trumpeter swan

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A large white swan (Cygnus buccinator) of western and central North America, having a loud buglelike call.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The largest North American swan, Cygnus buccinator; they have white plumage with a long neck, a short black bill.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun large pure white wild swan of western North America having a sonorous cry