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Message: <blockquote data-quote="kpgunathilaka" data-source="post: 6349153" data-attributes="member: 164286"><img src="http://www.stuorg.iastate.edu/swan/headsall.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" />Head and Bill Shape   <img src="http://www.stuorg.iastate.edu/swan/bluedot.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /> Trumpeter - bill heavy in proportion to head with a straight profile.  Angular head shape somewhat resembling canvasback duck.  Eye not distinct from bill.   <img src="http://www.stuorg.iastate.edu/swan/bluedot.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /> Tundra - bill more dish-shaped in profile, bill smaller in proportion to head compared to trumpeter.  Head smoothly rounded; eye usually distinct from bill.     The shape of the head profile may vary between individual birds.  Tundra swans, especially, have a wide range of head-bill shapes, some having very obvious concave bills, while others appear straighter.  Look carefully at the eye area for any yellow on the lore and to see if the eye is distinct from the bill as in the tundra swan.   <img src="http://www.stuorg.iastate.edu/swan/bluedot.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /> Snow Geese - less than one-half the size of a swan; total bill length is about 2"; bill is much smaller and dark pink and black in color.  Does not extend very close to the eye.  Outer primaries on adult snow geese are black.  Neck length is about the same length and distance from tip of bill to back of head.      <img src="http://www.stuorg.iastate.edu/swan/divider.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" />  Head and Neck Movement     Trumpeter swans frequently bob their head and necks up and down (head bobbing).  With this motion they also have a variety of vocalizations.  This combined activity apparently serves as a form of communication between individuals and within the group.  Head bobbing and vocalization activity increase when the birds are disturbed and reaches maximum intensity just prior to the birds taking flight.  This behavior may be brief or absent if the birds are suddenly startled and take flight.     Tundra swans do not bob their head and neck in this manner.  Occasionally tundra's will nod only their head up and down.  There is no defined preflight display as in the trumpeter.  <img src="http://www.stuorg.iastate.edu/swan/divider.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" />  Junvenile Identification     Both species of juvenile swans and juvenile snow geese have a gray body coloration.  Trumpeter and tundra swan bills are black at the tip and base, with pink in the middle.  From late December on, juvenile trumpeters are usually much darker and duller gray then juvenile tundra's.  Late in the season the bill color gradually fades to black in both species.  Mute juvenile plumage may be white or brownish; bill gray with black base.  Juvenile snow goose bills are primarily grayish in color until they are one-year-old.  <img src="http://www.stuorg.iastate.edu/swan/divider.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" />  <img src="http://www.stuorg.iastate.edu/swan/bills.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" />Bill Color <img src="http://www.stuorg.iastate.edu/swan/bluedot.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /> Trumpeter - black bill with red border on lower mandible; the red border may be present on some tundras. <img src="http://www.stuorg.iastate.edu/swan/bluedot.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /> Tundra - black bill, usually with yellow spot of varying size in front of eye; this spot may be absent on some tundras. <img src="http://www.stuorg.iastate.edu/swan/bluedot.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /> Mute - orange with prominent black knob at the base. <img src="http://www.stuorg.iastate.edu/swan/bluedot.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /> Snow/Blue Goose - bill much smaller, dark pink and black in color; does not extend very close to eye.   Bill Length <img src="http://www.stuorg.iastate.edu/swan/bluedot.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /> Trumpeter - end of beak to nostril 2 in. or more. <img src="http://www.stuorg.iastate.edu/swan/bluedot.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /> Tundra - end of beak to nostril up to 1.5 in. <img src="http://www.stuorg.iastate.edu/swan/bluedot.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /> Snow Goose - total beak length slightly over 2 in.  From tip of beak to back of head is about the same as length of neck  <img src="http://www.stuorg.iastate.edu/swan/divider.GIF" alt="" class="fr-fic fr-dii fr-draggable " style="" /></blockquote>

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