Mute Swan

Cygnus olor

Mute Swans in North America descended from swans imported from Europe from the mid 1800s through the early 1900s. People brought them in to adorn wealthy estates, parks, and zoos. Escapees established breeding populations in Canada and the USA. Now we can find them in the Northeast, the Mid-Atlantic, the Great Lake region, and Pacific Northwest.

We believe Mute Swans mate for life. However, changing of mates occurs infrequently, and swans will remate if their partner dies. If a male loses his mate and pairs with a young female, she joins him on his territory. If he mates with an older female, they go to hers. If a female loses her mate, she remates quickly and usually chooses a younger male.

The black knob at the base of the male Mute Swan’s bill swells during the breeding season and becomes noticeably larger than the female’s. The rest of the year, the difference between the sexes is not obvious.

These large birds have enormous appetites. A study done in Maryland found they ate up to 8 pounds a day of submerged aquatic vegetation. They removed food and habitat for other species faster than the grasses could recover.

Taxonomists regard Mute Swans as monotypic (there are no subspecies). Yet they come in two different color morphs (gray and white), most easily recognised in the downy young (called cygnets). The gray (or “Royal“) chicks start off with gray down and grow in gray-brown and white feathers, giving them a mottled look. White (or “Polish“) chicks have all white down and juvenile feathers. White morph adults may have pink or gray legs and feet instead of black. Otherwise, the adults look alike.

My favorite memories of meeting Mute Swans came at Point Pelee in Canada on the northwestern shore of Lake Erie. A rather cooperative pair of these elegant birds brought their young family to within a few feet of the shore to forage. The cygnets were too small to reach the grasses growing on the bottom of the shallow marsh. But the parents easily tipped down and brought up long strands and dropped them in front of the chicks to devour.