The shallow ponds, undisturbed lakes, slow rivers, wetlands, are preferred breeding habitats for swans. Due to their large size and weight, they require large water bodies or open lands for taking off.
They make their nests on mounds of aquatic vegetation close to the water’s edge. The nest is normally made by both parents that are used for several years after repair. Swans are monogamous, and both take care of eggs. Typically 3-8 eggs are laid by female swans, the number can increase up to 12 eggs in some species.
The trumpeter swan is the largest swan, which lays the largest egg among all flying birds. The egg weighs up to 11.3 ounces and has 2.9 inches in width, 4.5 inches in length.
In some species, both the parents incubate the eggs for 3-45 days, whereas in some other species females incubate, and the male guards the nest. Most of the species of swan show territorial behavior only during the breeding season and protect their nests from predators, and other animals.
However, some species are territorial year-round. After hatching the eggs, the cygnets become able to swim after few days. However, they complete long distances on their parents’ backs.
The swans show parental care for their young for 3-5 months in most species. However, the cygnets can feed on their own after few weeks. The black swan shows much longer parental care and cares for around 9 months.
The juveniles of tundra swans develop faster as compared to other swan species and are thought to fledge after 40-45 days.