21-7-2026 KNOCKNASTOOKA, IRELAND - MUTE SWAN (Cygnus olor)

The mute swan, Cygnus olor, is a majestic bird, easily recognized by its all-white plumage and the distinctive orange beak bordered with black. The male, known as a cob, is noted for a prominent knob atop the beak, which is more pronounced than that of the female, or pen.

Adult mute swans measure between 125 to 160 cm in length, with a wingspan of 200 to 240 cm. The males are generally larger than females and possess a larger knob on their bill. The species is one of the heaviest flying birds, with males reaching weights up to 14.3 kg and females up to 10.6 kg. Juveniles, or cygnets, are not as bright white as adults and have a dull greyish-black bill for their first year.

Native to Eurosiberia, the mute swan has been introduced to North America, Australasia, and southern Africa. It is partially migratory in northern latitudes, with some populations moving as far south as North Africa and the Mediterranean.

Mute swans are found in a variety of wetland habitats, including lakes, ponds, rivers, and coastal areas, where they build large mounds of vegetation for nesting.

Mute swans are territorial and monogamous, often reusing the same nest each year. They are less vocal than other swan species but are known for their aggressive defense of their nests and offspring. They can be seen performing a threat display known as busking, with wings half raised and neck curved back.

While not as vocal, mute swans produce a range of sounds including grunting, hoarse whistling, and snorting. They also have a rhythmic song during courtship displays and a unique throbbing sound from their wings in flight.

Mute swans lay 4 to 10 eggs, with the female brooding for around 36 days. Cygnets typically fledge at around 120 to 150 days old.