Long-tailed Duck 12/27/2011

Writeup of the Long-tailed Duck I found on SF Bay on the SF CBC:

Conditions:

On SF Bay on a sail boat with the sun located directly behind us.  The birds were not close; easily 150 yards or more away.  Optics were Zeiss 8×42 Victory.  I believe that David A. also saw the bird.

Description:

A duck flying in line with and in between 2 Surf Scoters.  It was superficially similar to a Surf Scoter with the following essential differences.  It was about 20% smaller than the Surf Scoters and had unmarked, all dark upperwings and underwings.  The breast was dark contrasting markedly with a white face and a white belly.

Analysis:

Very few ducks, sea ducks or otherwise, have all dark wings and pale faces.  Female Black Scoter can show pale on the face and all black wings but would be the same size as a Surf Scoter and not have a pale belly.  Female Harlequin Duck can show wings all dark (in bad light) and a pale belly but would not have a conspicuously white face.  So, we’re left with LONG-TAILED DUCK.  Aging and sexing Long-tailed Ducks is difficult even with close looks, but I would guess adult female if I pressed.

Trip report from October 8th Pelagic

Here’s the official trip report for the October 8th pelagic with Alvaro’s Adventures.  We went well south after hitting the buoy and it was darn rough getting home!

Canada Goose 3
Greater/Lesser Scaup 15
Surf Scoter 25
Red-throated Loon 4
Pacific Loon 1
Common Loon 27
Eared Grebe 9
Western Grebe 6
Black-footed Albatross 224
Northern Fulmar 150
Pink-footed Shearwater 1121
Flesh-footed Shearwater 7
Buller’s Shearwater 236
Sooty Shearwater 545
black-and-white shearwater sp. 1
Fork-tailed Storm-Petrel 4
Ashy Storm-Petrel 12
Brandt’s Cormorant 2
Double-crested Cormorant
Pelagic Cormorant 6
Brown Pelican
Great Blue Heron 3
Black-crowned Night-Heron 4
Black Oystercatcher 24
Whimbrel 10
Black Turnstone 34
Surfbird 9
Sanderling 75
Red Phalarope 1
Heermann’s Gull
Ring-billed Gull
Western Gull 865
Western x Glaucous-winged Gull (hybrid) 10
California Gull 710
Herring Gull 3
Glaucous-winged Gull 9
Elegant Tern 38
South Polar Skua 48
Pomarine Jaeger 43
Parasitic Jaeger 10
Long-tailed Jaeger 3
Common Murre 850
Pigeon Guillemot 1
Cassin’s Auklet 71
Rhinoceros Auklet 147
Tufted Puffin 14
Belted Kingfisher 4
Tree Swallow 5
Violet-green Swallow 5
swallow sp. 1
Western Meadowlark 4