Comments on: Loon Identification

By: Michael Retter

Michael Retter — Thu, 28 Aug 2008 21:26:11 +0000

Aaron and Jake have it right. All Commons, save the one Red-throat.

By: Jake

Jake — Thu, 15 Nov 2007 21:08:50 +0000

Matt,

Great stuff!

None of these loons are Pacific Loons; all but one are Common Loons. Bird #7 is without doubt a Red-throated Loon and not a YBLO (based on head shape and bill size/shape).

The vertical neck line is a good trait for Common Loon; all your birds show the slightly notched or irregular vertical neck line of a Common Loon. Only photo #1 is slightly suggestive of Pacific Loon, but the slight notch on the neck and bill shape quickly rule out that species and confirm it as Common Loon.

Keep up the great work and wonderful photos!

Jake

By: Aaron

Aaron — Mon, 12 Nov 2007 21:56:29 +0000

I think they are all Common Loons except for #7 which looks like a Red-throated. As you note, the one photo of that bird makes it difficult to tell, however the uptilted bill posture and lack of any distinctive dark/light division on the neck are suggestive of Red-throated. It was suggested that one of the birds might be a Yellow-billed. Superficially, it looks like a YBLO because it has an unusually large bill, however the top of the bill is dark from tip to base, the head is very dark for an imm. YBLO, and the head shape looks good for Common. I think the big problem here is that Common Loons, especially young Common Loons, are highly variable plumage-wise. Structure should be a huge clue to what the birds are, and plumage should come second because it is variable and subject to misinterpretation. In several of your comments, you say that the birds lack a partial white collar or don’t have as much white around the eyes as you think a Common should have, yet when I look at the photos I see a partial collar and normal white around the eye for Common Loon. None of these birds looks like a Pacific structurally, and the fact that some of them show some vaguely PALO like neck pattern features is merely coincidence.

By: Loon Identification Update | Sitka Nature

Loon Identification Update | Sitka Nature — Sun, 11 Nov 2007 06:01:29 +0000

[...] have had a few responses to the Loon Identification post I made yesterday. One of them pointed out that there is a discussion of Loons in the Peterson Field [...]

By: goff

goff — Sun, 11 Nov 2007 05:04:50 +0000

In looking back through my photos I realized that one of the photos I had included with Birds #5 and #6 actually belongs to Bird #4. It was taken after the bird stopped preening and started diving and feeding. This third photo is similar enough in appearance to photos for Birds #1, #2, #3, #5, and #6, that I’m now leaning toward considering them all first year Common Loons.

By: goff

goff — Sat, 10 Nov 2007 01:07:24 +0000

Tom,

Thanks for the comments, information, and links. The interesting thing about it is, I know for certain that both photos for #4 are of the same bird. The one on the left was taken first, then I took the second one after walking down on the breakwater to get closer. Obviously the lighting was not fantastic.

Yellow-billed Loon is certainly a possibility worth considering. I know they have been observed here before. However, based on what I have seen in the field guides, I would think the birds I have seen did not have yellow enough bills, and were too dark and/or gray for Yellow-billed Loons. However, I do not have a sense of the variation present in the species, so I don’t know.

Matt

By: Tom Rothe, ADF&G

Tom Rothe, ADF&G — Fri, 09 Nov 2007 23:15:23 +0000

Matt??

I’m not a loon expert either, but I am the state Waterfowl Coordinator and have been involved with loons, in the field or planning conservation efforts, for a long time. For ID assistance, I recommend Tamara Mills at USFWS in Anchorage 786-3517. She runs their loon programs and knows local experts.

In my assessment of the photos, I think there is a good chance that bird #4 is a yellow-billed loon (the right photo only) Right #4 has a classic YBLO head shape and angular mandible, but the left photo looks like a different bird. I also think loon #8 could be a YBLO, but the angle is not best for ID. Have a look at these websites:
http://www.absc.usgs.gov/staff/WTEB/jschmutz/jschmutz.htm
http://alaska.fws.gov/mbsp/mbm/loons/species/Yellow-billed-loon.htm

Hope this helps–good luck with the tough ones.

By: goff

goff — Fri, 09 Nov 2007 18:50:32 +0000

Thanks for the comments. After experiencing a little confusion trying to figure out which loons you were referring to, I realized it would be helpful to add numbers to each. I have also added a comparison at the top which leads me to change my mind about Birds #5 and #6, they now seem more likely to be Pacific Loons. I think that’s what you are suggesting as well.

One of the things I am hoping for is a little bit of a discussion about the variability of loon features within individuals and species. For example, presumably the neck can look thicker or thinner depending on whether it is stretched out or not. Perhaps the apparent size of the bill is subject to variation depending on posture as well. I would also imagine that there is variation among individuals within a species, but I really have no idea as to the extent of such variation. For me, as a relative newcomer to the challenges of bird identification, I think it would be helpful for me if I can get input from someone with the experience and understanding to be able to comment on the range of variation of particular characteristics, how much, if any, overlap there might be between species, and which things to emphasize if the evidence seems to be somewhat conflicting.

By: Carolyn Hoffman

Carolyn Hoffman — Fri, 09 Nov 2007 16:22:14 +0000

Okay, here’s my completely non-loon-expert take on your photos. The first 2 Pac.loons; next 4 Common loons, The next group of five: Pac not common (eyebrow did it for me), ?, common for the rest. RT loon would be my guess too for the next to last one, followed by common loon.

Carolyln H.