[obol] Re: more on Newport Brown Booby

  • From: Jack Williamson <jack.williamson.jr@xxxxxxxxx>
  • To: Shawneen <shawneenfinnegan@xxxxxxxxx>
  • Date: Sun, 25 Oct 2015 20:51:21 -0700

Shawneen,

Thank you for inviting me into the deep-end of the pool.

The excerpt below from the article you cite tells me that I should keep my
mouth shut and let people think I am an idiot, rather than open it and
prove them right.

*We inspected booby nests (briefly flushing adults) on a few occasions to
establish*
*contents and take photographs. We referred to Harrison (1983) for aging
and sexing Brown Boobies.*

*We distinguished adult males from adult females by their white head,
characteristic*
*(in varying degrees) of all eastern Pacific subspecies of the Brown Booby.*

Very best,


Jack Williamson
West Linn, Oregon

On Sun, Oct 25, 2015 at 8:09 PM, Shawneen <shawneenfinnegan@xxxxxxxxx>
wrote:

Jack: the western subspecies of Brown Booby that occurs along the west
coast is *brewsteri*. Adult males of this subspecies have frosty heads,
not dark brown like the females. Am in the car heading home from Neah Bay,
WA so don't have access to books but there is plenty in line.

For more about the crazy fast northward colonization of BRBO in the
Coronados read this:
https://sora.unm.edu/sites/default/files/journals/wb/v38n04/p0268-p0279.pdf

*Brown Booby; Sula leucogaster*
*S. l. brewsteri* - Islands in Gulf of California and off w Mexico
*S. l. etesiaca* - Islands off Central America and Colombia
*S. l. leucogaster* - Islands in Gulf of Mexico, Caribbean and tropical
Atlantic
*S. l. plotus* - Islands in Red Sea, tropical Indian Ocean and s China Sea
Sent from my iPhone

Shawneen Finnegan


On Oct 25, 2015, at 6:50 PM, Jack Williamson <jack.williamson.jr@xxxxxxxxx>
wrote:

Forgive me for not also agreeing with your observation of the left wing.

The tertials and secondaries (12 through 9 or 8, and maybe even 7) are
either missing or damaged.

But the bird flies and dives for food very well - we watched it evade
aggressive encounters with gulls while it made several (unsuccessful)
plunges into the bay for prey.

I hope that I am coming off in this string has helpful and not combative.





Jack Williamson
West Linn, Oregon

On Sun, Oct 25, 2015 at 6:16 PM, Jack Williamson <
jack.williamson.jr@xxxxxxxxx> wrote:

Wayne,

This bird clearly demonstrates the characteristics of a male as described
in the online version of Birds of North America . . .* "male typically
has gray-blue to steely-blue skin around eyes (and in some, this color
extends across proximal upper edge of bill), and yellow to bright yellow
skin at base of lower mandible. . *."

Please let me know if you disagree.
http://ebird.org/ebird/view/checklist?subID=S25540436

Very best







Jack Williamson
West Linn, Oregon

On Sun, Oct 25, 2015 at 5:34 PM, <whoffman@xxxxxxxx> wrote:

Hi -

I have examined my photos from today (taken under challenging
conditions) and have a few comments on the bird:

1. The face pattern indicates it is a female. As far as I know no
males have been confirmed north of California (does anyone know of any).

2. It appears to be a full adult, with fully white belly.

3. It is in tail molt, with new outer tail feathers, and old, faded
central feathers.

4. Its left wing frequently droops. Clearly it flies well, but it may
have some sort of wing injury.

Wayne




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