Swans are the largest, and generally considered the most beautiful, of the waterfowl. The Mute Swan is one of 7 species of swan worldwide. Adult females weigh around 9 kg, with males around 11 kg, although weights of up to 15 kg have been recorded. A male is known as a cob, a female is a pen, and the young are called cygnets. According to the magazine Wildlife Conservation, a swan can have 25,000 feathers.
Mute Swans are generally found in low-lying wetland areas of the northeastern Atlantic coast, and around Lake Michigan. They do not normally start to breed until they are at least 3 years old. Between March and May a huge nest is constructed, in which the pen lays a clutch of normally between 3 and 8 eggs (although as many as 13 have been recorded). The eggs are laid at 2 day intervals, with incubation starting with the last egg and taking 35 days. During the breeding season the male becomes very territorial and aggressive to any intruders. This behavior has been known to extend to swans fighting to the death. They often threaten humans who venture too close to their nests while issuing a warning call. Although they can inflict a painful blow with their wings, contrary to popular belief they do not bite.
The cygnets when hatched are grey and downy, but this down is soon replaced by brown feathers, which gradually turn white during the next 12 months. The parent birds strongly protect their offspring for the first few months but will drive them away by the following breeding season.
The cygnets will normally join flocks of other non breeding swans, especially during the malting season in July - August when they malt all their feathers and for a short time become flightless. They can fly in 3 to 4 months and generally stay with the parents until the next breeding season when they are asked to leave. Over the next two years the immature swans may start to form a pair bond with a mate and will look for a suitable territory on which to breed.
Mute Swans have been known to live for over 25 years, but most only survive to 5 or 6 years old. Many cygnets die in their first 12 months, often due to flying accidents.It is a popular misconception that Mute Swans pair for life and that a bird will pine to death when its partner dies. This is far from true, with some birds having as many as 4 mates in a life time, and in some cases actually 'divorcing' a mate in favour of a new one. There have even been incestuous relationships reported. However research does show that well established pairs tend to be more successful at raising their young.