** Reply to note from Doreen Linzell

>
> I found Michael Price's comment very interesting about the yellow bill
> of a loon being diagnostic. Here in Ohio we have a "raging
> controversy" about a loon that came our way last spring. The bird did
> have a yellow bill. But, many of the other features did not match
> with a yellow-billed loon. Photographs were taken and placed on the
> Internet for people to critique. Some experts (that actually saw the
> bird) said that it was definitely not a YELO. Others felt that it
> was. There was even talk that the bird might be a hybrid Common
> Loon/Yellow-billed Loon. My question is since you folks have more
> experience with both of these species, have you ever seen a hybrid of
> these two species?

I found Michael's comments interesting also since the only trenchant
characteristic for differentiating Yellow-billed from Common in any age
and plumage is the color of the culmen (the ridge of the upper mandible):
dark horn to blackish in Common for whole length of culmen and about 5mm
on either side, versus distal 1/2-2/3 whitish-yellow in Yellow-billed.
Note that the characteristic wedge-shape of the adult Yellow-billed is
often undeveloped in juveniles.

Re. hybrids: Godfrey in _Birds of Canada_ (1986) lists a probable
specimen Common X Yellow-billed taken at Port Credit, Ontario, 7 Dec.
1956; it is at the Royal Ontario Museum. This record was questioned by
Storer in 1978. AOU declared Common and Yellow-billed Loons a
superspecies in their 1983 checklist.

- Jack

Jack Bowling
Prince George, BC
jcbowling at mindlink.bc.ca