Date: 11/8/19 10:18 am
From: Richard Stevens <birdertoo...> [cobirders] <cobirders-noreply...>
Subject: [cobirders] Swan In Flight
Hello cobirders,

I have been asked twice now about the Tundra Swan photo on our webpage. "how to tell it is a Tundra Swan"?

Neck length: Trumpeter Swan neck length to body is larger than Tundra Swan

Head profile: some Trumpeter Swan has flat head, Tundra Swan rounded or smooth head

distance from bill tip to eye about two times the distance from eye to nape, while 1 to 1 1/2 in Tundra Swan

upper mandible of Trumpeter Swan almost straight, Tundra Swan is concave

Trumpeter Swan have massive bill, Tundra Swan not so massive

distance from bill tip to nostril of Trumpeter Swan is only a little less than distance from the nostril to eye; in Tundra Swan bill tip to nostril is about 1/2 distance from nostril to eye

if you hear them, Trumpeter Swan had deep, resonant, brassy trumpet-like voice; Tundra Swan has softer and more melodious voice (of course, not heard in photo)

field marks not set in stone, but collectively an indication of species

A lot to take in on a disappearing swan, however possible to look for with practice

Directions to birding spots on CoBus website:

Richard Stevens; Director, Colorado Birding Society
Denver, Colorado
Contact CoBus/Report Interesting Birds: 303-324-7994
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