ID Challenge -- The Answer

Though many folks perused the waterbird in our most recent ID Challenge, only two brave souls take a crack at naming it in a public comment. One answered correctly, which was not surprising given that person's years of birding experience and the fact that he lives in the coastal town where the quiz image was taken. Perhaps more useful was the incorrect answer because the species named in that answer offers a general appearance that is very similar to the quiz bird. The plumage similarities between these two species was the reason that I decided to post this ID challenge.

Wayne Hoffman was correct in identifying the quiz bird as a first year male Surf Scoter, and offering up that its appearance is suggestive of an eider. I purposely chose a shot where the bill was obscured, otherwise this quiz would not have been a challenge. John Plank guessed that it is an immature King Eider, not unreasonable given that (as he points out) we can't see the bill. A quick turn of the head and  this bird is readily identifiable as can be seen in the image below.

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Here is the quiz bird in a couple of far more revealing profile shots. The unmistakable bill pattern of a male Surf Scoter leaves no doubt about the identity of this bird, even though the plumage is somewhat atypical.

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When I found this bird, the first thing I noticed was its plumage. The combination of a near black head, light breast, and dark brown back and flanks were suggestive of a first year male King Eider. Fortunately, I had the benefit of being only about 30-40 meters away from the bird as is swam in comparatively placid waters between the jetties at the mouth of Yaquina Bay in Newport, Oregon. As soon as I saw the bill, I knew it was a Surf Scoter. If I'd previously seen a young male Surf Scoter that looked like this one, I didn't recall it, so I decided to take some pictures.

This first year male was in a flock of about a dozen male Surf Scoters, some adults and some first-year birds. Most of the first-year birds looked like the left hand bird in the photo below. They were almost entirely black with some brown still showing in their folded wings. Their bills appeared to be near identical to those of the adults, but they lacked the conspicuous white patches that mark the nape and forehead on adult males. All of the young males showed some white feathering on the nape, generally creating an area on the nape that was mostly black with some white mottling.

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The image above offers a nice comparison between typical first-year male Surf Scoter  (left) and the quiz bird (right), which is presumably of the same age class. This photo demonstrates how the timing and extent of seasonal molts can vary from one individual to the next.

According to Savard et al. (1998), molt sequences in Surf Scoters are highly variable. The prebasic molt in first-year birds is usually complete (except for flight feathers), resulting in first-year males that are almost entirely black in plumage. The left hand bird in the image above presents the typical appearance of a one-year-old male. However, in some individuals this molt is either delayed or incomplete, which surely explains the appearance of the quiz bird. These authors point out that some individuals retain juvenile abdominal feathering into first-basic plumage. It would appear that the worn and somewhat faded body feathers on the quiz bird are indeed retained from its juvenile plumage. Since these photos were taken on 22 May 2010  in Newport, Oregon, where Surf Scoters do breed, we can assume that this bird is nearly a full year old (hatched in the Summer of 2009). 

As mentioned above, the reason I chose this bird for an ID quiz was its similarity in appearance to a first-year male King Eider. At close range, few birders would have any difficulty identifying this bird to species. The long, sloping, multi-colored bill of male Surf Scoters is unmistakable. On the other hand, if one were to see this bird 300+ meters away, bobbing in and out of view between swells on a sunny day, distance and heat waves might make it difficult to discern the exact size, shape, and color pattern of the bill. Under such circumstances, the general plumage pattern shown by the quiz bird might cause many of us to think we were seeing a young eider. If this bird were a young King Eider, it would be whiter on the breast, have a shorter all-orange bill, and show a fairly obvious white patch on the lower flanks (just in front of the tail). 

This is yet another example of an age class of a species that is not thoroughly covered by popular field guides. Among the North American field guides that I own, Sibley, Kaufman, and the National Wildlife Federation guide (authored by Ned Brinkley) offer photos or illustrations of first-year males showing the mostly black plumage that is typical. Oddly, my 4th edition National Geographic guide includes an illustration of a light brownish, pale-breasted first-year male, but does not illustrate the more expected all-black first-year plumage. Further, it shows the  bird in a rolled over position preening its breast, not exactly the profile we normally see in a swimming scoter.

There is no substitute for experience when it comes to correctly identifying birds that are atypical in appearance. It's important to realize that not every bird you see will match up with an illustration in your favorite field guide and that even the most common species may occasionally cross you up with a suspended molt or transitional plumage.

Literature Cited:

Savard, Jean-Pierre L., Daniel Bordage and Austin Reed. 1998. Surf Scoter (Melanitta perspicillata), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/363

1

Hi RonWe do get one or two Green Finches here, you have really craputed your Green Finch in lovely condition. Thanks Ron lovelyRegards Dorothy

2

So I am not rattling wonderful through English and yet I find this actually easy to translate.
Richard Warke http://www.savethesantacruzaquifer.info/Richard-W-Warke-info.htm

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