Wintering Tundra Swans

Contributed by Lois Ports for Bristlecone Audubon Chapter 

On wintry days, flocks of North America’s most numerous swan gather on lakes, reservoirs and estuaries. They are known to stopover at Southfork Reservoir and the Ruby Lake National Wildlife Refuge. During flight there is a characteristic whistling in their wings which led Meriwether Lewis to call them “whistling swans”. The Tundra Swan is the most widespread of the two native swan species, the other being the Trumpeter Swan. Tundra Swans are a very large waterfowl (length: 47.2 – 57.9 in., wingspan: 66.1 in.) with heavy bodies (10-18 lb.) and long necks. Tundra Swans have entirely white plumage. The bill is mostly black and usually has a yellow spot at the base. The legs and feet are black. Immature birds are gray-tinged on the wings, head, and neck.

Tundra Swans breed on remote arctic wetlands of North America. Tundra Swans form permanent pair bonds by the time they are 2-3 years old. Once a pair forms, Tundra Swans feed and roost together year-round and are considered monogamous. They raise one clutch of eggs a year and typically have 3-7 cygnets. This species migrates in flocks composed of family groups, leaving arctic breeding grounds and migrating along traditional pathways to coastal North American wintering areas. Flock sizes range to over 100 individuals. Migrant flocks fly in a V formation and can fly at elevations up to 5,000 ft. during migration but typically fly at less than 1000 ft. during local movements. Migration routes are through interior North America with traditional stopover areas, primarily in the Great Basin, upper Mississippi River Valley, s. Ontario, and in se. Pennsylvania. Western wintering populations arrive in areas of the Great Basin including the Great Salt Lake area of Utah in early Oct; departing by mid-Nov and arriving in wintering areas in California and Oregon late Nov and early Dec.  Each year’s young remain with their parents until their arrival back on the breeding grounds the following year. This is a long-lived species with one record of a female living for over 23 years.

Tundra Swans can take off easily from land or water and fly with their necks extended straight out and their black legs trailing behind. On the water, Tundra Swans keep their necks straight and will often tip up to forage in the manner of dabbling ducks. When they are not breeding Tundra Swans form large, gregarious flocks that travel, forage and roost together.

Tundra Swans are very vocal throughout the year, especially on water and in flight, with calls serving wide variety of social functions. All calls, except the soft contact calls, are 1–3 syllable variations of ou, oh and the long vowel sound of oo with the sexes giving similar calls. Tundra Swans slap the water with their feet in response to an intruder or when they see or hear other swans in the distance. Air whistling through the wings of a swan in flight can be heard even when the bird is flying 100 feet or more overhead.

Historically, the Tundra Swan’s diet consisted primarily of submerged aquatic vegetation and aquatic organisms such as clams, worms, mussels, etc. Due to declines in such vegetation at some migratory stopover sites, and especially at wintering areas, has driven this species to also feed in grain fields.

To learn more about our area’s birds, plants and other wildlife follow us on FaceBook at Bristlecone Audubon. Contact us at bristleconeaudubon@gmail.com if you would like to receive our digital newsletter.

The Annual Elko – Spring Creek Christmas Bird Count will be held on Saturday, December 19, 2020. Due to Covid-19 we are changing some of our guidelines to ensure the safety of all participants. If you are interested in participating please contact Lois Ports at 775-753-2569 or at bristleconeaudubon@gmail.com.


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