Cygnus
buccinator
(Trumpeter
Swan)
Physical
Description:
Size: 60-72" (150-180
cm). A large, pure white swan with
long neck, flat head and heavy, all black bill. Swim with neck straight and
bill horizontal.
Similar Species- Tundra swan is smaller with a small yellow spot between the eye and the bill. Head rounder, call softer, high-pitched hoo-hoo-hoo given in flight.
Song:
A loud, booming horn-like call
on one pitch
Distribution:
Breeds in Alaska, western Canadian
provinces, southeastern Oregon, eastern Idaho, Montana, and northwestern Wyoming.
Introduced and established in Nevada and southwestern South Dakota. Winters
primarily from southern Alaska to Montana, and south to northern California,
sometimes Utah, New Mexico, and eastern Colorado.
Diet:
Adults feed on
aquatic vegetation, but may also graze in fields. Young eat aquatic beetles
and crustaceans, and, after 5 wk, aquatic plants. In Idaho, adults feed primarily
on water- milfoil and pondweed; existing evidence indicates that preferred winter
food is declining.
Ecology:
Builds
nest on ground. Forages on, or just under, water surface. Occurs as resident
along Yellowstone Park border; migrant, northern populations winter in Harriman
State Park and Island Park. Extensive studies have been done in Idaho on wintering
and nesting behavior and habitat. High first-year mortality in Tri-state (WY,
ID, MT) cygnet population. Low winter flows and cold conditions can negatively
impact wintering swans. Several breeding areas in Idaho outside of Fremont Co.
are result of transplants.
Reproduction:
clutch size varies from 2-9 eggs,
but is usually around 5 (in Idaho study, mean clutch size ranged 3.6-4.4).
Both sexes, but mainly the female, incubate eggs. Incubation lasts
33-37 days. Nestlings are precocial, but remain with adults
until subsequent spring. Fledging period lasts 100-120 days. In Idaho, productivity
of Trumpeter Swans has decreased in last 10 yr, perhaps due to poor cygnet survival.
Conservation:
Element Code: | ABNJB02030 |
Status: | Protected nongame species |
Global Rank: | G5 |
State Rank: | S1 |
National Rank: | N4B,N4N |
Important
State References:
Gale, R.S., E.O.
Garton, and I.J. Ball. 1987. The history, ecology, and management of the Rocky
Mountain population of trumpeter swans. Idaho Dept. Fish & Game, Boise.
314pp.