IDAHO RARE BIRD REPORT FORM
Species reported: Whooper Swan (Cygnus cygnus)
Date and time of record: Nov 26, 2008
Reporter: Jay Carlisle, Idaho Bird Observatory, Boise
State University, 1910 University Ave., Boise, ID 83725;
jaycarlisle@boisestate.edu
Other observers: none at time – many in coming days
Date report prepared: Jan 25, 2009
Locality: Snake
River along Bell Rapids Rd., Hagerman, Twin Falls Co.
Habitat: river
Conditions:
Sunny with cool temperatures; good lighting
Did you takes notes? No.
Did you consult a field guide or other reference
work? If so, which guide(s)? During observation: National Geographic and the Sibley
Guide
Description of bird: A large (white) swan with prominent yellow patch covering almost half
of upper mandible and central portion of lower mandible.
Behavior of bird: repeatedly submerging head to feed.
Was in company of about 6 Trumpeter Swans and many Canada Goose
How and when did you positively identify the bird, and
what clinched the identification for you? When I first arrived at the site and scanned
the swans, this one had its head submerged so all I saw were Trumpeters. When it raised its head and I saw the extensive
yellow on the bill, I knew it was either a Bewick’s (Tundra) or a Whooper (or
possibly some hybrid). I then studied
size & shape relative to nearby Trumpeters and determined that it was
nearly the same size (maybe 5% smaller but within range) and thus a large
swan. Also, the bill shape/size seemed
similar to Trumpeter Swan (pointing away from a Bewick’s). Study of the pattern (coming forward to a
point) and extent of yellow on bill made me more confident of the ID. Also, conversations with Cliff Weisse, esp.
regarding neck thickness, helped to confirm that the size & shape of the
bird was consistent with Whooper.
List similar species and how you eliminated them: similar species include Trumpeter Swan (similar in
size & shape but no yellow patch on bill), Tundra Swan (smaller with small
yellow patch restricted to lores), and ‘Bewick’s’ Swan (Eurasian form of Tundra
– yellow patch on basal half of bill but patch smaller than in Whooper and not
coming forward in a point along bill).
What is your experience with this or similar
species? I have seen 10s to
hundreds of Trumpeter and Tundra Swans but this is my first Whooper Swan and I
am yet to see a Bewick’s Swan.
Describe your general birding experience: I have been birding for about 15 years.
Were photos, video, and/or audio obtained? Yes, see attached.
These images were cropped and resized from the originals but no other editing was done. If you want to see the original click the image.
