Date: 2/4/18 10:58 am From: David Irons <llsdirons...> Subject: [obol] Re: Mysterious Red Lump on Cackling Goose
Red plastic USFWS neck collars are used only on the threatened population of Dusky Canada Geese. These numbered collars are used by biologists to monitor movements of these birds, which are slightly smaller and much darker that most Canadas and yet still considerably larger than Cackling Geese. They are much larger than the “Ridgway’s” Cackling Goose (B. h. minima), which is the predominant white-cheeked goose wintering in western Oregon.
This sub-population of Canada Goose winters almost entirely in northwest Oregon and a small portion of southwest Washington. In the 1960’s a network of four federal refuges (Finley, Ankeny, Baskett Slough and Ridgefield NWRs) was established to protect the wintering grounds of the then very fragile remaining population of Duskys. Recent estimates of the total population put it in the neighborhood of 10,000 birds.
This is a plastic collar. Based on the color the bird may be a Dusky Canada Goose. I've forgotten the color code. There's a combination of digits and letters, maybe other symbols, known as an alpha-numeric code, unique to each banded bird. I've used a scope to read the code on Tundra Swans and w/in days of reporting on line gotten a response--when and where the banding occured, typically in the summer on the breeding grounds when waterfowl are flightless during molt. The same swans I reported in Banks, 25 miles west of Portland, were reported at Ridgefield NWR and near Halsey, over 100 miles south of Ridgefield, w/in the same 30 day period. All of the swans I reported had been banded on Bristol Bay. Dusky Canada Geese nest only on the Copper River delta, and the many Cacklers I've seen with alpha-numeric codes are "true"Cacklers, which nest on the Yukon River delta. It is sometimes possible to communicate directly with the person who banded the birds. Lars
On Feb 3, 2018, at 7:18 PM, Anika Fiske wrote:
Hi All! I was birding at Coons Point today on Sauvie Island when i saw two Cackling Geese with red lumps on their necks. I've tried my best to research this with no luck. Does anyone know what this and would care to explain it to me? Thank you and happy birding!