IDAHO BIRD RECORDS COMMITTEE
RARE BIRD REPORT FORM

SPECIES:

Black Scoter

HOW MANY:

1

REPORTER:

Spencer Walters
POBox 450
Garden Valley, Idaho
208-631-4009

REPORTER EMAIL:

spencerw100@yahoo.com

OTHER OBSERVERS:

Jay Carlisle-carlislejay@yahoo.com-observed on 11-18-06

John Jann-observed on 11-19-06
Mike VanDyk-observed on 11-19-06

DATE REPORT PREPARED:

11-23-06

DATE SIGHTING OCCURRED:

November 17, 2006

LOCALITY OF OBSERVATION:

Cascade, Valley County, Southwest Idaho
Cascade Reservoir-Lakeshore Drive, south of Golf course

HABITAT:

Water

CONDITIONS:

I observed the bird for approx. 20 minutes under cloudy conditions with no wind. The temperature was approx. 35 Degrees F. The bird was first seen at about 40 yards and moved out to about 200 yards. The optic I used was a Bausch & Lomb 20-60 X 80 spotting scope

DID YOU TAKE NOTES?:

No, not at all

DID YOU CONSULT FIELD GUIDE OR OTHER REFERENCES?:

Yes, during the observation

WHAT GUIDE(S) OR REFERENCE(S) DID YOU CONSULT?:

The Sibley Guide To Birds by David Allen Sibley-copyright 2000 (used while observing the Black Scoter)


DESCRIPTION:

It had an overall dark appearance when first spotted. Upon watching through the scope, there was an obvious light cheek with a dark cap on it's rounded head. The dark cap extended down around the dark eye. When diving it would spread it's wings just enough to see them clearly. They were completely dark with no wing patches of any other color. The bill was thin looking in appearance. The body was darkish in appearance with the back being just slightly darker than the sides.

BEHAVIOR:

The bird was actively diving for extended periods of time-usually around 30 seconds. This continued the entire time I was there. It would be up for about 30 seconds and then dive again. It did not vocalize during the time I was there and it never flew. There was no interaction with any other birds and the closest birds to it were approx 50 yards away-Long-tailed ducks.

HOW AND WHEN DID YOU POSITIVELY IDENTIFY THE BIRD, AND WHAT CLINCHED THE IDENTIFICATION FOR YOU?

While watching the bird dive and consulting my guide book I was able to positively identify the bird. The head pattern and shape and overall coloration of the bird. Also the coloration of the wings and length of time diving.

HOW DID YOU ELIMINATE SIMILAR SPECIES, AND WHAT WERE THEY?

I eliminated other Scoter species by looking at head pattern and shape, size and length of bill, lack of white on wing. Surf Scoters-that I had previously seen that morning had two distinct whitish head patches, a white patch on the back of the neck and the bills were much thicker and were longer than the Black scoter. White-winged Scoter that I had previously seen also had two whitish head patches with one of them extending forward onto the bill. The bill of the White-winged Scoter was also longer than that of the Black Scoter. The WWSc had an obvious white wing patch when diving and it was visible when sitting.

I was able to rule out Ruddy Duck as it is smaller and more compact. The bill is thicker in appearance on a Ruddy Duck and has more of an upturned shape to it. The female RuDu has a horizontal dark line accross the cheek and the male RuDu has white cheek patches. Relative size of bird to bill makes the bill look much larger on Ruddy Duck.

It was different than a female Bufflehead in that it was longer bodied and did not have an oval white patch on the side of it's head. The patch was on the cheek and extended to the base of the bill. It was more off-white or dingy than white.

It was different than the Long-tailed ducks in that the dark cap extended down over the eye and it did not have the white stomach or rump of the long-tailed Ducks.

EXPERIENCE WITH THIS SPECIES (AND SIMILAR SPECIES):

My experience with Scoters is limited to this fall. I have been able to Identify all three Scoter species at Cascade Reservoir within the past month.

GENERAL BIRDING EXPERIENCE:

I have been birding for almost five years with a life list of 362 species. I would rate my level of expertise at very high in my region. I have spent numerous occasions both in spring and fall every year glassing duck species on Cascade Reservoir along with other reservoirs in sw Idaho.

WERE PHOTO(S), VIDEO, AND/OR AUDIO OBTAINED BY YOU?:

None