57-B-2017 Black Scoter

STATUS
Accepted
DATE VOTING COMPLETED
1ST ROUND
7-0
HOW MANY OBSERVED?
2 female-type Black Scoters (one seems like an adult female and the other a first-winter but not confident in aging)
DATE SIGHTING OCCURRED
DATE REPORT PREPARED
REPORTER
Austin Young
OTHER OBSERVERS
I found a single Black Scoter birding with Hunter Anderson on Nov. 20, but the next day 2 Black Scoters were observed in the same location (a second individual found by Jason Talbot). Many folks from around the state have come and seen the birds, including Pat Weber, Zeke Watkins, Melody Asher, Sharon Hayes, Jason Talbot, etc.
LOCALITY OF OBSERVATION
The birds were observed on the west side of Highway 30 bridge (Gridley Bridge) south of Hagerman 5-10 minutes. Specifically at: 42.757256, -114.877822. This spot is on the border of Twin Falls and Gooding Counties.
HABITAT WHERE THE BIRD WAS OBSERVED
The habitat was largely open water with a small, vegetative island in the vicinity (about 10 yards long and 5 yards wide).
SIGHTING DURATION, CONDITIONS, and EQUIPMENT USED
I observed the birds preening, resting, and diving on the water from about 150-200 meters away for about an hour. Great looks through Leupold Spotting Scope. The weather was overcast, warm, with sprinkling rain.
DID YOU TAKE NOTES?
Yes, later the same day
DID YOU CONSULT A FIELD GUIDE OR OTHER REFERENCE WORK?
Yes, later the same day
WHICH GUIDE(S) OR REFERENCE(S): DID YOU CONSULT?
National Geographic Guide to Birds of North America 6th ed. by Jon Dunn and Jonathan Alderfer. Published in 2011.
DESCRIPTION OF THE BIRD(s)
Both birds were female-type Black Scoters. The birds sported a classic duck shape but were fairly large with a uniformly blackish-brown body, pale grayish-brown cheeks, black bill, and dark eye. The wings were also entirely blackish-brown with no observed pattern. Drab birds but with a distinctive plumage.
BEHAVIOR OF THE BIRD(s)
Both birds were preening and resting but one began actively diving for a period of time. I did not observe the associating with each other, other observers on different days did, but I did observe one associating with a group of Lesser Scaup. It seemed to go where they went and "hung out" with them.
HOW AND WHEN DID YOU POSITIVELY IDENTIFY THE BIRD, AND WHAT CLINCHED THE IDENTIFICATION FOR YOU?
The larger size and overall dark coloration of the body brought the bird to my attention but the head pattern clinched the identification. The combo of pale cheeks and dark everywhere else, including bill, is distinctive.
HOW DID YOU ELIMINATE SIMILAR SPECIES? WHAT WERE THEY?
Other scoter species were eliminated by the face pattern and bill shape. White-winged Scoters tend to have a thinner bill and Surf Scoters have a broader bill.

Common Scoter, a very similar species from the northeast Atlantic Ocean area, was eliminated mostly by range but also Black Scoters are generally thicker and more robustly-shaped in comparison to Common Scoter. The scoters I observed were very stout with large round heads and faces, big rounded cheeks (when a bird was facing away), and thick necks.
WHAT IS YOUR EXPERIENCE WITH THIS (AND SIMILAR) SPECIES?
I have observed this species once before in the same plumage, so my familiarity is limited. I have extensive experience with the two other North American scoter species as well as the other commonly occurring waterfowl species in Idaho.
DESCRIBE YOUR GENERAL BIRDING EXPERIENCE
Extensive, especially in the intermountain west. I have about 10 years of solid birding experience.
ADDITIONAL INFORMATION (If any)
Mary Rumple's eBird checklist has a great photo of both birds in the same frame:
http://ebird.org/ebird/view/checklist/S40759581

Photos in eBird checklist as well.
WERE PHOTO(S), VIDEO, AND/OR AUDIO OBTAINED FROM THIS SIGHTING?
Photo
SUPPORTING IMAGES

FIRST ROUND VOTING:

Cliff Weisse
Accept

Description and photos support the identification of Black Scoter

Shirley Sturts
Accept

photos and description are convincing

Dave Trochlell
Accept

I don't know if the photos represent both scoters, but the one (or two) seen in these images is (or are) a Black Scoter.

Carl Lundblad
Accept

Well documented with photos, written details, and a discussion that even considers Common Scoter (nice). These were my Idaho-first Black Scoters (thanks, Austin!).

Darren Clark
Accept

Description and photographs eliminate similar species.

Jay Carlisle
Accept

well documented

Doug Ward
Accept

Excellent comparative description, including mention of primary field marks, coupled with diagnostic photos make this one easy to “accept”.