough time remains. If it cannot find a new mate, it may migrate to a different location with other unmated geese during the molting period.
Most geese do not spend time mourning their mate when it is time to produce and raise offspring. There are anecdotal cases of geese that seem to mourn their dead partner, but no research into these occurrences.
Do Geese Mate With Other Species?
Like all water birds in the Order Anseriformes, geese can and do mate with other species within their taxonomic family. Most of these matings result in hybrid geese that are fertile. When geese from two more distantly related species mate, they produce sterile offspring.
Mating between two different species of geese happens for a few reasons, including nest parasitism, copulations outside the pair bond, limited mate choices within a species, and captivity.
When a goose lays an egg in another species’ nest, the gosling that hatches will imprint on the mother that incubates the egg, despite their differences. It will grow up and likely choose a mate of the same species as its adopted mother.
Hybridization commonly occurs in the wild and captivity when multiple species of geese congregate in the same area. Scientists are interested in this topic and how it drives speciation within the taxonomic order of waterbirds.