Salem "Trumpeter Swan"

[october at ida dot net]

I viewed the photos of the juvenile swan at Salem, as well as Nicky
Davis's photos of the same individual, and feel strongly that this is a
juvenile Tundra Swan.  Here are my reasons:

-Bill is pink with black base and tip, typical of juvenile Tundra Swan but
not typical for Trumpeter.
-Eye appears separate from bare skin of bill, consistent with tundra Swan.
 On Trumpeters the eye looks like it's included in the bare/black
extension of the bill.
-Edge of feathering along bare skin at base of bill has sharp curve.  This
is difficult to explain but the shape of the junction between feathered
head and unfeathered (bare) base of bill differs between species.  If you
follow this edge from the eye towards the bottom of the bill, about half
way (or maybe 2/3 of the way) out it makes a sharp downward curve then
continues more or less vertically to the bottom of the bill.  Trumpeter
Swan has a more gentle curve and doesn't usually look vertical anywhere
along that junction.  I sent some photos of a Trumpeter for comparison of
this feature and eye placement to Nicky Davis a couple days ago; hopefully
they'll be posted later today).
-Back is more arched than on Trumpeter (which is flatter) and consistent
with Tundra.
-Wing coverts are white.  Tundras molt wing coverts sooner than Trumpeters
and appear very white backed this time of year.  Trumpeters still look
mostly brown (I checked ten or so juveniles in Island Park two days ago
and they all still had brown wing coverts).
-Neck seems a bit short and thin for Trumpeter but this is hard to judge
with no Trumpeters for direct comparison.

I just thought of some photos that may help.  They're posted at
http://www.octoberweb.com/birds/whooper/.  The top photo shows two
juvenile Trumpeters for bill color comparison.  It's hard to make out the
edge of the bare parts on this photo, but if you look hard you can sort of
make it out.  Eye placement is sort of visible on the right bird.  The
second photo show a Trumpeter and a possible Whooper Swan in which you can
see the shape of the back of Trumpeter as flatter than the Salem bird. 
This is also noticeable on the right Trumpeter in the first photo.

I'd be interested in what others think about these points.

Cheers,
Cliff


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