At the pond... Canada Goose

Western Canada Goose, Hillsboro, Oregon on 6 December 2008 by Greg Gillson.

 

Everyone knows the Canada Goose. Everyone except birders, that is. Why do I say this?

Birds of Oregon: a general reference (2003, Marshall, Hunter, and Contreras, editors) lists 8 subspecies of Canada Goose found in Oregon. Some birders attempt to identify these field identifiable subspecies, or races, when they can. Other birders, however, pay no attention to subspecies, as they can't count them as a separate species on their life list. And, well, many birds are just really hard (or impossible) to pin down to a subspecific identification. So why bother?

Well, surprise! The American Ornithologists Union (A.O.U.) recently "split" the Canada Goose into two separate species. The larger birds, some almost the size of swans, are still called Canada Goose, Branta canadensis, while the smaller geese, some the size of city park ducks, are now called Cackling Goose, Branta hutchinsii.

While your friend who knows next to nothing about birds confidently identifies the overhead skein of birds as "Canadian" Geese, you're not so sure anymore.

Cackling Geese cackle, of course, while Canada Geese honk. That's just a sweeping generality, as there seem to be several "tweener" populations that are very difficult to tell apart. In general, Cackling Geese have short necks, stubby little bills, and wing tips that extend well past the tail at rest.

The resident Canada Geese, the ones in city parks and wetlands that lead goslings around in April, are the Western Canada Geese. They are very large, have white breasts and long necks and bills. The bird in the photo above is a Western Canada Goose.

In winter, we are visited by the smaller, white-breasted, Lesser Canada Goose from the north. These are more common east of the Cascades than west.

And, in the Willamette Valley of western Oregon winters a dark breasted Dusky Canada Goose. The Vancouver Canada Goose is very similar. Some of these winter along the coast, as far south as the Nestucca National Wildlife Refuge near Pacific City, Oregon.

The Giant Canada Goose is a bird of the Great Plains that has been introduced widely in North America. There is an introduced resident population on the Lower Columbia River near Astoria, Oregon. Many of these released birds bred with the abundant local resident Western Canada Geese so that most birds here and elsewhere in the Pacific NW showing "Giant" field marks (white foreheads and larger than the Western race) are probably not pure.

I'll write again about the Cackling Goose later this winter. The main identification challenge is separating the Lesser Canada Goose from the Taverner's Cackling Goose. A good article on this is John Rakestraw's blog on the Lesser Canada Goose.

Dusky Canada Geese follow-up

It only has been two days since I saw and reported the red neck collar numbers of four Dusky Canada Geese I recorded at Jackson Bottom Wetlands in Hillsboro, Oregon. I received certificates of appreciation for reporting two of the geese. The certificate for 7JP is reproduced here.

Bird 7JP is a female, banded 5 August 2003 by Dr. Dirk Derksen and was at least one year old when banded. The banding location was 5 miles west of Alaganic, Alaska (see map).

The other goose, 84C is a male, banded 18 July 2005 and was at least one year old when banded. It was banded not too far from the other bird, 11 miles south of Cordova, Alaska, by Thomas Rothe.

Reporting neck collar numbers helps scientists figure out where these birds go and their survival rates. Notice that goose 7JP was banded 6 years ago and is at least 7 years old.


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Neck-collared Geese

Wednesday is Lunch with the birds time for me again at Jackson Bottom Wetlands. Today, highlights included a Bald Eagle chasing a Cackling Goose, a quick fly-by Merlin, and a flock of Dusky Canada Geese.

Dusky Canada Geese are not as big as the Western Canada Geese that are resident at the local ponds and raise their goslings here locally in the Pacific Northwest. But the Duskies are still about 2/3 larger than the Cackling Geese that are here by the thousands now.

Dusky Canada Geese are a dark-breasted population that nest on the Copper River delta in Alaska. The 1964 Alaska earth quake raised their swampy river delta 6 feet. Now Arctic Foxes and other predators could reach any nesting area that remained. Thus, the US Fish and Wildlife service set up 3 refuges for these birds in the 1970's in the Willamette Valley: Ankeny NWR, Finley NWR, and Baskett Slough NWR. Numbers of these geese have rebounded, but they are still not legal to hunt.

Several of the Dusky Canada Geese had red plastic neck collars with white numbers and letters written on them. [Cackling Geese have yellow neck collars; Western Canada Geese have blue or white neck collars.] I was able to make out the numbers on four birds, though they were quite distant, hidden behind the willows, it was a bit hazy today, and the eagle was stirring things up. Have I made enough excuses for the bad digiscoped photo to accompany this post?

You need a good spotting scope, and practice reading the stylized lettering, but finding flocks of geese or swans with neck collars and then submitting them can be quite fun. I filled out the web form for reporting the 4 neck collars (6NV, 7 JP, 7VF, 84C) at the bird banding laboratory on the USGS page.

In a few days I expect to hear back from the researcher working on these birds. I'll receive a thank you acknowledgement and learn something about where these birds were banded and how old they are. I'll write another post when I find out.