IBRC 20-B-10

IDAHO BIRD RECORDS COMMITTEE
RARE BIRD REPORT FORM

SPECIES: Cackling Goose (Branta hutchinsii)
HOW MANY: 2 - “Ridgway’s” (B.h. minima)

REPORTER: Doug Ward 8362 Selkirk Ct. Hayden, ID 83835
REPORTER EMAIL: ward@revettminerals.com
OTHER OBSERVERS: None

DATE REPORT PREPARED: 2/3/2010
DATE SIGHTING OCCURRED: 24 January 2010

LOCALITY OF OBSERVATION: Cougar Bay (BLM Access), Lake Coeur d’Alene; Kootenai County, Idaho
HABITAT: Ice covered and open water bay; mudflat beach
CONDITIONS: Birds approx. 75m from observation point on the beach. Observed between 3:30 – 4:15pm using both 8X40 binoculars and a 15-40X spotting scope (15-25X during observation). Lighting was cloudy, bright overcast with sun at my back.

DID YOU TAKE NOTES?: Yes, later the same day
DID YOU CONSULT FIELD GUIDE OR OTHER REFERENCES?: Yes, another day after the observation
WHAT GUIDE(S) OR REFERENCE(S) DID YOU CONSULT?:
1)“Distribution and Identification of Cackling Goose (Branta hutchinsii) Subspecies”; Mlodinow etal; North American Birds (pp 344-360 Vol.62; 2008)
2)“Complete Birds of North America”; National Geographic; 2005
3) Various internet sites for photographs

DESCRIPTION: “Ridgway’s” (B.h. minima) – small dark goose associating with both “Greater” & “Lesser” subspecies Canada Geese (Branta canadensis ssp.), “Taverner’s” (B.h. taverneri) Cackling Geese (see separate report), and Mallards (Anus platyrhynchos). Size & Structure: Not much larger than Mallards nearby; short legged, short, stocky neck which was nearly the diameter of small, rounded head. Bill stubby (~½ head length), and triangular in side view; upper mandible formed sharp angle with high (vertical) forehead (see attached sketch). Plumage: Head & neck black except for small white triangular shaped cheek patch which wrapped under throat and terminated just behind eye. Back, belly and chest dark brown lightly barred with lighter brown. Chest and black neck sharply demarcated; no white collar. Rump & undertail coverts white; tail black.
BEHAVIOR: Seen as a pair feeding on ice in a large, loose grouping of Canada Geese (~750 total; ~500 “Greater” ssp. & ~250 “Lesser” ssp.) and “Taverner’s” Cackling Geese (B.h. taverneri; see separte report). The Cackling Geese generally stayed associated with each other in groups of 2-5 scattered in the central portion of the larger flock. The “Ridgway’s” (B.h. minima) pair stayed close together and generally not with the “Taverner’s” (B.h. taverneri). Cackling Geese could be heard calling amongst the Canada’s (B. canadensis); generally shorter, higher pitched “honks”. The “Ridgway’s” call (seen calling) was distinctive; distinct two syllable, high pitched nasal call.

HOW AND WHEN DID YOU POSITIVELY IDENTIFY THE BIRD, AND WHAT CLINCHED THE IDENTIFICATION FOR YOU? The “Ridgway’s” Cackling Goose is fairly distinctive by its diminutive size, small round head, short stubby bill, and generally dark coloration.
HOW DID YOU ELIMINATE SIMILAR SPECIES, AND WHAT WERE THEY?
As these were black necked, white cheeked geese without additional white on the face, only Canada Goose (Branta canadensis) was considered to be addressed.

“Greater” Canada Goose (B. canadensis ssp.) is eliminated by the size differential of all the birds considered in direct comparison; these were all ½ the size or smaller than the “Greaters” present.

“Lesser” Canada Geese (B. canadensis ssp.) were much more problematic. Fortunately there were numerous individuals available for direct comparison not only in size, but more importantly head and bill structure. Generally the Cackling Geese (Branta hutchinsii) could be picked out by their shorter, thicker necks, high foreheads which accentuated the bird’s triangular profiled, short bills. The pair of “Ridgway’s” (B.h. minima) present stood out as different by their very small size (only slightly larger than Mallards (Anus platyrhynchos) present), stocky appearance, and very dark plumage.

EXPERIENCE WITH THIS SPECIES (AND SIMILAR SPECIES): I've seen numerous “Richardson’s” Cackling Geese (B.h. huchinsii) in Colorado and New Mexico - presplit. I've seen "Ridgway's" (aka "Cackling") twice before in Colorado - also pre-split.
GENERAL BIRDING EXPERIENCE: I've been birding for 37 years and consider myself an "advanced" birder.

WERE PHOTO(S), VIDEO, AND/OR AUDIO OBTAINED BY YOU?: None

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