Formerly known as whistling swans, tundra swans are regular migrants through the Brownsville area. In spring they arrive unpredictably in small flocks and remain for only a short time. Large concentrations arrive in the fall starting in late October and stay until late November or freeze-up.
- Length: 36 inches Wingspan: 85 inches
- Large, long-necked waterbird with short legs and a short duck-like bill
- Long neck held straight up with a kink at base
- Black bill with variably-sized yellow spot at base
- Culmen (upper bill) somewhat concave
- Black of bill extends up to eye but does not encircle it
- Straight demarcation on forehead between black bill and white feathering
- Black legs and feet
- Entirely white plumage
- Sexes similar
The very large Tundra Swan is unlikely to be confused with anything but other swans. White Pelicans, Whooping Cranes, Wood Storks, and Snow Geese are all white birds that from a great distance could look like swans but all have black primaries. The adult Mute Swan can be told from the adult Tundra Swan by its orange and black knobby bill. The adult Trumpeter Swan is very similar to the adult Tundra Swan but it is slightly larger, has a straight culmen (upper bill), the bill has no yellow spot, the eye is enclosed by black, and the white feathering on the head extends in a v shape into the dark bill. In the far northwest, a subspecies of the Tundra Swan shows more yellow at the base of the bill and could be confused with the Alaskan Whooper Swan. The Whooper Swan has yellow in the bill that goes beyond the nostril.
Males are called cobs; females, pens; young, cygnets. The clutch size varies from 2-8 rough-shelled, pale yellow creamy-white eggs. The eggs hatch in an average of 35 days. The cygnets hatch in late June and stay in families for about one year. At about 15 months they get their adult plumage.
Swans mate for life, however, if one of a pair dies the other will find a new mate. The young are precocious in that they enter the water soon after hatching.
Swans gather and pile up grass, sedges, and mosses within 100 yards of the Arctic coastline. The nests measure about 6 feet across and 12-18 inches high. During incubation, females alone care for the eggs while the males stand guard.
To achieve flight, swans face the wind, run along the surface of the water for 15 to 20 feet, flap their wings and beat the water with their feet alternately until they have gained sufficient headway to launch into the air. During flight in v-shaped formations, swans achieve speeds up to 100 miles /hour with a tail wind. They have been sighted at elevations of 6,000 to 8,000 feet and have been struck by aircraft resulting in at least two deaths.
Tundra Swan Links