Mute swan (Cygnus olor)

A mute swan in shallow water.

Mute swans are large water birds with white feathers and orange bills. Mute swans can chase other water birds, including loons, and can keep those birds from nesting. One bird can uproot about 8 pounds of submersed aquatic vegetation daily, reducing important native aquatic plants.

Mute swan

 

Description

Appearance

Mute swans are large water birds with white feathers and have orange bills (beaks) with black knobs. Male and female birds have the same coloration. Males can have larger black knobs than the females. Mute swans can have a wingspan of 7-8 feet, reach a height of 4 feet tall, and weigh 25-30 pounds.

While they are called mute swans because they are less vocal than other swan species, they do make sounds such as grunting, snorting, or hissing.

Young, immature swans are called cygnets. Cygnets can be either white or gray/brown. When the dark feathered individuals mature, they become white. Cygnets have dark or pinkish bills.

Habitat

They live on lakes and other wetlands. They mainly eat submerged aquatic vegetation, but also eat small aquatic animals.

Biology

Mute swans can stay at a location year-round if there are areas of open water and access to food. 

Mute swans are sexually mature at two years old. Many do not nest until they are 3-5 years old. Nests are mounds of aquatic vegetation and are usually made along shorelines. The breeding season generally begins in March and April. They lay 2-11 eggs (generally 5-7) which are incubated for 34-41 days. They eggs are 3.5-4.6 inches long and 2.3-2.9 inches wide and blue/green to white in color. Adult mute swans can be very territorial during the breeding season.

Origin and spread

Mute swans are native to Europe and Asia. They were introduced to the United States beginning in the 1800s to be part of parks, estates, and zoos. They have since escaped or been intentionally released. The first report of mute swans in Minnesota was in 1974 in Duluth.  The Minnesota Breeding Bird Atlas describes mute swans as very rare in Minnesota and they are not considered to have a breeding population. In the United States, mute swans are most common in Michigan and along the northeastern coast. Refer to the Cornell Lab for current range and sightings maps.

Don't be fooled by these look-alikes

  • Trumpeter swans, Cygnus buccinator (native) – Adult trumpeter swans are all white and have a black bill unlike the orange bill of a mute swan.
 
  • Tundra swans, Cygnus columbianus (native) - Adult tundra swans are all white and have a black bill unlike the orange bill of a mute swan. The tundra swan's bill often (but not always) has a yellow mark in front of its eye. Tundra swans only migrate through the state, which means they don’t breed in Minnesota and are unlikely to occur here during the summer months. Although a few individuals do overwinter in the state, frequently among groups of trumpeter swans, most are also absent during the winter months.
  • The Wisconsin Department of Natural Resources has a swan comparison chart of characteristics of trumpeter, tundra, and mute swans.
 

Regulatory classification

  • Mute swans are a Minnesota Department of Natural Resources Regulated Invasive Species meaning that it is legal to possess, sell, buy, and transport this species, but they may not be introduced into a free-living state. If you choose to possess mute swans, you must ensure that captive swans are confined so that they cannot escape.
  • If you breed mute swans, you must have a state game farm license, make sure the mute swans are prevented from escaping captivity, and follow all state game farm license requirements (Minnesota Rules, parts 6242.0500-6242.1200 and Minnesota Statutes, section 97A.105).

Threat to Minnesota

  • Mute swans can chase and compete with other water birds, including loons and native swans, and can keep those birds from nesting.
  • One mute swan can uproot about 20 pounds of submersed aquatic vegetation daily, reducing important native aquatic plants.
  • Mute swans can be aggressive towards people.

What you should do

  • Do not purchase mute swans. It is illegal to release mute swans, or allow mute swans to escape, into the environment in Minnesota.
  • If you choose to possess mute swans, you must ensure that captive swans are confined so that they cannot escape.
  • If you breed mute swans, you must have a state game farm license, make sure the mute swans are prevented from escaping captivity, and follow all state game farm license requirements (Minnesota Rules, parts 6242.0500-6242.1200 and Minnesota Statutes, section 97A.105).
  • Report observations of wild birds to the DNR Invasive Species Program and your local conservation officer. 

Reporting

Report observations of wild birds to the DNR Invasive Species Program and your local conservation officer. Please send photos, if possible, to aid in identification.

Resources

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