Cackling Goose Branta hutchinsii (pres leucopareia)
Vesona Park, Los Gatos, California. January 2006

The Canada Goose complex has been usually divided into subspecies along lines of size and color, with larger birds nesting mostly in the south and smaller birds mostly in the north. Lighter colored birds are generally found in the east, and darker ones in the west (although the Great Basin subspecies B. c. moffitti, is pale) Over the past seventy years, various ornithologists have proposed a number of different ways of classifying the races of Canada Goose, with as many as twelve and as few as eight subspecies and one, two, three, or even four different species. Some have even divided various populations finely, into more than eighty morphological groups.

In the 45th supplement of the AOU checklist (Banks et al 2004) the Canada Goose was formally split into two species and eleven subspecies (and one additional, presumably extinct, subspecies - asiatica). These eleven subspecies have been traditionally grouped into two or three groups according to size. The three-group system recognizes a group of large-sized subspecies, Canada Goose, a group of intermediate-sized subspecies, Lesser Canada Goose, and a group of small-sized subspecies, Tundra Goose. The two-group system recognizes a large form, Canada Goose, and a small form, Tundra Goose. Recent analysis of mitochondrial DNA tends to support the two-group system, and thus the basis for the recent split, though the name of Cackling Goose was given to the small species. (A problem for the field birder is that even though the split includes a large species (Canada Goose) and a small species (Cackling Goose), the intermediate forms (from the Lesser Canada Goose) were split between both species, with the subspecies taverneri going to Cackling Goose and parvipes going to Canada Goose (thus there is a complete overlap in size between these two new species, because taverneri and parvipes are both essentially equal in size).

• Canada Goose Branta canadensis - includes canadensis, interior, maxima, moffitti, parvipes, fulva, and occidentalis.
• Cackling Goose Branta hutchinsii - includes hutchinsii, leucopareia, taverneri, and minima.

Looking at reports on the internet, the bird in the images below appears - based on size, breast colour and neck collar - most likely to be leucopareia.

Leucopareia shows considerable variation in neck colour (paler versus darker brown), a paler breast than the almost purplish-sheened dark brown of minima, and has a full, partial, or non-existent whitish band across the base of the fore-neck (this particular individual has a strong white neck band expanding in front, with a dark border below). Most have a black stripe through white on throat (as this bird does), and square-shaped heads with a steep forehead and a stubby bill. They are seldom seen in Alaska outside of their Aleutian Islands breeding grounds and follow a coastal migration route through remote areas of the state and across the Gulf of Alaska on their way to and from their wintering grounds in California’s Central Valley. They often begin the winter near Colusa, Colusa and Sutter counties arriving in late October to mid-December, then move to wintering areas near Modesto, Stanislaus Co., and Los Banos, Merced Co. Migrants gather on the California coast near Crescent City, Del Norte County. They are also found on the Russian Commander Islands and the Kuril Islands off Japan. Although they formerly nested throughout most of the Aleutian Islands, foxes introduced for fur farming between the 1750s and 1939 extirpated Aleutian Canadas from most islands. In 1967, there were fewer than 800 left and it was listed as ‘endangered’. An intensive rangewide recovery program and restocking of geese on fox-free islands brought numbers back up. In 1991, the growing population numbered over 7,000 and it was downlisted to ‘threatened’. (Adapted from www.sibleyguides.com and www.oceanwanderers.com. Thanks too for identification criteria help from Joseph Morlan)

Cackling Goose Branta hutchinsii:

 

 

 

 

 

Canada Goose Branta canadensis:

 

For more information go to:
www.sibleyguides.com/canada_cackling

www.oceanwanderers.com/CAGO.Subspecies.html#cackling

All photographs © Charlie Moores