IBRC 57-B-11 - D

IDAHO BIRD RECORDS COMMITTEE
RARE BIRD REPORT FORM

SPECIES: Red-throated Loon
HOW MANY: 1 juvenile

REPORTER: Doug Ward 8362 Selkirk Ct. Hayden, ID 83835 (208) 762-7107
REPORTER EMAIL: dougward@frontier.com
OTHER OBSERVERS: This bird was also seen by numerous individuals as reported to the Inland Northwest Birders email list serve (Shirley Sturts, Janet Callen, & Roland Craft on the 8th, Garrett MacDonald on the 9th, and Ed & Kris Buchner on the 10th).

DATE REPORT PREPARED: 14 December 2011 based on notes made 10 November 2011
DATE SIGHTING OCCURRED: 7-11 November 2011

LOCALITY OF OBSERVATION: Cougar Bay, Lake Coeur d’Alene; Kootenai County, Idaho
HABITAT: Open water.
CONDITIONS: This bird was seen on three (3) different occasions over the period. The initial observation was very distant (500m+) under overcast conditions around 1pm for about 10 minutes using a 15-40X spotting scope (primarily at 30-40X). On my second observation, 10 November 2011 (from which these notes were made), this bird was seen at very close range (~30m) with excellent lighting using both 8X40 binoculars and my spotting scope; the time was also around noon and I observed the bird feeding for about 30 minutes. The last time I saw the loon was on 11 November 2011 in the same location; I was unable to relocate it on the 12th. As this bird had distinctive coloration, there is no question it was the same individual seen during the period.

This bird was also seen by numerous individuals as reported to the Inland Northwest Birders email list serve (Shirley Sturts, Janet Callen, & Roland Craft on the 8th, Garrett MacDonald on the 9th, and Ed & Kris Buchner on the 10th).

DID YOU TAKE NOTES?: Yes, later the same day
DID YOU CONSULT FIELD GUIDE OR OTHER REFERENCES?: Yes, later the same day
WHAT GUIDE(S) OR REFERENCE(S) DID YOU CONSULT?:
1)“Advanced Birding”; Ken Kauffman; 1990
2)“The Sibley Guide to Birds”; Sibley; 2000
3)“Complete Birds of North America”; National Geographic; 2005
4)“Seabirds: An Identification Guide”; Harrison; 1983

DESCRIPTION: Small, light weight loon in direct comparison to a nearby Common Loon (Gavia immer) as seen on 7 Nov.’11.
Plumage: This loon was an odd ball in terms of plumage from my prior experience as it was fairly dark overall with a brownish cast to its upper parts. Head/Back of Neck: generally medium grey, slightly darker on the crown and back of neck with a slight “hour glass” appearance on the neck (see attached sketch). Face: medium grey with the exception of a small amount of white in front of the eye, and a slightly darker diffuse malar stripe separating the face from the whitish chin. Throat/Neck: whitish blending into the pale grey sides of the neck; no clear demarcation. Upperparts: generally medium to dark brownish-grey. At close range appeared finely spotted with pale tan in an indistinct chevron pattern. Individual back feathers were pointed and dark brownish-grey in color with four (4) pale tan “spots” on the margins (see attached sketch).
Bill / Eye Color: Bill primarily grayish-horn with basal 2/3rds of culman dark. Eye appeared dark maroon in color.
Structure: Light weight and “skinny”, particularly in comparison to a Common Loon. Head was small and showed a slight double-peaked appearance in most situations. Bill was also light weight with a straight culman and upwardly curved lower mandible with the gonydeal break about 3/4ths of the distance from the base of the bill; tip very sharp looking. Neck was moderately long and somewhat thin in comparison to Common Loon proportions. Back looked low and long.
BEHAVIOR: Consistently held head and bill tilted up at about 10º; accentuated upturned bill shape. Fed regularly in deeper water on 7 November, but stayed in relatively shallow waters on the 10th and 11th.

HOW AND WHEN DID YOU POSITIVELY IDENTIFY THE BIRD, AND WHAT CLINCHED THE IDENTIFICATION FOR YOU? I originally misidentified this bird as a Pacific Loon (G. pacifica) when seen at the far distances on 7 November 2011. This initial identification was based on the size and structural differences in comparison to a nearby Common Loon, and its overall dark coloration; I made the mistake even after watching the bird for 10 minutes as I’d never seen a Red-throated (G. stellata) that dark. I discounted the fact that it was holding its head tilted up on poor viewing conditions and knowing that all loons will do this from time to time when actively feeding.

However, after relocating the bird on the 10th (after the correct identification had been made by others; notably Shirley Sturts etal ,and Garrett MacDonald), it was clear this was not a Pacific Loon. The principal separating marks include this bird’s upturned shape of the bill (straight culman with upwardly curved lower mandible) verses the straight, dagger like bill of the Pacific, the fact that this bird held its bill consistently elevated at around 10º, and this bird’s lack of the sharp demarcation between the grey neck and face with the white throat shown by Pacifics. In addition, this bird was pretty light weight in the neck and head versus a relatively bulky build of the Pacific. Artic (G. artica) Loon was also eliminated for similar reasons as stated for the Pacific Loon.
HOW DID YOU ELIMINATE SIMILAR SPECIES, AND WHAT WERE THEY? Identified as a loon based on previous experience with this family, but have compared to similar grebes as well given superficial similarities.
Common Loon eliminated by size and general build in direct comparison. Yellow-billed (G. adamsii) Loon also not considered for similar reasons.

I originally misidentified this bird as a Pacific Loon (G. pacifica) when seen at the far distances on 7 November 2011. This initial identification was based on the size and structural differences in comparison to a nearby Common Loon, and its overall dark coloration; I made the mistake even after watching the bird for 10 minutes as I’d never seen a Red-throated (G. stellata) that dark. I discounted the fact that it was holding its head tilted up on poor viewing conditions and knowing that all loons will do this from time to time when actively feeding. However, after relocating the bird on the 10th (after the correct identification had been made by others; notably Shirley Sturts etal ,and Garrett MacDonald), it was clear this was not a Pacific Loon. The principal separating marks include this bird’s upturned shape of the bill (straight culman with upwardly curved lower mandible) verses the straight, dagger like bill of the Pacific, the fact that this bird held its bill consistently elevated at around 10º, and this bird’s lack of the sharp demarcation between the grey neck and face with the white throat shown by Pacifics. In addition, this bird was pretty light weight in the neck and head versus a relatively bulky build of the Pacific. Artic (G. artica) Loon was also eliminated for similar reasons as stated for the Pacific Loon.

Western (A. occidentalis) and Clark’s (A. clarkia) Grebes eliminated by this bird’s comparatively shorter and thicker neck and larger head. In addition, this bird showed no sharply contrasting black and white plumage characteristics common to both of these species.

Red-necked Grebes (Podiceps grisegena) can be very dark with brownish coloration during this time of the year. Red-necked Grebes have thicker, shorter bills (>3/4 head length), shorter, stockier necks, and shorter length backs than do the loons. Aside from these general structural differences, this Red-throated Loon exhibited the classic upturned bill shape in comparison to the straight, dagger shape of the grebe.

EXPERIENCE WITH THIS SPECIES (AND SIMILAR SPECIES): I've seen numerous Red-throated Loons on the both the east and west coasts during the winter months. In addition, I'd seen a couple previously during the winter in Colorado as well as one on Hayden Lake, Kootenai Co., Idaho in October 2009. I've seen many Common, dozens of Pacifics, and three (3) Yellow-billed (CO & ID) Loons previously.
GENERAL BIRDING EXPERIENCE: I've been birding for 38 years and consider myself advanced - birding that is, not age.

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