Date: 7/4/25 9:56 am From: Zac Denning via groups.io <zdenning1...> Subject: Re: [northbaybirds] Odd loon at Bodega Bay
Hi Gene,
Loons can be flustering.
White flanks aren't that unusual for a first year Common Loon, and their
appearance also really varies. There's also variation amongst individual
loons in their plumage (plus wear / fading), as well as the bird's posture.
In addition, loons can control their buoyancy by inflating their air sacs,
or (with the help of their solid bones), when they deflate their air sacs,
they can ride low in preparation for diving. This means that the amount of
visible white flank will also vary depending on the bird's buoyancy at that
moment.
The head position, with bill tilted slightly upward, isn't diagnostic by
itself. Many loons will tilt their bills up slightly, and it doesn't look
very pronounced in your photos. This feature is most useful in Red-throated
loons, which spend more time with their bills tilted upwards. But as
always, using a combination of features (posture, plumage, etc) is usually
most reliable.
In this bird, the jagged border of the neck line, and deeply angled lower
mandible, points away from a Pacific/Arctic Loon.
I hope that helps,
Zac Denning
On Fri, Jul 4, 2025 at 8:15 AM NANCY AND EUGENE HUNN via groups.io
<enhunn323...> wrote:
> Leaning towards.immature female COLO rather than Arctic but still puzzled
> by white flanks and bill tilt.
>
> Gene Hunn
> Petaluma
>
>
>
